Conservation of Caribbean Island Herpetofaunas Volume 2: Regional Accounts of the West Indies
Conservation of Caribbean Island Herpetofaunas Volume 2: Regional Accounts of the West Indies Edited by
Adrian Hailey Byron S. Wilson Julia A. Horrocks
LEIDEN • BOSTON 2011
Cover photo: Sphaerodactylus copei, endemic to Hispaniola, from Haiti (photo by S.B. Hedges). IUCN Status: Not Assessed. This book is printed on acid-free paper. Library of Congress Cataloging-in-Publication Data Conservation of Caribbean island herpetofaunas / edited by Adrian Hailey, Byron S. Wilson, Julia A. Horrocks. p. cm. Includes bibliographical references and index. ISBN 978-90-04-19410-6 (hardback : alk. paper) – ISBN 978-90-04-18395-7 (vol. 1 : alk. paper) – ISBN 978-90-04-19408-3 (vol. 2 : alk. paper) 1. Amphibians–Conservation– Caribbean Area. 2. Reptiles–Conservation–Caribbean Area. I. Hailey, Adrian. II. Wilson, Byron S. III. Horrocks, Julia. IV. Title. QL656.A1C66 2011 597.8–dc22 2011008986
ISBN ISBN ISBN
978-90-04-18395-7 (volume 1) 978-90-04-19408-3 (volume 2) 978-90-04-19410-6 (set)
Copyright 2011 by Koninklijke Brill NV, Leiden, The Netherlands. Koninklijke Brill NV incorporates the imprints Brill, Hotei Publishing, IDC Publishers, Martinus Nijhoff Publishers and VSP. All rights reserved. No part of this publication may be reproduced, translated, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior written permission from the publisher. Authorization to photocopy items for internal or personal use is granted by Koninklijke Brill NV provided that the appropriate fees are paid directly to The Copyright Clearance Center, 222 Rosewood Drive, Suite 910, Danvers, MA 01923, USA. Fees are subject to change.
Contents Preface
1
Conserving the herpetofauna of Anguilla Karim V.D. Hodge, Robert Powell and Ellen J. Censky
3
An introduction to the herpetofauna of Antigua, Barbuda and Redonda, with some conservation recommendations Jennifer C. Daltry
17
Conservation of amphibians and reptiles in The Bahamas Charles R. Knapp, John B. Iverson, Sandra D. Buckner and Shelley V. Cant
53
The herpetofauna of Barbados: Anthropogenic impacts and conservation status Angela Fields and Julia A. Horrocks
89
Conservation of amphibians and reptiles in the British Virgin Islands: Status and patterns G. Perry and G.P. Gerber
105
The amphibians and reptiles of the Cayman Islands: Conservation issues in the face of invasions A.C. Echternacht, F.J. Burton and J.M. Blumenthal
129
A report on the status of the herpetofauna of the Commonwealth of Dominica, West Indies Anita Malhotra, Roger S. Thorpe, Eric Hypolite and Arlington James
149
Conservation of the herpetofauna of the Dominican Republic Robert Powell and Sixto J. Incháustegui
167
Conservation of the herpetofauna on the Dutch Windward Islands: St. Eustatius, Saba, and St. Maarten Robert Powell
189
vi
Contents
Amphibians and reptiles of the French West Indies: Inventory, threats and conservation Olivier Lorvelec, Michel Pascal, Claudie Pavis and Philippe Feldmann
205
The herpetofauna of Grenada and the Grenada Grenadines: Conservation concerns Robert W. Henderson and Craig S. Berg
239
An annotated checklist of the amphibians and terrestrial reptiles of the Grenadines with notes on their local natural history and conservation Jacques Daudin and Mark de Silva
259
Conservation of Jamaican amphibians and reptiles Byron S. Wilson
273
The terrestrial herpetofauna of Martinique: Past, present, future Michel Breuil
311
Conserving the Puerto Rican herpetofauna Rafael L. Joglar, Alberto O. Álvarez, T. Mitchell Aide, Diane Barber, Patricia A. Burrowes, Miguel A. García, Abimael León-Cardona, Ana V. Longo, Néstor Pérez-Buitrago, Alberto Puente, Neftalí Rios-López and Peter J. Tolson
339
The St. Vincent (Lesser Antilles) herpetofauna: Conservation concerns Robert Powell and Robert W. Henderson
359
Status, conservation, and introduction of amphibians and reptiles in the Turks and Caicos Islands, British West Indies R. Graham Reynolds
377
Conservation status of reptiles and amphibians in the U.S. Virgin Islands Renata J. Platenberg and Ralf H. Boulon, Jr.
407
Index of genera and species
429
Contents
Volume 1 Preface Introduction. Conservation of insular herpetofaunas in the West Indies Byron S. Wilson, Julia A. Horrocks and Adrian Hailey An overview of the evolution and conservation of West Indian amphibians and reptiles S. Blair Hedges The conservation status of amphibians in the West Indies S. Blair Hedges and Luis M. Díaz An overview of snake conservation in the West Indies Peter J. Tolson and Robert W. Henderson Introduced amphibians and reptiles in the greater Caribbean: Patterns and conservation implications Robert Powell, Robert W. Henderson, Michael C. Farmer, Michel Breuil, Arthur C. Echternacht, Gerard van Buurt, Christina M. Romagosa and Gad Perry Conservation of amphibians and reptiles in Aruba, Curaçao and Bonaire Gerard van Buurt Status and conservation of the reptiles and amphibians of the Bermuda islands Jamie P. Bacon, Jennifer A. Gray and Lisa Kitson Conservation of herpetofauna in the Republic of Trinidad and Tobago Adrian Hailey and Michelle Cazabon-Mannette Index of genera and species
vii
Preface A set of reviews on the Conservation of Caribbean Island Herpetofaunas was originally proposed, in August 2005, as a special issue of the journal Applied Herpetology under the guest editorship of herpetologists at the three campuses of the University of the West Indies, with the encouragement of the journal’s Editor-in-Chief, Mike Tyler. What proved to be the first part of a series was published in August 2006, and as the project expanded five parts were issued up to April 2009. Those included several non-review papers and others that were independently submitted to the journal and edited by Mike Tyler and then incorporated into the series (contents are listed at http://www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm). Applied Herpetology ceased publication at the end of 2009, still leaving several invited papers for the Caribbean series in various stages of completion. Brill, the publishers of the journal, agreed to reprint (with addenda giving updated information) the review papers from Applied Herpetology and the subsequently completed papers in book form. The first volume includes the non-geographic reviews (on taxa or issues), plus three reviews on territories that form part of the wider Caribbean region but are not biogeographically part of the West Indies. The second volume includes geographic reviews on the West Indies proper. Of the 26 papers in the two volumes, about a third (9) are new and the remaining 17 were previously published in Applied Herpetology. Apart from the Introduction, all the papers have been through the same assessment procedure of the original journal, involving at least two independent anonymous referees (to whom we are grateful for helping to maintain the quality of the series), and one or more stages of revision before acceptance. The editor responsible and the original acceptance date are indicated for each paper. Our aim was to provide a comprehensive set of articles detailing conservation concerns and actions on the amphibians and reptiles (including sea turtles) of the territories (islands or island groups) of the wider Caribbean, a region of notable biodiversity. The participation of Caribbean-based authors was especially encouraged. It was expected that the level of detail would vary among papers, depending on island size and herpetological richness, and the amount of published work available. Subjects for consideration included the general ecology of the islands; their human history, especially relating to development; major environmental problems; conservation legislation; protected areas relevant to herpetofauna; conservation status of the herpetofauna; notable species or groups; conservation programmes or
2
Preface
ecotourism involving amphibians and reptiles; introduced herpetofauna; and recommendations. The authors have, we believe, provided an exemplary set of papers describing the conservation situation of herpetofauna in the wider Caribbean, and in many cases charted the way ahead for the territories covered. We were unable to source accounts for the remaining territories (although almost 50 contributions were invited), but the gaps will hopefully stimulate new synthesis for those areas. It was economically possible to include only monochrome photographs in either the journal or the book, but colour versions of many of those are available at the web site address above. We thank Dr Margarita C. Cuevas Gozalo, the project editor at Brill for these volumes (and previously for Applied Herpetology), for her consistent help. Adrian Hailey, Byron S. Wilson, Julia A. Horrocks The University of the West Indies
Conserving the herpetofauna of Anguilla Karim V.D. Hodge1 , Robert Powell2,3 , Ellen J. Censky4 1 Director,
Department of the Environment, The Valley, AI-2640, Anguilla of Biology, Avila University, Kansas City, Missouri 64145, USA 3 Corresponding author; e-mail:
[email protected] 4 Milwaukee Public Museum, Milwaukee, Wisconsin 53233, USA 2 Department
Abstract. The herpetofauna of Anguilla, including Sombrero, which sits on its own island bank, includes three amphibians (all introduced), 13 or 14 lizards (two or three introduced, one extirpated, and two or three endemic), three snakes (two introduced), and six turtles (one introduced and one presumably native), including four sea turtles (mariners) known to occur at least occasionally in Anguillian waters. No negative effects of the introduced species have been documented, and two of them (Eleutherodactylus johnstonei and Anolis carolinensis) are largely restricted to artificial mesic areas, where they are unlikely to affect native fauna. Two of the three species with the greatest potential to cause harm (Rhinella marina and Pantherophis guttatus) are not known to breed in Anguilla. Iguana iguana poses a potential threat to native I. delicatissima through competition or hybridization. Of native species, I. delicatissima and the mariners are threatened primarily by habitat destruction and alteration tied to the growing human population and a burgeoning tourist industry. Populations of the endemic ground lizards, Ameiva corax and A. corvina, which are restricted to Little Scrub Island and Sombrero, respectively, and those of Sphaerodactylus sp. and Anolis gingivinus on Sombrero, appear to be stable, but might be vulnerable to stochastic events. Ground-dwelling species on Anguilla proper (Ameiva plei, Sphaerodactylus spp., Mabuya sp., and Alsophis rijgersmaei) are potentially vulnerable to introduced predators, such as the small Indian mongoose, which is prevalent on nearby St.-Martin/St. Maarten. Despite its relatively small size, homogenous topography, and relatively low diversity, Anguilla supports at least four terrestrial and four marine reptiles that are of global concern. Governmental and non-governmental entities have the knowledge and good intentions to legislate, implement, and enforce effective conservation efforts — but often lack the human and financial resources to do so. When complicated by some governmental agencies with firm commitments to development and a dearth of public lands, the result is at best a sporadic effort to support conservation. Key words: Amphibians; Anguilla; conservation; invasive species; reptiles; Sombrero.
Introduction The nation of Anguilla (∼102 km2 ) comprises the most northerly of the Leeward Islands. Located at 18◦ 30 N, 63◦ 50 W, Anguilla is subjected to the trade winds off
4
K.V.D. Hodge et al.
the Atlantic Ocean. A wet season extends from June to November and coincides with the Atlantic hurricane season. Most of the annual rainfall of 900-1000 mm typically falls within a few days, occasionally resulting in flooding of low-lying areas. Intense rain is essentially unknown during the dry season, although sporadic light showers might occur (Howarth and Robins, 1988; Anonymous, 1993). The Anguillian Archipelago is composed of Anguilla (90.7 km2 ) and affiliated satellites that range in size from mere emergent rocks and South Wager (0.0004 km2 ) to Dog Island (2.058 km2 ) and Scrub Island (3.451 km2 ). The nation of Anguilla also includes Sombrero (0.366 km2 ), which sits on its own island bank 61 km NNW of the island of Anguilla. Episodes of volcanic activity created the cores of the present islands some 20 million years ago. During glacial periods, sea levels dropped and the islands emerged as dry land, with all but Sombrero contributing to the contiguous Anguilla Bank, which also includes St. Maarten/St.-Martin, St.-Barthélemy, and their satellites (Christman, 1953). During interglacial periods, the islands that currently constitute Anguilla were submerged. Corals thrived in the shallow waters and eventually contributed to the surface layers of light-colored limestone rock that characterize the islands today. Unlike many other Lesser Antillean islands, Anguilla lacks the higher elevations (maximum elevation 65 m) that force moisture-laden winds to rise and cool, which causes water to condense and fall as rain. Consequently, winds pass over Anguilla, resulting in an almost unvarying dry climate. Even when rain falls, porous karstic limestone (weathered coral) allows water to seep through rather than accumulate on the surface. As a result, surface waters are invariably saline and fresh water is restricted to a narrow layer of subterranean water that floats on the deeper salt water that permeates the island’s core. This combination of low topography and permeable bedrock is responsible for the arid environment. Native, drought-resistant forests must also withstand the ravages of periodic hurricanes. For example, although heavily damaged by hurricanes in 1995, 1996, and 1999, relatively intact remnants of dry forests remain in Katouche Valley and in the vicinity of the proposed Fountain Cavern National Park near Shoal Bay East. Nevertheless, Anguilla’s forests have become severely deteriorated by ubiquitous goats, leaving degraded scrub forest, comprised primarily of acacias and mesquites, covering most of the island. Thus, a combination of natural and human-mediated forces affects Anguilla and its satellites, which tend to be smaller and lower — and even drier — than Anguilla proper. Once the home of Arawak and Carib peoples, with the earliest dates of human occupation dating to 400-600 AD (Crock and Petersen, 2004), Anguilla became an English colony after settlers arrived in 1650. The population, estimated in 2006 at ∼13,600 persons, is mainly of African descent. In 1967, Britain created a selfgoverning entity that encompassed Anguilla and the islands of St. Kitts and Nevis to the south. However, many Anguillians, arguing that they were not fairly represented by the St. Kitts-based administration, threw out the police force and declared their secession. British forces were sent and the Anguilla (Administrative) Order 1971
Conserving the herpetofauna of Anguilla
5
made provisions for the British Commissioner to work in consultation with the newly established Anguilla Council. Anguilla was formally separated from the Associate State of St. Kitts, Nevis, and Anguilla on 19 December 1980 and became an overseas territory of the United Kingdom (UK) (Petty, 1984, 1991). Carefully regulated tourism is the bedrock of the economy, with approximately 29% of the labor force employed in that industry in 2007 (Gardner, 2008). A tropical climate, fine beaches, reefs, and turquoise seas lure visitors, many of them from the United States. Conservation programs and biodiversity and environmental protection fall under the Department of Environment, whereas the Department of Fisheries and Marine Resources is responsible for fisheries management, marine parks development and management, and coastal zone management. The Anguilla National Trust serves to promote the permanent preservation of lands, their natural features, and animal and plant life. A moratorium on harvesting sea turtles and the sale of turtle products or byproducts was implemented initially in 1995. Specifically in regard to marine turtles, the UK ratified the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the Convention on Conservation of Migratory Species of Wild Animals (CMS). The UK also signed but has not yet ratified the Protocol Concerning Specially Protected Areas and Wildlife (SPAW Protocol) to the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region (Cartagena Convention), but has neither signed nor ratified the Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC). The utilization of marine turtles in Anguilla has direct relevance to the UK’s obligations under CITES and CMS, and could affect future obligations under SPAW and IAC. The Executive Council of the Government of Anguilla approved the extension of CITES, CMS, and SPAW, but not IAC. For SPAW and IAC, Richardson et al. (2006) recommended that governments of the overseas territories (OTs) consider the costs of compliance, especially those OTs that are under-resourced and have difficulty implementing the requirements of their current legislation. The extension of these international agreements to Anguilla would present complex legislative amendments and logistical difficulties, especially if Anguilla were to reinstate its marine turtle fishery (Richardson et al., 2006). In 2001, the government of Anguilla recognized the need to promote long-term economic and environmental sustainability. To that end, a National Environmental Management Strategy (NEMS) was developed, and then revised for 2005-2009 (Homer, 2004). The NEMS reviews key environmental problems and their causes, formulates national environmental objectives, and identifies actions to meet those objectives. It also spells out indicators by which the progress of environmental management will be monitored and measured, noting that the nation’s economic development is dependent on the protection and preservation of its natural resources. Relevant national legislation pertaining to the conservation of at least some elements of the herpetofauna includes the Marine Turtle Ordinance of 1984, the Marine Parks
6
K.V.D. Hodge et al.
Act of 2000, and the Beach Protection Act of 2000. In addition to the relevant governmental agencies, active NGOs with an environmental agenda include the Anguilla Beautification Club and the Environmental Club of the Albena Lake Comprehensive School (DFMR, 2006).
The Herpetofauna Three anurans, all introduced, have been recorded on Anguilla (Hodge et al., 2003; table 1). Eleutherodactylus johnstonei (Censky, 1989) and Osteopilus septentrionalis (Townsend et al., 2000) appear to be entrenched. The former is largely restricted to well-watered gardens in residential areas and the latter is associated with hotels, populated areas, and abandoned structures with sources of water, where they breed in cisterns and water tanks. Neither is encountered frequently, except after the rare periods of extensive rainfall. Only a few individuals of Rhinella marina have been found on Anguilla (at Sandy Ground and Crocus Bay). They are not known to have reproduced on Anguilla, and might be prevented from establishing populations by the scarcity of standing fresh water (Hodge et al., 2003). Reptiles are far more diverse. Eleven extant species of lizards, including one endemic (Ameiva corax), are known from Anguilla and its satellites (Hodge et al., 2003). Two or three (Anolis carolinensis, Iguana iguana, and possibly Hemidactylus mabouia) are invasives, although some H. mabouia and I. iguana almost certainly arrived on the island without human mediation (Censky et al., 1998; Hodge et al., 2003). A twelfth species (Anolis pogus) appears to be extirpated (Lazell, 1972). Three species have been recorded on Sombrero; one (Ameiva corvina) is endemic, and the taxonomic status of the other two is uncertain, although at least one (Sphaerodactylus sp.) appears to be endemic (Lazell, 1964; Hodge et al., 2003) and the other (presumably Anolis gingivinus) might be. Three species of snakes have been recorded on Anguilla (Hodge et al., 2003), two of which (Ramphotyphlops braminus and Pantherophis guttatus) are introduced (Censky and Hodge, 1997; Hodge et al., 2003). One terrestrial turtle (Chelonoidis carbonaria) occurs on Anguilla. Whether the current population is descended from ancestors that arrived naturally by means of overwater dispersal or with human mediation (either historical or recent) is unknown (Censky, 1988; Hodge et al., 2003). In fact, Anguillian tortoises probably have a mixed origin (Henderson and Powell, 2009). A single female Phrynops geoffroanus of unknown origin was found at Blowing Point on 4 December 2008. No evidence suggests that more have been introduced. Four species of sea turtles, locally called “mariners,” are known to occur historically in Anguillian waters, where they have been hunted for at least 1000 years (Godley et al., 2004). Caretta caretta and Dermochelys coriacea are rarely encountered today. Chelonia mydas and Eretmochelys imbricata both forage around Anguilla, but only the latter nests in discernible numbers (Procter and Fleming, 1999; Gumbs, 2005; Hodge et al., 2003).
Conserving the herpetofauna of Anguilla
7
Table 1. The herpetofauna of Anguilla and the islands in the Anguillian Archipelago from which they have been recorded (adapted from Hodge et al., 2003). Species with a formally recognized conservation status are marked as follows: CITES appendices are indicated by “I” or “II,” and IUCN Redlist status (IUCN, 2010) by CR (critically endangered), EN (endangered), VU (vulnerable), NT (near-threatened), and LC (least concern). Species endemic to the island from which they are recorded are indicated by END , those endemic to the Anguilla Bank by ANG , and those endemic to the West Indies by WI . Introduced species known to have become established are marked with an asterisk (*) and those known only as waifs with two asterisks (**). Question marks indicate species with uncertain or potentially mixed origins. Species
Status
Islands
Amphibia, Anura Rhinella marina** Eleutherodactylus johnstonei*,WI Osteopilus septentrionalis*,WI
LC LC LC
Anguilla Anguilla Anguilla
Reptilia, Squamata (lizards) Hemidactylus mabouia* (?) Thecadactylus rapicauda Sphaerodactylus parvusANG Sphaerodactylus sputatorWI Sphaerodactylus sp.END Anolis carolinensis* Anolis gingivinusANG
– – – – – LC –
Anolis pogusANG Iguana delicatissimaWI Iguana iguana* Mabuya sp.ANG Ameiva coraxEND Ameiva corvinaEND Ameiva pleiANG
– II, VU II – – – –
Anguilla Anguilla Anguilla, Scrub Island, Dog Island Anguilla, Scrub Island, Little Scrub Island, Dog Island Sombrero Anguilla Anguilla, Anguillita (?), Scilly Cay, Scrub Island, Dog Island, Prickly Pear Cay West, Prickly Pear Cay East, Sombrero1 Anguilla (extirpated) Anguilla Anguilla Anguilla, Dog Island Little Scrub Island Sombrero Anguilla, Scilly Cay, Scrub Island, Dog Island, West Cay, Prickly Pear Cay East
Reptilia, Squamata (snakes) Alsophis rijgersmaeiANG Pantherophis guttatus** Ramphotyphlops braminus*
EN LC –
Anguilla, Scrub Island Anguilla Anguilla
Reptilia, Testudines Dermochelys coriacea Caretta caretta Chelonia mydas Eretmochelys imbricata Chelonoidis carbonaria (?) Phrynops geoffroanus**
I, CR I, EN I, EN I, CR II –
– – – – Anguilla Anguilla
1 The
taxonomic status of the population on Sombrero has not been confirmed.
8
K.V.D. Hodge et al.
Conservation Concerns The introduced species are of no conservation concern, except in how they might affect native species. Eleutherodactylus johnstonei and Anolis carolinensis are unlikely to have much impact on natives in Anguilla in that they both are essentially restricted to artificially maintained mesic habitats out of which they seldom venture. Even their prey almost certainly is composed largely of exotic arthropods introduced with decorative plants from Florida or other West Indian islands and similarly restricted to moist enclaves. Similarly, Ramphotyphlops braminus probably does not have any impact on native reptiles, although its potential effect on native invertebrate prey is unknown. No evidence suggests that Rhinella marina or Pantherophis guttatus are established. If that were to occur, either species could pose a substantive threat to native taxa. The toad is a voracious and indiscriminate predator with the potential of decimating populations of ground-dwelling arthropods and even small vertebrates, such as the sphaerodactylid geckos. The snake is a particularly efficient predator quite capable of climbing. If a breeding population became established, the impact on terrestrial and arboreal vertebrates could be disastrous. In sharp contrast, populations of Osteopilus septentrionalis and Iguana iguana are firmly established, although the former is encountered frequently only during infrequent wet periods and iguanas remain largely restricted to the southern and eastern portions of the island, where escaped pets and individuals that arrived in 1995 via over-water dispersal (Censky et al., 1998) founded populations. No negative impact on native animals or plants has been documented, although treefrogs breed in cisterns and foul the drinking water. A threat would occur if either I. iguana population were to expand its range and come into contact with the native population of I. delicatissima, which is largely restricted to only about 2 km2 (∼3% of the island’s total area) along the northern coast from Little Bay west to the Brimigen Coast near Shoal Bay (Gerber, 1999; Hodge et al., 2003). If such contact were to occur, the I. delicatissima gene pool could become subsumed within that of I. iguana, much like what has occurred in the French West Indies (e.g., Breuil, 2002, 2009; Henderson and Powell, 2009). No conservation plans are necessary to address the two species with uncertain or mixed origins. Hemidactylus mabouia is a human commensal and, as such, thrives on Anguilla (Howard et al., 2001) and elsewhere. Chelonoidis carbonaria is not frequently encountered, but that is not unusual even on islands where the species is known to be abundant (e.g., Lazell, 2005). Of the native species, Anolis gingivinus is essentially ubiquitous on the entire Anguilla Bank, adapts well to human-mediated changes in its habitat, and probably is not threatened in any way at this time. Thecadactylus rapicauda, Sphaerodactylus parvus, S. sputator, Mabuya sp., Ameiva plei, and Alsophis rijgersmaei are similarly adaptable. The geckos often are edificarian (e.g., Howard et al., 2001), the skink and snake readily exploit rock walls and the latter not infrequently invades human habitations, and A. plei often reaches very high densities in human-modified habitats where it scrounges for food and exploits decorative plantings (Hodge et
Conserving the herpetofauna of Anguilla
9
al., 2003). However, ground-dwelling reptiles in the genera Mabuya, Ameiva, and Alsophis have been decimated on islands where the small Indian mongoose has been introduced (e.g., Powell and Henderson, 2005; Henderson and Powell, 2009). The contrast between mongoose-free Anguilla and mongoose-infested St. Maarten/St.Martin, both on the Anguilla Bank, is particularly notable. Skinks are almost never encountered on St. Maarten/St.-Martin, the snake is essentially extirpated, and A. plei is largely restricted to areas of high human traffic, where mongooses rarely venture (Powell et al., 1992; Powell and Henderson, 2005; Henderson and Powell, 2009). Consequently, the impact of introducing mongooses to Anguilla would almost certainly be disastrous — and the threat is very real, considering the proximity of and volume of traffic between the two islands. The remaining terrestrial reptiles, however, are of considerable conservation interest. The population of Iguana delicatissima, which once occupied the entire northern part of Anguilla, is now confined to an area of approximately 2 km2 . This is primarily due to habitat destruction and alteration attributable largely to development to accommodate the growing human population and the burgeoning tourist industry. Predation by introduced predators (dogs and cats), competition for food with introduced goats, and direct disturbances by humans have all taken a toll, and the potential threat of hybridization with introduced I. iguana was discussed previously. Recent estimates of total population size range from fewer than 100 to about 300 animals. Iguana delicatissima is listed in CITES Appendix I (UNEPWCMC, 2008) and on the IUCN Red List as “vulnerable” (IUCN, 2010). However, many isolated populations meet criteria for “critically endangered” status, including that on Anguilla (Hodge et al., 2003; Powell, 2004a). Powell (2004b) and Powell and Henderson (2005) recommended a reevaluation and a probable upgrade in status for the entire species. In 2009, The IUCN Iguana Specialist Group proposed an upgrade to “endangered.” Ameiva corax is restricted to Little Scrub Island (0.049 km2 ) (Censky and Paulson, 1992; Hodge, 2000; White et al., 2002), and Ameiva corvina (Censky and Paulson, 1992; Shew et al., 2002), Sphaerodactylus sp. (Lazell, 1964; Hodge et al., 2003), and the local population currently assigned to Anolis gingivinus are restricted to Sombrero. Because of the small size of the islands, these populations are vulnerable to stochastic events and qualify as “threatened” according to criteria for inclusion in the IUCN Red List (IUCN, 2010). However, the conservation status of these taxa has not been formally assessed and the taxonomic status of the gecko and the anole remains uncertain (both might merely represent isolated and recently established populations of species that are widely distributed on the Anguilla Bank). That said, short of protecting all genetically unique populations restricted to small islands (a discussion of which is beyond the scope of this review), these Anguillian lizards, like comparably small populations elsewhere in the West Indies and throughout the world, evolved on their small islands, their populations fluctuate in response to natural disturbances, and they might even benefit from small-scale human activities. On Little Scrub, the occasional fisherman brings fry for bait, and
10
K.V.D. Hodge et al.
food-limited A. corax (Censky and Powell, 2001) engages in feeding frenzies when they arrive. Likewise, A. corvina on Sombrero thrived around the living quarters of the lighthouse keepers (how the population is faring now that the lighthouse has been decommissioned is unknown). Nevertheless, populations of A. corvina dropped precipitously after Hurricane Luis in 1995, and habitats on Sombrero have been dramatically altered by human activity, including the excavation of pits for phosphate mining in which many lizards apparently drowned (Hodge et al., 2003). Powell and Henderson (2005) noted that the current status of these populations appears to be stable but recommended monitoring. Henderson and Powell (2009) suggested that some protected status was warranted, even if restricted to limiting large-scale human impact on Little Scrub Island and Sombrero. The status of the four species of marine turtles is similar to that throughout the region. All are listed in CITES Appendix I (UNEP-WCMC, 2008) and on the IUCN Red List (IUCN, 2010). Historically in Anguilla, marine turtles have been exploited for meat, eggs, oil, and shells, and utilized as a cultural symbol. Until 1995, an active turtle fishery annually harvested the two more abundant species (Chelonia mydas and Eretmochelys imbricata) for domestic meat and the export of meat and shells to St. Maarten/St.-Martin, Puerto Rico, and the U.S. Virgin Islands (Godley et al., 2004). Dermochelys coriacea is rare and Caretta caretta is spotted only occasionally in Anguillan waters (Procter and Fleming, 1999; Gumbs, 2005). Anguilla is important for sea turtle nesting and foraging (fig. 1). At present, D. coriacea, C. mydas, and E. imbricata are known to nest in Anguilla — but in critically low numbers. Urgent conservation action is needed to ensure the survival of nesting populations and facilitate their recovery (Godley et al., 2004). Eretmochelys imbricata is the main nesting species on the main island and especially on the undisturbed beaches of the outlying cays (Groombridge and
Figure 1. Major developments and sea turtle nesting beaches and foraging areas (modified from Gardner, 2008).
Conserving the herpetofauna of Anguilla
11
Luxmoore, 1989; Procter and Fleming, 1999). Important nesting sites for C. mydas include Dog Island and the Prickly Pear Cays. Dermochelys coriacea nests on the main island and Scrub Island, but no reliable reports document nesting by Caretta caretta (Meylan, 1983; Procter and Fleming, 1999). For D. coriacea, the number of nests per year was estimated as 25-100 (Turtle Expert Working Group, 2007). Anguilla is a significant foraging site for juvenile C. mydas and E. imbricata. Notable foraging sites for the former are Scilly Cay, Fish Hole Pond, Shoal Bay, North Hill Village, Lower South Hill, Long Bay, Meads Bay, Scrub Island, Sandy Island, Sombrero Island, Dog Island, and between Shoal Bay West and Blowing Rock. Foraging E. imbricata juveniles are present throughout the year, especially along the extensive reef north of the island and the offshore cays at sites such as Little Bay/Crocus Bay and North Cliffs (Groombridge and Luxmoore, 1989; Procter and Fleming, 1999; Gumbs, 2005). Caretta caretta probably forages around Dog Island, Scrub Island, and Sandy Island (Meylan, 1983; Procter and Fleming, 1999). With the present moratorium on turtle fishing in Anguilla, the main threat to nesting and foraging turtles is habitat loss associated with tourist development. Sand mining for construction, lighting, and noise (associated with tourism development) have reduced the quality of local nesting habitats. Additionally, degradation of foraging grounds (coral reefs and sea grass beds) also has impacted foraging turtle populations. For D. coriacea, the Turtle Expert Working Group (2007) ranked threats on nesting beaches as high (egg-take, killing of females, introduced predator impacts, and beach development), and threats in inter-nesting habitats as low (by catch, boat strikes, and targeted fishery). Global climate change is an important potential threat to turtles, and sea level rise, temperature increases, and increases in storm frequency could seriously impact nesting and foraging sites.
Conservation Action A report on biodiversity priorities in UK Overseas Territories (GHK Consulting, 2007) noted that Anguilla possesses two endemic reptiles (Ameiva corax and A. corvina) and six reptilian species (Alsophis rijgersmaei, the two endemic lizards, and three sea turtles) of global conservation concern. The report did not address the other potentially endemic species on Sombrero or the fourth species of marine turtle occasionally found in Anguillian waters. A workshop on invasive species (Anguilla National Trust, 2007) included the Cuban Treefrog (Osteopilus septentrionalis) in its list of the three species of greatest concern. The Native Plant and Animal Habitat Conservation (Biodiversity) Policy for Anguilla was approved by Executive Council on 4 October 2001. In that policy statement, the government indicated its intention to undertake the following actions pertaining to the herpetofauna: (i) Ensure the protection and restoration of key habitats and species through legislation and appropriate management structures and mechanisms, such as national parks and other protected areas. (ii) Establish and promote criteria for the selection of key habitats for protection measures.
12
K.V.D. Hodge et al.
(iii) Arrange for the acquisition of such lands, wherever feasible, that are critical for the protection of key habitats or ecosystems. (iv) Take necessary measures to control the intentional or accidental introduction or escape into or from the environment, of alien or modified organisms that are likely to impact adversely on other organisms or on the environment. Unfortunately, Gardner (2008) cited the Department of Environment as “inadequate,” stating that the Department has developed a biodiversity policy, but has been unable to get environmental protection policies incorporated in sector policies; he noted, however, that the Department is fairly new and has inadequate resources. Similarly, the Anguilla National Trust was deemed “inadequate”; its programs are sporadic and the institution possesses limited resources. The report’s summary statement noted further that environmental scrutiny of projects is severely hampered by major deficiencies in the current legislation dealing with planning, development control, and environmental management, and that overlapping mandates of some agencies hinder the efficient execution of the development control process. Gardner (2008) recommended that a “Strategy and Action Plan for Biodiversity Conservation” include: (a) A revision and approval of green space policy that should include an expansion of the definition of green space to include natural areas; (b) green spaces should be connected in order to maintain the mobility of wildlife species; (c) processes controlling development should be overhauled; and (d) environmental management should include: (i) A full system of protected areas; (ii) a comprehensive environmental monitoring program; and (iii) a declaration of all turtle nesting beaches as protected areas. The House of Assembly approved two relevant pieces of legislation in April 2009. The Trade in Endangered Species Act (TESA) was brought into force in November 2009, although approval of regulations by the Executive Council is still pending. The Biodiversity and Heritage Conservation Act (BHCA) has yet to be brought into force. TESA almost certainly will preclude resumption of sea turtle harvesting and could provide a vehicle to regulate the importation of Iguana iguana — if the authorities determine that this could have a negative impact on native species. BHCA defines protected areas, maintains buffer zones, and establishes means of enforcing boundaries on both public and private lands. This act also provides for conservation easements and protection of wildlife, whether listed in specific regulations or not. Listed species include both iguanas, the four sea turtles, the tortoise, and Eleutherodactylus johnstonei. However, the Environmental Protection Act (EPA) is still in draft form; and, without the EPA in place, the implementation of SPAW will be incomplete and implementation of the Convention on Climate Change and the Kyoto Protocol will lack legal authority. The Socio-economic and Environmental Assessment Report (SEEA; Talley, 2008) found that the general population has a high level of appreciation of biodiversity and the natural environment but a low level of knowledge. Almost half of the study population indicated that they would like more information about biodiversity and the natural environment. The SEEA recommended the
Conserving the herpetofauna of Anguilla
13
development and implementation of a campaign of public education and awareness of biodiversity and the natural resources, including the incorporation of biodiversity and environmental education in the curricula of the public and private school systems. Educational efforts relevant to the herpetofauna have included the publication of a guide to the reptiles and amphibians of Anguilla by Hodge et al. (2003), copies of which were distributed to local schools. In that volume, habitat loss, unintentional and intentional killing, natural disasters, and introduced exotic species were cited as the principal threats to Anguilla’s native reptiles. Habitat loss, clearly identified as the single greatest threat, was linked to development for the growing human population and the tourism industry — much of which is slated for the few remaining natural areas that serve as strongholds for at least some species. Recommendations included: (a) An increased emphasis on education about nature and natural resources, (b) habitat protection, (c) control or eradication of introduced exotic predators and competitors, and (d) consideration of establishing a captive breeding program for Iguana delicatissima. To enhance educational efforts, Hodge et al. (2003) further recommended that I. delicatissima become a national icon for conservation efforts. A first step along those lines occurred in 1997, when iguanas were featured on stamps issued by Anguillian postal authorities. Similarly, sea turtles could be used as symbols to link the intimate relationship Anguillians have with the surrounding seas and conservation efforts focusing on beaches and marine environments, the health of which is inextricably tied to that of the entire nation. Confounding ongoing conservation efforts is the fact that Anguilla has few Crown lands. Consequently, effective habitat protection must rely on collaborations with private landowners. Resolving concerns stemming from the rising value of land, pressures to develop land for housing or commercial endeavors, and a reluctance to cede control over property will be difficult at best.
Acknowledgements. Robert W. Henderson and Keith David commented on earlier drafts of this chapter. John S. Parmerlee, Jr. prepared the map. John B. Iverson identified the stray turtle from photographs. RP’s involvement in conservation efforts in Anguilla would not have been possible without the efforts of students in the 2000 Avila University Research Experiences for Undergraduates (REU) program, for which National Science Foundation (NSF) grant DBI-9732257 provided funding.
References Anguilla National Trust. (2007): Anguilla Invasive Species: Workshop Report, 29 May 2007. The Valley, Anguilla National Trust.
14
K.V.D. Hodge et al.
Anonymous. (1993): An environmental profile of Anguilla. Part 1: A resource management framework, an assessment of the critical environmental issues facing Anguilla. The Valley, unpubl. report, Govt. Anguilla. Breuil, M. (2002): Histoire naturelle des amphibiens et reptiles terrestres de l’Archipel Guadeloupéen. Guadeloupe, Saint-Martin, Saint-Barthélemy. Patr. Natur., Paris 54: 1-339. Breuil, M. (2009): The terrestrial herpetofauna of Martinique: Past, present, future. Appl. Herpetol. 6: 123-149. Censky, E.J. (1988): Geochelone carbonaria (Reptilia: Testudines) in the West Indies. Fl. Sci. 50: 108-114. Censky, E.J. (1989): Eleutherodactylus johnstonei from Anguilla, West Indies. Carib. J. Sci. 25: 229230. Censky, E.J., Hodge, K. (1997): Geographic distribution. Ramphotyphlops braminus. Herpetol. Rev. 28: 210. Censky, E.J., Hodge, K., Dudley, J. (1998): Over-water dispersal of lizards due to hurricanes. Nature 395: 56. Censky, E.J., Paulson, D.R. (1992): Revision of the Ameiva (Reptilia: Teiidae) of the Anguilla Bank, West Indies. Ann. Carnegie Mus. 61: 177-195. Censky, E.J., Powell, R. (2001): Little black dragons of Little Scrub Island. Fauna 2(3): 24-31. Christman, R.A. (1953): Geology of St. Bartholomew, St. Martin, and Anguilla, Lesser Antilles. Bull. Geol. Soc. Amer. 64: 65-96. Crock, J.G., Petersen, J.B. (2004): Inter-island exchange, settlement hierarchy and a Taíno-related chiefdom on the Anguilla Bank, northern Lesser Antilles. In: Late Ceramic Age Societies in the Eastern Caribbean, p. 139-156. Delpuech, A., Hofman, C.L., Eds, BAR Intl. Ser., Paris Monogr. 14, Oxford, Amer. Archaeol. Archaeopress. DFMR (Department of Fisheries and Marine Resources) (2006): Draft Plan for Managing and Developing the Marine Fisheries of Anguilla. The Valley, DFMR. Gardner, L. (2008): Anguilla National Biodiversity Strategy and Action Plan: Tourism Sector Report. Final Report, 11 March 2008. The Valley, Biodiversity Conservation Inc. Gerber, G.P. (1999): Conservation of the Lesser Antillean Iguana, Iguana delicatissima, on Anguilla. Unpubl. preliminary report, Fauna & Flora International, Cambridge. GHK Consulting. (2007): Costing Biodiversity Priorities in the UK Overseas Territories. Final Report, 2 April 2007. The Lodge, Bedfordshire, Royal Society for the Protection of Birds. Godley, B.J., Broderick, A.C., Campbell, L.M., Ranger, S., Richardson, P.B. (2004): An assessment of the status and exploitation of marine turtles in Anguilla. In: An Assessment of the Status and Exploitation of Marine Turtles in the UK Overseas Territories in the Wider Caribbean, p. 39-77. Final Project Report for the Department of Environment, Food and Rural Affairs and the Foreign and Commonwealth Office, London. Groombridge, B., Luxmoore, R. (1989): The Green Turtle and Hawksbill Turtle (Reptilia: Cheloniidae) World Status. Exploitation and Trade. Lausanne, CITES. Gumbs, J.C. (2005): A preliminary assessment of the foraging sea turtle populations of Anguilla. Testudo 6(2): 1-8. Henderson, R.W., Powell, R. (2009): Natural History of West Indian Reptiles and Amphibians. Gainesville, University Press of Florida. Hodge, K.V.D. (2000): Conservation Assessment of the Little Scrub Island Ground Lizard (Ameiva corax). Unpubl. Msc. Diss., Univ. Kent at Canterbury, Durrell Inst. Conserv. Biol. Hodge, K.V.D., Censky, E.J., Powell, R. (2003): The Reptiles and Amphibians of Anguilla, British West Indies. The Valley, Anguilla National Trust. Homer, F. (2004): National Environmental Strategy and Action Plan 2005-2009. Rev. draft, 7 December 2004. The Valley, Govt. Anguilla.
Conserving the herpetofauna of Anguilla
15
Howard, K.G., Parmerlee, J.S., Jr., Powell, R. (2001): Natural history of the edificarian geckos Hemidactylus mabouia, Thecadactylus rapicauda, and Sphaerodactylus sputator on Anguilla. Carib. J. Sci. 37: 285-288. Howarth, B., Robins, N.S. (1988): Contributions to the UNESCO Hydroecology Atlas of the Caribbean Islands, Volume 3: Anguilla. Brit. Geol. Surv. Tech. Rept. WD/88/30: 1-16. IUCN (International Union for the Conservation of Nature and Natural Resources). (2010): IUCN Red List of Threatened Species. Version 2010.1 (www.iucnredlist.org). Lazell, J. (1964): The reptiles of Sombrero, West Indies. Copeia 1964: 716-718. Lazell, J. (1972): The anoles (Sauria, Iguanidae) of the Lesser Antilles. Bull. Mus. Comp. Zool. 143: 1-115. Lazell, J. (2005): Tortoise tales. In: Island: Fact and Theory in Nature, p. 321. Lazell, J., Ed., Berkeley and Los Angeles, Univ. California Press. Meylan, A.B. (1983): Marine turtles of the Leeward Islands, Lesser Antilles. Atoll Research Bulletin 278: 3-6. Petty, C.L. (1984): Anguilla: Where There’s a Will, There’s a Way. The Valley, priv. publ. Petty, C.L. (1991): A Handbook History of Anguilla. The Valley, priv. publ. Powell, R. (2004a): Lesser Antillean iguanas, Iguana delicatissima and I. iguana. Iguana 11: 37. Powell, R. (2004b): Conservation of iguanas (Iguana delicatissima and I. iguana) in the Lesser Antilles. Iguana 11: 238-246. Powell, R., Henderson, R.W. (2005): Conservation status of Lesser Antillean reptiles. Iguana 12: 6277. Powell, R., Passaro, R.J., Henderson, R.W. (1992): Noteworthy herpetological records from Saint [sic] Maarten, Netherlands Antilles. Carib. J. Sci. 28: 234-235. Procter, D., Fleming, L.V., Eds (1999): Biodiversity: The UK Overseas Territories. Peterborough, Joint Nature Conserv. Comm. Richardson, P.B., Broderick, A.C., Campbell, L.C., Godley, B.J., Ranger, S. (2006): Marine turtle fisheries in the UK Overseas Territories of the Caribbean: Domestic legislation and the requirements of multilateral agreements. J. Intl. Wildl. Law Policy 9: 223-246. Shew, J.J., Censky, E.J., Powell, R. (2002): Ameiva corvina. Cat. Amer. Amphib. Rept. 747: 1-2. Talley, C.R. (2008): Socio-economic and Environmental Assessment Report Prepared for Anguilla National Biodiversity Strategy and Action Plan. The Valley, Biodiversity Conservation Inc. Townsend, J.H., Eaton, J.M., Powell, R., Parmerlee, J.S., Jr., Henderson, R.W. (2000): Cuban Treefrogs (Osteopilus septentrionalis) in Anguilla, West Indies. Carib. J. Sci. 36: 326-328. Turtle Expert Working Group. (2007): An assessment of the Leatherback Turtle population in the Atlantic Ocean. NOAA Technical Memorandum NMFS-SEFSC-555, Washington, D.C. UNEP-WCMC (United Nations Environment Programme World Conservation Monitoring Centre). (2008): UNEPWCMC Species Database: CITES-Listed Species (http://www.cites.org/eng/ resources/species.html). White, A.M., Censky, E.J., Powell, R. (2002): Ameiva corax. Cat. Amer. Amphib. Rept. 746: 1-2.
Accepted: October 11, 2010 (AH).
An introduction to the herpetofauna of Antigua, Barbuda and Redonda, with some conservation recommendations Jennifer C. Daltry Fauna & Flora International, Jupiter House, Station Road, Cambridge CB1 2JD, United Kingdom e-mail:
[email protected] Abstract. At least 29 reptiles and amphibians have been documented on Antigua, Barbuda and Redonda, of which 21 are probably native. These include four species of marine turtles, two of which (Eretmochelys imbricata and Chelonia mydas) are known to nest on the nation’s numerous sandy beaches and forage in nearshore waters. The low-lying and largely sedimentary islands of Antigua (280 km2 ) and Barbuda (161 km2 ) formed a single island as recently as 12,000 years ago and exhibit a similar herpetofauna with high endemicity. At least four terrestrial species are endemic to the Antigua and Barbuda bank: Alsophis antiguae, Ameiva griswoldi, Anolis wattsi, Sphaerodactylus elegantulus (a possible fifth being Barbuda’s Anolis forresti, if not synonymous with A. wattsi), and a further five are Lesser Antillean endemics. Only six species have been documented on the small, rugged volcanic island of Redonda (1 km2 ), but as many as half of them occur nowhere else (Ameiva atrata, Anolis nubilus, and a potentially new Sphaerodactylus sp.). Centuries of forest clearance, overgrazing and development, coupled with the introduction of small Asian mongooses (Herpestes javanicus), black rats (Rattus rattus) and other alien invasive species, has endangered many of the nation’s wildlife, and at least four indigenous reptiles have been extirpated (Boa constrictor, Clelia clelia, Iguana delicatissima, and Leiocephalus cuneus). Recent moves to enlarge the nation’s protected area network are encouraging, but need to be supported with stronger legislation and proper investment in management staff and resources. This paper presents conservation recommendations and describes two projects that have adopted innovative approaches to save the most critically endangered reptiles – the Jumby Bay Hawksbill Project and the Antiguan Racer Conservation Project. Key words: Alsophis antiguae; Antigua; Antiguan Racer Conservation Project; Barbuda; invasive species; Jumby Bay Hawksbill Project; marine turtles; mongoose; rats.
Introduction Ecology and biogeography Situated near the centre of the Lesser Antillean Archipelago, the nation of Antigua and Barbuda comprises the islands of the Antigua Bank (Antigua, 280 km2 and
18
J.C. Daltry
Figure 1. Map of Antigua.
Barbuda, 161 km2 ) and the uninhabited volcanic island of Redonda (approximately 1 km2 ). Antigua (fig. 1), at 17◦ 10 N, 61◦ 55 W, is geologically and biologically the most diverse of the three main islands, with flat and scrubby plains giving rise to gently rolling limestone hills in the north and to higher volcanic hills in the south (maximum height 402 m, Boggy Peak). Its coastline is deeply indented with, as the local saying goes, “one beach for every day of the year”, together with numerous fringing coral reefs and shoals. Scant natural vegetation remains, with the best examples around Ayers Creek, Half Moon Bay, Nonsuch Bay and on the small offshore islands strewn along the northeast and east coast. Wallings Forest, a small area of secondary moist evergreen forest, has been protected by law since 1912 and is regenerating well. Though this is a relatively dry island, averaging only 1,050 mm rainfall per year, there is considerable variation in rainfall between years and between different parts of the island (TAC, 2005). Like Barbuda and Redonda, Antigua lacks rivers and is frequently subject to severe droughts. Barbuda (fig. 2; 17◦ 35 N, 61◦ 48 W) is one of the lowest-lying inhabited islands in the Caribbean, with ‘The Highlands’ reaching no more than 39 m above sea level. It is also one of the driest, with rainfall averaging between 750 mm and 900 mm per annum (TAC, 2005). A scrubby coralline limestone island, Barbuda is more uniform in appearance than Antigua and is mostly covered in limestone and sand, including a well developed dune system. The island’s most notable geographic feature is Codrington Lagoon, the largest lagoon in the Eastern Caribbean, running along most of its western flank. Barbuda and Antigua are 43 km apart, but share the same shallow Antigua Bank and would have formed a single large island during periods of reduced sea level in the past (most recently approximately 12,000 years ago). This shared history accounts for their very similar native herpetofauna.
The herpetofauna of Antigua, Barbuda and Redonda
19
Figure 2. Map of Barbuda.
Redonda (fig. 3a) has never been physically connected to these or any other islands. Only 2.4 km long, 480 m wide and 297 m high, this small, rugged volcanic island is surrounded by steep cliffs which make landing difficult. Redonda is 48.5 km from Antigua, 19.5 km from Montserrat and 28.5 km from Nevis. Lindsay and Horwith (1997) identified 54 vegetation types on Antigua, Barbuda and Redonda, most of which can be seen on Antigua. Not surprisingly, the three islands share many plant and animal species with other Lesser Antillean islands, but diversity and level of endemicity varies widely among different taxonomic groups. For example, 1,158 terrestrial species of plants have been recorded in Antigua, Barbuda and Redonda, but only one (0.09%) is suspected to be nationally endemic. The national bird list contains 182 species (Horwith and Lindsay, 1997), two-thirds of which are migratory, and only one or two (0.5-1.1%) are endemic subspecies. The low level of endemicity among plants and birds contrasts sharply with the high level seen among the native herpetofauna, with at least 42% of species on Antigua and Barbuda endemic to these islands, and 50% on Redonda (see below). Native terrestrial mammals comprise 10 species of bats (three of which are nationally extinct) as well as an extinct muskrat, and an extinct rice rat or Oryzomyine rodent (Lindsay and Horwith, 1997). The terrestrial invertebrates are largely unknown, but research on other Caribbean islands suggests that as many as 80% of beetles could be endemic (Michael Ivie, pers. comm.). Human history According to archaeological evidence, a non-agricultural and aceramic Amerindian people inhabited Antigua continuously or sporadically from about 3500 to 100 BC. Between 50 and 1100 AD, a second group of agricultural and pottery-making peoples, generally called Arawaks, migrated from South America and occupied the
20
J.C. Daltry
(a)
(b) Figure 3. Important offshore habitats include (a) the uninhabited volcanic island of Redonda, located approximately 50 km west of Antigua (photo John Cancalosi), and (b) Great Bird Island, one of the last islets where the Antiguan racer occurs, but which is visited regularly by tourists. (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm).
northern and eastern parts of Antigua. A third ethnic group, the Caribs, conducted foraging trips to Antigua from Dominica and St Kitts, and their raids continued well into the European settlement period. Columbus sighted Antigua in 1493, but the island was not colonized by Europeans until 1642. English settlers brought Irish and, later, African slaves, and established sugar, cotton and other plantations, which replaced the native vegetation across 92% of Antigua. Being less suitable for arable farming, Barbuda was used to raise grazing animals. These various waves of human settlers brought with them a number of invasive mammals, including agouti, rats, rabbits, deer, goats, pigs, and mongooses, many of which still remain (Horwith and Lindsay, 1997). Redonda was largely spared from human disturbance apart from a short but intensive period of guano mining by the Redonda Phosphate Company from 1869
The herpetofauna of Antigua, Barbuda and Redonda
21
until the First World War, using labour from Montserrat. The legacies of this industry include some ruins, a herd of feral goats and countless black or ship rats (Rattus rattus). Antigua, Barbuda and Redonda became fully independent from Great Britain in 1981. Redonda remains uninhabited, while the population of Antigua and Barbuda has stabilized at around 67,000 and 1,200 respectively. The end of the plantation era in the 1960s was marked by many arable fields falling into disuse and developing into secondary forest or scrubland. The economy was rejuvenated by tourism, which currently accounts for 60% of the GDP. Nearly three-quarters of a million visitors come to Antigua and Barbuda every year (http://www.ab.gov.ag/). Most are cruise ship passengers who stay for only one day and head for the beach. Beach-based tourism has stimulated the rapid growth of coastal developments, with resulting problems for native herpetofauna, especially turtles. Antigua’s accessibility and central position in the Lesser Antillean archipelago has also made it a popular hub for people and cargo moving into and out of this region. Arrivals are projected to increase, which is likely to exacerbate the risk of more non-native species being introduced (see under Threats).
Herpetofauna Amphibians The abundant Lesser Antillean whistling frog Eleutherodactylus johnstonei, is a highly successful Lesser Antilles endemic that has become widespread across the Caribbean. This diminutive frog is not known from Redonda, but is probably indigenous to Antigua and Barbuda: fossil remains formerly identified as Hyla barbudensis (Auffenberg, 1958) are now considered to belong to this species. The similar E. martinicensis was first documented on Antigua by Schwartz (1967) and a map presented by Schwartz and Henderson (1991) illustrates a number of confirmed localities across the main island. Although E. martinicensis has become widespread in the Lesser Antilles, it is suspected to have originated somewhere in the French West Indies (Kaiser, 1992; Censky and Kaiser, 1999). The two Eleutherodactylus are not easy to tell apart, and further research is warranted to determine the current status and distribution of E. martinicensis. The mountain chicken (Leptodactylus fallax) has also been listed as a historical record for Antigua, based on Dunn (1934). According to Kaiser and Hardy (1994), however, the evidence is weak and not supported by a voucher specimen. Mountain chickens still occur in the wet forests of Dominica and Montserrat, and until recently it was not uncommon for live specimens to be taken to Antigua for food (Mark Day, pers. comm.). At least two amphibians have been introduced in recent times. The cane toad (Bufo marinus) was intentionally brought to Antigua during the 1800s and is still very common, especially around villages and fields. It has not spread to
22
J.C. Daltry
Antigua’s offshore islands, Redonda or Barbuda. The Cuban tree frog (Osteopilus septentrionalis) was recently recorded on Long Island, northeast Antigua, and is suspected to have been introduced accidentally on ornamental plants (Horwith and Lindsay, 1997). It has already spread to several sites in the northern part of Antigua (pers. obs.). Marine turtles Four of the country’s five chelonians are marine turtles — the hawksbill (Eretmochelys imbricata), the green (Chelonia mydas), the leatherback (Dermochelys coriacea) and the loggerhead (Caretta caretta) (table 1). Hawksbill turtles are by far the most numerous, with some 400-500 nests per year (Fuller et al., 1992), especially on the Antiguan beaches of Jabberwock, Rendezvous Bay, Turtle Bay, Green Island, Long Island, Sandy Island and Long Bay, and Barbuda’s Welcher Bay. Green turtles are scarcer and have been hunted more intensively for their meat. Though nesting has been reported on more than 20 Antiguan beaches to date, the number of nests has ‘declined dramatically’ (Anon, 2001). Leatherback turtles are seasonal visitors and nest only infrequently. No loggerhead nests have been recorded, despite this species being recorded in national waters. Neither the Kemp’s ridley (Lepidochelys kempi) nor the olive ridley (L. olivacea) has been confirmed in Antiguan waters, but there have been anecdotal accounts of olive ridley turtles being caught in Barbuda (summarized by Fuller et al., 1992). Terrestrial reptiles 18 indigenous terrestrial reptiles have been recorded on Antigua, Barbuda and/or Redonda, together with at least four species that were probably brought to the islands by humans. The red-footed tortoise (Geochelone carbonaria) was almost certainly introduced to Antigua and Barbuda from South America by early Amerindian visitors (see Censky, 1988). These tortoises are not uncommon, and are often kept as pets and even relocated. For example, 22 captive-bred tortoises have been released on Antigua’s Green Island during the past decade and are occasionally sighted there (Varnham, 2001). The national reptile list contains four geckos. The common woodslave or house gecko (Hemidactylus mabouia) is abundant on Antigua, especially around buildings, and was recently reported on Redonda (Censky and Kaiser, 1999), but curiously, it is absent from Barbuda. The giant woodslave (Thecadactylus rapicauda), which is also widespread in the Lesser Antilles, is common on Barbuda, Antigua and its larger offshore islands. The dwarf gecko Sphaerodactylus elegantulus (fig. 4a) is strictly endemic to Antigua and Barbuda, and is common on the main islands and offshore islands. An as-yet unidentified Sphaerodactylus was collected from Redonda in the late 1990s (Hinrich Kaiser, pers. comm.) and could be a new species or subspecies. The only known skink in the Lesser Antilles, Mabuya sloanii (previously identified as M. bistriata or M. mabouya), has been documented on Redonda
Introduced
Native
Native
Native
Osteopilus septentrionalis
Eretmochelys imbricata
Chelonia mydas
Dermochelys coriacea Caretta caretta
Introduced
Native?
Geochelone carbonaria
Hemidactylus mabouia
Native
Introduced
Bufo marinus
(Not assessed)
Critically Endangered Endangered
Endangered
Critically Endangered
App. II
App. I
App. I
App. I
App. I
App. II
App. II
App. II
App. II
Table 1. Amphibians and reptiles of Antigua, Barbuda and Redonda. Species Native/ Conservation CITES SPAW Introduced status Protocol (IUCN, 2004) EleutherodactyNative App. II lus johnstonei EleutherodactyIntroduced App. II lus martinicensis
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes (Extinct)
Yes
Yes
Yes
Yes
Yes
No
No
No
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
No
No
No
No
Distribution Barbuda Redonda
Yes
Antigua
during
19th
century.
This species may have originated from Africa, but fossils have been found on both Antigua and Barbuda that date from the late Quaternary. A specimen on Redonda was identified from a photograph (Censky and Kaiser, 1999) Continued
Common on Antigua (especially Green Island) and Barbuda
Documented in national waters, but no records of nesting
Rarely nests on Antigua or Barbuda
Reported to be declining. Nests on Antigua and Barbuda
Population appears stable (rising on Long Island). Nests on Antigua and Barbuda
Contemporary sightings on northern parts of Antigua, including Long Island
Introduced Common
Endemic to Lesser Antilles. Recorded on Antigua, but considered by Hedges (1999) to have been introduced
A Lesser Antillean endemic. Abundant
Comments
The herpetofauna of Antigua, Barbuda and Redonda 23
(Not assessed) (Not assessed)
Native
Native?
Native
Native
Native
Native?
Anolis leachi
Anolis wattsi
Anolis nubilus
Leiocephalus cuneus
(Not assessed)
(Not assessed)
(Not assessed)
(Not assessed)
Vulnerable
Native
Introduced?
(Not assessed) (Not assessed)
Native? Introduced
Native
Conservation status (IUCN, 2004) (Not assessed)
Native/ Introduced
Mabuya sloanii Gymnophthalmus underwoodi Iguana delicatissima Iguana iguana
Thecadactylus rapicauda Sphaerodactylus elegantulus Sphaerodactylus sp.
Table 1. (Continued). Species
App. II
App. II
CITES
SPAW Protocol
Yes (Extinct)
No
Yes
Yes
Yes (Extinct) Yes (Extinct)
No Yes
No
Yes
Yes
Antigua
Yes (Extinct)
No
Yes
Yes
Yes? (Extinct) No?
No Yes
No
Yes
Yes
No
Yes
No
No
Yes? (Extinct) Yes? (Extinct)
Yes No?
Yes
No
No
Distribution Barbuda Redonda
Known from fossil record. Extinct Lesser Antillean endemic Continued
Endemic to Redonda. Status unknown
Endemic to Antigua and Barbuda. Abundant. Some authors consider the Barbuda population to be a separate subspecies or species (forresti)
Endemic to Antigua and Barbuda. Common
The origin and taxonomic status of West Indian Iguana iguana is unresolved
A Lesser Antillean endemic
G. pleii may also be present
Specimen collected from Redonda by Kevel Lindsay and Hinrich Kaiser is yet to be identified, presumed endemic
Endemic to Antigua and Barbuda
Not uncommon
Comments
24 J.C. Daltry
(Not assessed) (Not assessed)
Native
Native
Native?
(Introduced)
Native
Introduced?
Native?
Ameiva atrata
Typhlops monastus
Boa constrictor
Elaphe guttata
Alsophis antiguae
Leptotyphlops tenella Clelia clelia
Critically Endangered
(Not assessed)
(Not assessed)
Native
Conservation status (IUCN, 2004) (Not assessed)
Ameiva griswoldi
Table 1. (Continued). Species Native/ Introduced CITES
App. III
SPAW Protocol
No?
Yes?
Yes
Yes (Extinct) (Yes)
Yes
No
Yes
Antigua
Yes (Extinct)
No
Yes (Extinct)
No
No
Yes
No
Yes
No
No
No
No
No
No
Yes
No
Distribution Barbuda Redonda
Fossil evidence
One dubious record on Antigua
Endemic to Antigua and Barbuda. Scarce, but increasing
Listed on Antigua by Kairo et al. (2005), but no voucher specimen collected
Known only from sub-fossil record
A Lesser Antillean endemic. Identified as the subspecies geotomus, which also occurs on St Kitts and Nevis
Endemic to Redonda. Status unknown
Endemic to Antigua and Barbuda. Probably qualifies as Vulnerable, based on decreasing range (unpubl. data)
Comments
The herpetofauna of Antigua, Barbuda and Redonda 25
26
J.C. Daltry
(a)
(b) Figure 4. Two endemics (a) the dwarf gecko, Sphaerodactylus elegantulus and (b) the Antiguan racer, Alsophis antiguae. (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm).
(Dunn, 1936), but its status is unknown. The skink also occurs on neighbouring Montserrat and other volcanic leeward islands. The Lesser Antillean iguana (Iguana delicatissima), has been confirmed from sub-fossils on Antigua and was still reported well into the late 20th Century, but is probably no longer present (Kevel Lindsay, pers. comm.). Etheridge (1964) and Pregill et al. (1994) describe unidentified iguana remains from Barbuda, which might have been the same species. Iguana bones are often unearthed in Amerindian middens around the islands (Reginald Murphy, pers. comm.), and it is likely that iguanas were dispersed around the Eastern Caribbean by people (Steadman et al., 1984). The common iguana (Iguana iguana species complex) has also occasionally been recorded on Antigua. These iguanas may have been brought from Montserrat or other islands (as pets or for food) and/or dispersed on debris during hurricanes: at least a dozen worn-looking individuals appeared in coastal areas within a few days following Hurricane Luis in 1995 (Censky et al., 1998), and were identified by their biometrics as having originated from the introduced population on Guadeloupe.
The herpetofauna of Antigua, Barbuda and Redonda
27
Most if not all of the common iguanas on mainland Antigua subsequently died, or were kept as pets or killed for their meat (Day et al., 2000). An unidentified iguana has also been recorded on Redonda (Underwood, 1962), but no sightings have been reported in over 60 years. In view of Redonda’s proximity to Montserrat and Antigua, either species of Iguana could feasibly occur there. Fossils of the curly-tailed tropidurid lizard Leiocephalus cuneus have been found on both Antigua and Barbuda (Etheridge, 1964; Watters et al., 1984), and the cause and timing of its extinction is not known. Lanagan (1844), cited by Horwith and Lindsay (1997), describes a ground lizard of ‘disgusting appearance’ with a tail ‘of extreme length . . . giving the creature, when walking, a kind of snake-like motion’. When alarmed, it reportedly ‘throws this unwieldy member over its back, and starts away with the greatest activity’. No other lizard on Antigua today fits this description, which might suggest that the curly-tailed lizard was still present in the 19th century. At least three species of anole lizards are present, all of which are endemic and still common. Anolis leachi is endemic to Antigua and Barbuda, but has been introduced to Bermuda. The smaller Watts’ anole (A. wattsi), is probably endemic to Antigua and Barbuda, but has been introduced to St. Lucia (Horwith and Lindsay, 1997), and Trinidad (White and Hailey, 2006). Some authors (e.g., Malhotra and Thorpe, 1999) consider the populations on Barbuda to be a separate, endemic species, A. forresti, which has recently invaded St Kitts. The final anole, A. nubilus, is endemic to Redonda. The Teiidae family is represented by three species. The omnivorous Antiguan ground lizard (Ameiva griswoldi) (fig. 5a) is clearly endemic to Antigua and Barbuda, but is patchily distributed and shows considerable geographic variation in size and colour pattern (Smith et al., 2002). The largest and most brightly specimens can be seen on Great Bird Island (fig. 3b), whereas those on mainland Antigua tend to be smaller and more cryptic in appearance, perhaps in response to higher predation pressure (i.e., mongooses, cats and hawks). Ground lizards are still locally abundant on parts of Barbuda and on approximately half of Antigua’s mongoosefree offshore islands (Galley Islands, Great Bird, Green, Lobster, Long, Red Head, Prickly Pear and York Islands), but their area of distribution is decreasing steadily (Smith et al., 2002). For that reason, this endemic species would probably qualify as Vulnerable or Endangered under IUCN criteria. A second endemic macroteiid, the little-known and almost entirely black A. atrata (fig. 5b), is confined to Redonda and is most closely affiliated to Montserrat’s A. pluvionotata. (Censky and Kaiser, 1999, list both A. atrata and A. pluvionotata on Redonda, but this may have been in error.) It is not known how many remain. The parthenogenic microteiid Gymnophthalmus underwoodi is a relative newcomer, but has quickly become established across Antigua and Barbuda (Censky and Lindsay, 1997). The astonishing speed with which this lizard can increase was recently illustrated on Great Bird Island, off the northeast coast of Antigua. In spite
28
J.C. Daltry
of extensive herpetological studies through the 1990s, this species was not recorded on the island until 2001, when two were seen (Brian Smith, pers. comm.). 23 individuals were seen the following year (McIntyre and Phillpot, 2002), and by 2005 this species was so abundant that as many as five individuals could be found within one square metre (pers. obs.). Horwith and Lindsay (1997) also cite anecdotal reports of ‘a shiny greenish colored lizard about 0.6 metres in length’. No specimens have been seen by scientists, but the reports raise the intriguing possibility of another species, perhaps akin to the rarely-seen galliwasp (Diploglossus montiserrati) of Montserrat. No snakes have been recorded on Redonda. As many as six species have been credited to Antigua and Barbuda, but some of the reports are dubious and only two species are currently confirmed present. The blind snake (Typhlops monastus geotomus) is common on both Antigua and Barbuda. Remains have been found of Boa constrictor on Antigua and Clelia clelia on Barbuda (Auffenberg, 1958; Steadman et al.,1984; Pregill et al., 1994). There is a lone Antiguan record of Leptotyphlops tenella, but many authors have cast doubt on its validity because this South American snake has not been found anywhere else in the Antilles (Schwartz and Henderson, 1991). The nation’s best-known endemic is the Critically Endangered Antiguan racer (Alsophis antiguae) (fig. 4b), first described as a subspecies of Lesser Antillean racer (A. antillensis) by Parker in 1933. Three years later, Parker (1936) elevated the racer to the rank of full species and declared it extinct. The type locality was given as the main island of Antigua, but no racers have been collected here since the 1940s, probably largely due to the introduction of small Asian mongooses in the late 19th century (Henderson and Sajdak, 1986; Henderson, 1989). The Antiguan racer is also known from Barbuda, from sub-fossil remains (Pregill et al., 1994), and the timing and reason for its extinction there is unknown. The snakes persisted for a few more decades on some of the offshore islands, but by the 1980s, they were confined to Great Bird Island (fig. 3b) (Sajdak and Henderson, 1991). Three specimens were collected from Great Bird in the 1960s (Lazell, 1967), and a fourth in 1987 by Robert Henderson (1989). A census in 1995 found only 51 individuals remained (Daltry and Day, 1996). Since then, however, the racer has also been reintroduced to two more offshore islands, and its numbers are climbing steadily (see below). The Antiguan racer exhibits some unusual characteristics, including strong sexual dichromaticism and ambush-hunting behaviour (Daltry and Day, 1996; Henderson et al., 1996), which are rare among colubrid snakes. Kairo et al. (2005) list another colubrid — the American corn snake (Elaphe guttata) — as an alien invasive species on Antigua, but do not provide the source of this information. Sightings of arboreal snakes have been reported by a number of Antiguans in recent years, and a specimen of an unidentified colubrid was deposited at the Environmental Awareness Group office in 2006 (pers. obs.). The identity and origin of these snakes deserves further investigation.
The herpetofauna of Antigua, Barbuda and Redonda
29
Significance of Antigua, Barbuda and Redonda When each island is viewed individually, the number of reptiles and amphibians is fairly low, as one would expect from their small size and considerable distance from South America or large islands (Censky and Kaiser, 1999). Combined, however, the three islands contain approximately 21 indigenous species (four marine, 17 terrestrial: table 2), which compares favourably with other Lesser Antillean nations. What is even more significant about this herpetofauna is its high level of endemicity. Eight reptiles (47% of the native land herpetofauna) are national endemics, and at least one frog and three reptiles (24% of native land species) are Lesser Antillean endemics. Unfortunately, extinction rates have also been high, with at least four indigenous species lost: Iguana delicatissima, Leiocephalus cuneus, Boa constrictor and Clelia clelia. As on many other Eastern Caribbean islands, the density of amphibian and reptile species can be remarkably high. Anolis wattsi attains record densities of 7,143/ha on forested parts of Great Bird Island, while even the large Ameiva griswoldi has been recorded at densities of 483/ha on Red Head Island (Smith and Colbert, 2002; Smith et al., 2001, 2002). This high lizard biomass undoubtedly has a significant influence upon the island’s ecosystem, not least through the consumption of millions of invertebrates every day. Buoyed by the prolific lizard populations, the Alsophis antiguae population on Great Bird Island has reached densities of 16.2/ha, which is among the highest recorded density of any one snake species. Six species are rated as globally threatened by IUCN (2004), but it is important to remember that only a small percentage of squamate reptiles have been assessed and this figure may well rise upon further investigation. The threatened reptiles include the Critically Endangered (cf. IUCN) Alsophis antiguae and Eretmochelys imbricata, both the foci of two long-running conservation programmes (see below).
Threats Alien invasive species Alien invasive species are widely regarded as the second greatest threat to biodiversity worldwide after habitat loss (IUCN, 1998), and the number one threat to biodiversity on small islands (Kairo et al., 2005). Alien species can endanger native wildlife populations through increased predation, competition, hybridization, disease transmission and/or habitat alteration. On Antigua, Barbuda and even Redonda, at least 18 alien invasive species have become established, the second highest national total in the Lesser Antilles (after Barbados: Kairo et al., 2005). The greatest hazards from the standpoint of the reptiles and amphibians are discussed below. Carnivores. The small Asian mongoose (Herpestes javanicus, often incorrectly called by the junior synonym auropunctatus), was introduced to Antigua in the
(b)
All islands
441
4
17
8
4
Table 2. Summary of the herpetofauna of Antigua, Barbuda and Redonda. Land area No. of native Indigenous land species (km2 ) marine reptiles No. of native No. of national No. of Lesser land species (bank) endemics Antillean endemics Antigua 280 4 12 5 4 Barbuda 161 4 12 5 4 Redonda 1 4 6 3 (1)
8
No. of introduced alien species 8 2 0
29
Total no. of species documented 24 18 10
23
Total no. of species extant in 2006 20 13 9
Figure 5. Two ground lizards (a) male Ameiva griswoldi and (b) Redonda ground lizard (Ameiva atrata). (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm).
(a)
30 J.C. Daltry
The herpetofauna of Antigua, Barbuda and Redonda
31
1890s in a largely futile attempt to control rats. Mongooses are highly proficient diurnal hunters that frequently kill more than they need to eat, and their arrival coincided with the decline of a number of indigenous animals on the main island of Antigua, including the Antigua burrowing owl (Speotyla cunicularia amaura), Alsophis antiguae and Ameiva griswoldi (Faaborg and Arendt, 1985). Studies elsewhere in the Caribbean have found that mongooses can have a significant impact on marine turtle nests (Eckert, 1995). Fortunately, the mongoose has not yet reached Barbuda, Redonda or some of the offshore islands, and it certainly must be prevented from doing so. Feral and pet cats (Felis catus) present similar dangers and are well established on mainland Antigua and Barbuda. Feral dogs (Canis lupus familiaris) are less widespread and not such effective hunters, but were indicated as a concern on Antigua and Barbuda by Kairo et al. (2005). Rats. The black rat (Rattus rattus) and the larger brown rat (R. norvegicus) were probably introduced during early European settlement. Both species are highly fecund and adaptable, and the black rat especially has spread throughout Antigua, Barbuda and Redonda, including nearly all of the offshore islands. Specific problems attributed to rats include predation on eggs and juveniles, and modification of habitats by preying on seeds and seedlings. Black rats have even been documented attacking snakes: in 1995, many Antiguan racers exhibited severe rat bite injuries, including amputated tails in 50% of females and 31% of males. The Antiguan Racer Conservation Project eradicated rats from Great Bird Island in 1995 and have removed them from a further ten islands since, but constant vigilance is required to prevent rats from reinvading via the many boats in Antiguan waters. Invasive large herbivores. These include feral goats (Capra hircus) on Redonda, goats, sheep (Ovis aries) and fallow deer (Dama dama) on Antigua, and goats and donkeys (Equus asinus) on Barbuda. At high densities, all of these animals are prone to overgraze fragile island vegetation, leading to loss of food and cover for iguanas and other native herpetofauna, and the wider problems of desertification (TAC, 2005). Feral goats are especially destructive in small island ecosystems (see citations in Campbell and Donlan, 2005). Up until 1995, the long list of feral ungulates included a herd of Andean llamas (Lama glama), which severely degraded the natural vegetation on Codrington Island (pers. obs.). Alien invasive herpetofauna. As shown in table 1, a number of non-native reptiles and amphibians have invaded Antigua and Barbuda, including Bufo marinus, Iguana iguana and Gymnophthalmus underwoodi. Their effects on the indigenous herpetofauna are poorly documented, but experience elsewhere within this region has shown the harm that such alien amphibians and reptiles can cause. Bufo marinus, for example, is known to be highly capable of destroying native wildlife by means of predation, competition, and even poisoning of snakes and other animals that attempt to eat them (Lever, 2001). On Dominica, the recently arrived Anolis
32
J.C. Daltry
cristatellus (native to the Puerto Rican Bank) appears to be steadily displacing the endemic Anolis oculatus as it spreads across the island (Kairo et al., 2005; Roger Thorpe, pers. comm.), while on Guadeloupe, common iguanas have extirpated the indigenous Lesser Antillean iguanas from many areas by means of aggressive competition and hybridization (Day et al., 2000). Alien reptiles and amphibians could potentially also bring deadly parasites and pathogens to Antigua, as described below. Alien pathogens and parasites. Two non-native parasites are of immediate concern, though there are undoubtedly others. First, the Antiguan racer has been found to be allergic to the common snake mite Ophionyssus natricis (Gibson, 1997), which could feasibly be brought into its habitat on the bodies of introduced reptiles or even on the clothes of visitors. This tiny parasite is difficult to detect and unfed protonymphs can live for as many as 19 days before dying of starvation (Camin, 1953). Second, the indigenous Eleutherodactylus johnstonei may be at risk from the chytrid fungus Batrachochytrium dendrobatidis. Amphibian chytridiomycosis was first described in 1998 from carcasses collected at the sites of mass mortality in the montane rain forests of Australia, Costa Rica and Panama (Daszak et al., 1999) and has since been linked to the population declines and extinctions of more than 90 species on five continents. It made its debut in the Lesser Antilles in late 2001 or 2002 on Dominica, with devastating results for the resident mountain chicken frogs (Magin, 2003). The fungus can survive outside amphibians in damp conditions, and can be transported on other organisms, ornamental plants, soil, boots and clothes. It will be difficult to prevent it from spreading throughout the Caribbean. Of the above, the mongoose, domestic goat, domestic cat, black rat, cane toad and the chytrid fungus all rank among “100 of the world’s worst invasive alien species”. More details of these species and the problems they cause can be found at: http://www.issg.org/. Habitat loss and alteration Though never as lushly vegetated as Dominica, St Lucia or some of the other, more mountainous islands in the Lesser Antilles, Antigua would probably be unrecognisable to Columbus today. No primary forest remains and, while secondary woodland is now fairly extensive (34% of Antigua, 66% of Barbuda), some changes to the watersheds and soils during the plantation era were irreversible (CARICOM/FAO/ODA, 1993; TAC, 2005). Natural forest regeneration continues to be suppressed by grazing animals, fire and by the spread of the highly invasive lemon grass (Cymbopogon citratus) and neem tree (Azadirachta indica). Lindsay and Horwith (1997) rated as many as half of the nation’s 54 vegetation types as threatened. The loss of nesting habitat is perhaps the greatest threat to the turtles that nest on Antigua and Barbuda habitat (Horwith and Lindsay, 1997). Sand-mining and ever-expanding residential and tourism developments have led to the clearance
The herpetofauna of Antigua, Barbuda and Redonda
33
of stabilizing native beachside vegetation (all too often replaced by lawns and ornamental plants) and severe beach erosion by the wind and sea, which has been further exacerbated by recent hurricanes (e.g., Ryder et al., 1989). Furthermore, lights from beachside hotels and holiday homes can draw newly-hatched turtles dangerously inland, away from the sea (see Horrocks et al., 1989; Witherington and Martin, 2000). Coral reefs and sea grass beds — where marine turtles feed — have been severely damaged by dredging, divers, boat moorings, pollution, and other problems. More than 95% of the hard corals in surveyed waters at depths of less than 9 m are dead (Horwith and Lindsay, 1997). Hunting and other human disturbance Antigua’s larger reptiles have traditionally been hunted for their meat and other products. Hoyle (1994) estimated that approximately 30 turtles and several thousand eggs were taken every year through the 1990s, and observed a wide range of turtle products on sale in Antigua. The same problem could have contributed to the demise of Antigua’s indigenous iguanas, and might jeopardise any attempt to reintroduce them. In recent decades, Caribbean reptiles have also received increased attention from collectors and pet keepers. Even though Antiguan racers are difficult to keep in captivity (Gibson, 1997), expatriates living in Antigua have admitted to taking snakes from Great Bird Island. In 2005, tour operators and local fishermen combined forces to evict a foreign visitor who was observed walking around the island with snake bags (Aldrick Nicholas, pers. comm.). The presence of large numbers of people in some of Antigua’s important wildlife habitats can be damaging in multiple ways. Some of the most worrying examples have been observed on Great Bird Island, which contains globally important populations of Alsophis antiguae and Ameiva griswoldi. As many as 400 visitors have been recorded on this 8.4 ha islet simultaneously (Daltry, 1999), and the annual total has climbed from 17,000 to 40,000 in the past decade (unpubl. data). Most people come to enjoy the attractive scenery, swim or snorkel around the fringing reefs, and have a barbecue on the beach. An increasing number of groups stay overnight: with dozens of tents recorded at Easter. On busy weekends, vibrations from amplified music can often literally be felt hundreds of metres inland. Such intensive human activity is likely to place additional stresses on the native reptiles by interrupting their hunting and other normal activities and causing them to flee as much as several times a day: indeed, local biologists have noticed a significant shift in snake numbers away from the busiest areas in recent years (Ingrid Sylvester, pers. comm.). Tourists have been observed killing lizards, while even those with a more enlightened attitude towards reptiles can cause harm, as exemplified by two British visitors who unwittingly drove a young male Alsophis antiguae into the sea while attempting to take its photograph (Daltry, 1999). Other problems include trampling of turtle nesting sites, bush fires, cutting of trees for firewood, the clearance of undergrowth using strimmers, littering, and the spread of alien invasive species.
34
J.C. Daltry
As the previous paragraph illustrates, the recreational use of Great Bird Island currently predominates over all other uses, conservation included. While this is an extreme example, similar problems plague many turtle nesting beaches and other heavily visited sites around Antigua. Foreign visitors especially often express astonishment that no money from tourism feeds back into supporting the management of these sensitive areas. Restricted population sizes and distribution ranges The fact that many of the nation’s endemics are restricted to small islands makes them inherently vulnerable to the hazards of demographic stochasticity (chance variation in births, deaths and sex ratio), environmental catastrophes such as hurricanes, and the loss of genetic diversity in successive generations (Gilpin, 1996). Possible examples of this theme include small colonies of Ameiva griswoldi on Maiden Island and Rabbit Island, which dwindled and eventually died out in 1997 and 1999 respectively, for no obvious reason (pers. obs.). Many workers have suggested that a population size of at least 500 breeding adults is required to enable species to persist and retain the ability to adaptively evolve (e.g., Frankel and Soulé, 1981; Lande and Barrowclough, 1996). The Antiguan racers on Great Bird Island have been reduced to only 50 individuals in the past, and can have only rarely exceeded 120. This population now exhibits many classic symptoms of inbreeding, including low fertility (Gibson, 1997) and a high prevalence (at least 20% of individuals) of visible congenital defects such as kinked tails, fused scales and deformed eyes (Daltry, 1999). Climate change and hurricanes While hurricanes are a natural hazard in this region, historically striking at the rate of one every 50 years, many workers predict an increase in the number and severity of hurricanes in the Caribbean (e.g., Goldenberg et al., 2001). As possible evidence of this trend, no less than four severe (Categories 3-5) hurricanes struck Antigua between 1995 and 2005, causing immense damage to infrastructure, beaches, vegetation and reefs (TAC, 2005). Turtle nests and wildlife on low-lying islands are especially at risk of flooding during hurricanes, and this hazard could worsen in view of projected sea level rises of around 50 cm by the end of the 21st century (e.g., Church et al., 2001). The Antiguan Racer Conservation Project reported a 20% decrease in the Antiguan racer population in the wake of Hurricane Georges, which caused the inundation of 20% of Great Bird Island by rough seas in September 1998 (Daltry, 1999). Some of the effects of climate changes may be more insidious. For example, reptiles that exhibit temperature sex determination, including all of Antigua’s marine turtles, could potentially develop skewed sex ratios in response to global warming, especially if their choice of nesting areas is limited (see Glen and Mrosovsky, 2004).
The herpetofauna of Antigua, Barbuda and Redonda
35
Legal Protection International treaties Antigua and Barbuda was among the first nations to sign the Convention on Biological Diversity in 1992. It has also ratified the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region and signed the convention’s Protocol Concerning Specially Protected Areas and Wildlife (“SPAW Protocol”). All six Caribbean sea turtles and, surprisingly, Eleutherodactylus johnstonei and E. martinicensis, are on Annex II, which indicates that they merit strict protection by all parties. Iguana delicatissima and Iguana iguana have been placed on Annex III, which indicates that their use requires careful regulation. Antigua and Barbuda has been a party to the Convention on the International Trade in Endangered Species (CITES) since 1997, which places restrictions on the international trade of species listed in CITES Appendices, including all of the Caribbean sea turtles, Geochelone carbonaria, and all members of the genus Iguana. National legislation In spite of the above international signals of its firm commitment to conserve native species and habitats, Antigua and Barbuda’s national legislation still leaves much to be desired. Legislation relative to the protection of wildlife outside of protected areas is found only in the Wild Birds Protection Ordinance (1913) and the Turtle Ordinance (1927). The latter imposed size and seasonal bans on turtle hunting and egg collection, but illegal hunting is not uncommon and is rarely punished (Hoyle, 1994; James, 2001). Even the Critically Endangered Alsophis antiguae is not protected by law and it appears that this and other endemic species can be freely caught, killed, kept as pets or traded. A Forestry and Wildlife Act was drafted in 1988, which could potentially provide better protection to endangered species (Jeffrey and Henry, 2000). The draft new Environment Law also makes stronger provision for the protection of native wildlife (Carol-Faye George, pers. comm.). There are also worryingly few legal mechanisms to control the introduction and dispersal of foreign herpetofauna or other potentially invasive alien species on Antigua and Barbuda. The Animals (International Movement and Disease) Act, however, usefully prohibits the entry of reptiles, birds and insects without a license (Kairo et al., 2005). Legislation to protect habitats is also fairly weak. In practice, private land owners often appear to have considerable freedom to modify their land, even those areas that are known to be used by nesting sea turtles or other endangered species. CCA (1991) bemoaned the confusion over institutional responsibilities to manage important habitats, as well as inadequate staffing and budgets. Coastal habitats in particular still seem to fall into a grey area where no government institution appears to have clear management authority.
36
J.C. Daltry
The protection of important areas is feasible under the Forest Ordinance Act (1941) and Forestry Regulations (1952), which provide for the protection of forested lands, but are ‘no longer enforced’ (CARICOM/FAO/ODA, 1993). Marine parks are mandated by the Marine Areas (Preservation and Enhancement) Act of 1972 and Fisheries Act of 1983, which provides for the declaration of restricted marine areas to preserve and protect flora and fauna. The Act also authorizes the declaration of any area of Antigua and Barbuda waters and adjacent land to be ‘a marine reserve for the purpose of giving special protection to the area’s natural beauty, flora, fauna and habitats’. Both the Forestry Unit and Fisheries Division urgently need more trained staff and resources to establish and manage such areas, however. At the time of writing, for example, the Fisheries Division does not even have a boat! The National Parks Act of 1984 created the Antigua and Barbuda National Parks Authority to ‘preserve, protect, manage and develop the natural physical and ecological resources of the historical and cultural heritage of Antigua and Barbuda’. Unfortunately, the National Parks Act does not provide a definition of ‘national park’, and the first and only operational national park has apparently delivered only a limited environmental benefit so far (see below). Mounting concern at the loss of Antigua’s biodiversity and natural beauty has, however, triggered a number of important new initiatives to bring more habitats under protection, including areas that are known to be of particular importance to endemic and endangered herpetofauna. Some of these are outlined below. Protected areas Only one national park — Nelson’s Dockyard National Park — is fully operational and is managed primarily for its tourism attractions, which include the historic Nelson’s Dockyard and other historical and archaeological sites. This multipleuse park covers 8% of Antigua and Barbuda’s land mass (more than 3,100 ha) but has a small staff that is chiefly concerned with services at the dockyard. CCA (1991) criticized the lack of effective land use and development control in the park, which suffers from severe overgrazing (CARICOM/FAO/ODA, 1993). This is a pity because the park’s substantial terrestrial and marine areas could potentially be made more suitable for turtles and other native reptiles. Several additional national parks have been very recently decreed or proposed, including the Great Bird Island National Park, which has been gazetted three times but is awaiting final approval from Parliament. It remains to be seen how this popular yet fragile park will be managed. Recent consultations, led by the Environmental Awareness Group, found that the majority of local stakeholders wished for these islands to ‘remain unchanged’ and some called for controls over the number of visitors (Lucia Mings, pers. comm.). The Wallings Conservation Area (Forest Reserve) was established in 1912, when five hectares of trees were planted to restore and protect an important watershed in Antigua’s southern hills. It is managed by the Forestry Unit and has become a popular recreational site for local and foreign visitors. Few native reptiles remain,
The herpetofauna of Antigua, Barbuda and Redonda
37
but the area could potentially support more species (e.g., Iguana delicatissima) if mongooses can be controlled. Barbuda’s Codrington Lagoon features a Bird Sanctuary for an impressive colony of frigate birds, and the sandy beaches of the lagoon are known to be important for nesting turtles. The Diamond Reef Marine Park (2,000 ha), north of Antigua, and Palaster Marine Park (500 ha), south of Barbuda, were established in 1973. Both parks have been demarcated with buoys and, while they might have a useful role in preserving turtle feeding grounds, they are not actively managed. Several additional marine protected areas have been identified and designated, perhaps the most significant of which is the North East Marine Management Area. Declared in 2006, this provides protection under the Fisheries Act for approximately 2,100 ha from the northern tip of Antigua to the south-east, including Great Bird Island, Rabbit Island, Green Island, Long Island and other coastal sites of outstanding herpetological importance (Philmore James, pers. comm.). Again, it is unclear how this protected area will be managed.
Herpetofaunal Conservation Programmes There are two long-running herpetological conservation projects, both of which have a strong focus on Antigua’s offshore islands. Neither receives government funding, and both rely heavily on grants, donations and the efforts of volunteers. Jumby Bay Hawksbill Project This project (www.jbhawksbillproject.org) was founded by John Fuller, Esq. (St John’s, Antigua) and Dr Jim Richardson (University of Georgia) in 1986, after being alerted by informed residents that Pasture Beach was an important hawksbill nesting beach on Long Island, a 122 ha island in Antigua’s North Sound. The mission of the Jumby Bay Hawksbill Project is ‘to better understand the life history of the hawksbill turtle, in hopes that our findings will serve as a foundation for wise management and policy making. We seek to increase public awareness of sea turtles regionally and internationally through school visits and educational turtle watches for residents and tourists. Only through long-term public support will Antigua and Barbuda’s hawksbills have a chance at survival and recovery’ (www.jbhawksbillproject.org). The project is maintained by the Wider Caribbean Sea Turtle Conservation Network (WIDECAST), with financial and logistical support provided annually by the Jumby Bay Island Company (JBIC) and local landowners. From 15 June to 15 November every year, project researchers conduct nightly nine-hour beach patrols to monitor nesting activity, and thereby encounter nearly 100% of all nesting females. Every female receives two tags (issued by the WIDECAST Marine Turtle Tagging Centre based at the University of the West Indies, Barbados), or is identified by existing tags, and information about the turtle’s size, condition, nest-placement and
38
J.C. Daltry
timing is gathered. To minimize stress, biometric data is generally collected during egg-laying (Stapleton and Stapleton, 2006). Small numbers of guests frequently accompany the researchers to help spot nests and, perhaps more importantly, to learn about hawksbill turtles and the need to conserve both the turtles and the habitats on which they rely. After two decades of research, much has been learned about the reproductive behaviour and population dynamics of the Jumby Bay hawksbills (Corliss et al., 1989; Richardson et al., 1989, 1999; Ryder et al., 1989; Mrosovsky et al., 1992; Hoyle and Richardson, 1993; Kerr et al., 1999; Frick et al., 2003; Glen and Mrosovsky, 2004; Mason et al., in press). The comprehensive nature of the project has meant that the data are useful far beyond the national context, and they are often cited in international assessments and policy documents (e.g., IUCN, 2002). In addition to the regular programme of population studies, other research initiatives include a genetic study, conducted in collaboration with the University of West Indies as part of a wider investigation into the diversity and international movements of hawksbill turtles (Bass, 1999). A telemetry study conducted in partnership with NOAA/NMFS also helped to shed light on the movements of the Long Island turtles. Satellite transmitters were attached to four female hawksbills in 1998 and during that first year, one turtle remained close to Jumby Bay while the other three dispersed to forage around St. Kitts, St. Eustatius, and Redonda respectively. The three dispersed turtles eventually returned to nest on Pasture Beach but the resident turtle did not, leading researchers to believe that her transmitter had fallen off in near-shore waters; her fate remains unknown (Andrews and Richardson, unpubl. data). Gravid females tagged at Pasture Bay have subsequently been recaptured in St. Kitts and Dominica (Meylan, 1999) and elsewhere, underscoring the management complexity surrounding these highly migratory species. Since the first studies began, the Jumby Bay Hotel has been established on Long Island, together with a number of exclusive homes, a putting green and other facilities, co-managed by the JBIC. The project team works very closely with the hotel and homeowners. Many guests and residents enjoy viewing the turtles during the nesting season, while the project researchers benefit from transport and a field office provided by the JBIC. The ongoing residential developments have inevitably led to changes in the island’s natural vegetation, but the project team has worked with island residents since 1998 to make sure that beachside vegetation is preserved or restored with indigenous species. ‘Beach gardens’, comprised of railroad vines, scaveola, sea-grapes and other plants, have been planted in areas where vegetation has been lost, and appear to have successfully attracted more nesting females (Muenz and Andrews, 2002, in press). Probably in no small part due to increased protection in this region, public education and nesting habitat restoration efforts, recent analyses have shown a significant increase in the local hawksbill turtle population (fig. 6). Sixty-three nesting females, including 23 neophytes (untagged and presumed new recruits into the breeding population), were observed and tagged on Long Island 2005, exceeding
The herpetofauna of Antigua, Barbuda and Redonda
39
Figure 6. Neophytes, remigrants, and total nesting females documented on Long Island, Antigua, West Indies, during monitoring from 1987 to 2005. (Data courtesy of Peri Mason, Jumby Bay Hawksbill Project.)
by more than 20% the previous record of nesting turtles in a single year. A total of 195 nests were deposited on Pasture Bay Beach during the patrol season (15 June to 16 November 2005), and an additional 26 nests laid on peripheral beaches (Stapleton and Stapleton, 2006). Antiguan Racer Conservation Project The Antiguan Racer Conservation Project (www.antiguanracer.org) was formed in 1995 by a consortium of governmental and non-governmental organisations with the primary goal of saving the ‘world rarest snake’ from extinction. The founders were the Environmental Awareness Group, Antiguan Forestry Unit, Fauna & Flora International, Island Resources Foundation and Durrell Wildlife Conservation Trust, which were joined by Dr Brian Smith of Black Hills State University in 1999. In 2003, a Steering Committee was created to enlist the help of additional government agencies in project planning, including the Fisheries Division, Ministry of Tourism, Environment Division and National Parks Authority. The distribution range of the Antiguan racer had shrunk to the mongoose-free Great Bird Island (8.4 ha), and the population numbered no more than 51 individuals (Daltry and Day, 1996). Two were found dead in 1995, apparently killed by visitors, but the most immediate threat to the species was inferred to be the large number of Rattus rattus on the island (see Threats above). Among the first direct interventions by the project was the eradication of rats from Great Bird Island using waxy briquettes impregnated with brodifacoum (Day
40
J.C. Daltry
and Daltry, 1996). The effort succeeded, and within 18 months, the racers had increased to just over 100 adults and subadults (snakes aged one year or more) (Cooper, 1997; Daltry and Day, 1997). The snake carrying capacity of Great Bird is constrained, however, by its relatively small area and the fluctuating number of lizards (Daltry et al., 2001). To enable the racers to increase to a more viable level, the project team embarked on an ambitious reintroduction program to restore the snakes on at least five offshore islands that could support a total meta-population of at least 500 breeding adults (ARCP, 1999). First, it was necessary to eradicate rats and, where present, mongooses from potentially suitable islands and neighbouring islands (to reduce the risk of the mammals reinvading) (Varnham et al., 1998; Varnham, 2001). The Antiguan racer was successfully introduced to Rabbit Island (2.1 ha) in 1999 and to Green Island (45.2 ha) in 2001 (Daltry, 2000; Daltry et al., 2002), and plans are underway to reintroduce the snakes to an additional island in 2007. Post-release monitoring using radiotelemetry and direct observations have revealed that the racers adapted easily to the new islands and even exhibit growth spurts when released from the competitive environment on Great Bird Island (Buley, 2000; Daltry et al., 2003). To monitor changes in the population size, all captured racers are individually marked with microchip tags, which have greatly aided understanding of their biology. For example, we now know that racers can live for up to 10 years, but the population turnover is very high, with an annual mortality rate of 44% that is independent of age (Daltry et al., 2003; Wright et al., 2004). This finding suggests that the population inherently unstable and liable to crash within as little as 18 months if breeding is suppressed. Every year, a census lasting approximately 40 days is conducted by project staff and volunteers using a standard mark-recapture method, with estimates generated using Begon’s (1979) weighted mean (Daltry et al., 2001). Although the accuracy of estimates has inevitably decreased as the area of distribution has increased, the number of racers is projected to exceed 250 adults and subadults in 2006, a five-fold increase since the project began (see fig. 7). The snakes’ main prey species — Anolis wattsi, A. leachi and Ameiva griswoldi — have also been the subject of intensive field-based investigations (e.g., Smith and Baum, 2000; Smith and Colbert, 2002; Smith et al., 2001, 2002). The success of the racer reintroduction program to date has been in no small part due to more than ten years of hard work to raise public awareness of these harmless snakes, by means of the media, production of publicity materials, school visits, guided field trips and even input into the national standard primary and secondary school curriculum (McCauley, 1999a, 1999b). Acceptance of, and even pride in, Antigua’s native snake has grown measurably since the mid 1990s. In spite of increased human-snake encounters, there have been no reported deliberate killings for several years. Many tourist boat crews and other regular visitors to the islands have helped to support the project in many ways, including teaching new visitors that the racers are harmless and rare. An ongoing problem, however, is the
The herpetofauna of Antigua, Barbuda and Redonda
41
Figure 7. Changes in the total number of adult and subadult Antiguan racers (Alsophis antiguae), 1995 to 2005.
perennial risk of rats reinvading the islands, carried as stowaways on boats. Rattus rattus reappeared on Great Bird Island in 2001 but were immediately destroyed. The same species reinvaded Green Island in 2005, and a second eradication attempt will take place in 2006. As the racer meta-population has become more secure, the project has expanded its focus to conserving the biodiversity of Antigua’s offshore islands, and has gained the synonym Offshore Islands Conservation Project. The eradication of invasive rats from ten islands has led to a conspicuous increase in bird populations, including a number of regionally threatened seabirds, and is thought to have reduced predation on sea turtle eggs (Varnham, 2001, 2005). The project researchers also conduct annual student internship schemes whereby local and foreign students study the island wildlife and contribute to conservation planning. Other project activities include training teachers and tour operators, running ‘floating classrooms’ for local schools, social surveys, and protected area planning (e.g., Anthonyson and McCauley, 2002). The recent gazetting of Great Bird, Red Head, Rabbit, Green and many other islands as part of a new national park and marine reserve will, it is hoped, help to maintain the beauty and diversity of this landscape. Also of particular relevance to this paper is a new initiative by the project members to reintroduce Lesser Antillean iguanas Iguana delicatissima, to Antigua from other populations in the West Indies. The offshore islands could provide suitable initial release sites, where threats from invasive species and hunters can be more easily controlled. The findings of recent feasibility studies suggest that at least two of the larger offshore islands have suitable habitat to support several thousand iguanas (Matthew Morton, pers. comm.).
42
J.C. Daltry
Conclusions and Recommendations Antigua, Barbuda and Redonda collectively support a diverse herpetofauna, with exceptionally high levels of endemicity. Ten of the native species are endemic, and six are ranked as globally threatened (IUCN, 2004), including the Critically Endangered hawksbill turtle, leatherback turtle and Antiguan racer. No fewer than four indigenous species have already been lost and further measures are needed to ensure the survival of the rest. A comprehensive national Sea Turtle Recovery Action Plan (Fuller et al., 1992) provides many recommended actions to conserve marine turtles and their habitats, while ARCP (1999) and Daltry (1999) detail specific actions for the Antiguan racer. The National Biodiversity Strategy and Action Plan also details many objectives and actions to enhance the conservation of Antigua and Barbuda’s biological diversity, including its reptiles and amphibians (Jeffrey and Henry, 2000). While some of these are now being addressed, such as the expansion of the national protected area network, many issues still require urgent attention. Space does not permit details here, so the following checklist is merely an outline of what needs to be done to conserve the indigenous herpetofauna of Antigua, Barbuda and Redonda. While government agencies such as Forestry, Environment, Fisheries and National Parks should necessarily take a prominent role, greater success could be achieved by working in collaboration with nongovernmental organisations such as the Environmental Awareness Group, the scientific community, schools and youth groups, tourism industry, private land owners and the general public. 1. Develop and enforce protective national and international legislation for all globally threatened species. The draft Forestry and Wildlife Act (1988) should be updated and enacted to make it a criminal offence to capture, kill or trade in endangered terrestrial species without a license. Priority species for inclusion are: Alsophis antiguae, Ameiva griswoldi, Ameiva atrata, Anolis nubilus and Iguana delicatissima. Fuller et al. (1992) identified a number of deficiencies in the 1990 Fisheries Regulations that comprise the current legal framework for the management of marine turtle exploitation in Antigua and Barbuda, with the most important of these deficiencies being: minimum size limits that focus exploitation on large juveniles and breeding-age adults, and a closed season that does not fully encompass the breeding season (as the majority of hawksbills are still nesting when the season opens on 1 September, much of the breeding population could be legally exterminated). Legislation pertaining to marine turtles should be reviewed, and consideration given to the banning of hunting and egg collection until and unless it can be demonstrated to be genuinely sustainable. The draft new Environment Law also offers stronger protection for marine and terrestrial biodiversity and should be enacted as a matter of urgency.
The herpetofauna of Antigua, Barbuda and Redonda
43
2. Develop and implement management plans and management structures for all protected areas, which take into account the needs of herpetofauna. All of the existing and proposed protected areas need management plans, developed in consultation with a wide range of stakeholders, including wildlife conservation experts. For environmentally sensitive areas such as Great Bird Island National Park, the protected area managers must take great care to ensure that recreational and other human uses do not degrade habitats or disturb wildlife. Another important consideration (for all areas) is how to prevent and/or remove harmful alien invasive species. Effective management will undoubtedly require many more trained staff and resources than are currently available, and self-financing mechanisms (e.g., user fees, tourism concessions) will need to be explored. 3. Develop management agreements with landowners and local communities for priority sites which reflect the needs of herpetofauna. Owners of homes and hotels situated along known turtle nesting beaches, for example, could be more positively engaged in ensuring the beaches remain safe and attractive for turtles. The Jumby Bay Hawksbill Project has valuable experience of this approach, and the WIDECAST network as a whole has been proactive in creating a variety of best practices documents (e.g., Choi and Eckert, 2006) to assist beachfront property owners in designing and implementing ‘turtle-friendly lighting’ and taking other conservation-oriented actions. Agreements may be informal or legally binding in the form of a covenant or contract: the Mill Reef Club, for example, established a 99 year covenant to protect Green Island, Smith Island and York Island from development. 4. Eradicate invasive mammals from priority conservation sites, including Antigua’s North Sound islands and Redonda, and implement measures to prevent invasion. Mongoose, rats and goats are among the principle threats to native herpetofauna and other wildlife. Their removal tends to be easier on small offshore islands, but significant control could be exerted even on larger areas. Preventing (re)invasion by invasive alien species is also a considerable challenge, requiring a combination of public awareness, legislation, and, ideally, rigorous screening of incoming goods and vessels (IUCN, 2000; Kairo et al., 2005). Particular attention should be paid to preventing mongooses from invading Barbuda or Redonda, where they would decimate endemic reptile populations and other wildlife. The Antiguan Racer Conservation Project has useful experience in eradicating rats from small islands and rat prevention techniques. 5. Control the introduction of alien reptiles and amphibians. Non-native reptiles and amphibians may transmit diseases or parasites to indigenous species, and can potentially become feral and invasive. The import and trade of iguanas, boa constrictors and other pets to Antigua and Barbuda should be subject to strict controls, preferably prohibited.
44
J.C. Daltry
6. Continue to reintroduce endangered reptiles to islands within their former range. To achieve a more viable population size, Antiguan racers must be reintroduced to at least five islands to provide a total area of at least 70 ha, and these islands need to be well-vegetated and free of alien predators, notably mongooses, rats and cats. The feasibility of reintroduction to Barbuda should also explored, in view of the absence of mongooses and availability of suitable prey. Lesser Antillean iguanas have been extirpated from Antigua and Barbuda, but could potentially be returned from other Lesser Antillean states, if hunting, habitat degradation and predation by mongooses can be prevented. Probably the best release site or sites in the short term would be Antigua’s larger offshore islands, where such threats can be controlled more easily (Matthew Morton, pers. comm.). 7. Enlist greater public and political interest and support for indigenous herpetofauna and their habitats through education. To reach a wide audience, the awareness strategy should make use of a wide range of approaches, including all varieties of media. In the case of reptiles that people find repulsive or frightening, previous studies have shown that providing information alone may do disappointingly little to modify opinions or behaviour — the target audience often needs to see the animal at close quarters (Morgan and Gramann, 1989). Special attention should be given to the reasons and methods for preventing the spread of alien invasive species, because effective control requires public cooperation. To achieve greater political attention for conservation in Antigua and Barbuda, it may be necessary to demonstrate links between conservation and tourism, for example, by promoting turtle-watching on Antigua or nature tours to Redonda. 8. Encourage and enable more research on herpetofauna. Research can play an important role in conservation by revealing threats to wildlife, identifying possible solutions, and evaluating whether conservation interventions have had the desired effect. Biological research in Antigua and Barbuda is commonly conducted by foreign scientists, and it very important to enable and encourage local students and naturalists to get involved and improve their skills and knowledge. Suggested topics for research include: (a) Study and monitor the distribution, status and ecology of all endemic and endangered species, including the endemic lizards of Redonda. (b) Elucidate the impact of Gymnophthalmus lizards on native herpetofauna, and, if necessary, develop a strategy to contain their spread. (c) Resolve the taxonomic relationship of Anolis forresti and Anolis wattsi. (d) Resolve the status and distribution of Eleutherodactylus martinicensis. (e) Verify the presence of Elaphe guttata, or other alien snakes, and assess their distribution and status. Acknowledgements. I thank Dr Julia Horrocks for inviting this manuscript, which I hope will stimulate greater interest in the herpetofauna of Antigua, Barbuda
The herpetofauna of Antigua, Barbuda and Redonda
45
and the long-overlooked Redonda. For sharing their knowledge and reference materials over the years, special thanks are owed to Kevel Lindsay, Gillian Cooper, Dr Brian Cooper, Kim Derrick, Ingrid Sylvester, Donald Anthonyson, Carole McCauley, Mykl Clovis, Junior Prosper, Victor Joseph, Winston Downes, Lucia Mings, Harmony Hall, Adriel Thibou, McRonnie Henry, Everette Williams, Dr Reg Murphy, Florita Kentish, Trisha Lovell, Cheryl Jeffrey-Appleton, Ato Lewis, Kim Walter, Cortright Marshall, and many other leading lights in the management and conservation of Antigua and Barbuda’s natural resources. This paper also draws on information kindly provided by Dr Brian Smith, Karen Varnham, Dr Hinrich Kaiser, Toby Ross, Sarah McIntyre, Polly Phillpot and staff of the Island Resources Foundation, Durrell Wildlife Conservation Trust and Jumby Bay Hawksbill Project. Peri Mason (Jumby Bay Hawksbill Project), Dr Karen Eckert (WIDECAST) and an anonymous reviewer kindly reviewed earlier drafts. Nevertheless, I take full responsibility for the opinions expressed in this paper and for any errors. Fieldwork and the preparation of this manuscript were supported by Fauna & Flora International, Disney Wildlife Conservation Fund, Durrell Wildlife Conservation Trust, Whitley Award Scheme, Organization of American States, and British Airways Assisting Conservation. The rat eradication work described in this paper was made possible with the kind support of Syngenta Agrochemicals. References Anon (2001): Antigua and Barbuda’s First National Report to the Convention on Biological Diversity. Office of the Prime Minister, St John’s, Antigua and Barbuda. Anthonyson, D., McCauley, C. (2002): A Survey of Fishermen: North Sound, Antigua. Antiguan Racer Conservation Project, Environmental Awareness Group, St John’s, Antigua. Auffenberg, W.A. (1958): A small fossil herpetofauna from Barbuda, Leeward Islands. Quart. J. Flor. Acad. Sci. 21: 248-254. ARCP — Antiguan Racer Conservation Project (1999): Re-introduction of the Antiguan Racer, Alsophis antiguae (Serpentes: Colubridae) to Offshore Islands Around Antigua, West Indies. Proposal to the IUCN/SSC Re-introduction Specialist Group, Cambridge, Fauna & Flora International. Bass, A.L. (1999): Genetic analysis to elucidate the natural history and behavior of hawksbill turtles (Eretmochelys imbricata) in the Wider Caribbean: a review and reanalysis. Chel. Conserv. Biol. 3: 195-199. Begon, M. (1979): Investigating Animal Abundance. London, Edward Arnold. Buley, K. (2000): The Reintroduction of the Antiguan Racer Alsophis antiguae: 2nd Phase of Radiotelemetry Study (19th February-6th March 2000). Antiguan Racer Conservation Project, Durrell Wildlife Conservation Trust, Jersey, Channel Islands. Camin, J.H. (1953): Observations on the life history and sensory behaviour of the snake mite, Ophionyssus natricis (Gervais) (Acarina, Macronyssidae). Chicago Acad. Sci. Spec. Publ. 10: 1-75. Campbell, K., Donlan, C.J. (2005): Feral goat eradications on islands. Conserv. Biol. 19: 1362-1374. CCA — Caribbean Conservation Association (1991): Country Environmental Profile: Antigua and Barbuda. Caribbean Conservation Association, St Michael, Barbados. CARICOM/FAO/ODA (1993): National Forestry Action Plan: Antigua and Barbuda: Main Report. Tropical Forests Action Programme, Food and Agriculture Organization.
46
J.C. Daltry
Censky, E. (1988): Geochelone carbonaria (Reptilia: Testudines) in the West Indies. Flor. Sci. 50: 108-114. Censky, E., Lindsay, K. (1997): Note on Gymnophthalamus underwoodi (Antillean lizard). Herpetol. Rev. 28: 210. Censky, E.J., Hodge, K., Dudley, J. (1998): Evidence of over-water dispersal of lizards due to hurricanes. Nature 395: 556. Censky, E., Kaiser, H., (1999): The lesser Antillean fauna. In: Caribbean Amphibians and Reptiles, p. 181-221. Crowther, B.I., Ed. San Diego, Academic Press. Choi, G.-Y., Eckert, K.L. (2006): Sea Turtles and the Hotel Industry: Best Practices Manual for Beachfront Properties in the Wider Caribbean Region. Wider Caribbean Sea Turtle Conservation Network (WIDECAST) and the Caribbean Alliance for Sustainable Tourism (CAST). WIDECAST Technical Report No. 6. Beaufort, North Carolina. Church, J.A., Gregory, J.M., Huybrechts, P., Kuhn, M., Lambeck, K., Nhuan, M.T., Qin, D., Woodworth, P.L. (2001): Changes in sea level. In: Climate Change 2001: The Scientific Basis, p. 639-693. Houghton, J.T., Ding, Y., Griggs, D.J., Noguer, M., van der Linden, P.J., Xiaosu, D., Eds. Cambridge, Cambridge University Press. Cooper, G. (1997): Antigua racer population up more than 50%. The EAGer (newsletter of the Environmental Awareness Group, St Johns, Antigua) 3: 1. Corliss, L.A., Richardson, J.I., Ryder, C., Bell, R. (1989): The hawksbills of Jumby Bay, Antigua, West Indies. In: Proc. of the Ninth Ann. Workshop on Sea Turtle Conserv. Biol. p. 33-35. Eckert, S.A., Eckert, K.L., Richardson, T.H., Eds, NOAA Technical Memorandum NMFS-SEFC232, U.S. Department of Commerce, Miami, Florida. Daltry, J.C. (1999): Status, Distribution and Natural History of the Antiguan Racer (Alsophis antiguae): Field Research and Conservation Technical Report. Antiguan Racer Conservation Project Report No. 4. Cambridge UK, Fauna & Flora International. Daltry, J.C. (2000): Re-introduction of the Antiguan Racer Alsophis antiguae, November-December 1999. Cambridge, UK, Fauna & Flora International. Daltry, J.C., Day, M.L. (1996): The Status, Distribution and Natural History of the Antiguan Racer (Alsophis antiguae): Findings of the First Field Study. Antiguan Racer Conservation Project Report No. 1. Cambridge, UK, Fauna & Flora International. Daltry, J.C., Day, M.L. (1997): The Status, Distribution and Natural History of the Antiguan Racer (Alsophis antiguae): Findings of the Second Field Study. Antiguan Racer Conservation Project Report No. 3, Cambridge, UK, Fauna & Flora International. Daltry, J.C., Bloxam, Q., Cooper, G., Day, M.L., Hartley, J., Henry, M., Lindsay, K., Smith, B.E. (2001): Five years of conserving the ‘world’s rarest snake’, the Antiguan racer Alsophis antiguae. Oryx 35: 119-127. Daltry, J.C., McCauley, C., Morton, M. (2002): Re-introduction of the Antiguan Racer Alsophis antiguae, to Green Island: Interim Report. Antiguan Racer Conservation Project, St John’s, Antigua and Barbuda. Daltry, J.C., Morton, M., Smith, B.E., Sylvester, I. (2003): The 2003 Antiguan Racer Census and Reintroduction. Antiguan Racer Conservation Project, St John’s, Antigua and Barbuda. Day, M.L., Daltry, J.C. (1996): Rat eradication to save the Antiguan racer. Aliens (journal of the IUCN/SSC Invasive Species Specialist Group) 3: 14-15. Daszak, P., Berger, L., Cunningham, A.A., Hyatt, A.D., Green, D.E.., Speare, R. (1999): Emerging infectious diseases and amphibian population declines. Emerging Infectious Diseases Journal 5: 735-748. http://www.cdc.gov/ncidod/eid/vol5no6/daszak.htm Day, M.L., Breuil, M., Reichling, S. (2000): Lesser Antillean iguana Iguana delicatissima. In West Indian Iguanas: Status Survey and Conservation Action Plan, p. 62-67. Alberts, A., Ed., IUCN/SSC West Indian Iguana Specialist Group. Dunn, E.R. (1936): Notes on American mabuyas. Proc. Acad. Nat. Sci., Phil. 87: 553-557.
The herpetofauna of Antigua, Barbuda and Redonda
47
Eckert, K.L. (1995): Hawksbill Sea Turtle, Eretmochelys imbricata. In: National Marine Fisheries Service and U.S. Fish and Wildlife Service Status Reviews for Sea Turtles Listed Under the Endangered Species Act of 1973, p. 76-108. Plotkin, P.T., Ed., National Marine Fisheries Service, Silver Spring, Maryland, USA. Etheridge, R. (1964): Late Pleistocene lizards from Barbuda, British West Indies. Bull. Flor. State Mus. Biol. Sci. 9: 43-75. Faaborg, J., Arendt, W. (1985): Wildlife assessments in the Caribbean. U.S. Department of Agriculture, Forest Service, Institute of Tropical Forestry, Rio Piedras, Puerto Rico. Frankel, O.H., Soulé, M.J. (1981): Conservation and Evolution. Cambridge, Cambridge University Press. Frick, M.G., Mason, P.A., Williams, K.L., Andrews, K., Gerstung, H. (2003): Epibionts of hawksbill turtles, Eretmochelys imbricata, in a Caribbean nesting ground: a potentially unique association with snapping shrimp. Mar. Turt. News. 99: 8-11. Fuller, J., Eckert, K,L., Richardson, J.I. (1992): WIDECAST Sea Turtle Recovery Action Plan for Antigua and Barbuda. CEP Technical Report No. 16. UNEP Caribbean Environment Programme, Kingston, Jamaica. 88 pp. Gibson, R. (1997): Conservation of the Antiguan racer Alsophis antiguae: the captive component. Proc. 1997 Int. Herpetol. Soc. Symp., International Herpetological Society. Gilpin, M.E. (1996): Spatial structure and population vulnerability. In: Viable Populations for Conservation, p. 125-139. Soulé, M.E., Ed. Cambridge, Cambridge University Press. Glen, F., Mrosovsky, N. (2004): Antigua revisited: the impact of climate change on sand and nest temperatures at a hawksbill turtle (Eretmochelys imbricata) nesting beach. Glob. Change Biol. 10: 2036-2045. Goldenberg, S.B., Landsea, C.W., Mestas-Nuñez, A.M., Gray, W.M. (2001): The recent increase in Atlantic hurricane activity: causes and implications. Science 20: 474-479. Hedges, S.B. (1999): Distribution patterns of amphibians in the West Indies. In: Patterns of Distribution of Amphibians: A Global Perspective, p. 211-254. Duellman, W.E., Ed. Baltimore, Johns Hopkins University Press. Henderson, R.W. (1989): A new subspecies of Alsophis antiguae (Serpentes: Colubridae) from Great Bird Island (Antigua), Lesser Antilles. Carib. J. Sci. 25: 119-122. Henderson, R.W., Sajdak, R.A. (1986): West Indian racers: a disappearing act or a second chance? Lore 36: 13-18. Henderson, R.W., Powell, R., Daltry, J.C., Day, M.L. (1996): Alsophis antiguae Parker. Cat. Amer. Amph. Rept. 632: 11-13. Horrocks, J.A., Oxenford, H.A., Willoughby, S. (1989): Nest site location and clutch mortality of hawksbill turtles Eretmochelys imbricata in Barbados, West Indies. In: Proc. of the Ninth Ann. Workshop on Sea Turtle Conserv. Biol., p. 239-241. Eckert, S.A., Eckert, K.L., Richardson, T.H., Eds, NOAA Technical Memorandum NMFS-SEFC-232, U.S. Department of Commerce, Miami, FL. Horwith, B., Lindsay, K. (1997): A Biodiversity Profile: Antigua, Barbuda, Redonda. Eastern Caribbean Biodiversity Programme Biodiversity Publication 3, Island Resources Foundation. Hoyle, M. (1994): Continuing sea turtle exploitation in Antigua and Barbuda, West Indies. Mar. Turt. News. 64: 21-22. Hoyle, M., Richardson, J.I. (1993): The Jumby Bay Hawksbill Project: Survivorship, Mortality, Recruitment and Reproductive Biology and Behavior of Adult Female Hawksbill Sea Turtles (Eretmochelys imbricata) Nesting at Pasture Bay, Long Island, Antigua, W. I. Unpublished Technical Report, Georgia Sea Turtle Cooperative, Institute of Ecology, University of Georgia, Athens, GA. 76 pp. IUCN — The World Conservation Union (1998): Invaders from Planet Earth. World Conservation 28, 29 (double issue): 63 pp.
48
J.C. Daltry
IUCN — The World Conservation Union (2000): Guidelines for the Prevention of Biodiversity Loss caused by Alien Invasive Species. IUCN/SSC Invasive Species Specialist Group, The World Conservation Union, Gland, Switzerland. IUCN – The World Conservation Union (2002): Hawksbill Turtles in the Caribbean Region: Basic Biological Characteristics and Population Status. CITES Wider Caribbean Range State Hawksbill Turtle Dialogue meetings. www.cites.org IUCN — The World Conservation Union (2004): 2004 IUCN Red List of Threatened Species. www.iucnredlist.org, downloaded on 10 April 2006. James, S. (2001): Coastal stewardship in Antigua and Barbuda. Paper presented to IUCN/CSI Conference on Environment and Development in Coastal Regions and in Small Islands, Dominica. Jeffery, C., Henry McR. (2000): Antigua & Barbuda Biodiversity Strategy and Action Plan. St John’s, Antigua. Kairo, M., Ali, B., Cheeseman, O., Haysom, K., Murphy, S. (2005): Invasive Species Threats in the Caribbean Region: Report to the Nature Conservancy. Egham, United Kingdom, CABI Bioscience. Kerr, R., Richardson, J.I., Richardson, T.H. (1999): Estimating the annual size of hawksbill (Eretmochelys imbricata) nesting populations from mark-recapture studies: the use of long-term data to provide statistics for optimizing survey effort. Chel. Cons. Biol. 3: 251-256. Kaiser, H. (1992): The trade-mediated introduction of Eleutherodactylus martinicensis (Anura: Leptodactyliidae) on St Bathelemy, French Antilles, and its implications for Lesser Antillean biogeography. J. Herpetol. 26: 264-273. Kaiser, H., Hardy, J.D. (1994): Eleutherodactylus martinicensis. Catalogue of America Amphibians and Reptiles, Soc. Stud. Amph. Rep. 582: 1-4. Lanagan, F.T. (1844): Antigua and the Antiguans, Vol II. Saunders and Otley, London. 355 pp. Lande, R., Barrowclough, G.F. (1996): Effective population size, genetic variation, and their use in population viability analysis. In: Viable Populations for Conservation, p. 87-124. Soulé, M.E., Ed., Cambridge, UK, Cambridge University Press. Lazell, J.D. Jr. (1967): Wiederentdeckung von zwei angeblich ausgestorbenen Schlangenarten der westindischen Inseln. Salamandra 3: 91-97. Lever, C. (2001): The Cane Toad: The History and Ecology of a Successful Colonist. West Yorkshire, Westbury Publishing. 230 pp. Lindsay, K., Horwith, B. (1997): A Vegetation Classification: Antigua, Barbuda, Redonda. Eastern Caribbean Biodiversity Programme Biodiversity Publication 2, Island Resources Foundation. Magin, C. (2003): Chytridiomycosis on Dominica: Briefing Sheet 1. Cambridge UK, Fauna & Flora International. Malhotra, A., Thorpe, R.S. (1999): Reptiles and Amphibians of the Eastern Caribbean. London and Oxford, MacMillan Education. Mason, P., Stapleton, S., Ballentine, A. (in press): Nest site selection in hawksbill turtles (Eretmochelys imbricata) within and among seasons, Antigua, West Indies. In: Proc. Twenty-Fourth Ann. Symp. Sea Turtle Biol. Conserv. McCauley, C. (1999a): Environmental Education Status Report. Antiguan Racer Conservation Project, Report No. 6. Environmental Awareness Group, St Johns, Antigua. McCauley, C. (1999b): Report on offshore island workshop for tour operators. Environmental Awareness Group, St Johns, Antigua. McIntyre, S., Phillpot, P. (2002): Antiguan Racer Census 2002 Report. Unpublished report to the Antiguan Racer Conservation Project. Meylan, A.B. (1999): International movements of immature and adult hawksbill turtles (Eretmochelys imbricata) in the Caribbean Region. Chel. Conserv. Biol. 3: 289-194. Morgan, J.M., Gramann, J.H. (1989): Predicting effectiveness of wildlife education programs: a study of students’ attitudes and knowledge towards snakes. Wildl. Soc. Bull. 17: 501-509. Mrosovsky, N., Bass, A.L., Corliss, L.A., Richardson, J.I., Richardson, T.H. (1992): Pivotal and beach temperatures for hawksbill turtles nesting in Antigua. Can. J. Zool. 70: 1920-1925.
The herpetofauna of Antigua, Barbuda and Redonda
49
Muenz, T.K., Andrews, K.M. (2002): The recovery of nesting habitat: A proactive approach for conservation of the hawksbill sea turtle, Eretmochelys imbricata, Long Island, Antigua, West Indies. In: Proc. 22nd Ann. Symp. Sea Turtle Biol. Conserv. p. 105. Seminoff, J.A., Ed., NOAA Technical Memorandum NMFS-SEFSC-503. Muenz, T.K., Andrews, K.M. (in press): The reconciliation of hawksbill habitat with vegetation islands on Long Island, Antigua, West Indies. In: Proc. 24th Ann. Symp. on Sea Turtle Biol. Conserv. Parker, H.W. (1933): Some amphibians and reptiles from the Lesser Antilles. Ann. Mag. Nat. Hist. 11: 151-158. Parker, H.W. (1936): Some extinct snakes of the West Indies. Ann. Mag. Nat. Hist. 18: 227-233. Pregill, G.K., Steadman, D.W., Waters, D.R. (1994): Late Quaternary vertebrate faunas of the Lesser Antilles: historical components of Caribbean biogeography. Bull. Carnegie Mus. Nat. Hist. 30: iv + 51p. Richardson, J.I., Bell, R., Richardson, T.H. (1999): Population ecology and demographic implications drawn from an 11-year study of nesting hawksbill turtles, Eretmochelys imbricata, at Jumby Bay, Long Island, Antigua, West Indies. Chel. Conserv. Biol. 3: 244-250. Richardson, J.I., Corliss, L.A., Ryder, C., Bell, R. (1989): Demographic patterns of Caribbean hawksbills, Jumby Bay, Antigua. In: Proc. 9th Ann. Workshop on Sea Turtle Conserv. Biol., p. 253-256. Eckert, S.A., Eckert, K.L., Richardson, T.H., Eds. NOAA Tech. Memo. NMFS-SEFC232. Ryder, C., Richardson, J.I., Corliss, L.A., Bell, R. (1989): Habitat preference and beach management for nesting hawksbills, Jumby Bay, Antigua, West Indies. In: Proc. 9th Ann. Workshop on Sea Turtle Conserv. Biol., p. 263-266. Eckert, S.A., Eckert, K.L., Richardson, T.H., Eds. NOAA Tech. Mem. NMFS-SEFC-232. Sajdak, R.A., Henderson, R.W. (1991): Status of West Indian racers in the Lesser Antilles. Oryx 25: 33-38. Schwartz, A. (1967): Frogs of the genus Eleutherodactylus in the Lesser Antilles. Stud. Fauna Curacao and Caribbean Islands 23: 1-62. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions and Natural History. Gainesville, University of Florida Press. 720 pp. Smith, B.E., Baum, R.E. (2000): Surveys of the Lizards Anolis wattsi and Ameiva griswoldi on Antiguan Offshore Islands I. Summer 1999. Antiguan Racer Conservation Project. Report No.5. Pre-publication Draft Report. Smith, B.E, Colbert, P.L. (2002): Surveys of the Lizard Anolis wattsi on Antiguan Offshore Islands III: Summer 2001. Antiguan Racer Conservation Project Report No. 7. South Dakota, Black Hills State University. Smith, B.E., Baum, R.E., Massie, J.L., Davis, O. (2001): Surveys of the Lizards Anolis wattsi and Ameiva griswoldi on Antiguan Offshore Islands II: Summer 2000. Antiguan Racer Conservation Project Report No. 6. South Dakota, Black Hills State University. Smith, B.E., Davis, O., Bartscher, N.S. (2002): Surveys of the lizard Ameiva griswoldi on Antiguan offshore islands III: Summer 2001. Antiguan Racer Conservation Project Report No. 8. South Dakota, Black Hills State University. Stapleton, S., Stapleton, C. (2006): Tagging and Nesting Research on Hawksbill Turtles (Eretmochelys imbricata) at Jumby Bay, Long Island, Antigua, West Indies: 2005 Annual Report. Prepared for the Jumby Bay Island Company, Ltd. by the Wider Caribbean Sea Turtle Conservation Network (WIDECAST). 22 pp. Steadman, D.W., Watters, D.R., Pregill, G.K., Olson, S.L. (1984): Fossil vertebrates from Antigua, Lesser Antilles: Evidence for late Holocene human-caused extinctions in the West Indies. Proc. Nat. Acad. Sci 81: 4448-4451. TAC — Technical Advisory Committee (2005): United Nations Convention to Combat Desertification: Draft National Action Plan for Antigua and Barbuda. Report commissioned by the Environment Division, Ministry of Public Works and Environment, St John’s, Antigua.
50
J.C. Daltry
Underwood, G. (1962): Reptiles of the Eastern Caribbean. Caribbean Affairs (new series) no. 1. University of the West Indies, Trinidad. Varnham, K. (2001): Restoration of Green Island, Antigua, West Indies, Rat Eradication Project: Interim Report, July 2001. Antiguan Racer Conservation Project, St John’s, Antigua. Varnham, K. (2005): Rats and Antiguan racer snakes. Biol. Sci. Rev. Sept 2005: 7-10. Varnham, K., Ross, T., Daltry, J., Day, M., Cooper, G., Lindsay, K. (1998): Recovery of the Antiguan racer. Aliens (journal of the IUCN/SSC Invasive Species Specialist Group) 8: 21. Watters, D.R., Reitz, E.J., Steadman, D.W., Pregill, D.K. (1984): Vertebrate from archaeological sites on Barbuda, West Indies. Ann. Carnegie Mus. 53: 383-412. White, G.L., Hailey, A. (2006): The establishment of Anolis wattsi as a naturalized exotic lizard in Trinidad. Appl. Herpetol. 3: 11-26. Witherington, B.E., Martin, R.E. (2000): Understanding, Assessing, and Resolving Light-Pollution Problems on Sea Turtle Nesting Beaches (revised edition). Florida Fish and Wildlife Conservation Commission, FMRI Technical Report TR-2. 73 pp. Wright, K.M., Sylvester, I., Daltry, J.C. (2004): Ten years after: A look at the recovery of the “world’s most endangered snake”, the Antiguan racer (Alsophis antiguae). Proc. Assoc. Rept. Amph. Vet. Ann. Conf., 2004.
Accepted: September 22, 2006 (JAH). Reprinted from Applied Herpetology 4: 97-130 (2007).
Addendum Since this paper was first published in 2007, Lindsay and Mussington (2009) have confirmed that the alien green iguanas (Iguana iguana) are still present and probably breeding on Barbuda, but that there have been no recent confirmed reports of this species from Antigua. The Antiguan Racer Conservation Project (ARCP), also known as the Offshore Islands Conservation Programme, has successfully reintroduced Antiguan racers to a fourth island, the 7-ha York Island in the North East Marine Management Area. Rats were eradicated from York Island in 2007, and goats were removed in 2009. In 2010, the world population of this critically endangered snake was estimated to number more than 500 individuals, a ten-fold increase since the project began in 1995. Explanation is needed for why I have retained the scientific name Alsophis antiguae Parker throughout this paper when other publications have treated the Great Bird Island (GBI) population as a separate taxon. Based on the examination of only four young adult racers from GBI, Henderson (1989) described this population as a new subspecies, A. a. sajdaki, characterised by a “reduced number of ventrals (x in males = 186, x in females = 186), and ventrals + subcaudals (303 in one male); it has a subtle, lineate pattern (overall impression is of a taupe or graycolored snake with little discernible pattern), without a sharply defined pattern of contrasting colors”. Hedges et al. (2009) went further by upgrading sajdaki to a full species, based only on the colour pattern differences and non-overlapping ventral scale counts alleged by Henderson (1990 [sic]). No relevant additional morphometric or genetic data were presented by Hedges et al. to support this
The herpetofauna of Antigua, Barbuda and Redonda
51
decision. Henderson and Powell (2009) followed suit in calling the GBI population “A. sajdaki” and regarded A. alsophis as being both restricted to mainland Antigua and extinct, without providing new evidence. Examination of 356 live individuals on GBI by myself and my ARCP colleagues, however, have found this population to be more highly variable than any of these authors could have known. The racers exhibit remarkably strong sexual dimorphism and changes in pattern and hue with age: while some specimens on GBI, mostly young adult females, fit Henderson’s description, ARCP photographs show individuals ranging from a uniform colour to those with clearly distinct patterns (blotches, stripes, spots), and hues ranging from silver grey, through reddish brown, chocolate brown to almost black. Ventral numbers are also highly variable. The ARCP database reveals that ventral scales range from 186-199 in females (n = 216) and 186-194 in males (n = 140); ventrals + subcaudals 296-319 in males. Thus, while GBI scale counts tend to be at the lower end of the species range, there is a much higher degree of overlap with the mainland population than Henderson (1989) realised. The evidence from ARCP’s large sample greatly weakens the argument for regarding the GBI and mainland forms as separate subspecies, let alone separate species. Moreover, I would contend the evolution of two species on the Antigua Bank is improbable on biogeographical grounds: GBI is less than 2.5 km from mainland Antigua (with a very shallow sea and several other islands in between) and would have been connected by land bridges until approximately 6,000 years ago (Brian Cooper, Environmental Awareness Group, pers. comm.). Therefore, until and unless new genetic or other data are presented, the racers on and re-introduced from GBI and the (extirpated) population on mainland Antigua should continue to be called Alsophis antiguae. If any reader wishes to revisit the taxonomy of A. antiguae, the full ARCP database will be provided on request. Finally, since this paper was published, the Environmental Awareness Group, Fauna & Flora International and other member organisations of Offshore Islands Conservation Programme have initiated consultations and research with a view to removing alien invasive rats and goats from Redonda by 2015. The Redondan lizards Ameiva atrata, Anolis nubilus and Sphaerodactylus sp. were all still present in 2009, but the latter two in particular appeared to be patchy and relatively scarce. References Hedges, S.B., Couloux, A., Vidal, N. (2009): Molecular phylogeny, classification, and biogeography of West Indian racer snakes of the Tribe Alsophiini (Squamata, Dipsadidae, Xenodontinae). Zootaxa 2067: 1-28. Henderson, R.W. (1989): A new subspecies of Alsophis antiguae (Serpentes: Colubridae) from Great Bird Island (Antigua), Lesser Antilles). Carib. J. Sci. 25: 119-122. Henderson, R.W., Powell, R. (2009): Natural History of West Indian Reptiles and Amphibians. Gainesville, University Press of Florida. Lindsay, K., Mussington, J. (2009): Iguana iguana in Antigua and Barbuda, West Indies. Appl. Herpetol. 6: 189-190.
Conservation of amphibians and reptiles in The Bahamas Charles R. Knapp1,2,3 , John B. Iverson4 , Sandra D. Buckner5 , Shelley V. Cant6 1 Daniel
P. Haerther Center for Conservation and Research, John G. Shedd Aquarium, Chicago, Illinois 60605, USA 2 Corresponding author; e-mail:
[email protected] 3 San Diego Zoo Institute for Conservation Research, Escondido, California 92027, USA 4 Earlham College, Richmond, Indiana 47374, USA 5 P.O. Box N-8893, Villa Capulet, Montague Foreshore, Nassau, The Bahamas 6 Bahamas National Trust, P.O. Box N-4105, Nassau, The Bahamas Abstract. The Bahamas are unique relative to other countries and dependent territories in the West Indies because they comprise 29 islands, hundreds of cays, and thousands of emergent rocks spread over 215,000 km2 of ocean. The native herpetofauna of The Bahamas is derived primarily from Cuba and Hispaniola, and numbers 46 species comprised of three frogs (including one endemic), 25 lizards (13 endemic), 11 snakes (7 endemic), two freshwater turtles, and five sea turtles. Of the native terrestrial species, 85% are either not assessed or data deficient to affirm IUCN listing, thus stressing the need for more research in The Bahamas. Currently, there are few legislative laws directly protecting the herpetofauna of The Bahamas although all three rock iguanas (Cyclura) are technically given full protection under the Wild Animals (Protection) Act of 1968. In 2009, the Bahamian Ministry of Agriculture and Marine Resources amended the Fisheries Regulations governing marine turtles in order to give full protection to all sea turtles found in its waters. Other species are afforded protection in a fairly extensive system of 25 national parks, though threats from various fronts hinder safeguarding all species. Major threats to the Bahamian herpetofauna include inappropriate development, apathy, over-exploitation of wildlife, lack of law enforcement, hurricanes, introduced species, and disturbance by tourist activities. We explore the challenges for long-term conservation of the Bahamian herpetofauna and provide suggestions to help mitigate pressures on amphibian and reptile populations. Key words: Bahamas National Trust; Conservation; Cyclura; development; sea turtle; tourism; Trachemys.
Introduction The Commonwealth of the Bahamas encompasses an extensive, northwest to southeast-trending archipelago of low (maximum elevation 63 m), limestone islands and cays spread over a distance of approximately 870 km in the western Atlantic Ocean. The geographic archipelago, however, extends farther southeast to include
54
C.R. Knapp et al.
the Turks and Caicos Islands (TCI), which are a separate political entity. The Bahamas are unique relative to other countries and dependent territories in the West Indies because they comprise 29 islands, hundreds of cays, and thousands of emergent rocks spread over 215,000 km2 of ocean. The vast expanse of territorial waters and remote islands promotes both challenges and opportunities to the study and conservation of its herpetofauna. The remoteness of many islands over an expansive sea makes continued monitoring and law enforcement difficult and logistically challenging. The numerous islands and cays, however, are ideal natural laboratories for the study of ecology, evolution, and natural history (e.g., Calsbeek and Smith, 2003; Losos et al., 2004; Iverson et al., 2004a; Schoener et al., 2004; Knapp et al., 2006; Bjorndal and Bolten, 2008; Losos, 2009; Cox and Calsbeek, 2010; see also Franz et al., 1996 for a detailed compilation of earlier references). From a conservation perspective, the numerous cays scattered within this expansive archipelago offer an equal opportunity to study conservation mitigation strategies such as translocation (Knapp, 2001; Knapp and Malone, 2003) or non-native species eradication (Hayes et al., 2004). Yet, in relation to their accessibility from North America and biological interest, the herpetofauna of the Bahamas have been relatively insufficiently studied. Here we encourage further study of the Bahamian herpetofauna that will advance our understanding of its ecology and facilitate its conservation management. For this review, we limit our treatment to include only the herpetofauna, conservation concerns, priorities, and policies of the Commonwealth of The Bahamas. However, because the TCI share the same geographic archipelago and were affected similarly by prehistoric peoples, we include discussion of the TCI in a historical perspective.
Annotated History of The Bahamas In October 1492, Christopher Columbus made landfall on the island of San Salvador in The Bahamas. The origin of the name “Bahamas” is unclear, but it is thought to be derived from the Spanish baja mar, meaning “shallow seas” (Albury, 1975) or the Lucayan word for Grand Bahama Island, ba-ha-ma “large upper middle land” (Granberry and Vescelius, 2004). At the time of Columbus’ arrival there were from 40,000 to 80,000 native people known as Lucayans inhabiting most of the larger islands in the archipelago. Within 30 years these people were eliminated by disease, hardship, and slavery (Keegan, 1997). The Bahamas were mostly deserted from 1513 to 1648 until English Puritans from Bermuda sailed to Eleuthera in 1648 and established the first permanent European settlement in The Bahamas. In 1670, King Charles II granted The Bahamas to the Lords Proprietors of the Carolinas, who rented the islands from the king with rights of trading, tax, appointing governors, and administering the country. The Bahamas were made a British crown colony in 1718 (Albury, 1975). The first evidence of extensive, human-mediated habitat degradation followed the American War of Independence when thousands of pro-British loyalists and
Conservation of amphibians and reptiles in The Bahamas
55
enslaved Africans moved to The Bahamas to establish a short-lived plantation economy. From 1784 to 1788 the Bahamian population more than doubled to nearly 10,000 because of the loyalist influx. During the late 18th and early 19th centuries, thousands of forested hectares were cleared for timber, cotton, and sisal (Albury, 1975). Slavery was abolished in 1834 and the descendants of enslaved and liberated Africans comprise the current majority of the population. In 1964 Great Britain granted The Bahamas limited self-government and in 1969 the colony became The Commonwealth of The Bahamas. On 10 July 1973 The Bahamas became an independent country and a member of the British Commonwealth which is now known as The Commonwealth of Nations. Today the human population of 307,552 is centered predominantly in the capital of Nassau on New Providence, and on Grand Bahama Island. The Bahamas is one of the wealthiest West Indian countries with an economy heavily dependent on tourism and offshore banking. Tourism together with tourism-driven construction and manufacturing accounts for approximately 60% of Gross Domestic Product and directly or indirectly employs half of the archipelago’s labor force (Central Intelligence Agency, 2010).
Physical Geography The Bahamas is composed of an extensive group of 29 major islands and 661 smaller cays associated with an exposed, shallow water carbonate bank system located between 20◦ 53 -27◦ 30 N and 72◦ 37 -80◦ 54 W. The northwestern Bahamas are composed primarily of two large banks — the Great Bahama Bank and Little Bahama Bank (fig. 1). The Great Bahama Bank is the largest in the geographic archipelago and includes Andros, the Berry Islands, Bimini Islands, Cat Island, Eleuthera, Exuma Cays, Long Island, New Providence, and the Ragged Islands. These islands are separated from each other by shallow (up to 30 m) marine waters (Olson and Pregill, 1982). The Little Bahama Bank caps the northern extent of the Bahamas and includes Grand Bahama and Abaco. The southeastern Bahamas consists of smaller carbonate platforms (e.g., Crooked and Acklins Islands), many of which are almost entirely exposed as single islands (e.g., Conception Island, San Salvador, Rum Cay, Samana Cay, Mayaguana, Great Inagua, and Little Inagua). At the height of the Wisconsin glaciation 17,000 years before present (BP) sea levels were as much as 135 m below modern levels (Clark and Mix, 2002), thus consolidating many of the contemporary islands rising from the major banks throughout the archipelago (fig. 1). As a result, land area in the Bahamas was increased by more than an order of magnitude, from 11,406 km2 at present, to ∼124,716 km2 (Morgan, 1989). The Great Bahama Bank constituted the majority of land area and was separated from Cuba by the 17 km-wide Old Bahama Channel, which presumably facilitated the northward dispersal of flora and fauna. Between 14,000 and 6000 years BP sea level rose and fragmented the carbonate banks into the smaller islands and cays representing the present topography of The Bahamas
56
C.R. Knapp et al.
Figure 1. Map of the major land units of The Bahamas. Current extent of islands indicated in black; extent during the height of the Wisconsin glaciation indicated in gray. Abbreviations are AN = Andros; AB = Abaco; BER = Berry Islands; BIM = Bimini; CAT = Cat Island; CON = Conception Island; CS = Cay Sal; CA = Crooked and Acklins Islands; EL = Eleuthera; EX = Exuma Cays; GB = Grand Bahama; GI = Great Inagua; LI = Little Inagua; LG = Long Island; MAY = Mayaguana; MPV = Mira Por Vos; NP = New Providence; PL = Plana Cays; RAG = Ragged Islands; RUM = Rum Cay; SAM = Samana Cays; SAN = San Salvador.
(Morgan, 1989). Today, the Bahamian region is separated from neighboring Florida (90 km from Bimini to the southeastern coast of Florida), Cuba (17 km from Cay Lobos to the northern coast of Cuba), and Hispaniola (110 km from Great Inagua to Ile des Tortues, Haiti) by deep channels and basins (Franz et al., 1996). Despite the overall low elevation of the Bahamas, Correll and Correll (1982) describe nine rather diverse plant communities: coastal rock, sand strand formation and Uniola, coastal coppice, whiteland, fresh water formations, tidal flats and salt marshlands, mangrove, blackland, and pineland. These communities are not distributed evenly throughout the archipelago because their occurrence is dependent on location, topography, and substrate. In general however, the larger islands are predominantly in the northern region of the archipelago and are characterized by tropical to subtropical dry forest with pine (Pinus caribaea var. bahamensis) representing the signature species. Relative to the entire archipelago, the northern islands experience more rainfall and more seasonal and cooler conditions. This region (Grand Bahama, Abaco, New Providence, and North Andros) receives rainfall ranging from 1250 to 1500 mm per year. Rainfall decreases southward across the archipelago, ranging from 750 to 1000 mm in the south central islands (Exumas, Long Island, Crooked and Acklins Islands, Mayaguana) and 625 to
Conservation of amphibians and reptiles in The Bahamas
57
750 mm in the southeastern islands (Inagua Islands; Little et al., 1976). The forest type in these southern regions is considered dry tropical forest dominated by xerophytic broadleaf scrub communities.
History of Human Impacts Colonization of The Bahamas by Amerindians was relatively late in the cultural history of the West Indies. The Lucayan people began to colonize the islands ca. A.D. 600 and like other prehistoric societies in the West Indies, were the first humans to exploit the terrestrial and marine herpetofauna of the region (Keegan, 1997). Archeological excavations from middens throughout the geographic Bahama archipelago (including TCI) reveal a number of reptilian genera, including Chelonia, Eretmochelys, and Trachemys. The most notable remains include an extinct tortoise (Chelonoidis; formerly Geochelone) species (Newsom and Wing, 2004; Franz and Franz, 2009). Christopher Columbus reported that rock iguanas (Cyclura) were one of the Lucayan’s favorite foods in The Bahamas (Campbell, 2006). Cyclura are also the dominant terrestrial vertebrate recovered from one archaeological site in the TCI. This same site also revealed a decline in number and sizes of green turtles (Chelonia mydas) harvested over time (Carlson, 1999). To date, it cannot be demonstrated unequivocally that the Lucayan people were responsible for the extinction or extirpation of terrestrial herpetofauna in The Bahamas, as demonstrated on other oceanic islands after the arrival of prehistoric people (Steadman et al., 2002). However, the coincidence of human colonization and extinction of tortoises in The Bahamas and TCI suggest that Lucayans directly or indirectly caused the demise of some species or populations (Newsom and Wing, 2004; Franz and Franz, 2009). Though the Lucayans initially impacted the herpetofauna of The Bahamas, the period after European discovery was the most severe for species and populations. Marine turtles were heavily exploited throughout the West Indies, and Carr (1956) noted that “More than any other dietary factor, the green turtle supported the opening up of the Caribbean. . . ”. As a result of unsustainable harvest throughout the West Indies over the past 500 years, green turtle populations have been reduced to less than 1% of pre-Columbian population levels (Bolten and Bjorndal, 2003). With the exception of hawksbill turtles (Eretmochelys imbricata), which received protection in 1986, sea turtles have been harvested legally in the Bahamas (but see the 2009 ban, below). Even in marine protected areas sea turtles were harvested occasionally by Bahamians and cruising yachtsmen (Bjorndal et al., 2003). McKinnen (1804) described accounts of Bahamians at times eating crocodiles on Acklins Island while rock iguanas have always been valued highly for food and were often caught in baited crayfish pots in the Exumas (Bailey, 1925), or more recently on Andros using hunting dogs and guns (Charters, 1999). It is postulated that the irregular distribution of ground-dwelling Ameiva and Leiocephalus lizards in the Exumas is the result of human perturbations during the Loyalist Era (Dodd
58
C.R. Knapp et al.
and Franz, 1996). Indeed, for 200 years all islands inhabited during this period were most likely affected by introduced domesticated animals and habitat degradation, thereby making interpretations of contemporary biogeographic patterns problematic (Dodd and Franz, 1996).
The Native Herpetofauna The native herpetofauna of The Bahamas (table 1) numbers 46 species comprised of three frogs (including one endemic), 25 lizards (including 13 endemics), 11 snakes (including 7 endemics), two freshwater turtles, and five sea turtles. General natural history information (or lack thereof) with pertinent references for the Bahamian herpetofauna can be found in Henderson and Powell (2009). We retain the Bahamian locality record for the snake, Hypsirhynchus parvifrons, until additional surveys are conducted. This snake is endemic to Hispaniola but a partial specimen was collected in 1974 by D.W. Buden on Little Inagua and was presumed to be from a local population of unknown taxonomic status (Schwartz and Thomas, 1975). Later, Schwartz and Henderson (1991) considered the population status as unknown while more recently Henderson and Powell (2009) presumed the specimen previously collected as a vagrant. The recent addition of Little Inagua into the Bahamian national park system will hopefully facilitate future survey expeditions to the island. The herpetofauna of The Bahamas is expanded further with the inclusion of 22 non-native species (5 frogs, 7 lizards 5 snakes, 4 turtles, and 1 crocodilian), of which a minimum of 16 are established and breeding. Of the native herpetofauna, there are 21 endemic Bahamian species, an additional four species that are endemic to the Bahamian archipelago (including the TCI), and 21 species that are endemic to the West Indies (table 1). A native giant tortoise species (Chelonoidis; formerly Geochelone) is extinct (Auffenberg, 1967; Steadman et al., 2007; Franz and Franz, 2009) and the Cuban crocodile (Crocodylus rhombifer) is now extirpated (Franz et al., 1995; Steadman et al., 2007). The Cuban crocodile was once widespread throughout The Bahamas and may have been a major terrestrial and aquatic predator in the past (see comments in Franz and Franz, 2009). Fossils of large iguanas (Cyclura), which most likely predate human occupation, have been recovered from Abaco on the Little Bahama Bank suggesting that their range was once more widespread (R. Franz, pers. comm.). The herpetofauna of the Great Bahama, Little Bahama, and Cay Sal Banks are generally derived from Cuba (e.g., Malone et al., 2000; Glor et al., 2005; also see earlier references summarized in Franz et al., 1996). The relationships of species in the southeastern Bahamas are not fully resolved, although many have affinities with Hispaniola or Puerto Rico (e.g., Hower and Hedges, 2003; also see earlier references summarized in Franz et al., 1996). This biogeographic pattern is consistent with regional ocean currents facilitating overwater dispersal. Recent taxonomic and biogeographic investigations have modified traditional nomenclature (e.g., Cubophis vudii, Epictia columbi; Hedges et al., 2009; Adal-
Conservation of amphibians and reptiles in The Bahamas
59
Table 1. Distribution of native amphibians and reptiles of The Bahamas with their IUCN status designations. Distributions are arranged by bank system or single islands (if not associated with a bank). Endemic species to The Bahamas are identified with an asterisk while species endemic to the Bahamian archipelago (including TCI) are identified with a dagger. Sea turtles are not identified to bank system. Abbreviations are as follows: CS = Cay Sal; LBB = Little Bahama Bank; GBB = Great Bahama Bank; CON = Conception Island; RUM = Rum Cay; SAN = San Salvador; CA = Crooked and Acklins; PL = Plana Cays; SAM = Samana; MAY = Mayaguana; GI = Great Inagua; LI = Little Inagua. IUCN status abbreviations are CR = Critical; EN = Endangered; VU = Vulnerable; LC = Least Concern; DD = Data Deficient; NE = Not Evaluated. Species AMPHIBIA, ANURA Family Eleutherodactylidae Eleutherodactylus planirostris Eleutherodactylus rogersi* Family Hylidae Osteopilus septentrionalis
IUCN CS LBB GBB CON RUM SAN CA PL SAM MAY GI LI status
LC DD
"
LC
"
REPTILIA, SQUAMATA Family Iguanidae Cyclura carinata† CR Cyclura cychlura* VU Cyclura rileyi* EN Family Leiocephalidae Leiocephalus carinatus NE Leiocephalus greenwayi* NE Leiocephalus inaguae* NE Leiocephalus loxogrammus* NE Leiocephalus punctatus* NE (also recorded from MPV — see Fig. 1) Family Phyllodactylidae Tarentola americana NE Family Polychrotidae Anolis angusticeps NE Anolis brunneus* NE Anolis distichus NE Anolis fairchildi* NE Anolis sagrei NE Anolis scriptus† NE Anolis smaragdinus* NE Family Sphaerodactylidae Aristelliger barbouri* NE Sphaerodactylus argus NE Sphaerodactylus corticola* NE Sphaerodactylus inaguae* NE NE Sphaerodactylus mariguanae† Sphaerodactylus nigropunctatus NE Sphaerodactylus notatus LC Family Teiidae Ameiva auberi NE Ameiva maynardi* NE
" " "
" " "
"
"
"
"
" " " "
"
"
" " " "
"
" "
"
" " " " " "
"
"
"
"
"
"
"
"
"
" "
"
"
" "
" " " " "
"
" "
" " "
" "
" "
"
" "
"
" " "
60
C.R. Knapp et al.
Table 1. (Continued.) Species Family Boidae Epicrates chrysogaster† Epicrates exsul* Epicrates striatus Family Dipsadidae Cubophis vudii* Hypsirhynchus parvifrons (see the native herpetofauna) Family Leptotyphlopidae Epictia columbi* Family Tropidophidae Tropidophis canus* Tropidophis curtus* Family Typhlopidae Typhlops biminiensis* Typhlops lumbricalis Typhlops paradoxus* REPTILIA, TESTUDINES Family Chelonidae Caretta caretta Chelonia mydas Eretmochelys imbricata Lepidochelys olivacea Family Emydidae Trachemys stejnegeri Trachemys terrapen Family Dermochelyidae Dermochelys coriacea
IUCN CS LBB GBB CON RUM SAN CA PL SAM MAY GI LI status NE NE NE
"
NE NE
"
NE NE NE
"
"
"
"
"
"
NE NE NE
" "
" " "
"
" "
" " "
EN EN CR VU NE NE
" "
CR
steinsson et al., 2009), resulting also in the addition of Bahamian endemics (e.g., Eleutherodactylus rogersi, Tropidophis curtus, Typhlops biminiensis, T. paradoxus; Lynch and Duellman, 1997; Hedges, 2002; Heinicke et al., 2007; Thomas and Hedges, 2007; Hedges et al., 2008) or the collapse of former endemic subspecies (Cyclura carinata bartschi) into regional species designations (Bryan et al., 2007), thus underscoring the need for additional taxonomic research with associated ecological investigations for the Bahamian herpetofauna. Although some species such as Anolis sagrei and Osteopilus septentrionalis have broad ranges throughout the larger bank systems (table 1), other species from large bank systems have restricted and fragmented ranges of only a few islands (e.g., Cyclura cychlura figginsi, C. c. inornata, C. rileyi cristata). In addition, other species not associated with large bank systems are often restricted to one or a few isolated islands (Anolis fairchildi, Leiocephalus greenwayi, L. inaguae, Sphaerodactylus inaguae, Epictia columbi, Typhlops paradoxus; table 1).
Conservation of amphibians and reptiles in The Bahamas
61
Threats Major threats to the herpetofauna of The Bahamas include inappropriate development, apathy, over-exploitation of wildlife, lack of law enforcement, hurricanes, introduced species, and disturbance by tourist activities. Mean number of annual foreign human arrivals to the Bahamas from 1998 to 2008 numbered 4,353,769 (range 3,347,665 to 5,003,967), roughly half of which were cruise ship passengers (Bahamas Ministry of Tourism, 2010). The surge in tourism has spurred unprecedented development projects throughout the country. Until recently most high-density and large-impact development projects were confined to New Providence and Grand Bahama. However, visitation to the Family Islands (i.e., more remote islands away from the two main population centers) comprises approximately 16% of all Bahamian tourism (Lowe and Sullivan-Sealy, 2003) and is projected to increase as more development projects gain momentum on these islands. The entry into formerly pristine areas by large-scale developers has been welcomed by some interested in new employment and business opportunities, but feared by others concerned about the environment. Indeed, many of these largescale development projects (e.g., Baker’s Bay, Abaco; Bimini Bay, Bimini) incite confrontation between job production and economic development versus sound environmental policy and social considerations (Gruber and Parks, 2002). Moreover, the Bahamian government is challenged with a lack of institutional capacity and adequate human resources to fully implement and monitor environment-friendly policies across the spectrum of ministries and departments. When environmental impact assessments are conducted, they lack focus towards amphibians and reptiles, likely because of their secretive habits, small population sizes, and the difficulty in finding them in the field during rapid assessments (Gibbons et al., 2000; Tolson and Henderson, 2006). Realistically, however, amphibians and reptiles in general are often ignored and underappreciated relative to other fauna in the archipelago. Indeed, reptiles generally, but snakes in particular, are feared and often killed on sight (Tolson and Henderson, 1993). The remoteness of most islands throughout the archipelago, and general lack of law enforcement, facilitates inappropriate activities and illegal wildlife exploitation. Though most illegal acts are likely unrecorded, in 1999 two Florida men were found guilty of illegally trafficking two species of protected rock iguanas (C. cychlura figginsi and C. rileyi cristata) from The Bahamas (U.S. Department of Justice, 1998). In 2001 three individuals were apprehended collecting lizards in the Cayman Islands, having been tracked smuggling Ameiva, Anolis, and Leiocephalus species out of the Bahamas from Eleuthera and Grand Bahama. More recently, two tourists in 2009 were arrested for capturing and eating an Allen Cays rock iguana (C. cychlura inornata) after the offenders posted pictures on the social networking website Facebook (IRCF, 2009). Rock iguanas, and non-native iguanas, are also moved illegally within The Bahamas in order to establish personal populations or remove potential problem animals from tourist destinations (Smith and Iverson, 2006; S. Buckner, J. Iverson, C. Knapp, pers. obs.). These unauthorized translocations are never based
62
C.R. Knapp et al.
on science and disregard population management protocols, and the unique genetic and behavioral structure of isolated populations (Malone et al., 2003; Bissell and Martins, 2004). The island of South Bimini once harbored a dense population of boas (Epicrates striatus fosteri), but these animals were removed illegally by the hundreds during the 1970s for the pet trade (Tolson and Henderson, 1993). Though numbers are unclear, non-Bahamians also visit Andros Island and smuggle boas (E. striatus fowleri) for the pet trade (H. Saunders, pers. comm.). For example, in 2001 a Florida man pled guilty for attempting to smuggle three E. striatus fowleri from Andros out in his hand luggage at Nassau International Airport. The snakes were confiscated by the Royal Bahamas Police Force, but as the individual had already passed through US Customs and Immigration, he was prosecuted in the U.S. District Court in Miami (U.S. Department of Justice, 2001). Even with a nationwide ban on sea turtle harvest, enforcement in remote areas such as the uninhabited Conception Island National Park is problematic, and green turtles are occasionally removed from Conception Creek by humans from neighboring islands or on visiting yachts (Bjorndal et al., 2003). In the southern region of the archipelago, non-nationals illegally take sea turtles or remove them from nesting beaches (Franz et al., 1996; K. Bjorndal, pers. comm.). Rock iguanas are also hunted illegally for food on Andros Island (Knapp, 2007). Historically, most rock iguana hunting occurred on North Andros because of the extensive logging roads and larger human settlements. Poachers now travel south to catch rock iguanas because of their scarcity on North Andros. At least two interior camps that people use periodically while hunting iguanas (among other activities) have been identified on Alcorine and Mangrove Cays (Knapp, 2005, 2007). Hurricanes commonly are interpreted to be a major catastrophic event affecting marine and terrestrial systems (e.g., Spiller and Agrawal, 2003; Scheffers and Scheffers, 2006; Crabbe et al., 2008). Though multiple factors influence species persistence on islands after a catastrophic event (Schoener et al., 2004), the herpetofauna and vegetation tend to be relatively more affected on low-elevation islands (Schoener et al., 2001; Spiller and Agrawal, 2003). This is a major concern for the Bahamian herpetofauna because most islands are low in elevation, and the entire range for some species and subspecies is one or a few small islands (e.g., Anolis fairchildi, C. cychlura inornata, Leiocephalus greenwayi, L. inaguae), thereby increasing their susceptibility to potential extirpation from impacts associated with storm-surge inundation and strong winds. Indeed, populations of A. sagrei in the Exuma Island chain have been extirpated after hurricanes, though recolonization for this widespread species often occurs via overwater dispersal (Schoener et al., 2001; Calsbeek and Smith, 2003). Other taxa are single-island endemics (table 1; Schwartz and Henderson, 1991), or less likely to overwater disperse at such rapid rates (e.g., rock iguanas; Malone et al., 2003), and are therefore more susceptible to extirpation. Finally, though some reptile eggs can survive periods of seawater immersion (Losos et al., 2003), hatch failure of Bahamian species ovipositing in
Conservation of amphibians and reptiles in The Bahamas
63
Figure 2. A minimum of 20 C. cychlura inornata rock iguanas congregate on a small section of Leaf Cay beach to be fed by Exuma tourists. This is not typical behavior (Color original — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm).
subterranean chambers has been attributed to major storm events and elevated water tables (Iverson et al., 2004a). Recently, the threat of tourism and associated food provisioning has emerged as a considerable problem. This activity is increasingly common in the Exumas and may pose a severe threat to the long-term survival of the native endangered rock iguanas. Tourist visits to some of these small islands have increased from approximately 20 persons per day in the 1980s to currently more than 150 persons per day (Iverson et al., 2004a). Presently, most tourists are brought to islands by operators using fast powerboats from Nassau in the north or Great Exuma in the south of the island chain. Throughout the Exumas, however, cruising yachtsmen or resort guests are visiting and feeding rock iguanas at an increasing daily rate (fig. 2). These daily island visits, especially to cays not commonly visited in the past, have caused rapid (within 1.5 years) behavioral changes in rock iguana populations (C. Knapp, pers. obs.). Island visits by tourists are expected to increase throughout the Exumas, leaving virtually no rock iguana population free from the potential impacts of food provisioning, often with unsuitable items (e.g., bread, cereal, ground beef; Hines, 2007; Knapp et al., 2008). The disastrous effects of feral, non-native mammals (e.g., hogs, mongoose, cats, dogs, rats, mice, hoofed stock, etc.) on island reptile populations are welldocumented (Iverson, 1978; Henderson, 1992; Haneke, 1995; Mitchell, 1999; Tolson, 2000; Hayes et al., 2004; Borroto-Paez, 2009). The problem is exacerbated by the difficulty in restricting pet ownership rights of private individuals, who often visit properties or islands other than their own. For example, despite the fact that since 1992 signs have been erected intermittently on the private islands of Leaf Cay
64
C.R. Knapp et al.
Figure 3. Representative sign erected on cays inhabited by rock iguanas in the Bahamas (Color original — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm).
and U Cay in the Allen Cays (home of C. cychlura inornata) banning dogs (e.g., fig. 3), visitors must regularly be asked to remove their dogs (or cats) from these islands. A particularly striking Bahamian example involves the single population of White Cay rock iguanas (C. rileyi cristata) in the southern Exumas. This population was decimated in the mid-1990s when a person thoughtlessly removed a non-native raccoon from a private island and released it on White Cay (Iverson, unpublished; Hayes et al., 2004). The serendipitous discovery of the raccoon on White Cay in 1996, soon after its arrival, allowed for its removal in 1997, likely saving the taxon from extinction (Hayes et al., 2004). The invasion of The Bahamas by black and norway rats (Rattus sp.) continues (Lee and Clark, 1995; Hall et al., 1998; Hayes et al., 2004), and their negative effects on island reptiles have been clearly demonstrated for many species (Case and Bolger, 1991; Cree et al., 1995; Tolson, 2000; Towns et al., 2007). Although suspected (Hayes et al., 2004), the direct negative impact of rats on rock iguanas (Cyclura) in the West Indies has not been confirmed directly, and positive population responses of rock iguanas following rat removal are not yet available (Hayes et al., 2004). Nevertheless, rat eradication programs (Hayes et al., 2004) have been successful on both White Cay (Exumas) and Low Cay (San Salvador), and
Conservation of amphibians and reptiles in The Bahamas
65
current efforts to eradicate rats on islands with important breeding bird populations (W. Mackin, pers. comm.) should also benefit the herpetofauna on those islands. Feral pigs affect almost all aspects of ecosystem structure and function (Singer et al., 1984; Lacki and Lancia, 1986) as well as negatively influence wildlife by competing for resources, altering habitat structure and quality, and preying on native species including amphibians and reptiles (Coblentz and Baber, 1987; Taylor and Hellgren, 1997; Jolley et al., 2010). For example, Bratton (1975) reported a decline in species richness of small mammal and herpetofaunal communities in deteriorated habitat where wild pigs forage. Pigs were introduced in the early 20th century to Abaco, Andros, and Great Inagua and are a particular concern in locations where native species are already struggling. For example, Knapp (unpubl. data) found a negative correlation across 39 sites between the presence of feral pigs and the number of amphibian and reptile species on Andros Island as well as observing no rock iguanas from sites with feral pig activity. More studies need to be conducted to quantify the impacts of feral pigs, and efforts must be made to eliminate or reduce population sizes whenever possible.
Introduced Herpetofauna The number of non-native amphibians and reptiles introduced into The Bahamas is becoming a pervasive problem and likely to increase unless proactive steps are taken to mitigate causes. There are currently a minimum of 16 documented breeding and established species of non-native amphibians and reptiles in The Bahamas (table 2) representing 26% of its terrestrial herpetofaunal diversity. These introductions are derived from both accidental and intentional actions, and are exacerbated by a combination of factors including the proximity to the United States, importation of materials and ornamental plants, the pet trade, interisland translocations within country, and tourism (Lee, 2004). Only a single genus of iguana (Cyclura) is native to The Bahamas; however, two additional genera have established breeding populations in the Berry Islands. The green iguana (Iguana iguana) was first observed on Great Stirrup Cay in the Berry Islands in 1992 (S. Buckner unpubl. data) after apparently being released by an unidentified individual. In 2000, an agent for the cruise line that uses the cay for tourists expressed concern that the green iguana population was multiplying and was considered a “menace”. He also reported that another unidentified species of iguana was present on the cay. In 2009 green iguanas were observed on both Great Stirrup and Little Stirrup Cay (J. Wasilewski, unpubl. data). Additionally, spiny-tailed iguanas (Ctenosaura similis) were also observed on Great Stirrup Cay (E. Freid, unpubl. data) and in Bullock’s Harbour on Great Harbour Cay all in the Berry Islands (J. Wasilewski, unpubl. data). While Iguana iguana is not listed as being introduced on New Providence, Abaco or Great Exuma, individual green iguanas have been located intermittently over the last two decades and subsequently held captive at Ardastra Gardens, Zoo and Conservation Centre, or other facilities.
66
C.R. Knapp et al.
Table 2. Non-native amphibians and reptiles recorded from The Bahamas. Refer to fig. 1 for island abbreviations. Family Species
Location
Breeding Source population
Hylidae Hyla squirella
GB, SAN
yes
Crombie, 1972; Lee, 2004; S. Buckner, unpublished data
Microhylidae Gastrophryne carolinensis
GB, NP
yes
Schwartz and Thomas, 1975; Lee, 2004
Ranidae Lithobates clamitans Lithobates grylio
GB AB, AN, NP
unknown yes
GB
unknown
Lee, 2004 Schwartz and Thomas, 1975; Franz et al., 1996; Lee, 2004 Schwartz and Thomas, 1975; Schwartz and Henderson, 1991
AB, NP
yes
Buckner and Franz, 1994a; Meshaka, 1995; Lee, 2004
AB, EL, EX, yes LG, NP, SAN
Franz et al., 1993; Buckner and Franz, 1994b; Lee, 2004; Krysko and Borgia, 2005; Krysko and Thomas, 2007; S. Buckner and W. Hayes, unpublished data
Sphaerodactylidae Sphaerodactylus copei
AN, NP
yes
Garman, 1888; Schwartz and Henderson, 1991; Lee, 2004
Polychrotidae Anolis equestris
NP
yes
S. Buckner and S. Cant, unpublished data
Corytophanidae Basiliscus sp.
NP
unknown
S. Buckner, unpublished data
Iguanidae Ctenosaura similis
BER
yes
BER
yes
E. Freid and J. Wasilewski, unpublished data S. Buckner and J. Wasilewski, unpublished data
Lithobates sphenocephala Gekkonidae Hemidactylus garnotii
Hemidactylus mabouia
Iguana iguana
Colubridae Pantherophis guttatus GB, NP Pantherophis alleghaniensis AB Opheodrys aestivus EL
yes yes yes
Buckner and Franz, 1994c; Lee, 2004 Buckner and Franz, 1994d; Lee, 2004 S. Buckner, unpublished data
Natricidae Thamnophis sauritus Thamnophis sirtalis Storeria dekayi
no no yes
Buckner and Franz, 1998a; Lee, 2004 Buckner and Franz, 1998b; Lee, 2004 Lee, 2004, 2005
NP AB GB
Conservation of amphibians and reptiles in The Bahamas
67
Table 2. (Continued.) Family Species Emydidae Terrapene carolina Trachemys decorata Trachemys scripta Trachemys sp.
Alligatoridae Alligator mississippiensis
Location
Breeding population
Source
GB NP GB AN, BIM, EL, EX, GB, LG
unknown yes yes yes
Lee, 2004 Lee, 2004 Lee, 2004 Seidel and Adkins, 1987; Schwartz and Henderson, 1991; Franz et al., 1993; Mealey et al., 2002; Lee and Ross, 2001; Lee, 2004
BER
no
Carey, 2002; Lee, 2004
It is suspected that in some of these incidences, green iguanas were pets that had escaped from cruising boats (S. Buckner, unpubl. data). The potential impact of these two introduced iguanas on the native endangered rock iguanas is unknown, but efforts should be directed to extirpate these introduced species before they are transported to other islands in the archipelago. At least two American Alligators (Alligator mississippiensis) are known to have been introduced to The Bahamas (Carey, 2002; Lee, 2004). The first was observed in a golf course pond on Great Harbour Cay in 1995, which was removed in 2002 with no evidence of reproduction at that time (Lee, 2004). The second was removed from the same golf course in 2009 (Bahamas National Trust, 2009) suggesting that there was more than one animal introduced originally, reproduction had taken place, or a later introduction occurred. The native reptiles most severely affected by non-native introductions currently are freshwater turtles. The genus Trachemys has a wide distribution across North, Central, and South America, as well as the West Indies (Iverson, 1992). One subspecies (T. stejnegeri malonei) is endemic to Great Inagua in the Bahamas. In addition, a population of Trachemys on Cat Island was originally described as an endemic species, Trachemys felis (Seidel, 1996). However, subsequent research demonstrated that the Cat Island population was the same species as the Jamaican slider (Trachemys terrapen; Seidel, 1988, 1996). Most authors have speculated that this turtle was introduced to Cat Island by humans (e.g., Iverson, 1992; Seidel, 1988, 1996); however, Lee and Ross (2001) argued that it is also possible that the species was originally endemic to the Bahamas, and subsequently introduced to Jamaica. In either case, because of their use for human consumption (Berman, 1994; Seidel, 1996), sliders have probably been transported among islands by humans for perhaps 1300 years (Lee and Ross, 2001). Over the past 50 years the genus has also become popular in the pet trade, with turtles (especially juveniles) translocated around the world (Close and Seigel, 1997). As a result, sliders have been reported from New Providence, Grand Bahama, Bimini, Eleuthera, the Exumas, Andros, and Long Island (Franz et al., 1993; Lee and Ross, 2001; Mealey et al., 2002; Lee,
68
C.R. Knapp et al.
2004). Unfortunately, genetic identification of most of these records is lacking. The population on New Providence, however, represents a hybrid swarm of T. s. malonei and T. terrapen (Seidel and Adkins, 1987; Seidel, 1996), and possibly also North American red-eared sliders, T. scripta elegans (Lee and Ross, 2001). Populations on Great Exuma and Andros are also considered hybrid swarms possibly originating from New Providence (Seidel, 1988; Franz et al., 1993). These unauthorized translocations represent a considerable threat to the genetic integrity of the two long-established Bahamian forms, the Cat Island slider (Trachemys terrapen) and the Inagua slider (T. stejnegeri malonei). Unfortunately, no conservation efforts have been developed at this time for Trachemys management and habitat protection (Lee and Carey, 2001).
Conservation Legislation Currently, there are few legislative laws directly protecting the herpetofauna of The Bahamas. All Cyclura are given full protection under the Wild Animals (Protection) Act of 1968. Under this act it is illegal to take or capture (or attempt to take or capture), or attempt to export any wild animal specified in the Schedule. With the exception of hawksbill turtles (E. imbricata), which received protection in 1986, sea turtles have been harvested legally by Bahamians in The Bahamas annually from 1 August to 31 March. The only restriction was a carapace length of 76 cm for loggerhead (C. caretta) and 61 cm for green (Chelonia mydas) turtles. In 2009, the Bahamian Ministry of Agriculture and Marine Resources amended the Fisheries Regulations governing marine turtles in order to give full protection to all sea turtles found in its waters. The new regulations prohibit the harvesting, possession, purchase and sale of turtles, their parts and eggs, as well as the molestation of marine turtle nests. The Bahamas is party to multilateral environmental agreements that include the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The Bahamas has been a signatory since 1979 and though no Bahamian amphibians are CITES listed, reptiles listed under Appendix I include all five sea turtle and three rock iguana (Cyclura) species. Reptiles listed under Appendix II include Epicrates chrysogaster, E. exsul, E. striatus, Tropidophis canus, and T. curtus. The Bahamas also enacted the Wildlife Conservation and Trade Act, 2004. The purpose of this act is to implement the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), with a view to the protection of wild species from harm through unsustainable exploitation. The Bahamas signed the Convention of Biological Diversity in 1992. This convention concerns the conservation of biological diversity as a whole and the sustainable use of its resources. Under this convention The Bahamas is obliged to address the threat of invasive species and require environmental impact assessments for development projects. The Convention on Wetlands of International Importance — the Ramsar Convention was signed by the Bahamas in 2007. The Ramsar Convention
Conservation of amphibians and reptiles in The Bahamas
69
is an intergovernmental treaty that provides the framework for national action and international cooperation for the conservation and wise use of wetlands and their resources. This convention has brought about the creation of the National Wetland Policy and the National Wetlands Committee which oversees many development projects that affect wetlands in The Bahamas. In 2008, The Bahamas along with the Dominican Republic, Jamaica, Grenada, St. Vincent, and the Grenadines launched the Caribbean Challenge, which is an effort by regional governments to build political support and generate long-term funding to protect at least 20 percent of participating countries’ marine and coastal habitats by 2020.
Protected Areas Relevant to Herpetofauna All national parks in The Bahamas are managed by the Bahamas National Trust (BNT). The BNT was mandated by an act of Parliament in 1959 with the responsibilities and legal authority to manage the national parks of the country. The BNT is the only non-governmental organization in the world to have ultimate responsibility for a country’s entire national park system. In 2002, the size of the national park system of The Bahamas doubled with the addition of 10 new protected areas. These new areas, incorporating both marine and terrestrial habitats, increased the total national system to more than 283,280 ha and the total number of protected sites to twenty-five. One additional national park and the expansion of two others were declared in 2009 with official boundaries currently being drafted. Although the expansion of protected areas is admirable in principle, many of the parks are remote, making it an extreme challenge to manage, monitor, and staff them. Thus, some parks remain “parks on paper”. For example, Grand Bahama has two park wardens for three national parks, Abaco has one warden for five national parks, Andros has one warden for five national parks, New Providence has one warden for four national parks, the Exuma islands have two wardens for two national parks, and Great Inagua has one warden for two national parks. Wardens have the power, authorities, and protection of an officer of the law while inside the boundaries of BNT property. With the doubling of the park system in 2002, the Central Andros National Parks (total area 115,770 ha) were established to protect inland forest, coral reef, and wetland nursery areas on North Andros Island. Unfortunately, these protected areas are not ideal for rock iguana conservation because they are located on North Andros Island, which was severely degraded habitat for rock iguanas because of feral animals, loss of habitat, logging roads that allow access to the island interior, and illegal hunting pressure. Therefore, after nearly a decade of rock iguana research and advocacy on South Andros, the government of The Bahamas expanded the Central Andros National Parks to include critical habitat for the Andros rock iguana (C. cychlura cychlura) in the southern and central parts of the island. The expansion is significant because it is the first Bahamian protected area designated in part to
70
C.R. Knapp et al.
protect a terrestrial reptile. The expansion also includes newly documented juvenile loggerhead (Caretta caretta) sea turtle aggregations, which hold vast promise for future research (A. Bolten and K. Bjorndal, pers. comm.). Union Creek Reserve (UCR) comprises an area of approximately 2000 ha and is located on the north coast of Great Inagua. The UCR is populated by hawksbill (E. imbricata) and green (C. mydas) sea turtle aggregations, which have been studied continually since 1975 (Bjorndal and Bolten, 1988a, 1988b, 2010; Bolten and Bjorndal, 1992; Bjorndal et al., 2000, 2003, 2005). Turtles in UCR have had legal protection from exploitation since 1965, which is well enforced by wardens of the Bahamas National Trust. Recently, however, all turtles have received legal protected status throughout The Bahamas (see Conservation legislation). Both hawksbill and green turtle aggregations in UCR are mixed stocks derived from several rookeries in the Atlantic, based on analyses of mtDNA sequences (Bowen et al., 2007; Bjorndal and Bolten, 2008). Another important green sea turtle aggregation is protected at Conception Creek within the Conception Island National Park. This population has also been under long-term study (Bjorndal et al., 2003), but it is remote and difficult to monitor. Little Inagua National Park was established in 2002 and is the largest uninhabited island in the West Indies (12,691 ha). The biodiversity implications for its terrestrial herpetofauna are enormous. The only Bahamian record for the snake, Hypsirhynchus parvifrons is from the island. The island exists in an undeveloped condition, although feral animals and poaching of wildlife by non-Bahamians are serious problems, particularly for sea turtles. Little Inagua is also a documented nesting location for green sea turtles primarily, but also hawksbill and loggerhead turtles (K. Bjorndal, pers. comm.). Established in 1958, the Exuma Cays Land and Sea Park (ECLSP) was the first park of its kind in the world and is the oldest national park in The Bahamas. The ECLSP is located in the central Bahamas and encompasses a 35 km long section of the northern Exuma Cays, covering an area of 45,600 ha. The waters of the ECLSP have been managed as a no-take marine fishery reserve since 1986, offering populations of commercially important marine species respite from over-exploitation. Though the park is mostly water, the cays provide vital refuge for snakes (Cubophis, Epicrates, and Tropidophis) and endangered rock iguanas. Translocated populations of three rock iguanas (C. rileyi nuchalis, C. cychlura inornata, and C. cychlura figginsi) have been established within the ECLSP as safeguard populations.
Conservation Initiatives It is difficult to gain traction for conservation programs that focus on the herpetofauna of The Bahamas. As a maritime nation, conservation concerns and management of marine resources receive considerably more attention. In addition, humans instinctively fear reptiles (LoBue and De Loache, 2008) and as a consequence most
Conservation of amphibians and reptiles in The Bahamas
71
people want to eliminate, rather than study or conserve them (Tolson and Henderson, 2006). Therefore, conservation programs for amphibians and reptiles are limited, with the majority of effort focused on the most critically threatened taxa. Rock iguanas Determined efforts to raise awareness for protecting the three species of endangered Bahamian rock iguanas (Cyclura) have been ongoing since the 1990s. Because the remoteness of many rock iguana populations makes monitoring difficult, signs have been erected advertising the protected status of rock iguanas and informing tourists of their dwindling numbers and susceptibility to domestic pets (fig. 3). This is especially important given that Allen Cays rock iguanas (C. cychlura inornata) were recently poached and eaten by North American yachtsmen from a cay without signs. To raise awareness and create talking points among Bahamians, rock iguana tee shirts, brochures, and posters endorsed by the Bahamas National Trust, and funded by a variety of private sources and non-profit organizations, have been distributed throughout the archipelago. In 1992 the San Salvador rock iguana (C. rileyi rileyi) was depicted on the Bahamian $1 bill to commemorate the Quincentennial of Columbus’ landing on San Salvador. Additionally, Bahamian amphibians and reptiles have been depicted on a number of postage stamps within country. In 2009, The Bahamas National Trust initiated a revenue-generating mechanism for rock iguana conservation that is linked with signs and brochures recently produced. The mechanism is an “Iguana Fund” link on the BNT website (www.bnt.bs) where people can donate specifically to rock iguana conservation causes. Two rock iguana conservation workshops have been held in The Bahamas with members of the International Union for the Conservation of Nature (IUCN) Iguana Specialist Group. The first meeting on San Salvador in 2000 involved a protected areas management strategy for Bahamian rock iguanas and seabirds. The document (Carey et al., 2001) produced from that workshop prioritized critical areas requiring protection in order to ensure the long-term survival of the three rock iguana taxa in The Bahamas. The second workshop was convened in 2005 on South Andros Island with local experts and stakeholders to draft a cooperative species conservation and management plan for the Andros rock iguana. The overall goal of the plan was to prioritize the conservation actions necessary to ensure the long-term survival of the Andros rock iguana throughout its range. The work presented in the plan detailed the management of the wild population, implementing education awareness programs, establishing and managing a national park, and mobilizing financial, technical and human resources (IUCN, 2010). The recovery plan was also intended to guide decision makers in government, and inspire funding agencies and the international conservation community to provide the attention this unique rock iguana species deserves. An innovative, grassroots rock iguana conservation effort was initiated in 2005 by Ricardo Johnson, a local high school teacher on Andros Island. The foundation
72
C.R. Knapp et al.
for this initiative is the Central Andros Iguanas Football Club, which today has approximately 75 members aged 7 to 16. Mr. Johnson and Club members are personally spearheading an effort to increase local pride for their native rock iguana by wearing jerseys depicting rock iguanas and by distributing information cards. Though the Shedd Aquarium and the International Reptile Conservation Foundation donated initial funds for jerseys and equipment, it is the push from the local stakeholder level which makes this initiative so promising, important, and in need of a dedicated funding source. Educating local stakeholders about conservation and habitat protection is critical for any successful conservation program. Working with the Andros Ministry of Education, teacher training workshops facilitated by the San Diego Zoo and Bahamas National Trust were held on Andros Island in 2007. The workshops engaged teachers with novel activities that advanced interest in the pine woodland ecosystem and its flagship species, the Andros rock iguana. Transportable education kits were also distributed to schools. These kits contained all necessary instructions and materials for lessons focused on the science of understanding the iguanas’ decline and management actions needed to ameliorate it. In 2002, scientists from Loma Linda University and the Gerace Research Center developed an innovative, handson experience for the educators and students (grades 4-10) of San Salvador Island (Carter et al., 2005). The three, one-day programs were titled “Celebrating Biodiversity 2002”. Following an introductory multimedia presentation, approximately 150 participants were engaged in three one-day activities including a boat trip to visit the endangered rock iguanas (C. rileyi rileyi) on Green Cay and the nearby seabird colonies, a hands-on learning experience about research techniques at a mock field camp, and an introduction to the island’s rich biodiversity including invertebrates, plants, seabirds, and reptiles. At the end of the program, students were given tee shirts, a certificate, and a challenge to become better-informed stewards of their unique and fragile ecosystems. Sea turtles Concerted education outreach efforts for sea turtles have been ongoing since 1979, when Carr and Bjorndal (1979) published an article in The Bahamas Naturalist. Since that time, many programs and individuals have been involved, culminating in the passage of regulations banning all harvest of sea turtles in The Bahamas, effective September 2009. A current effort by the organization, Family Island Sea Turtle Research and Education, established by Steve Connett and Barbara Crouchley promotes education about sea turtles in many of the Family Islands throughout The Bahamas. During presentations, fishery regulations are discussed and the work of the BNT is advanced to local inhabitants. At times, school children participate with tagging turtles. The program has been successful in reaching even remote areas of the archipelago (e.g., Rum Cay and Crooked Island). In addition, the Bahamas Sea Turtle Conservation Group (BSTCG) works to increase awareness about sea turtles and the threats facing them. Through education and protection, the
Conservation of amphibians and reptiles in The Bahamas
73
group hopes to motivate humans to respect the ocean ecosystems and conserve sea turtles. In the years just prior to the ban on sea turtle harvesting in The Bahamas, the BSTCG website recorded more than 5500 online signatories petitioning for the ban. Finally, educators from the Bahamas Reef Environment Educational Foundation (BREEF) speak to about 1500 children annually about sea turtle conservation during general marine conservation talks. Some protected areas in The Bahamas include important sea turtle foraging aggregations and habitat, such as the Union Creek Reserve and Conception Island National Park. Little Inagua National Park includes important nesting areas for sea turtles in The Bahamas. The Department of Marine Resources is now working on designating more marine protected areas, some of which will be important for sea turtle populations. Snakes and other reptiles The Bahamas lack a large, public zoological institution, yet confiscated reptiles are often housed at the Ardastra Gardens, Zoo and Conservation Centre in Nassau. Ardastra also exhibits, among other reptiles, Bahamian boas (Epicrates striatus), dwarf boas (Tropidophis curtus), and curly-tail lizards (Leiocephalus carinatus). Snake education is a priority at Ardastra and since 1998 approximately 10,000 local area students annually receive interactive educational experiences with snakes. Small scale workshops are sometimes conducted at Ardastra where the public is invited to learn how to handle a wild snake in the event that one is found in the home. At times, snakes are taken to public events at shopping malls to reach members of the public that do not usually enter Ardastra Gardens. The Bahamas National Trust (BNT) also educates 10,000 students annually through environmental educational programs, yet only a fraction of these programs concern snakes. Consequently, approximately 250 and 200 students participate annually in BNT snake conservation education on New Providence and Grand Bahama, respectively. Other than these few programs, snakes receive no conservation attention, which is problematic given the general fear of snakes among residents and tourists. In 1994, the BNT launched the Discovery Club program to implement fun environmental education programs for its young members. Discovery Club kids participate in activities that lead toward badge awards including bugs, astronomy, camping, coral reefs, and muddy mangroves. Recently, a “Herps” badge was included, which will optimistically expand amphibian and reptile awareness throughout the country, especially since the Discovery Club has been expanded from Nassau and Grand Bahama to include the Family Islands of Abaco (spearheaded through “Friends of the Environment”), Andros, Eleuthera, and the Exumas. Long-term research The Bahamian archipelago serves as a natural laboratory and from an ecological perspective the long-term research of Thomas Schoener and Jonathan Losos,
74
C.R. Knapp et al.
with their graduate students, should be recognized for its importance to our understanding of ecology (Losos and Spiller, 1999; Losos et al., 2004), evolution (Losos et al., 1997; Schoener et al., 2005), and ecosystem impact and recovery after catastrophic events (Spiller et al., 1998; Schoener et al., 2001, 2004). See also Franz et al. (1996) for a complete list of references prior to 1996. From a conservation perspective, long-term studies of natural populations and communities are generally regarded as indispensable for understanding normal population trends and fluctuations, or direct responses to disturbance (Tinkle, 1979). Evaluating the real and potential impacts of disturbance, however, requires good quality life history and demographic data (Iverson et al., 2006). Unfortunately, little of such research has focused on long-lived lizards (i.e., those that mature at >5 years; e.g., reviews in Vitt and Pianka, 1994). This is particularly disconcerting because long-lived lizards, especially those on islands, are disproportionately threatened with extinction (Alberts, 2000). The longevity of such lizards presents an obstacle to obtaining multi-generational data that can be used to quantify life history traits and permit population modeling because the work is often time-consuming and expensive. Consequently, developing sound management strategies for such species are often hindered. In 1980 John Iverson led an Earthwatch program to The Bahamas for the primary purpose of surveying the rock iguanas in the Exuma Island chain from the Allen Cays in the north to White (Sandy) Cay in the south (ca. 200 kilometers). An attempt was made to visit every island previously reported to harbor rock iguanas, as well as those suggested by local Bahamians or known to have suitable habitat. A secondary purpose of that program was to identify a long-term field site for Earlham College student-faculty research on rock iguanas. Because of its proximity to other inhabited islands and (at that time) its low visitation rate by tourists, the Allen Cays were selected for ongoing mark-recapture studies. Between 1982 and 2010, Iverson made 26 research trips to the Allen Cays, ranging in duration from 3 to 31 days (mode 9 days), and involving two to twelve Earlham students, faculty, or alumni per visit (mode 12). Most of those trips were self-funded by the participants, with some supplemental funding provided by endowed student-research funds through Earlham College. The long-term study of the Allen Cays populations has provided data on growth (Iverson et al., 2004b), reproduction (Iverson et al., 2004a; Knapp et al., 2006), demography (Iverson et al., 2006), variation in sex ratio (Smith and Iverson, 2006), longevity (Iverson et al., 2004a), and the second life table for a West Indian rock iguana (Iverson, 2007). This work has also produced numerous anecdotal natural history observations (e.g., Smith et al., 2008, 2009a, 2009b; Hines et al., 2010), and has provided valuable research and practical experiences for undergraduate students (e.g., Valiulis et al., 2004; Pieper et al., 2009). Ultimately, this study has provided baseline demographic data for managing this subspecies, identifying factors that may contribute to population increases and declines, and can be extrapolated to similarly imperiled species with the goal of reversing their declines.
Conservation of amphibians and reptiles in The Bahamas
75
Two additional long-term research projects have been on-going since the early 1990s for Bahamian rock iguanas. Along with their graduate students, William Hayes and Ron Carter from Loma Linda University have been studying the ecology of all three Cyclura rileyi subspecies including population assessments, behavioral ecology, reproduction, movement patterns, and morphological variation (Carter and Hayes, 2004; Hayes et al., 2004). Long-term studies of Cyclura cychlura have also been conducted in the Exumas and on Andros Island by Charles Knapp from Shedd Aquarium and the San Diego Zoo Institute for Conservation Research. Work in the Exumas quantified the success of a rock iguana translocation program (Knapp, 2001; Knapp and Malone, 2003), while on Andros the research has included home range and habitat preference (Knapp and Owens, 2005), nesting ecology and reproductive variation (Knapp et al., 2006; Knapp and Owens, 2008), dispersal and survival of hatchlings (Knapp et al., 2010), and tourist and local attitudes towards rock iguanas (Knapp, 2007). The research and educational outreach endeavors of Carter, Hayes, and Knapp have been applied directly toward national park recommendations on San Salvador and Andros Islands (e.g., Hayes, 2003). Sea turtles are also long-lived reptiles with life history traits that make them vulnerable to overexploitation. Accurate analyses of population trends and demographic parameters are critical for modeling population growth, understanding recovery of depleted populations, and for developing and assessing management plans for these species (Bjorndal et al., 2005). However, not only are long-term research programs involving sea turtles time consuming and expensive, many species disperse over large geographic areas and/or have life stages inaccessible to scientists. Research on sea turtles contributing to both local and regional conservation management has been on-going in The Bahamas since 1975 by Karen Bjorndal and Alan Bolten from the University of Florida. The majority of work has been conducted on three species at two sites — Union Creek, Great Inagua and Conception Creek, Conception Island. Selected results stemming from the long-term program include investigating nutrition and grazing behavior of green turtles (Bjorndal, 1980), examining growth rates of green, hawksbill, and loggerhead turtles (Bjorndal and Bolten, 1988a, 1988b, 2010), exploring size- and sex-specific relationships of blood profiles for green turtles (Bolten and Bjorndal, 1992), evaluating a density-dependent effect on growth rates of green turtles (Bjorndal et al., 2000), estimating annual survival probabilities of green turtles (Bjorndal et al., 2003), generating estimates of annual abundance for juvenile green turtles and suggesting best approaches for monitoring sea turtle population trends (Bjorndal et al., 2005), reporting that estimates of connectivity and genetic diversity in sea turtle populations are affected by the level of temporal variation in contributions from source stocks (Bjorndal and Bolten, 2008), and evaluating hawksbill turtle success in a peripheral habitat (Bjorndal and Bolten, 2010). There is often a disconnect between conservation biology within the academic environment and conservation action outside of academia (Kainer et al., 2006). The
76
C.R. Knapp et al.
research of Bjorndal, Bolten, Hayes, Iverson, and Knapp attempt to bridge the gap between conservation research and applied management. The long-term commitment by these researchers has earned them the trust and respect of the Bahamian government and Bahamas National Trust. All either serve as scientific advisors on the BNT Council, or chair and/or serve as members on the BNT science advisory committee (SAC). The SAC is a multi-disciplinary network of scientists and experts whose knowledge, experience, and interest in the Bahamian environment and its natural resources provide immeasurable contributions to advancing the mission of the BNT. The purpose of the SAC is to advise the Council of the Bahamas National Trust on science-related matters and conservation issues in the Bahamas.
Ecotourism Endeavors In The Bahamas, tourism has traditionally been a coastal industry focusing on cruise ship and resort clientele (Lowe and Sullivan-Sealy, 2003). However, studies elsewhere demonstrate that revenues earned through ecotourism, if managed properly, have potential to augment local economies, positively influence local attitudes, and fund conservation initiatives (Archabald and Naughton-Treves, 2001; Walpole and Goodwin, 2001; Walpole et al., 2001). A major component attracting ecotourists is a flagship species (Krüger, 2005), and if such species are absent, the ecotourism market can be severely limited (Munn, 1992). The Bahamas, however, do not retain traditionally charismatic, mammalian megafauna, but instead are inhabited by three species of rock iguana (Cyclura) and five species of sea turtles. Promoting non-traditional flagship species such as reptiles tends to be more difficult than their high-profile mammalian counterparts (but see Tisdell and Wilson, 2002; Walpole and Leader-Williams, 2002 for exceptions with nesting sea turtles and the Komodo dragon, respectively). However, because rock iguanas are large, photogenic, and charismatic, they have the potential to serve as flagship species for ecotourism endeavors and conservation of the tropical dry forest and beach scrub ecosystems they inhabit. Tourist surveys from Andros Island revealed that visitors specific to that island are nature-oriented and supportive of national parks and associated entrance fees. There also is visitor interest in guided field tours to observe rock iguanas and other wildlife on the island (Knapp, 2007). Currently, a small ecotourism market exists in the form of annual “citizen scientist” research expeditions dedicated to the study of Bahamian rock iguanas. Participants of these Shedd Aquarium (Chicago, Illinois) research expeditions pay (∼US $2000) to participate in long-term rock iguana research projects on Andros and several islands in the Exuma Island chain (Knapp, 2004). Additionally, tour companies based in Nassau and Great Exuma offer one-day excursions to islands in the northern and central Exuma chain to view rock iguanas. While promoting conservation is not the focal point of the one-day rock iguana viewing excursions, the willingness of tourists (as many as 150 per day; Iverson et al., 2006) to pay (∼US $200) to observe rock iguanas, among other activities, underscores the
Conservation of amphibians and reptiles in The Bahamas
77
potential for a sustainable ecotourism market if company actions are modified to promote conservation and sustainable activities. Scuba divers also are valuable participants in ecotourism and provide coastal areas with economic incentives to protect and preserve local marine wildlife and habitats (Arin and Kramer, 2002). Thousands of scuba divers visit The Bahamas annually and the ban on killing sea turtles in Bahamian waters not only benefits sea turtles but also could substantially benefit the tourism industry through increased fees. Surveys suggest that scuba divers are willing to pay almost US $30 more per dive for an increased chance to observe a sea turtle in the wild (White, 2008). In order to capture the increased dive value for conservation activities, nongovernmental organizations and dive operators should establish conservation funds, or non-governmental organizations establish their own funds and solicit donations from divers.
Recommendations and Conclusions The Bahamas need more local voices to promote conservation of native amphibians and reptiles. Cultivating respect and concern for Bahamian herpetofauna that may ultimately lead to conservation must be fostered within and outside the classroom. Most (84%) Bahamians live in urban areas (Central Intelligence Agency, 2010), and thus the majority lack awareness about nature and ecological concepts. The Bahamas National Trust has increased its effort to connect people to nature by expanding the national park system and augmenting environmental education opportunities for school groups. However, an environmental curriculum needs to be enhanced in schools and standardized throughout the country. Complimentary educational messages should be implemented and promoted whenever possible. For example, though no potently venomous snakes inhabit The Bahamas, they are still killed routinely by people who fear them. Additionally, domesticated mammals allowed to roam or released intentionally on islands have the potential to decimate the herpetofauna. Therefore, special educational efforts should be implemented to address these issues. The College of The Bahamas must engage students in field research opportunities and promote environmental education as a career. Undoubtedly, careers in environmental sciences are limited in The Bahamas, but the country needs a wider diversity of ecologists with broad interests beyond marine science or ornithology. The Bahamas National Trust and Bahamian government have made immense progress with efforts to increase the number of protected areas in country. However, the challenge remains to ensure that protected areas are suitably staffed, patrolled, and their benefits advanced to Bahamians. Moreover, amphibians and reptiles are an underappreciated cultural legacy in The Bahamas. Care should be taken to consider the herpetofauna when prioritizing conservation areas based on ecosystem function, rarity, endemism, and sociopolitical, legislative, and economic factors. Areas have been identified and proposed in the past for protection that would include
78
C.R. Knapp et al.
herpetofauna of concern, such as Cay Sal and Plana Cays, and these proposals should be revisited. Indeed, the greatest sea turtle nesting area in The Bahamas occurs on the Cay Sal Bank (Addison and Morford, 1996; Addison, 1997) and plans to develop these islands are a great risk to these turtles. A proposal is under review by The Bahamas Government, which was submitted by the Bahamas National Trust, for a National Park on San Salvador that would include habitat for endangered reptiles such as C. rileyi rileyi and the island endemic Epictia columbi. We encourage the acceptance of the proposal. Finally, both within and outside protected areas, law enforcement must serve more as a deterrent to curtail illegal acts perpetrated against wildlife. One of the most critical issues for the herpetofauna of The Bahamas is habitat loss or alteration due to tourism development or tourism-driven activities. Herpetofaunal inventories should be emphasized in all environmental impact assessments. Correctly managed tourism has the potential to ensure the long-term survival of both endangered species and their habitats via educational and economic opportunities (Giannecchini, 1993; Knapp, 2004). These opportunities, however, rely on healthy animal populations and sustainable management. Behavioral alterations and longterm physiological consequences stemming from tourism activities such as food provisioning should be monitored and managed with species health in mind. Moreover, tourism companies profiting from activities involving the interactions with the native herpetofauna (e.g., scuba diving and rock iguana viewing) should be engaged and encouraged to add a small contribution to each ticket or package sold with proceeds benefiting research and conservation activities for the focal species. The introduction and naturalization of non-native plants and wildlife is a global problem that particularly affects islands (Gibbons et al., 2000). From a pet trade and tourism attraction perspective, if non-native species continue to be imported into the country, then the problem of invasive species will persist and escalate because most pet owners are not aware of the consequences associated with their release. The colonies of introduced iguanas in the Berry Islands could be devastating if people decide to transport them to other islands, as witnessed in the Exumas with native rock iguana species (S. Buckner, J. Iverson, C. Knapp, pers. obs.). With the exception of Trachemys, the Bahamian government does not grant permits for the importation of amphibians or reptiles. To be sure, non-native reptiles are still finding their way into the country (table 1; S. Buckner, unpubl. data). Therefore, the Bahamian government should reduce the risk of accidental importation by educating custom officers about the threat of non-native species, and by eliminating the importation of Trachemys. Research must be initiated for the vast number of Bahamian species that are data deficient or not evaluated in regards to IUCN listings. We cannot protect what is unknown and 85% of the native, terrestrial Bahamian herpetofauna is understudied with little known about their ecology and natural history (table 1). Amphibian population declines were first recognized as a global phenomenon in the early 1990s (Wake, 1991) and current extinction rates for amphibians are estimated as
Conservation of amphibians and reptiles in The Bahamas
79
much as 200 times higher than background (Roelants et al., 2007). While there is no evidence of disease or decline in Bahamian amphibian populations, baseline population and disease-monitoring studies should be initiated prior to the advent of declining populations. In addition, reports of sea turtle nesting in The Bahamas are incomplete (Carr et al., 1982). Thus, additional information concerning the location of significant nesting beaches is invaluable for turtle management and conservation in The Bahamas (Addison and Morford, 1996). The potential impacts of non-native mammals are understood theoretically, but we have little understanding concerning impacts that non-native herpetofauna will have on Bahamian amphibians and reptiles. Therefore, studies should also focus on native-non-native interactions. At present, Bahamian biodiversity is catalogued nationally through The Bahamas National Herbarium, The Bahamas National Entomological Collection, and a National Collection of Bird Skins, yet there is no national herpetological collection. The Bahamas should establish a national herpetological specimen collection for scientific, training, and educational purposes. In advance preparation of such a collection, Sandra Buckner is currently the custodian of all native and non-native herpetological specimens that have been collected when specimens are found dead. Finally, long-term monitoring of amphibian and reptile populations is essential and must be aided by establishing standard methods and techniques. It is equally important that the Bahamian government, Bahamas National Trust, College of the Bahamas, and other conservation organizations in country recognize that rigorous field programs focusing on the distribution, abundance, status, and trends of populations and species are critical and worthwhile. When long-term and widespread monitoring becomes the norm, declines are less likely to go unnoticed and more likely to be addressed unequivocally.
Acknowledgements. We thank The Bahamas Environment, Science, and Technology Commission, The Bahamas National Trust, and The Bahamas Department of Agriculture, for permission over the years to conduct research in The Bahamas. Karen Bjorndal and Alan Bolten provided valuable comments to the manuscript. We thank the many researchers who have allowed one or more of us to accompany them in the field and also for their interest in the herpetofauna of The Bahamas. These include J. Bendon, K. Bjorndal, A. Bolten, R. Carter, S. Conners, K. Dodd, R. Franz, C. Hass, W. Hayes, W. Meshaka Jr., S. B. Hedges, K. Hines, L. Roth, J. Rothchild, D. Steadman, and J. Wasilewski. David Lee provided literature. The original manuscript was improved with reviews by Richard Franz, Kenney Krysko, and an anonymous reviewer. This work was made possible in part because of years of research in The Bahamas, supported by (in alphabetical order) the American Zoological Association Conservation Endowment Fund, Chicago Zoological Society Board of Trade Endangered Species Fund, Chicago Herpetological Society, Disney Wildlife Conservation Fund, Earlham College, International Iguana Foundation, John G. Shedd
80
C.R. Knapp et al.
Aquarium, Tiamo Resorts of South Andros, University of Florida, U.S. Fish and Wildlife Service (USFWS) International Conservation Fund, Zoological Society of San Diego, and the vast number of dedicated students and volunteers who assisted with rock iguana field work.
References Adalsteinsson, S.A., Branch, W.R., Trape, S., Vitt, L.J., Hedges, S.B. (2009): Molecular phylogeny, classification, and biogeography of snakes of the Family Leptotyphlopidae (Reptilia, Squamata). Zootaxa 2244: 1-50. Addison, D.S. (1997): Sea turtle nesting on Cay Sal, Bahamas, recorded June 2-4, 1996. Bahamas J. Sci. 5(1): 34-35. Addison, D.S., Morford, B. (1996): Sea turtle nesting activity on the Cay Sal Bank, Bahamas. Bahamas J. Sci. 3(3): 31-36. Alberts, A.C., Ed. (2000): West Indian Iguanas: Status Survey and Conservation Action Plan. Gland, Switzerland, IUCN. Albury, P. (1975): The story of the Bahamas. London, MacMillan Education LTD. Archabald, K., Naughton-Treves, L. (2001): Tourism revenue-sharing around national parks in western Uganda: Early efforts to identify and reward local communities. Environ. Conserv. 28: 135-149. Arin, T., Kramer, R.A. (2002): Divers’ willingness to pay to visit marine sanctuaries: An exploratory study. Ocean Coast. Manage. 45: 171-183. Auffenberg, W. (1967): Notes on West Indian tortoises. Herpetologica 23: 34-44. Bahamas Ministry of Tourism. (2010): Foreign arrivals to The Bahamas by first port of entry (www.tourismtoday.com/docs/stats/Air%20Sea%20Landed%20&%20Cruise%20Arrivals%2019 98-2008.xls). Bahamas National Trust. (2009): Alligator captured at Great Harbour Cay. BNT Trust Notes 6(3): 8. Bailey, A.M. (1925): The iguanas of Bitter Guana Cay. Nat. Hist. 25: 391-393. Berman, M.J. (1994): Preliminary report on a vertebrate assemblage excavated from the Three Dog Site, San Salvador, Bahamas. In: Proceedings of the 5th Symposium on the Natural History of the Bahamas, p. 5-13. Kass, L.B., Ed., San Salvador, Bahamian Field Station. Bissell, A.N., Martins, E.P. (2004): Behavior and ecology of rock iguanas, II: Population differences. In: Iguanas: Biology and Conservation, p. 109-118. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Berkeley, University of California Press. Bjorndal, K.A. (1980): Nutrition and grazing behavior of the green turtle Chelonia mydas. Mar. Biol. 56: 147-154. Bjorndal, K.A., Bolten, A.B. (1988a): Growth rates of immature green turtles, Chelonia mydas, on feeding grounds in the southern Bahamas. Copeia 1988: 555-564. Bjorndal, K.A., Bolten, A.B. (1988b): Growth rates of juvenile loggerheads, Caretta caretta, in the southern Bahamas. J. Herpetol. 22: 480-482. Bjorndal, K.A., Bolten, A.B. (2008): Annual variation in source contributions to a mixed stock: Implications for quantifying connectivity. Mol. Ecol. 17: 2185-2193. Bjorndal, K.A., Bolten, A.B. (2010): Hawksbill sea turtles in seagrass pastures: Success in a peripheral habitat. Mar. Biol. 157: 135-145. Bjorndal, K.A., Bolten, A.B., Chaloupka, M.Y. (2000): Green turtle somatic growth model: Evidence for density dependence. Ecol. Appl. 10: 269-289. Bjorndal, K.A., Bolten, A.B., Chaloupka, M.Y. (2003): Survival probability estimates for immature green turtles Chelonia mydas in the Bahamas. Mar. Ecol. Prog. Ser. 252: 273-281.
Conservation of amphibians and reptiles in The Bahamas
81
Bjorndal, K.A., Bolten, A.B., Chaloupka, M.Y. (2005): Evaluating trends in abundance of immature green turtles, Chelonia mydas, in the Greater Caribbean. Ecol. Appl. 15: 304-314. Bolten, A.B., Bjorndal, K.A. (1992): Blood profiles for a wild population of green turtles (Chelonia mydas) in the southern Bahamas: Size-specific and sex-specific relationships. J. Wildlife Dis. 28: 407-413. Bolten, A.B., Bjorndal, K.A. (2003): Green turtles in the Caribbean: A shared resource. In: CoastalMarine Conservation: Science and Policy, p. 225-226. Ray, G.C., McCormick-Ray, J., Eds, London, Blackwell Scientific. Borroto-Paez, R. (2009): Invasive mammals in Cuba: An overview. Biol. Invasions 11: 2279-2290. Bowen, B.W., Grant, W.S., Hillis-Starr, Z., Shaver, D.J., Bjorndal, K.A., Bolten, A.B., Bass, A.L. (2007): Mixed-stock analysis reveals the migrations of juvenile hawksbill turtles (Eretmochelys imbricata) in the Caribbean Sea. Mol. Ecol. 16: 49-60. Bratton, S.P. (1975): The effect of European wild boar (Sus scrofa) on Gray Beech Forest in the Great Smoky Mountains. Ecology 56: 1356-1366. Bryan, J.J., Gerber, G.P., Welch, M.E., Stephen, C.L. (2007): Re-evaluating the taxonomic status of the Booby Cay Iguana, Cyclura carinata bartschi. Copeia 2007: 734-739. Buckner, S.D., Franz, R. (1994a): Geographic distribution: Hemidactylus garnoti. Herpetol. Rev. 25: 164. Buckner, S.D., Franz, R. (1994b): Geographic distribution: Hemidactylus mabouia. Herpetol. Rev. 25: 164. Buckner, S.D., Franz, R. (1994c): Geographic distribution: Elaphe guttata. Herpetol. Rev. 25: 166. Buckner, S.D., Franz, R. (1994d): Geographic distribution: Elaphe obsoleta. Herpetol. Rev. 25: 166. Buckner, S.D., Franz, R. (1998a): Geographic distribution: Thamnophis sauritus sackenii. Herpetol. Rev. 29: 55. Buckner, S.D., Franz, R. (1998b): Geographic distribution: Thamnophis sirtalis sirtalis. Herpetol. Rev. 29: 55. Calsbeek, R., Smith, T.B. (2003): Ocean currents mediate evolution in island lizards. Nature 426: 552-555. Campbell, D.G. (2006): The animals Columbus saw: The controversial first zoology of the Bahama Islands. Bahamas Nat. J. Sci. 1(2): 4-15. Carey, E. (2002): Alligator removed from Great Harbour Cay, Bahamas. IUCN-Crocodile Spec. Group Newsl. 21(3): 12-13. Carey, E., Buckner, S.D., Alberts, A.C., Hudson, R.D., Lee, D., Eds. (2001): Protected Areas Management Strategy for Bahamian Terrestrial Vertebrates: Iguanas and Seabirds. Apple Valley, Minnesota, IUCN/SSC Conservation Breeding Specialist Group. Carlson, L.A. (1999): Aftermath of a feast: Human colonization of the southern Bahamian Archipelago and its effects on the indigenous fauna. Unpublished Ph.D. dissertation. Gainesville, University of Florida. Carr, A.F. (1956): The Windward Road: Adventures of a Naturalist on Remote Caribbean Shores. New York, Alfred Knopf. Carr, A., Bjorndal, K. (1979): Turtles of The Bahamas. Bahamas Nat. 4: 17-20. Carr, A.F., Meylan, A., Mortimer, J., Bjorndal, K., Carr, T. (1982): Surveys of sea turtle populations and habitats in the western Atlantic. Southeast Fisheries Center, NOAA technical Memo, NMFSSEFC-91. Panama City, Florida, National Marine Fisheries Service. Carter, R.L., Hayes, W.K. (2004): Conservation of an endangered Bahamian iguana. II. Morphological variation and conservation recommendations. In: Iguanas: Biology and Conservation, p. 258-273. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Berkeley, University of California Press. Carter, R.L., Hayes, W.K., Voegeli, V., Voegeli, S. (2005): Celebrating Biodiversity 2002 — Conservation education: A responsibility of higher education. In: Proceedings of the 10th Symposium on
82
C.R. Knapp et al.
the Natural History of the Bahamas, p. 12-17. Buckner, S.D., McGrath, T.A., Eds, San Salvador, Gerace Research Center. Case, T.J., Bolger, D.T. (1991): The role of introduced species in shaping the distribution and abundance of island reptiles. Evol. Ecol. 5: 272-290. Central Intelligence Agency. (2010): The World Factbook (www.cia.gov/library/publications/theworld-factbook/geos/bf.html). Charters, S. (1999): The day is so long and the wages so small: Music on a summer island. London, Marion Boyars Publishers, Ltd. Clark, P.U., Mix, A.C. (2002): Ice sheets and sea level of the Last Glacial Maximum. Quat. Sci. Rev. 21: 1-7. Close, L.M., Seigel, R.A. (1997): Differences in body sizes among populations of red-eared sliders (Trachemys scripta elegans) subjected to different levels of harvesting. Chelonian Conserv. Biol. 2: 563-566. Coblentz, B.E., Baber, D.W. (1987): Biology and control of feral pigs on Isla Santiago, Galapagos, Ecuador. J. Appl. Ecol. 24: 403-418. Correll, D.S., Correll, H.B. (1982): Flora of the Bahama Archipelago. Vaduz, Liechtenstein, J. Cramer. Cox, R.M., Calsbeek, R. (2010). Sex-specific selection and intraspecific variation in sexual size dimorphism. Evolution 64: 798-809. Crabbe, M.J.C., Martinez, E., Garcia, C., Chub, J., Castro, L., Guy, J. (2008): Growth modelling indicates hurricanes and severe storms are linked to low coral recruitment in the Caribbean. Mar. Environ. Res. 65: 364-368. Cree, A., Daugherty, C.H., Hay, J.M. (1995): Reproduction of a rare New Zealand reptile, the tuatara, Sphenodon punctatus, on rat-free and rat-inhabited islands. Conser. Biol. 9: 373-383. Crombie, R.I. (1972): The presence of Hyla squirella in the Bahamas. Q. J. Fla. Acad. Sci. 35: 49-52. Dodd, C.K., Jr., Franz, R. (1996): Species richness and biogeography of the herpetofauna in the Exuma Cays Land and Sea Park, Bahamas. In: Contributions to West Indian Herpetology: A Tribute to Albert Schwartz, p. 359-369. Powell, R., Henderson, R.W., Eds, Society for the Study of Amphibians and Reptiles, Ithaca. Franz, R., Franz, S. (2009): A new fossil tortoise in the genus Chelonoidis (Testudies: Testudinidae) from the northern Bahamas, with an osteological assessment of other Neotropical tortoises. Bull. Fla. Mus. Nat. Hist. 49: 1-44. Franz, R., Dodd, C.K., Buden, D.W. (1993): Distributional records of amphibians and reptiles from the Exuma Islands, Bahamas, including the first reports of a freshwater turtle and an introduced gecko. Carib. J. Sci. 29: 165-173. Franz, R., Morgan, G.S., Albury, N., Buckner, S.D. (1995): Fossil skeleton of a Cuban crocodile (Crocodylus rhombifer) from a blue hole on Abaco, Bahamas. Carib. J. Sci. 31: 149-152. Franz, R., Dodd, C.K., Buckner, S.D. (1996): A review of herpetology of the Bahamian Archipelago. Bahamas J. Sci. 3(3): 22-30. Garman, S. (1888): Reptiles and batrachians from the Caymans and from the Bahamas, collected by Prof. C.J. Maynard from the Museum of Comparative Zoology at Cambridge. Bull. Essex Inst. 20: 101-113. Giannecchini, J. (1993): Ecotourism: New partners, new relationships. Conserv. Biol. 7: 429-432. Gibbons, J.W., Scott, D.E., Ryan, T.J., Buhlmann, K.A., Tuberville, T.D., Metts, B.S., Greene, J.L., Mills, T., Leiden, Y., Poppy, S., Winne, C.T. (2000): The global decline of reptiles, deja-vu amphibians. Bioscience 50: 653-667. Glor, R.E., Losos, J.B., Larson, A. (2005): Out of Cuba: Overwater dispersal and speciation among lizards in the Anolis carolinensis subgroup. Mol. Ecol. 14: 2419-2432. Granberry, J., Vescelius, G. (2004): Languages of the Pre-Columbian Antilles. Tuscaloosa, The University of Alabama Press. Gruber, S.H., Parks, W. (2002): Mega-resort development on Bimini: Sound economics or environmental disaster? Bahamas J. Sci. 9(2): 2-18.
Conservation of amphibians and reptiles in The Bahamas
83
Hall, J.S., Dougherty, P.L., Stihler, C.W. (1998): Study of the black rat on San Salvador Island, Bahamas. Bahamas J. Sci. 5(3): 34-36. Haneke, B. (1995): A study of Mona Rock Iguana (Cyclura cornuta stejnegeri) nesting sites on Mona Island, Puerto Rico. J. Inter. Iguana Soc. — Iguana Times 4(4): 61-71. Hayes, W.K. (2003): Can San Salvador’s iguanas and seabirds be saved? Bahamas J. Sci. 11(1): 2-8. Hayes, W.K., Carter, R.L., Cyril, S., Jr., Thornton, B. (2004): Conservation of an endangered Bahamian rock iguana. I. Population assessments, habitat restoration, and behavioral ecology. In: Iguanas: Biology and Conservation, p. 232-257. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Berkeley, University of California Press. Hedges, S.B. (2002): Morphological variation and the definition of species in the snake genus Tropidophis (Serpentes, Tropidophiidae). Bull. Nat. Hist. Mus. Lon. 68(2): 83-90. Hedges, S.B., Duellman, W.E., Heinicke, M.P. (2008): New World direct-developing frogs (Anura: Terrarana): Molecular phylogeny, classification, biogeography, and conservation. Zootaxa 1737: 1-182. Hedges, S.B., Couloux, A., Vidal, N. (2009): Molecular phylogeny, classification, and biogeography of West Indian racer snakes of the Tribe Alsophiini (Squamata, Dipsadidae, Xenodontinae). Zootaxa 2067: 1-28. Heinicke, M.P., Duellman, W.E., Hedges, S.B. (2007): Major Caribbean and Central American frog faunas originated by ancient oceanic dispersal. Proc. Natl. Acad. Sci. USA 104: 10092-10097. Henderson, R.W. (1992): Consequences of predator introductions and habitat destruction on amphibians and reptiles in the post-Columbus West Indies. Carib. J. Sci. 28: 1-10. Henderson, R.W., Powell, R. (2009): Natural History of West Indian Reptiles and Amphibians. University of Florida Press, Gainesville. Hines, K. (2007): Preliminary diet analyses of Cyclura cychlura inornata and Cyclura cychlura figginsi: Assessing potential impacts of tourist feeding. IUCN-Iguana Specialist Group Newsl. 10(1): 13. Hines, K.N., Knapp, C.R., Zachariah, T.T., Iverson, J.B., Smith, G.R. (2010): Cychlura cychlura inornata. Paraphimosis and prolapsed cloaca. Herpetol. Rev. 41: 77-78. Hower, L.M., Hedges, S.B. (2003): Molecular phylogeny and biogeography of West Indian teiid lizards of the genus Ameiva. Carib. J. Sci. 39: 298-306. International Union for Conservation of Nature (IUCN) Andros Iguana Conservation Action Plan, 2005-2011. Gland, Switzerland: IUCN/SSC Iguana Specialist Group. IRCF. (2009): News briefs: Visitors arrested in the Exuma Cays for killing iguanas. IRCF Rep. Amphib. Conserv. Nat. Hist. 16: 60-61. Iverson, J.B. (1978): The impact of feral cats and dogs on populations of the West Indian rock iguana, Cyclura carinata. Biol. Conserv. 14: 63-73. Iverson, J.B. (1992): A Revised Checklist with Distribution Maps of the Turtles of the World. Privately published. Iverson, J.B. (2007): Juvenile survival in the Allen Cays Rock Iguana (Cyclura cychlura inornata). Copeia 2007: 740-744. Iverson, J.B., Hines, K.N., Valiulis, J.M. (2004a): The nesting ecology of the Allen Cays rock iguana, Cyclura cychlura inornata in the Bahamas. Herpetol. Monogr. 18: 1-36. Iverson, J.B., Smith, G.R., Pieper, L. (2004b): Factors affecting long term growth of the Allen Cays Rock Iguana, Cyclura cychlura inornata. In: Iguanas: Biology and Conservation, p. 176-192. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Berkeley, University of California Press. Iverson, J.B., Converse, S.J., Smith, G.R., Valiulis, J.M. (2006): Long-term trends in the demography of the Allen Cays Rock Iguana (Cyclura cychlura inornata): Human disturbance and densitydependent effects. Biol. Conserv. 32: 300-310. Jolley, D.B., Ditchkoff, S.S., Sparklin, B.D., Hanson, L.B., Mitchell, M.S., Grand, J.B. (2010): Estimate of herpetofauna depredation by a population of wild pigs. J. Mammal. 91: 519-524.
84
C.R. Knapp et al.
Kainer, K.A., Schmink, M., Covert, H., Stepp, J.R., Bruna, E.M., Dain, J.L., Espinosa, S., Humphries, S. (2006). A graduate education framework for tropical conservation and development. Conserv. Biol. 20: 3-13. Keegan, W.F. (1997): Bahamian Archaeology. Nassau, Media Publishing. Knapp, C.R. (2001): Status of a translocated Cyclura iguana colony in the Bahamas. J. Herpetol. 35: 239-248. Knapp, C.R. (2004): Ecotourism and its potential impacts on iguana conservation in the Caribbean. In: Iguanas: Biology and Conservation, p. 290-301. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Berkeley, University of California Press. Knapp, C.R. (2005): Working to save the Andros iguana. Iguana 12: 8-13. Knapp, C.R. (2007): The potential for iguana-based ecotourism on Andros: A first assessment. Bahamas Nat. J. Sci. 2: 10-17. Knapp, C.R., Malone, C.L. (2003): Patterns of reproductive success and genetic variability in a translocated iguana population. Herpetologica 59: 195-202. Knapp, C.R., Owens, A.K. (2005): Home range and habitat associations of a Bahamian iguana: Implications for conservation. Anim. Conserv. 8: 269-278. Knapp, C.R., Owens, A.K. (2008): Nesting behavior and the use of termitaria by the Andros Iguana (Cyclura cychlura cychlura). J. Herpetol. 42: 46-53. Knapp, C.R., Iverson, J.B., Owens, A.K. (2006): Geographic variation in nesting behavior and reproductive biology of an insular iguana (Cyclura cychlura). Can. J. Zool. 84: 1566-1575. Knapp, C., Hines, K., Zachariah, T. (2008): Health assessment for Exuma Island iguanas. IUCNIguana Spec. Group Newsl. 11(2): 8-9. Knapp, C.R., Alvarez-Clare, S., Perez-Heydrich, C. (2010): The influence of landscape heterogeneity and dispersal on survival of neonate insular iguanas. Copeia 2010: 62-70. Krüger, O. (2005): The role of ecotourism in conservation: Panacea or Pandora’s box? Biodivers. Conserv. 14: 579-600. Krysko, K.L., Borgia, A.P. (2005): Geographic distribution: Hemidactylus mabouia. Herpetol. Rev. 36: 468. Krysko, K.L., Thomas, T.M. (2007): Geographic distribution: Hemidactylus mabouia. Herpetol. Rev. 38: 351. Lacki, M.J., Lancia, R.A. (1986): Effects of wild pigs on beech growth in Great Smoky Mountains National Park. J. Wildlife Manage. 50: 655-659. Lee, D.S. (2004): Additional reptiles and amphibians introduced to the Bahamas: A growing conservation concern. Bull. Chi. Herpetol. Soc. 39: 161-164. Same text appears in Lee, D.S. (2005): Reptiles and amphibians introduced to the Bahamas; a potential conservation crisis. Bahamas J. Sci. 12(2): 2-6. Lee, D.S., Clark, M.K. (1995): Seabirds of the Exumas Land and Sea Park. Part 2. Bahamas J. Sci. 2(2): 15-21. Lee, D.S., Carey, E. (2001): Conservation concerns facing the Inagua slider. Turtle Tortoise Newsl. 3: 7-9. Lee, D.S., Ross, P. (2001). The Cat Island Turtle a reptile of problematic origin; including a bibliography of the genus Trachemys in the West Indian region. In: Proceedings of the 8th Symposium on the Natural History of the Bahamas, p. 36-74. Clark-Smith, C., Smith, G., Eds, San Salvador, Gerace Research Center. Little, B.G., Buckley, D.K., Jefferiss, A., Stark, J., Young, R.N. (1976): Land resources of the Commonwealth of the Bahamas. Volume 4a: Andros Island. Land Resources Division, Tolworth Tower, Surrey, UK. LoBue, V., De Loache, J.S. (2008): Detecting the snake in the grass attention to fear-relevant stimuli by adults and young children. Psychol. Sci. 19: 284-289. Losos, J.B. (2009): Lizards in an evolutionary tree: Ecology and adaptive radiation of anoles (Organisms and Environments). Berkeley, University of California Press.
Conservation of amphibians and reptiles in The Bahamas
85
Losos, J.B., Spiller, D. (1999): Differential colonization success and asymmetrical interactions between two lizard species. Ecology 80: 252-258. Losos, J.B., Warheit, K.I., Schoener, T.W. (1997): Adaptive differentiation following experimental island colonization in Anolis lizards. Nature 387: 70-73. Losos, J.B., Schoener, T.W., Spiller, D.A. (2003): Effect of immersion in seawater on egg survival in the lizard Anolis sagrei. Oecologia 137: 360-362. Losos, J.B., Schoener, T.W., Spiller, D.A. (2004): Predator-induced behaviour shifts and natural selection in field experimental lizard populations. Nature 432: 505-508. Lowe, A.M., Sullivan-Sealy, K. (2003): Establishing sustainable tourism in the Exuma Cays, Bahamas. Bahamas J. Sci. 11: 17-24. Lynch, J.D., Duellman, W.E. (1997): Frogs of the genus Eleutherodactylus in western Ecuador. Systematics, ecology, and biogeography. Special Publication. Nat. Hist. Mus., Univ. Kansas 23: 1-236. Malone, C.L., Wheeler, T., Taylor, J.F., Davis, S.K. (2000): Phylogeography of the Caribbean Rock Iguana (Cyclura): Implications for conservation and insights on the biogeographic history of the West Indies. Mol. Phylogenet. Evol. 17: 269-279. Malone, C.L., Knapp, C.R., Taylor, J.F., Davis, S.K. (2003): Genetic consequences of Pleistocene fragmentation: Isolation, drift, and loss of diversity in rock iguanas (Cyclura). Conserv. Genet. 4: 1-15. McKinnen, D. (1804): A tour through the British West Indies, in the years 1802 and 1803 giving particular account of the Bahama Islands. London, J. White. Mealey, B.K., Parks, G.M., Schooley, J., Rothchild, J., Roth, L., Snodgrass, D., Baldwin, J.D. (2002): Discovery of freshwater turtles in Bimini, Bahamas. Bahamas J. Sci. 9(2): 58-62. Meshaka, W.E., Jr. (1995): Geographic Distribution: Hemidactylus garnoti. Herpetol. Rev. 26: 108. Mitchell, N.C. (1999): Effect of introduced ungulates on density, dietary preferences, home range, and physical condition of the iguana, Cyclura pinguis on Anegada. Herpetologica 55: 7-17. Morgan, G.S. (1989): Fossil Chiroptera and Rodentia from the Bahamas, and the historical biogeography of the Bahamian mammal fauna. In: Biogeography of the West Indies: Past, Present, and Future, p. 685-740. Woods, C.A., Ed., Gainesville, Sandhill Crane Press. Munn, C.A. (1992): Macaw biology and ecotourism, or when a bird in the bush is worth two in the hand. In: New World parrots in crisis: Solutions from conservation biology, p. 47-72. Beissinger, S.R., Snyder, N.F.R., Eds, Washington, Smithsonian Institution Press. Newsom, L.A., Wing, E.S. (2004): On land and sea: Native American uses of biological resources in the West Indies. Tuscaloosa, The University of Alabama Press. Olson, S.L., Pregill, G.K. (1982): Fossil vertebrates from the Bahamas. In: Smithsonian Contributions to Paleobiology, No. 48, p. 1-7. Olson, S.L., Ed., Washington, Smithsonian Institution Press. Pieper, L., Pasachnik, S., Hines, K. (2009): John Iverson: Researcher, teacher, friend. IRCF Rep. Amphib. Conserv. Nat. Hist. 16: 48-53. Roelants, K., Gower, D.J., Wilkinson, M., Loader, S.P., Biju, S.D., Guillaume, K., Moriau, L., Bossuyt, F. (2007): Global patterns of diversification in the history of modern amphibians. Proc. Nat. Acad. Sci. USA 104: 887-892. Scheffers, A., Scheffers, S. (2006): Documentation of the impact of Hurricane Ivan on the coastline of Bonaire (Netherlands Antilles). J. Coastal Res. 22: 1437-1450. Schoener, T.W., Spiller, D.A., Losos, J.B. (2001): Natural restoration of the species-area relation for a lizard after a hurricane. Science 294: 1525-1528. Schoener, T.W., Spiller, D.A., Losos, J.B. (2004): Variable ecological effects of hurricanes: The importance of seasonal timing for survival of lizards on Bahamian islands. Proc. Natl. Acad. Sci. USA 101: 177-181. Schoener, T.W., Losos, J.B., Spiller, D.A. (2005): Island biogeography of populations: An introduced species transforms survival patterns. Science 310: 1807-1809.
86
C.R. Knapp et al.
Schwartz, A., Thomas, R. (1975): A checklist of West Indian amphibians and reptiles. Carnegie Mus. Nat. Hist. Spec. Publ. 1: 1-216. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. University of Florida Press, Gainesville. Seidel, M.E. (1988): Revision of the West Indian emydid turtles (Testudines). Am. Mus. Novit. 2918: 1-41. Seidel, M.E. (1996): Current status of biogeography of the West Indian turtles in the genus Trachemys (Emydidae). In: Contributions to West Indian Herpetology: A Tribute to Albert Schwartz, p. 169174. Powell, R., Henderson, R.W., Eds, Society for the Study of Amphibians and Reptiles, Ithaca. Seidel, M.E., Adkins, M.D. (1987): Biochemical comparisons among West Indian Trachemys (Emydidae: Testudines). Copeia 1987: 485-489. Singer, F.J., Swank, W.T., Clebsch, E.E. (1984): Effects of wild pig rooting in a deciduous forest. J. Wildlife Manage. 48: 464-473. Smith, G.R., Iverson, J.B. (2006): Changes in sex ratio over time in the endangered iguana Cyclura cychlura inornata. Can. J. Zool. 84: 1522-1527. Smith, G.R., Pieper, L., Iverson, J.B. (2008): Leiocephalus carinatus. Sap feeding. Herpetol. Rev. 39: 228. Smith, G.R., Pieper, L., Iverson, J.B. (2009a): Osteopilus septentrionalis. Successful reproduction. Herpetol. Rev. 40: 207. Smith, G.R., Hines, K., Pasachnik, S., Pieper, L., Phelps, E., Iverson, J.B. (2009b): Cyclura cychlura inornata. Cause of mortality. Herpetol. Rev. 40: 341-343. Spiller, D.A., Agrawal, A.A. (2003): Intense disturbance enhances plant susceptibility to herbivory: Natural and experimental evidence. Ecology 84: 890-897. Spiller, D.A., Losos, J.B., Schoener, T.W. (1998): Impact of a catastrophic hurricane on island populations. Science 281: 695-697. Steadman, D.W., Pregill, G.K., Burley, D.V. (2002): Rapid prehistoric extinction of iguanas and birds in Polynesia. Proc. Natl. Acad. Sci. USA 99: 3673-3677. Steadman, D.W., Franz, R., Morgan, G.S., Albury, N.A., Kakuk, B., Broad, K., Franz, S.E., Tinker, K., Pateman, M.P., Lott, T.A., Jarzen, D.M., Dilcher, D.L. (2007): Exceptionally well preserved late Quaternary plant and vertebrate fossils from a blue hole on Abaco, The Bahamas. Proc. Natl. Acad. Sci. USA 104: 19897-19902. Taylor, R.B., Hellgren, E.C. (1997): Diet of feral hogs in the western South Texas Plains. Southwest. Nat. 42: 33-39. Thomas, R., Hedges, S.B. (2007): Eleven new species of snakes of the genus Typhlops (Serpentes: Typhlopidae) from Hispaniola and Cuba. Zootaxa 1400: 1-26. Tinkle, D.W. (1979): Long-term field studies. Bioscience 29: 717. Tisdell, C., Wilson, C. (2002): Ecotourism for the survival of sea turtles and other wildlife. Biodivers. Conserv. 11: 1521-1538. Tolson, P.J. (2000): Control of introduced species. In: West Indian Iguanas: Status Survey and Conservation Action Plan, p. 86-89. Alberts, A.C., Ed., Gland, Switzerland, IUCN. Tolson, P.J., Henderson, R.W. (1993): The natural history of West Indian boas. R & A Publishing Limited, Taunton, England. Tolson, P.J., Henderson, R.W. (2006): An overview of snake conservation in the West Indies. Appl. Herpetol. 3: 345-356. Towns, D.R., Parrish, G.R., Tyrrell, C.L., Ussher, G.T., Cree, A., Newman, D.G., Whitaker, A.H., Westbrooke, I. (2007): Responses to tuatara (Sphenodon punctatus) to removal of introduced Pacific rats from islands. Conserv. Biol. 21: 1021-1031. United States Department of Justice. (1998): United States Attorney Southern District of Florida, News Release October 30. United States Department of Justice. (2001): United States Attorney Southern District of Florida, News Release July 25.
Conservation of amphibians and reptiles in The Bahamas
87
Valiulis, J.M., Hines, K.N., Iverson, J.B. (2003): Adventures of the Iguana Patrol. In: Islands and the Sea: Essays on Herpetological Exploration in the West Indies, p. 39-48. Henderson, R.W., Powell, R., Eds, Society for the Study of Amphibians and Reptiles, Ithaca. Vitt, L.J., Pianka, E.R. (1994): Lizard Ecology: Historical and Experimental Perspectives. Princeton, Princeton University Press. Wake, D. (1991): Declining amphibian populations: A global phenomenon. Science 253: 860. Walpole, M.J., Goodwin, H.J. (2001): Local attitudes towards conservation and tourism around Komodo National Park, Indonesia. Envir. Conserv. 28: 160-166. Walpole, M.J., Goodwin, H.J., Ward, K.G.R. (2001): Pricing policy for tourism in protected areas: Lessons from Komodo National Park, Indonesia. Conserv. Biol. 15: 218-227. Walpole, M.J., Leader-Williams, N. (2002): Tourism and flagship species in conservation. Biodivers. Conserv. 11: 543-547. White, L. (2008): Sea the value: Quantifying the value of marine life to divers. Unpublished Master’s thesis. Durham, Duke University.
Accepted: August 11, 2010 (AH).
The herpetofauna of Barbados: Anthropogenic impacts and conservation status Angela Fields, Julia A. Horrocks1 Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Bridgetown BB11000, Barbados 1 Corresponding author; e-mail:
[email protected] Abstract. A maximum of fifteen extant terrestrial species of herpetofauna may be found in Barbados today. Four are endemic, three are native, and eight are introduced or probably introduced. Two lizards, Anolis sagrei and Ameiva ameiva, and two snakes Ramphotyphlops braminus and Mastigodryas bruesi are introductions that have occurred in the last few decades. Two endemics, the snake Liophis perfuscus and the gecko Phyllodactylus pulcher, may be extinct, while new sightings have been made of the endemic fossorial worm snake, Tetracheilostoma carlae. Both amphibian species are abundant and widely distributed; Rhinella marina, being highly invasive. The threats to terrestrial herpetofauna include habitat alteration and loss, deliberate harm, introduced species, and potentially, collection for the pet trade. Three marine turtles, Chelonia mydas, Dermochelys coriacea and Eretmochelys imbricata nest on Barbados. Not previously reported to nest on Barbados, the number of nests made by Chelonia mydas is increasing. Nesting habitat for the large population of hawksbills, Eretmochelys imbricata, on the west and south coasts of the island is threatened by coastal development. Key words: Amphibians; Barbados; Leptotyphlops carlae; reptiles; sea turtles; snakes Tetracheilostoma carlae.
Introduction Barbados is a small island (430 km2 ) of low relief, lying to the east of the Lesser Antilles island chain (N 13◦ 52 W 59◦ 32 ). It sits on an accretionary prism, or ridge, formed by the convergence of two tectonic plates; Barbados being the only part of the ridge that was pushed up high enough to allow coral growth and eventually to emerge above sea level. About 85% of the island is composed of a porous Pleistocene coral cap that rises in a series of terraces to the highest point of approximately 340 m. The core of the island dates back 20-50 mya, but the coral cap is probably less than 1 million years old (Speed, 1994; but see Thorpe et al. 2005), making it younger than the neighbouring volcanic islands to the west.
90
A. Fields, J.A. Horrocks
Insights into the herpetofauna extant in Barbados prior to human settlement are provided by Ray’s (1964) descriptions of fossils found at Spring Bay, St. Philip. Early mentions of the island’s post-European colonization herpetofauna are those made by Ligon (1657), Hughes (1750) and Schomburgk (1848), and lists have been provided since by Feilden (1889a, 1889b), Grant (1959), Schwartz and Henderson (1988, 1991), Corke (1992) and Fields and Horrocks (2009). From these lists we know that several species have declined in abundance (e.g., green and hawksbill sea turtles), and that at least two species, a giant Geochelone tortoise and an iguana (Ray 1964), and possibly five species, if Liophis perfuscus, Phyllodactylus pulcher and Mabuya mabouya are included, have been extirpated or have gone extinct. Several new species have also been introduced in the last fifty years (e.g., Underwood et al., 1999; Watson, 2008). Several articles have been written on the amphibians and reptiles of Barbados, particularly on the whistling frog (e.g., Ovaska 1991a, 1991b, 1992), snakes (e.g., Underwood et al., 1999; Hedges, 2008), and the sea turtles (e.g., Horrocks and Scott, 1991; Beggs et al., 2007; Browne et al., 2009). This paper is a modified version of an annotated checklist of the herpetofauna of Barbados that appeared in the Journal of the Barbados Museum and Historical Society in 2009. The purpose of the current paper is to review the anthropogenic impacts on the herpetofauna in Barbados, and to comment on the conservation status of species.
Major Anthropogenic Impacts on the Herpetofauna in Barbados Habitat alteration and loss Barbados was first settled by Pre-Ceramic people around 4000 years ago (Drewett, 2002, 2004). However, most of these early settlements were on the coast and it was not until European settlement in the sixteenth and seventeenth centuries that large scale modification of the interior environment began. Early descriptions of the island suggest a heavily forested landscape (Colt, 1631; Ligon, 1657), with vegetation extending down to the shore (Watts, 1966). Today only relics of this vegetation remain; in Turner’s Hall Wood, in patches at the base of Hackleton’s Cliff and in some gullies (Beard, 1949; Carrington et al., 2003). The last remaining significant wetland areas are Graeme Hall Swamp and Chancery Lane Swamp on the south coast, and Long Pond and Green Pond on the east coast, although there are small areas of highly disturbed wetlands on the west coast (e.g., Holetown Hole). The original forests of Barbados were largely cleared for agricultural purposes, firstly to produce food for the settlers and later to cultivate sugar cane, so that by 1665 most of the forest cover had been destroyed (Watts, 1966). The acreage of land under sugarcane cultivation has fallen steadily since, and within the past 40 years, the total area of land under sugarcane cultivation is estimated to have decreased by approximately 75%. Fueled by an increasing demand on land for housing and recreational activities, much of the former agricultural land has been transformed
The herpetofauna of Barbados
91
into pasture and secondary woodlands, residential developments and golf courses. Helmer et al. (2008) have estimated that scrub/forest cover increased by over 900% between 1945 and 2000, while Bunce (2007) has described the construction of villas, golf courses and residential enclaves as the ‘leisuring’ of the rural landscape in Barbados, and as profound a transformation of the Barbadian landscape as that which occurred during the development of the plantation environment in the 1600s. Nevertheless, as a consequence of increased woodland cover and decreased use of agro-chemicals, habitat quality for some herpetofauna may have increased in recent decades. Introduction of alien species Since human settlement, Barbados has experienced introductions of alien species that are likely to have had a significant impact on the island’s native herpetofauna. Notable among these are introductions of predatory mammalian species. These include rats (Rattus norvegicus and R. rattus) whose arrival date is unknown, green monkeys (Chlorocebus sabaeus) and raccoons (Procyon lotor), both of which are assumed to have arrived soon after settlement in 1627, and mongooses (Herpestes javanicus) which were introduced prior to 1879 to control rats. These are all highly adaptable species with opportunistic feeding habits, and some are considered highly invasive, e.g., mongooses have been implicated in the extirpation of herpetofauna and birds elsewhere in the Caribbean (see Henderson, 1992). Green monkeys in Barbados are known to feed on small lizards (Horrocks, 1986), and raccoons (extirpated from Barbados during the 1960s) are known to eat a wide range of foods, including frogs, snakes and turtle eggs (Stuewer, 1943). The deliberate introduction of the cane toad, Rhinella marina, circa 1833 (Esteal, 1981; Estoup et al., 2001) to control sugar cane insect pests, increased the number of amphibian species on the island to two, but this species of toad may consume small vertebrates such as lizards (Gray et al., 2009) and may compete with insectivorous species (Shine, in press). The widespread development of tourism infrastructure over the past 30 years, along the west and south coasts in particular, has continued the degradation of natural habitats and has afforded new opportunities for the introduction of alien species on construction materials and nursery plants. Over-exploitation and deliberate harm Sea turtles have been exploited since Barbados was first settled (Drewett, 1991); and objects made from carapacial bones are displayed in the Barbados Museum. Sea turtles are still the only forms of herpetofauna in Barbados protected from exploitation by legislation. Nesting turtles and eggs of all species have been protected since 1904, but penalties were an insufficient deterrent (Horrocks, 1992). In 1998, an indefinite moratorium was instigated through the Fisheries (Management) Regulations, 1998 (Fisheries Act Cap. 391), with penalties of up to US$25,000 and up to 2 years in prison.
92
A. Fields, J.A. Horrocks
Snakes and lizards, when seen in or around homes, are frequently killed, often due to fears that they are poisonous. International trade All species of sea turtles are listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and the redfooted tortoise, Geochelone carbonaria, is listed on Appendix II. Commercial trade in Appendix I species is prohibited and trade of Appendix II species in Barbados is controlled through the International Trade in Endangered Species of Wild Fauna and Flora Act, 2006-3. This Act also regulates trade in some species, native or naturalised, that are not listed in the CITES appendices, but whose populations may also be or become threatened by international trade. Species whose trade is regulated under this act are the whistling frog Eleutherodactylus johnstonei, the lizards Phyllodactylus pulcher, Hemidactylus mabouia, Anolis extremus, Kentropyx borckiana and Gymnophthalmus underwoodi, and the snakes Liophis perfuscus, Mastigodryas bruesi and Leptotyphlops bilineatus. Given the widespread attention that Leptotyphlops carlae (since reclassified as Tetracheilostoma carlae, Adalsteinsson et al., 2009) received upon the announcement that it is the smallest snake in the world (Hedges, 2008), the name in the legislation needs amending in order to provide the protection that T. carlae may need from collectors. The composition of herpetofauna in Barbados has been affected in recent years by the deliberate or accidental release of reptiles that have been introduced into Barbados as pets (e.g., Ameiva ameiva and the red-eared slider Trachemys scripta elegans). Ameiva ameiva is now breeding in the wild (see below). Although T. s. elegans has been occasionally encountered in the wild, the existence of a breeding population is doubtful. Some exotic species of snakes have been seen and/or killed in the wild in Barbados in recent years, and fears of large pythons and an anaconda, illegally acquired and reportedly released into the wild, led to the setting up of a Government-sponsored snake task force to respond to sightings and to attempt to recapture snakes. A breeding population of the Cuban iguana, Cyclura nubila, is held at the Barbados Wildlife Reserve, St. Peter. Habitat protection There is currently no legislation to protect habitat for rare or endemic terrestrial herpetofauna in Barbados. Legal protection of corals and beaches through relevant sections of the Coastal Zone Management Act, 1998-39, offers some protection to foraging and nesting habitats of sea turtles, but in general specific habitat protection has lagged behind species protection for sea turtles. Consideration is currently being given to listing the major hawksbill nesting beach at Needham’s Point, St. Michael, as a restricted area, subject to constraints on building and other activities, under Part III Preservation and Enhancement of Marine Areas of the Act.
The herpetofauna of Barbados
93
Conservation Status of Herpetofauna of Barbados Amphibians Barbados receives an average of 140 cm of rain per year, but due to its porous limestone cap, it has almost no permanently flowing, above-ground rivers, and scarce standing water. Amphibians may not have been able to reach Barbados naturally. This is borne out by Ligon (1657) who wrote, “Toads or frogs we have none”. Today, only one species of frog and one species of toad are present on the island. Eleutherodactylus johnstonei (Leptodactylidae). This is the most widely distributed frog in the Eastern Caribbean (Schwartz and Henderson, 1991; Kaiser and Hardy, 1994). Whether E. johnstonei is native to Barbados (Marsh, 1983; Corke, 1992) or introduced (Feilden, 1889a; Bayley, 1950; Kaiser, 1997), this frog is present throughout the island especially in disturbed habitats, e.g., cane fields, gullies and other wooded areas, gardens, under leaf litter, and in the axils of bromeliads. Frogs have been observed in the empty shells of Megalobulimus oblongus (Schwartz, 1967), and eggs in the empty shells of the recently introduced giant African snail, Achatina fulica. Rhinella marina (Bufonidae). The cane toad (formerly known as Bufo marinus and Chaunus marinus) was introduced into Barbados from Guyana (Schomburgk, 1848; Easteal, 1981) to control sugar cane pests. Schomburgk (1848) described the toad as occurring in large numbers, but by the early 1900s loss of suitable habitats, in part through the clearing of gullies and reduction of plantation estate ponds, had resulted in a decrease in the number of cane toads on the island (Tucker, 1939). Today, however, toads are locally very abundant wherever water is present. The only confirmed predator of adult cane toads in Barbados are mongooses; the latter attacking the legs of the toad (J. Horrocks, pers. obs.). Reptiles The reptiles of Barbados include marine and terrestrial species. The island is relatively depauperate in terrestrial reptiles compared to most other islands in the Lesser Antilles (Corke, 1992). Chelonia mydas (Cheloniidae). Juvenile green turtles of 30-70 cm CCL (curved carapace length) are present in the waters surrounding Barbados throughout the year, but adults are rarely seen (Luke et al., 2004). Green turtles are herbivorous and in the Caribbean they feed primarily on the sea grass Thalassia testudinum. Sea grasses are relatively rare around Barbados, perhaps explaining the rarity of subadults and adults. The best developed sea grass areas for green turtles are found on the south coast and in protected bays on the east coast, e.g., Bath and Consett
94
A. Fields, J.A. Horrocks
Bay. Prior to 2005, there were no documented incidents of green turtles nesting in Barbados. Since then, there have been confirmed reports of 10-15 nests per year, mainly on south east coast beaches, e.g., Foul Bay, Bottom Bay and Long Beach and occasionally on the east coast, e.g., Morgan Lewis. Green turtles are the primary species that aggregate at the popular “Swim with the Turtle” sites. These tourist attractions are maintained by daily provisioning of the turtles with fish. The catamarans and yachts that carry visitors on day cruises feed the turtles and allow visitors to swim with them. Although green turtles are naturally herbivorous, they are clearly also opportunistic in their feeding activity. These animals are exposed to potential collisions with boats and props, and several show scarring. The effects of the provisioned diet on these turtles are being monitored through a collaborative initiative between the Barbados Sea Turtle Project (BSTP) of the University of the West Indies (UWI) and Ross University Veterinary School, St. Kitts. Tagging of these animals is undertaken as part of the BSTP’s monitoring programme (Horrocks et al., 2007), and a tag from an animal was returned from the Miskito Cays in Nicaragua in 2009, suggesting that animals can emigrate far from Barbados to settle on other feeding grounds. Their learned association of food with boats may make them vulnerable to turtle fisheries elsewhere in the region, e.g., Grazette et al. (2007). Green turtles strand several times a year on the beaches of Barbados, mainly on the east coast of the island. Causes are usually unknown but drowning in fishing nets is often suspected. Fibropapillomatosis (FP) has been observed in several individuals, but the distribution of affected turtles is confined to very specific areas of the east coast (Gamache and Horrocks, 1991). The incidence of green turtles stranding with FP is now rare. However, this may be due to the closure of the fishery in 1998, which has meant that fishers are no longer catching and examining animals closely. Eretmochelys imbricata (Cheloniidae). In the early 1990s, approximately 50 hawksbills nested in Barbados each year (Horrocks, 1992). The numbers of nesting females have increased significantly since then, with most recent counts being over 400 females per year (Beggs et al., 2007; BSTP unpublished data). The Barbados rookery is now one of the two largest in the Wider Caribbean (Yucatan, Mexico being the largest), contributing young turtles to foraging grounds throughout the region (Browne et al., 2009). Hawksbills feed on reef-associated sponges in the Caribbean region (Meylan, 1988). Foraging by hawksbills around Barbados is likely to be more or less coincident with the distribution of coral reefs around the island. Size classes from 23 cm to 102 cm CCL are seen in Barbados’ nearshore waters, but adult-sized animals only during the breeding season. Abreu-Grobois et al. (2006) studied the genetic composition of juvenile hawksbill turtles feeding around Barbados. This population is a mixed stock, with individuals originating mainly from nesting beaches within the
The herpetofauna of Barbados
95
Caribbean (including Barbados), but with small numbers originating in West Africa. Work to further define the stock origins is ongoing (D. Browne, in prep.). Following the moratorium on sea turtle capture in 1998, the threats to hawksbill recovery have shifted away from over-harvest. Although poaching of nesting turtles still occurs on isolated beaches, the more serious threat to long term population stability is the loss and deterioration of nesting habitat. Disorientation by coastal lighting is a major cause of mortality of newly hatched turtles (Horrocks, 2001) and to a lesser extent, nesting females. The latter have been killed crossing roads and falling into ditches after failing to successfully orient towards the sea. Erosion of beaches due to poor development practices and rising sea level has resulted in the washing out of a high percentage of nests in recent years. Three additional species of chelonid sea turtles, Caretta caretta, Lepidochelys kempi and Lepidochelys olivacea have been occasionally observed in Barbados, either stranded on a beach, usually on the east coast and often with missing flippers, or landed by offshore fishers. A Kemp’s ridley (L. kempi), the most endangered of all sea turtle species, was landed and killed illegally in April 2010. Dermochelys coriacea (Dermochelyidae). Nesting by leatherbacks is much rarer in Barbados than that by hawksbills. Between 100 and 200 nests are made by leatherbacks annually, between April and June, primarily on the remote and high energy Atlantic beaches of the east coast between Cattlewash and Pico Tenerife (Beggs et al., 2006). Nests are occasionally made on the west and south coasts of Barbados too. The evidence currently available from satellite tracking in the western Atlantic suggests that adults engage in routine breeding migrations from the cold temperate North and North-East Atlantic waters to the Caribbean (e.g., Eckert, 2006). The leatherback is therefore not resident around Barbados, but travels to these waters only during the nesting season. Although it has been illegal to kill all species of nesting turtle or to take their eggs since 1904, leatherbacks were seemingly rarely eaten anyway relative to other sea turtle species, as the meat was not considered as palatable (Horrocks, 1992). Leatherback juveniles and adults occasionally strand on the east coast, including some very small and rarely seen size classes (Horrocks, 1989). Strandings are usually of animals missing flippers or heads, presumably caused by predation in the smaller animals, but by interactions with fishing gear and fishers in the case of adults. Their habit of nesting on the more isolated east coast, high wave energy beaches in Barbados has meant that they have not been as seriously affected by coastal development as has the hawksbill turtle. Their nesting beaches are however contaminated with ocean-borne garbage and discarded fishing gear, which has sometimes resulted in entanglement of turtles and obstruction of nests. Geochelone carbonaria (Testudinidae). The red-footed tortoise was probably introduced to Barbados after European colonization (Censky, 1988). Although the
96
A. Fields, J.A. Horrocks
existence of a breeding population outside of captivity is unlikely, occasionally adult individuals are seen in gullies. The largest captive population is held at the Barbados Wildlife Reserve, St. Peter. The most recent estimate of the population size at the Reserve, based on the last census in December 2008, is 550 individuals (Carlisle Sutton, pers. comm.). Many tortoises are kept as pets and hundreds, mostly small juveniles, are exported from Barbados each year to supply the pet trade, e.g., in 2007, 751 juveniles and two adults were exported (Govt. of Barbados, 2008). Hemidactylus mabouia (Gekkonidae). Locally known as the house lizard, wood slave or poison lizard, this gecko is very common island-wide in edificarian habitats. It is a nocturnal Old World species, thought to have been introduced from Africa during the Slave Trade era. It can also be found away from buildings, in crevices in cliffs, under rocks and tree bark, and in caves. Phyllodactylus pulcher (Gekkonidae). This leaf-toed gecko is endemic to Barbados and is the generitype for the genus (Schwartz, 1979). At the time of his writing, Schwartz knew of no recent collections and was unable to collect any himself. However, a specimen was subsequently photographed in the early 1990s at Ragged Point, St. Philip (by J. Horrocks, fig. 1), These photographs showed the bifurcate toes, the brown line extending from the nostril through the eye to the shoulder and the banding of the tail, as described by Dixon (1967). The specimen was seen at night, indicating a nocturnal habit characteristic of many geckos. It has not been seen in recent times and is consequently of significant conservation concern (Weiss and Hedges, 2007).
Figure 1. Phyllodactylus pulcher. (Photograph by J. Horrocks. Colour original — see www.ahailey.f9. co.uk/appliedherpetology/cariherp.htm.)
The herpetofauna of Barbados
97
Gymnophthalmus underwoodi (Gymnophthalmidae). First reported from Barbados by Grant (1958), this unisexual, parthenogenetic microteiid (Hardy et al., 1989) has been subsequently reported from Guadeloupe, St. Vincent, Trinidad and Tobago, Guyana and Surinam (Schwartz and Henderson, 1991), and more recently in Antigua and Barbuda (Censky and Lindsay, 1997). Though cryptic in habit, it is often seen moving swiftly through leaf litter or grass, around human habitation, and in rural as well as coastal areas. It has been observed climbing low walls to get from one grassy area to another. Anolis extremus (Polychrotidae). Known locally as the green or tree lizard. While these lizards are most commonly seen in trees, on the trunk and on larger branches in the canopy, on low shrubs, on walls of buildings, fences and on the ground, Nummelin (1992) reported that juveniles were commonly found amid forest floor vegetation. The green lizard is abundant in all parishes, in woodlands, gullies and residential areas, but seldom in grasslands. Anolis extremus breeds year round with a peak in the rainy season (Nummelin, 1992). It is preyed on by mongooses (Henderson, 1992), green herons (Butorides virescens), cattle egrets (Bubulcus ibis), Carib grackles (Quiscalus lugubris), the grey kingbird (Tyrannus dominicensis), the centipede (Scolopendra subspinipes) and domestic cats. Anolis sagrei (Polychrotidae). The brown anole is native to Cuba and the Bahamas, but has been introduced to Jamaica, the Cayman Islands, Mexico, Florida (Campbell, 2000), Grenada (Green et al., 2002), and recently to Barbados, although the date of introduction is unknown. It has been observed at three locations in Barbados: Pleasant View, St. Michael, Prospect, St. James and Castle Grant, St. Joseph. It was observed (by A. Fields) at the St. Michael location in April 2008, but may have been present at the St. Joseph site prior to this. A. sagrei is observed on low shrubs, piles of garden cuttings, lawns, low walls and on fences; its habitat overlapping with that of Anolis extremus. Adult male A. sagrei have been observed head bobbing, displaying the red gular flap, and erecting the crest in the presence of Anolis extremus (see fig. 2). Mabuya mabouya (Scincidae). Based on the existence of two specimens in the British Museum of Natural History taken in the 1800s, the skink was likely to have been native to Barbados (B. Hedges, pers. comm.). However, it has not been recorded in Barbados since, and is presumed to be locally extinct. Ameiva ameiva (Teiidae). An introduced population, thought to have originated from Trinidad, now exists on the island (Watson, 2008). They are the descendents of three pet lizards that were intentionally released into the wild in the late 1990s (Corrie, 2001). The species at present appears confined to the parishes of St. Michael and Christ Church. In some areas Ameiva coexists with a native macroteiid, Kentropyx borckiana.
98
A. Fields, J.A. Horrocks
Figure 2. Anolis sagrei. (Photograph by Angela Fields. Colour original — see www.ahailey.f9. co.uk/appliedherpetology/cariherp.htm.)
Kentropyx borckiana (Teiidae). Also found in northeastern South America (Schwartz and Henderson, 1991), the species was reported from Barbados in the1800s (Cope, 1862), and was deemed ‘quite common’ at some locations (Feilden, 1889a). Its numbers apparently decreased to very low levels in subsequent years, for though Grant (1959) reported its presence on the island in the late 1950s, the species appeared to be unknown to locals until the capture of a specimen in 1988 that merited an article in a local newspaper requesting identification of the “strange reptile” (The Barbados Advocate, 1988). Corke (1992) reported it as rare. No formal survey has been conducted, but Kentropyx is now a relatively common sight in the parishes of St. Michael, St. James, St. Joseph, Christ Church and St. Philip. It is not known whether the species is native to Barbados, nor whether the population that now exists is the result of a recent introduction or a resurgence of the original population. Being parthenogenetic, it is capable of rapid population increases. It thrives in residential areas, is terrestrial, but can be found on low shrubs and will climb low walls. Its diet on Barbados is not fully known, but includes insects and juvenile green anoles, Anolis extremus. It is preyed on by domestic cats, and presumably mongooses. Tetracheilostoma carlae (Leptotyphlopidae). This small threadsnake (fig 3.) was reported from Barbados 120 years ago as Stenostoma bilineatum Sch (Feilden, 1889b). Emsley (1966) confirmed its presence on the island from a specimen found in the parish of St. John, calling it Leptotyphlops bilineata. On the basis of morphological and molecular data, Hedges (2008) recognized the Barbadian snake as an endemic species, separate from Leptotyphlops bilineatus (Martinique) and L. breuili (St. Lucia). It has since been re-classified as Tetracheilostoma carlae (Adalsteinsson et al., 2009). While the existence of a small “two-lined” snake was known to some Barbadians, Hedges (2008) noted that it had only actually been documented from locations in St. John and St. Joseph. Examination of a photograph taken in 2005, of a snake found
The herpetofauna of Barbados
99
Figure 3. Tetracheilostoma carlae. (Photograph by Angela Fields. Colour original — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm.)
under a rock at Hillaby, St. Thomas, gives a third locality for the species. It is known that threadsnakes are fossorial and have a diet of ants and termites (Hedges, 2008), but little further is known of the biology of T. carlae, except that it is bisexual and probably lays only one egg in a clutch (Hedges, 2008). Its cryptic habit makes it uncommonly encountered, and little is known about its abundance. More effort is needed to assess the distribution of this snake, characterize its habitat requirements, and to ensure that the species and its habitats are adequately protected. An additional threat to the species is the introduction of a similar sized blind snake, Ramphotyphlops braminus (see below). The latter species is not readily distinguished by the untrained eye, but may be more common and may create difficulties for initiatives aimed at protecting T. carlae, and regulating R. braminus. Ramphotyphlops braminus (Typhlopidae). Referred to as the flowerpot snake, this small blind snake, native to Southeast Asia is now introduced into Barbados, most likely with horticultural imports. The date of its arrival is unknown, but must be over ten years ago, as photographs of the snake taken in the late 1990s exist. Specimens have been found in St. Michael, St. James, St. Thomas, St. Peter, St. Joseph and Christ Church. It is seen in garden beds, and occasionally in houses. Ramphotyphlops braminus is parthenogenetic (Nussbaum, 1980) and lays up to 7 eggs (Vitt and Caldwell, 2009). It is therefore capable of rapid population increase, whereas Tetracheilostoma carlae, with its clutch size of one (Hedges, 2008), is not. Its diet of ants and termites is the same as that of T. carlae, making R. braminus a very plausible, and potentially serious, competitor of the Barbadian endemic. Liophis perfuscus (Colubridae). The presence of this snake on the island prior to European settlement was established by Ray (1964), and Liophis is generally believed to be the snake referred to in Ligon (1657), but see Underwood et al. (1999). By the time Feilden (1889a) reported on the herpetofauna of Barbados,
100
A. Fields, J.A. Horrocks
the snake was rare, a decline in its population that continued over the years. Barbour (1930) and Westermann (1953), as cited in Emsley (1963), considered it to be extinct at the time they wrote. Subsequently, Emsley (1963) reported the “re-discovery” of the species in the north-east of the island, describing it as locally common. However, Emsley’s is the last recorded sighting and collection of Liophis. Despite several surveys in the areas where Liophis was known to occur, no specimens have been found and it is assumed to be extinct. Mastigodryas bruesi (Colubridae). This semi-arboreal snake is believed to have been introduced into Barbados 30-40 years ago, possibly with banana plants originating in St. Vincent (Underwood et al., 1999). Once restricted to a small area located within the parishes of St. John, St. Joseph and St George in the east of the island (Underwood et al., 1999), and overlapping with the range of both Liophis perfuscus and Tetracheilostoma carlae, the range of Mastigodryas on the island now seems to be expanding. Specimens have recently been observed in St. Thomas. The possibility exists that the decline in L. perfuscus may have been partly attributable to the introduction of M. bruesi.
Conclusion Although monitoring programmes have provided data on the status of sea turtles nesting in Barbados and those foraging along its shores, little quantitative data exist on the distribution, abundance and ecology of Barbados’ terrestrial herpetofauna. The extirpations and possible extinctions of reptiles that have occurred over the past 50 years suggest that all remaining native species, with the possible exception of Anolis extremus, require careful monitoring and protection. This may include listing on the IUCN Red List, as appropriate. Effective protection of their habitats requires further research which should be conducted as a matter of urgency. Despite an increase in scrub/forested habitat suitable for reptiles, the impacts of recently introduced, more opportunistic species (e.g., the flower pot snake), is a matter of concern and may add an additional stressor on already depleted populations. Often surrounded by superstition, ignorance, and fear, conservation of this group is more challenging, requiring actions to increase public education, awareness and participation.
Acknowledgements. We would like to thank Jonathan Losos and Bob Powell for confirmation of the identity of Anolis sagrei; Blair Hedges, Adrian Hailey and an anonymous reviewer for commenting on earlier drafts. We thank Dr Karl Watson, Editor of the Journal of the Barbados Museum and Historical Society for allowing the paper to be reprinted in the revised form.
The herpetofauna of Barbados
101
References
Abreu-Grobois, A., Horrocks, J.A., Krueger, B., Formia, A., Browne, D., Beggs, J. (2006): Hawksbill turtles foraging around Barbados, West Indies, originate from rookeries both within and outside of the Wider Caribbean. In: Book of Abstracts. Twenty Sixth Annual Symposium on Sea Turtle Biology and Conservation. International Sea Turtle Society, Crete, Greece, p. 179. Frick, M., Panagopoulou A., Rees A.F., Williams, K., Compilers. Adalsteinsson, S.A., Branch, W.R., Trape, S., Vitt, L.J., Hedges, S.B. (2009): Molecular phylogeny, classification, and biogeography of snakes of the Family Leptotyphlopidae (Reptilia, Squamata). Zootaxa 2244: 1-50. Bayley, I. (1950): The whistling frogs of Barbados. J. Barbados Mus. Hist. Soc. 17: 161-170. Beard, J.S. (1949): Natural vegetation of the Windward and Leeward Islands. Oxford, Clarendon Press. Beggs, J.A., Horrocks, J.A., Kruger, B. (2006): Nesting of leatherback turtles, Dermochelys coriacea, in Barbados, West Indies. In: Proceedings of the Twenty Third Symposium on Sea Turtle Biology and Conservation, p. 169. Pilcher, N. J., Compiler, NOAA Technical Memorandum NMFSSEFSC-536. Beggs, J., Horrocks, J.A., Krueger, B. (2007): Increase in hawksbill Eretmochelys imbricata sea turtle nesting in Barbados, West Indies. Endang. Species Res. 3: 159-168. Browne, D.C., Horrocks, J.A., Abreu-Grobois, F.A. (2009): Population subdivision in hawksbill turtles nesting on Barbados, West Indies, determined from mitochondrial DNA control region sequences. Conserv. Genet. 11: 1541-1546. Bunce, M. (2007): The ‘leisuring’ of rural landscapes in Barbados; new spatialities and the implications for sustainability in small island states. Geoforum 39: 969-979. Campbell, T.S. (2000): The brown anole, Anolis sagrei. Institute for Biological Invasions invader of the month (http://invasions.bio.utk.edu/invaders/sagrei.html, July 08, 2009). Carrington, C.M.S., Horrocks, J.A. and Mahon, R. (2003): Gully Ecosystem Management Study: Report on the biodiversity conservation subcomponent. The Government of Barbados, Ministry of Physical Development and Environment. Censky, E.J. (1988): Geochelone carbonaria (Reptilia:Testudines) in the West Indies. Florida Sci. 50: 108-114. Censky, E., Lindsay, K. (1997): Note on Gymnophthalamus underwoodi (Antillean lizard). Herpetol. Rev. 28: 210. Colt, H. (1631): The voyage of Sir Henry Colt. In: Colonising expeditions to the West Indies and Guiana 1623-1667 (1925), p. 54-102. Harlow, V.T., Ed., London, Hakluyt Society. Corke, D. (1992): The status and conservation needs of the terrestrial herpetofauna of the Windward Islands (West Indies). Biol. Conserv. 62: 47-58. Cope, E.D. (1862): On the genera Panolopus, Centropyx, Aristelliger and Sphaerodactylus. Proc. Acad. Nat. Sci. Philadelphia 13: 494-500. Corrie, D.G. (2001): A guide to Barbadian Herpetofauna (Including Introduced Species). St. Michael, First Nations Publications. Dixon, J.R. (1962): The leaf-toed geckos, Genus Phyllodactylus, of Northeastern South America. Southwest. Nat. 7: 211-226. Drewett, P.L. (1991): Prehistoric Barbados. London, Archetype Publications. Drewett, P.L. (2002): Amerindian Stories: An Archaeology of early Barbados. Barbados, Barbados Museum and Historical Society. Drewett, P.L. (2004): Post-Saladoid society on Barbados. In: Late Ceramic Age Societies in the Eastern Caribbean, p. 215-230. Delpuech, A., Hofman, C.L., Eds, Paris Monographs in American Archaeology 14. BAR International Series 1273.
102
A. Fields, J.A. Horrocks
Eckert, S.A. (2006): High-use oceanic areas for Atlantic leatherback sea turtles (Dermochelys coriacea) as identified using satellite telemetered location and dive information. Marine Biology 149: 1257-1267. Emsley, M.G. (1963): The rediscovery of Cope’s Liophis perfuscus in Barbados. Copeia 1963: 577579. Emsley, M.G. (1966): The confirmation of the blind snake Leptotyphlops in Barbados. Copeia 1966: 125. Esteal, S. (1981): The history of introductions of Bufo marinus (Amphibia: Anura); a natural experiment in evolution. Biol. J. Linn. Soc. 16: 93-113. Estoup, A., Wilson, I., Sullivan, C., Cornuet, J.-M., Moritz, C. (2001): Inferring population history from microsatellite and enzyme data in serially introduced cane toads, Bufo marinus. Genetics 159: 1671-1687. Feilden, H.W. (1889a): Notes on the reptiles of Barbados. The Zoologist 13: 295-298. Feilden, H.W. (1889b): Addendum to the list of reptiles found in Barbados. The Zoologist 13: 352353. Fields, A., Horrocks, J.A. (2009): An annotated checklist of the herpetofauna of Barbados. J. Barbados Mus. Hist. Soc. 55: 263-283. Gamache, N., Horrocks, J.A. (1991): Fibropapilloma disease in green turtles around Barbados, West Indies. In: Proceedings of the 11th Annual Workshop on Sea Turtle Biology and Conservation, p. 158-160. Salmon, M., Wyneken, J., Eds, NOAA Technical Memorandum NMFS-SEFSC-302. Government of Barbados. (2008): Annual Report for Barbados 2007. CITES Management Authority Annual Report to the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Grant, C. (1958): A new Gymnophthalmus (Reptilia, Teidae) from Barbados. Herpetologica 14: 227228. Grant, C. (1959): Herpetology of Barbados, B.W.I. Herpetologia 15: 97-101. Grazette, S., Horrocks, J.A., Phillip, P., Isaac, C. (2007): An assessment of the marine turtle fishery in Grenada, West Indies. Oryx 41: 330-336. Gray, G., Massam, M., Pearson, D., Kruger, E. (2009): Pestnote: Cane toad. Govt. Western Australia, Dept. Agri. Food/Dept. Env. Conserv. Note 363. Green, B.T., Yorks, D.T., Parmer-Lee J.S., Jr., Powell, R., Henderson, R.W. (2002): Discovery of Anolis sagrei in Grenada with comments on its potential impacts on native anoles. Carib. J. Sci. 38: 270-272. Hardy, L.M., Cole, C.J., Townsend, C.R. (1989): Parthenogenetic reproduction in the Neotropical unisexual lizard, Gymnophthalmus underwoodi (Reptilia: Teiidae). J. Morphology 201: 215-234. Hedges, S.B. (2008): At the lower size limit in snakes: Two new species of thread snakes (Squamata: Leptotyphlopidae: Leptotyphlops) from the Lesser Antilles. Zootaxa 1841: 1-30. Helmer, E.H., Kennaway, T.A., Pedreros, D.H., Clark, M.L., Marcano-Vega, H., Tieszen, L.T., Ruzycki, T.R., Schill, S.R., Carrington, C.M.S. (2008): Land cover and forest formation distributions for St. Kitts, Nevis, St. Eustatius, Grenada and Barbados from decision tree classification of cloudcleared satellite imagery. Carib. J. Sci. 44: 175-198. Henderson W.R. (1992): Consequences of predator interactions on amphibians and reptiles in the Post-Columbus West Indies. Carib. J. Sci. 28: 1-10. Horrocks, J.A. (1986): Life history characteristics of a feral population of vervets (Cercopithecus aethiops sabaeus) in Barbados. Int. J. Primatol. 7: 31-47. Horrocks, J.A. (1989): Leatherback injured off Barbados, West Indies. Mar. Turtle Newsl. 46: 9-10. Horrocks, J.A. (1992): WIDECAST Sea Turtle Recovery Action Plan for Barbados. Eckert, K.L., Ed., CEP Technical Report No. 12. UNEP Caribbean Environment Programme, Kingston, Jamaica. 61 pp. Horrocks, J. (2001): Sea turtles and beachfront lighting: an interactive workshop for industry professionals and policy-makers in Barbados. Marine Turtle Newsletter 93: 18-19.
The herpetofauna of Barbados
103
Horrocks, J.A., Scott, N. (1991): Nest site location and nest success in the hawksbill turtle Eretmochelys imbricata in Barbados, West Indies. Mar. Ecol. Prog. Ser. 69: 1-8. Horrocks, J.A., Richardson, K.A., Krueger, B.H. (2007): Impacts of the “Swim with the Turtles” attractions on endangered green turtles (Chelonia mydas) around Barbados. Report to the Coastal Zone Management Unit, Government of Barbados. Hughes, G. (1750): The Natural History of Barbados. London. Kaiser, H. (1997): Origins and introductions of the Caribbean frog, Eleutherodactylus johnstonei (Leptodactylidae): Management and conservation concerns. Biodivers. Conserv. 6: 1391-1407. Kaiser, H., Hardy, J.D., Jr. (1994): Eleutherodactylus johnstonei. Cat. Amer. Amphib. Rept. 581: 1-5. Ligon, R. (1657): A true and exact history of the island of Barbadoes, London. Luke, K., Horrocks, J., Leroux, R., Dutton, P. (2004): Origins of green turtle feeding aggregations around Barbados, West Indies. Mar. Biol. 144: 799-805. Marsh, R.E. (1983): Unquestionable evidence that the whistling frog of Barbados is indigenous. J. Barbados Mus. Hist. Soc. 37: 68-71. Meylan, A.B. (1988): Spongivory in hawksbill turtles: A diet of glass. Science 239: 393-395. Nummelin, M. (1992): Seasonal occurrence of juvenile Anolis extremus Garman in forest patches in Barbados. J. Barbados Mus. Hist. Soc. 43: 24-31. Nussbaum, R.A. (1980): The brahminy blind snake (Ramphotyphlops braminus) in the Seychelles archipelago: Distribution, variation, and further evidence for parthenogenesis. Herpetologica 36: 215-221. Ovaska, K. (1991a): Reproductive phrenology, population structure, and habitat use of the frog Eleutherodactylus johnstonei in Barbados, West Indies. J. Herpetol. 25: 424-430. Ovaska, K. (1991b): Diet of the frog Eleutherodactylus johnstonei (Leptodactylidae) in Barbados, West Indies. J. Herpetol. 25: 486-488. Ovaska, K. (1992): Short- and long-term movements of the frog Eleutherodactylus johnstonei in Barbados, West Indies. Copeia 1992: 569-573. Ray, C.E. (1964): A small assemblage of vertebrate fossils from Spring Bay, Barbados. J. Barbados Mus. Hist. Soc. 31: 11-22. Schomburgk, R.H. (1848): The History of Barbados. London, Frank Cass Publishers. Schwartz, A. (1967): Frogs of the genus Eleutherodactylus in the Lesser Antilles. Stud. Fauna Curacao Carib. Isl. 24: 1-62. Schwartz, A. (1979): The Status of Greater Antillean Phyllodactylus (Reptilia, Gekkonidae). J. Herpetol. 13: 419-426. Schwartz, A., Henderson, R.W. (1988): West Indian Amphibians and Reptiles: A Check-list. Milwaukee Publ. Mus. Contrib. Biol. Geol: 74: 1-264. Schwartz, A., Henderson, R.W. (1991): Amphibians and reptiles of the West Indies: Descriptions, distributions, and natural history. Gainesville, University of Florida Press. Shine, R. (in press): The ecological impact of invasive cane toads (Bufo marinus) in Australia. Quart. Rev. Biol. Speed, R.C. (1994): Barbados and the Lesser Antillean forearc. In: Caribbean Geology: An Introduction, p. 179-192. Donovan, S.K., Jackson, T.A., Eds, Kingston, UWI Publishers’ Association. Stuewer, F.W. (1943): Raccoons: Their habits and management in Michigan. Ecol. Monogr. 13: 203257. Thorpe, R.S., Leadbeater, D.L., Pook, C. (2005): Molecular clocks and geological dates: Cytrochrome b of Anolis extremus substantially contradicts dating of Barbados emergence. Mol. Ecol. 14: 20872096. Tucker, R.W.E. (1939): Bufo marinus in Barbados. Barbados Agric. J. 18: 145-150. Underwood, G., Daltry, J., Horrocks, J.A. (1999): A new snake from Barbados. J. Barbados Mus. Hist. Soc. 45: 67-78. Vitt, L.J., Caldwell, J.P. (2009): Herpetology. Burlington, USA, Academic Press. Watson, K. (2008): Natural history observations for 2008. J. Barbados Mus. Hist. Soc. 54: 261-268.
104
A. Fields, J.A. Horrocks
Watts, D. (1966): Man’s influence on the vegetation of Barbados, 1627-1800. Univ. of Hull, Occasional Papers in Geography, No. 4, 96 pp. Weiss A.J., Hedges, S.B. (2007): Molecular phylogeny and biogeography of the Antillean geckos Phyllodactylus wirshingi, Tarentola americana, and Hemidactylus haitianus (Reptilia, Squamata). Mol. Phylogen. Evol. 45: 409-416.
Accepted: August 9, 2010 (AH).
Conservation of amphibians and reptiles in the British Virgin Islands: Status and patterns G. Perry1,2 , G.P. Gerber3 1 Dept.
of Natural Resource Management, Box 42125, Texas Tech University, Lubbock, TX 79409-2125, USA 2 Corresponding author; e-mail:
[email protected] 3 Conservation and Research for Endangered Species, Zoological Society of San Diego, 15600 San Pasqual Valley Road, Escondido, CA 92027-7000, USA Abstract. The British Virgin Islands (BVI) forms part of the Puerto Rican Bank and its fauna is closely related to that of the US Virgin Islands and Puerto Rico. Humans have inhabited the region for several thousand years and their impacts have continuously included habitat modification, hunting, and introduction of invasive species. Those are the three main causes of concern for the present-day herpetofauna of the BVI, which contains 34 amphibian and reptile species. Of these, five (15%) are common, three (9%) are at risk, eight (23%) are endangered, ten (29%) are data deficient, two (6%) are extinct, and six (18%) are introduced or cryptogenic. Several endemic species are only found on tiny islets where stochastic events can easily lead to their extinction. The native iguana, Cyclura pinguis, and the sea turtles found in the region are in an especially sensitive condition. Habitat destruction and fragmentation are ongoing and likely to accelerate. Invasive species are still arriving, establishing, and spreading. Thus, although the short-term conservation status of the BVI herpetofauna appears unlikely to change, we are more concerned about the mid-term outlook. We recommend some specific remedies intended to offset these pressures and provide long-term protection to the biota of the BVI. Key words: Amphibians; British Virgin Islands; conservation; Cyclura pinguis; invasive species; reptiles; sea turtles.
Introduction Human impacts on species and ecosystems are still expanding, despite often already being more pervasive than can be sustainably supported. Global amphibian declines have drawn considerable attention and debate. They appear primarily correlated with a complex and often site-specific combination of the loss of appropriate habitat, pollution, and the introduction of invasive predators and diseases (e.g., Adams, 1999; Stallard, 2001; Blaustein and Kiesecker, 2002; Muths et al., 2003; Lannoo, 2005). Less attention has been paid to the rapid disappearance of reptile species
106
G. Perry, G.P. Gerber
(Gibbons et al., 2000). The IUCN (1996) classified vertebrates into four categories based on conservation status and found similar rates of endangerment in both groups (Critically endangered: 9% in amphibians, 10% in reptiles; Endangered: 16% and 14%, respectively; Vulnerable: 39% and 38%). In a recent update (IUCN, 2004) they identified 61% of evaluated reptile species as endangered, compared to 32% of evaluated amphibians. Similar patterns and concerns are apparent in the Caribbean. For example, Powell and Henderson (2005) estimated that almost half of Lesser Antillean terrestrial reptiles have been substantially negatively affected by human activities. Unfortunately, the herpetofauna of the British Virgin Islands (BVI, about 150 km2 total land area) has not been systematically evaluated since MacLean (1982), the exception being a recent book (Lazell, 2005) that focuses on a single island. Here we review the current conservation status of all reptiles and amphibians known from the BVI, drawing upon both published and unpublished work. We begin with a brief description of the historical and biogeographical setting, then provide species accounts. Taxa of special concern are then discussed in additional detail, and we close with a review of broad patterns and likely future trends.
The Setting History Humans first arrived in the BVI some 4000-6000 years ago, primarily inhabiting the larger islands (Wilson, 2001) but utilizing some of the smaller ones for protracted periods. Their presence has clearly had extensive impacts on the local fauna (Lazell, 2005), which suffered both additions and extinctions. The current name was given to the islands by Columbus, whose 1493 visit ultimately resulted in the extirpation of Amerindians from the area and in additional plant and animal introductions and extinctions. European settlement began in 1648, when the Dutch claimed Tortola (Jenkins, 1923), and the islands changed hands multiple times before the British finally acquired them in 1672 (Rogozinski, 1992). Slaves were brought in from Africa to support the agricultural effort which converted much of the land area into plantations. England abolished slavery in 1808 and enacted the Emancipation Proclamation in 1834, and the islands have enjoyed various levels of self-rule ever since. The population in 1844 was 6,689 (Fergus, 2003), declined to 4,639 by 1891, grew to 10,000 in the late 1970s, and is currently estimated at 22,643 people, more than three times what it was 150 years ago (BVI Government, 2005). The current annual population growth rate is 2.06%, and population pressure in the BVI is growing, especially on Tortola (which has over 80% of the total population on less than 40% of the BVI land area). The second largest island, Virgin Gorda, doubled its population between 1960 and 1980 and saw an increase of almost 75% from 1980 to 1991. Despite a relatively high emigration rate, the population of the BVI is expected to double in about 35 years (BVI Government, 2005). The current economy is primarily based on tourism and offshore banking. Growth in population
Conservation of amphibians and reptiles in BVI
107
and tourism has resulted in ongoing construction throughout the islands, with roads and buildings being added on a regular basis, natural habitats increasingly being lost and fragmented, and increasing problems with trash disposal. Biogeography In the late Pleistocene, a single land mass stood where Puerto Rico, its associated islands, the US Virgin Islands (USVI, except St. Croix) and the BVI now lie (fig. 1). Today called the Puerto Rican Bank, it was roughly twice the area of Puerto Rico today, and became increasingly fragmented as sea-levels rose in the Holocene (Heatwole and MacKenzie, 1967). As a result, the biotas of these politically disparate units are highly similar (see for example, Platenberg and Boulon, 2006). However, rapid evolution has produced a number of unique species on some of the islands, and dispersal and extinction related to island biogeographic processes resulted in a mosaic of distribution patterns. Some of the species, such as Anolis cristatellus and Sphaerodactylus macrolepis, are present on nearly every piece of dry land in the region (Lazell, 1983), whereas others, such as A. ernestwilliamsi, are only found on a single small rock. The genera, however, are all wide-spread throughout the region: there are no endemic genera on the Puerto Rican Bank, and the taxa found there have been shown to be related to species found both to the east and west (Thomas, 1999). Much additional information about the biogeography of the region can be found in Woods and Sergile (2001).
Species Accounts Information in this section is heavily based on MacLean (1982), with updates drawn from our own observations and from additional sources, which are the only ones cited in the text. Scientific names follow the most accepted current usage. Common names given are those normally in general or regional use. These are often abbreviated for local use, and ‘Puerto Rican racer’, for example, is normally locally simply referred to as ‘racer’. Distribution information primarily follows MacLean (1982) and Mayer and Lazell (1988). The ‘major islands’ referred to are Anegada, Tortola, and Virgin Gorda (fig. 1). Few studies have assessed the population sizes of any of these species, and our assignment of status is based on what literature exists and our personal experience. Species are identified as Common (present on many islands in large or stable numbers); At risk (distribution is limited and numbers are declining); Endangered (the species has a very limited distribution and small numbers and is thus in immediate risk); Data deficient (studies identifying population trends are lacking); Extinct (in the BVI — the species may still exist elsewhere); Introduced (non-native taxa which arrived in the BVI relatively recently and with human assistance); or Cryptogenic (impossible to reliably classify as native — see Carlton, 1996). Most species are not locally protected or considered to be of concern, the exception being the iguana and sea turtles.
Figure 1. Map of the Puerto Rico Bank (inset) and the British Virgin Islands. Islands named in the text are indicated, but not all islets are named on the map. Dotted lines represent the 100 m depth contour and the approximate areas above sea level during the last glacial maximum. Stippling shows the distribution of karst habitats on present day islands.
108 G. Perry, G.P. Gerber
Conservation of amphibians and reptiles in BVI
109
Amphibia Leptodactylidae. Leptodactylus albilabris (white-lipped frog). All major and some smaller islands: At risk. This species requires fresh water for reproduction. Although it can breed in ditches, populations appear to be declining. Its tadpoles may be vulnerable to competition from Osteopilus septentrionalis tadpoles (see Smith, 2005, for related work). A study of population trends is desirable. Eleutherodactylus antillensis (bo-peep, Antillean or churi coqui). Tortola, Virgin Gorda, and many small cays: Common. MacLean (1982) reported it as being found on ‘all major islands’ but we are not aware of any populations on Anegada. This species appears to be declining wherever Osteopilus septentrionalis spreads, but numbers are still high. Populations appear to positively respond to increased rainfall (Ovaska, in Lazell, 2005). Eleutherodactylus cochranae (bo-peep, whistling coqui). Tortola, Virgin Gorda: Data deficient. This species appears to be declining wherever Osteopilus septentrionalis spreads. Eleutherodactylus schwartzi (bo-peep, Virgin Islands coqui). Tortola, Virgin Gorda, Great Dog; (re?)introduced: Little Thatch (Lazell, 2002): At risk. This species appears to be declining wherever Osteopilus septentrionalis spreads, has disappeared in the USVI (Philibosian and Yntema, 1976; Platenberg and Boulon, 2006), and has been identified by the IUCN as Endangered (IUCN, 2004). The Great Dog population is somewhat distinct (Ovaska et al., 2000), extremely limited in range, and very susceptible to development there. Additional study, and perhaps protection, of that population is urgently needed, and protection of other remaining BVI populations may well be warranted. Bufonidae. Bufo (Peltophryne) lemur (Puerto Rican crested or lowland Caribbean toad). Virgin Gorda: Extinct. No specimens have been collected from the BVI in many decades. Captive husbandry and reintroduction are ongoing in Puerto Rico (Miller, 2005). Whether such a program can succeed in the BVI will depend on the ability to provide and protect appropriate low-elevation habitat, much of which has been destroyed by development. Hylidae. Osteopilus septentrionalis (Cuban treefrog). Tortola, Virgin Gorda, Beef Island, Peter Island (Owen et al., 2005a, 2006): Introduced. Individuals have also been collected on Necker and Guana Island (Owen et al., 2005a, 2006), but neither island appears to have a breeding population at the moment. This species is spreading rapidly, with frequent new island records. The diet suggests the potential to severely impact native species (Owen, 2005) and the tadpoles are known to impact those of some native anurans (Smith, 2005). Testudines Sea turtles. See additional information under Species of Special Concern, below. Dermochelyidae. Dermochelys coriacea (leatherback or trunk turtle). Nesting only, primarily on Tortola and adjacent Beef Island: Endangered. Cheloniidae. Chelonia
110
G. Perry, G.P. Gerber
mydas (green turtle). Common in coastal waters, nesting widespread in low numbers: Endangered. Eretmochelys imbricata (hawksbill turtle). Common in coastal waters, nesting widespread in low numbers: Endangered. Caretta caretta (loggerhead turtle). Infrequent in coastal waters, nesting extremely rare, if at all: Endangered. Testudinidae. Geochelone carbonaria (red-legged or red-footed tortoise). Tortola, Virgin Gorda; (re?)introduced: Guana, Necker (Lazell, 2002): At risk (Introduced?). These turtles may not be native to the BVI, as populations have been widely transported throughout the Caribbean starting in Amerindian times (Censky, 1988). Both the Guana and Necker populations appear to be breeding well in their new habitats (Lazell, 2002), but Tortola and Virgin Gorda animals are uncommon in the wild, presumably as a result of habitat loss. Emydidae. Pseudemys nelsoni (Florida red-bellied turtle). Tortola (Owen et al., 2005b): Introduced. A few individuals have been collected at the botanical garden ponds, but absence of suitable habitat and fresh water bodies makes them of relatively little concern. Trachemys scripta elegans (red-eared slider). Tortola, Virgin Gorda (Owen et al., 2005b): Introduced. Several individuals of this damaging invasive, including juveniles, have been collected, suggesting reproduction is occurring. However, absence of suitable habitat and ecologically similar native species makes them of relatively little concern. Sauria Polychrotidae. Anolis cristatellus (Puerto Rican crested anole; man-lizard [mostly used for the males]). All major islands and most small rocks and cays: Common. This species is ubiquitous, highly tolerant of human presence and development, and well-studied (Perry, 2005). It has been introduced in other locations (e.g., Brach, 1977). Diet occasionally includes other lizards (Owen and Perry, 2005). Anolis ernestwilliamsi (Carrot Rock or Ernest’s anole). Carrot Rock, Peter Island: Endangered (possibly extinct on Peter Island; Perry, 1995). This large anole is only found on Carrot Rock, a tiny and highly exposed location. Population size is doubtlessly small and susceptible to stochastic events such as hurricanes. Anolis stratulus (Puerto Rican saddled anole). All major islands and many smaller cays: Common. BVI populations (Rodda et al., 2001) are much less dense than those seen in Puerto Rico (Reagan, 1992), and the species is rarely seen on Anegada, for example. However, there is no indication of population declines. Contrary to the view of MacLean (1982), these animals will occasionally take vegetable material (Perry and Lazell, 1997; Rios-López, 2004). Anolis pulchellus (Puerto Rican grass or bush anole). All major islands and some smaller ones: Common. This species is restricted to open or edge habitats where grass or narrow stems are available, and can tolerate human-impacted areas. They are often hard to see, both because of their excellent camouflage and tendency to be active during cooler times of day (G. Perry and
Conservation of amphibians and reptiles in BVI
111
K.R. LeVering, unpublished). Like A. stratulus, these animals will occasionally take vegetable material (Perry and Lazell, submitted). Anolis roosevelti (Culebra Island giant anole). Tortola: Extinct (in the BVI). MacLean (1982) was not sure whether Tortola sightings were genuine but Gaa (1987) unearthed museum specimens. Some animals may remain on Culebra off the Puerto Rico shore and a recovery plan exists (Campbell and Dodd, 1982), but the species may be globally extinct. Iguanidae. Cyclura pinguis (Anegada or stout iguana). Anegada; (re?)introduced: Guana, Necker (Lazell, 2002), Norman, Little Thatch (Perry et al., 2006): Endangered. See expanded discussion in Species of Special Concern, below. Iguana iguana (green or common iguana). Peter Island (Carey, 1972), Tortola: Introduced. Green iguanas are certainly native to part of the Lesser Antilles (e.g., Saba, Netherlands Antilles; Powell et al., 2005), and MacLean (1982) considered Virgin Islands populations to also be native. However, BVI animals appear more similar in appearance to animals found in the pet trade than to native Caribbean populations. Genetic studies to identify their origin are warranted. The main concern is their ability to take over habitat that might otherwise be appropriate for the native Cyclura pinguis. Gekkonidae. Hemidactylus mabouia (common house gecko; wood slave). All major islands and some smaller ones: Cryptogenic. This species is common around human habitation, but generally uncommon or absent in native habitats (Rodda et al., 2001). There is no evidence of broad impacts on native species, but little effort has been devoted to identifying such patterns. The house gecko was likely introduced throughout the region in slave ships arriving from Africa. Thecadactylus rapicauda (turnip-tailed gecko). Necker Island: Cryptogenic. This species is widespread in the Lesser Antilles but is only recorded from one location in the BVI. The population on Necker is often associated with human habitation, but can also be found in native habitats (Lazell, 1995). It may be anthropogenic in origin. Despite being small the population appears stable. Sphaerodactylus macrolepis (Puerto Rican dwarf gecko or sphaero). All major islands and most small cays and rocks: Common. This species reaches incredibly high densities in areas with deep leaf-litter (Rodda et al., 2001). It shows some signs of physiological variation even within islands (MacLean, 1985), suggesting that future speciation may occur on a small scale. Sphaerodactylus parthenopion (BVI dwarf gecko or sphaero). Tortola (?), Virgin Gorda: Data deficient. Carey (1972) and MacLean (1982) only reported this species from Virgin Gorda, but Procter and Fleming (1999) also report it from Tortola and Heatwole et al. (1981) from Mosquito Island. One of the world’s smallest lizards, the biology of this species is poorly understood and population trends are unknown. Distribution within the islands it resides on appears fairly limited and likely to be further curtailed by development. Sphaerodactylus sp. (proposed: Carvel Rock dwarf gecko or sphaero). Carvel Rock: Endangered. This population appears morphologically distinct but is
112
G. Perry, G.P. Gerber
yet to be described. Given the extremely limited range — a small part of a single small rock — it appears especially susceptible to stochastic events such as hurricanes. Scincidae. Mabuya sloanii (Antillean slipperyback or skink). All major islands and some smaller ones: Data deficient. This species appears widespread but is never common. Its biology is poorly understood and population trends are unknown. Carey (1972) reports that their numbers in the BVI were much reduced because of the introduced mongoose (Herpestes javanicus). Given the broad range of the mongoose in the BVI, this is a source of concern. Mabuya macleani (Carrot Rock slipperyback or skink). Carrot Rock: Endangered. Only recently described (Mayer and Lazell, 2000), this species has an extremely limited range and is thus highly vulnerable. However, the Carrot Rock population is relatively dense. Almost nothing is known about its biology or population trends. Teiidae. Ameiva exsul (Puerto Rican ground lizard). All major islands and some smaller ones: Data deficient. Members of the genus Ameiva appear especially susceptible to predation by the introduced mongoose (Herpestes javanicus; Henderson, 1992). Given the broad range of the mongoose in the BVI, this is a source of concern for many populations. This species is common on the mongoose-free islands of Guana (Nicholson et al., 2005) and Anegada (G. Gerber, unpublished) but infrequently seen on most other islands, despite being very tolerant of development and fragmentation. Amphisbaenidae. Amphisbaena fenestrata (Virgin Islands worm lizard). Great Camanoe, Great Thatch, Guana, Tortola, Virgin Gorda: Data deficient. This secretive species spends most of its time underground as it cannot avoid dehydration on the surface (Perry et al., 2004). Very little is known about its biology, but there is no indication of population decline and it is likely to exist on additional islands. Serpentes Typhlopidae. Typhlops richardii (Virgin Islands blind snake). Guana, Necker (?), Tortola: Data deficient. These subterranean animals are not often seen above-ground and little is known about their biology. However, data collected by Rodda et al. (2001) suggest they are found in large numbers. The Necker population may belong to T. catapontus (J. Lazell, pers. com.) and needs to be reexamined. Populations are known from additional islands but which of the two species they belong to has not been studied. Typhlops catapontus (BVI blind snake). Anegada, Virgin Gorda: Data deficient. These subterranean animals are not often seen above-ground and little is known about their biology and population trends. Blind snakes are known from additional islands, but whether they belong to this species or to the one that precedes remains unstudied.
Conservation of amphibians and reptiles in BVI
113
Boidae. Epicrates monensis (Virgin Islands boa). Tortola: Data deficient. This species is considered endangered in the USVI (US Fish and Wildlife Service, 1980), where a reintroduction program is ongoing (Tolson, 2005). In contrast, Lazell (2005) believes it ‘is the most common snake on Tortola’. Proposed studies of population status in the USVI (R. Platenberg, pers. com.) may help shed light on this issue, but a study of the BVI population is highly desirable. Colubridae. Arrhyton exiguum (Puerto Rican garden or ground snake). All major islands and some smaller ones: Data deficient. This small, nocturnal snake is only found at low densities and is very poorly studied. Sightings on Guana appear fairly constant, but broad population trends are unknown. Alsophis portoricensis (Puerto Rican racer). All major islands and many smaller ones: Data deficient. Members of the genus Alsophis appear especially susceptible to predation by the introduced mongoose (Herpestes javanicus; Henderson, 1992). Given the broad range of the mongoose in the BVI, this is a source of concern. Populations on the mongoose-free islands of Guana (Barun et al., submitted) and Anegada (G. Gerber, unpublished) appear healthy, but numbers on other islands are generally much lower. Recent information suggests these animals swim well, perhaps enhancing their inter-island dispersal abilities (Powell et al., in press).
Species of Special Concern Two types of organisms native to the BVI are of particular concern, and we provide more detailed information about both in this section. The first is the endemic iguana, Cyclura pinguis, which is one of the most endangered lizards on Earth and the most endangered animal species in the BVI. Cyclura pinguis is listed as Critically Endangered in the IUCN Red List of Threatened Species (IUCN, 2004) and Endangered in the U.S. Fish and Wildlife Service List of Endangered and Threatened Wildlife and Plants (USFWS, 1999). It is protected from international trade by inclusion in Appendix I of the Convention on the International Trade of Endangered Species of Wild Fauna and Flora (CITES, 2005). The other is a group of species, marine turtles, which are at risk world-wide and which are likewise protected by a number of international agreements, including CITES. Their situation will likely require regional cooperation to resolve. The endemic iguana Cyclura pinguis was described approximately 90 years ago (Barbour, 1917), at which time it was restricted to Anegada, a 39 km2 island located on the northeastern edge of the Puerto Rican Bank in the BVI (fig. 1). However, fossils of C. pinguis are common in late Pleistocene deposits (15,000-20,000 years old) from limestone caves in northern Puerto Rico (Pregill, 1981). There is considerable debate over when population declines occurred. Pregill (1981) and Pregill and Olson (1981)
114
G. Perry, G.P. Gerber
provide evidence of the disappearance of C. pinguis and other xerophylic reptile species in Puerto Rico at the end of the Pleistocene, well before human colonization of the region. They hypothesize that the extinctions resulted from a significant reduction in xeric habitats, brought about by climatic changes associated with the end of the last ice age and rising ocean levels throughout the West Indies. Pregill (1981) and Pregill and Olson (1981) view Anegada as exemplifying prototypical Cyclura habitat and serving as a climatic refugium for C. pinguis. Anegada is similar to Caribbean islands with other Cyclura (Alberts, 2000) and different in substrate, topography, and vegetation from other large islands on the Puerto Rican Bank. Anegada is composed entirely of sedimentary substrates (limestone, coral, and sand), is flat and low-lying (8.5 m max.), and supports only xerophylic vegetation. In contrast, other islands are characterized by volcanic and metamorphic substrates, mountainous terrain (up to 523 m in the BVI), and semi-mesic vegetation. However, remains of C. pinguis have been recovered from Native American middens on St. Thomas, USVI (Barbour, 1919; Pregill, 1981), and some authors (e.g., Wing, 2001; Lazell, 2005; S.T. Turvey, pers. com.) believe the iguana survived much later and was extirpated from most of its range by humans. Ultimately, this issue must take a back seat to the urgent problem of guaranteeing the survival of the species beyond the next few years. Iguanas were reported to be plentiful and sometimes hunted in parts of Anegada in the early 1800’s (Schomburgk, 1832), but were described as rare by the early 1900’s (Barbour, 1917). In 1968, Carey (1975) observed that adult iguanas outnumbered juveniles and concluded that the population was in decline. He attributed this to negative interactions with introduced mammals, which included rats, cats, dogs, goats, sheep, donkeys, and cattle. Mitchell (1999), who conducted her studies between 1988 and 1994, corroborated Carey’s conclusions and described further declines in range, abundance, and individual condition. She estimated the total population at 164 animals. Consistent with this information, Perry et al. (2006) showed that body condition declined from Carey’s (1975) work to that of Mitchell (1999). The most recent studies on Anegada, ongoing since 1998, indicate the population is largely restricted to a core area of 3 km2 on the north coast and likely numbers less than 300 individuals, although a recent population estimate is needed. Most of the current population is comprised of adults, and although successful reproduction is still noted, almost no recruitment occurs because of predation of juveniles by feral cats (Gerber, 2004). Current conservation efforts consist of two largely disparate programs; one aimed at preserving the species and its habitat on Anegada, another that seeks to establish the species on other islands as a precaution against extinction. In 1997, the BVI National Parks Trust and the IUCN Iguana Specialist Group (ISG) established an in situ headstart and release program for C. pinguis on Anegada to bolster recruitment until feral cats and other introduced mammals could be controlled (Bradley and Gerber, 2005). Nests are located each summer and fenced off for protection. When hatchlings emerge in the fall they are collected for captive rearing until large enough
Conservation of amphibians and reptiles in BVI
115
to survive with cats. Since 2003, 12 male and 12 female headstarted iguanas have been fitted with radiotransmitters and released each October. Survival of released iguanas has averaged 85%, providing the population with a substantial increase in young adults (Bradley and Gerber, 2006). The other conservation program has focused on translocating C. pinguis to privately owned islands with limited development and few introduced mammals. Between 1984 and 1986, eight C. pinguis (three males and five females, 224509 mm SVL) were moved from Anegada to Guana Island, north of Tortola (Goodyear and Lazell, 1994). The translocation was successful and in 2002 the Guana population of C. pinguis was estimated at 100 individuals (Perry and Mitchell, 2003). Four hatchling C. pinguis from Guana were released on Necker Island, north of Virgin Gorda, in 1995 (Lazell, 1995). This translocation has also been successful, with reproduction reported on site (Lazell, 2002), but no population estimate is available. Two adults (a male and a female) and 10 juveniles from the Guana population have recently been released on Norman Island, south of Tortola, and five hatchlings have been placed in a headstart facility on Little Thatch Island, between Tortola and St. John (J. Lazell, pers. com.), but it is too early to evaluate the success of either translocation. Despite these efforts, full recovery of C. pinguis will require considerable additional effort. The Anegada population, potentially the largest and certainly the best documented historically, requires habitat protection and eradication of feral mammals. Anegada’s western salt ponds and surrounding habitat were declared a Ramsar site in 2000, providing limited protection for approximately half of the core iguana area on the island. However, establishment of a proposed National Park, encompassing the entire core iguana habitat, is needed to adequately protect this area from ongoing development and other direct human impacts. A detailed feral mammal eradication plan for Anegada is currently being developed, but funding for implementation has not been obtained yet. Other populations likely remain extremely genetically limited (Perry et al., 2006), raising concerns about their longterm viability without an influx of additional animals. A recovery plan for the Anegada population (in press) does not take into consideration the translocated populations, as lack of coordination between the two programs has hampered cooperative efforts. Sea turtles Four species of marine turtle, belonging to two families, are known from the BVI. Adult leatherbacks are largely pelagic, feeding on jellyfish and other soft-bodied invertebrates. They can be found in the BVI between March and July, when females visit coastal waters and come onto sandy north-shore beaches to nest. Juvenile leatherbacks have been reported from a variety of coastal waters worldwide (Eckert, 1999), but not from the BVI. In contrast, both adult and juvenile green and hawksbill turtles are commonly found in BVI coastal waters year-round and predominantly feed on marine vegetation and sponges, respectively. Both species nest, in low
116
G. Perry, G.P. Gerber
numbers, on beaches throughout the BVI. Loggerheads, which feed primarily on crustaceans and mollusks, are the least common turtle in the BVI. Sea turtles have historically been harvested in the BVI, and are consequently much less abundant today than during past times (Eckert et al., 1992; Godley et al., 2004). Eggs of all marine turtles have been exploited for food in the BVI, as elsewhere. Leatherbacks (locally known as trunks) were traditionally slaughtered for their meat and to render oil, thought to have medicinal value, when they came ashore to nest (Lettsome, 1989). In the 1920s and 1930s, ‘trunkers’ recall as many as six females coming ashore per night on several Tortola beaches (Lettsome, 1989; Eckert et al., 1992). In the 1960s, two or more females were still coming ashore each night on some beaches, but by the 1980s leatherbacks had all but disappeared from the BVI, with fewer than 10 nesting attempts per year (Chambers and Lima, 1990; Eckert et al., 1992; Hasting, 2003). Other marine turtle species were also taken on nesting beaches in the BVI but levels of exploitation and numbers of females nesting are not well documented. In 1981, Fletemeyer (1984) estimated the number of females in the BVI nesting population at 75±25 greens, 50±25 hawksbills, and a ‘few’ loggerheads. In contrast, surveys conducted in 1990 and 1991 (Hasting, 1992) reported only 6 and 17 nests for the three species combined, respectively. Unlike leatherbacks, other sea turtles, primarily greens and hawksbills, have traditionally also been harvested from the sea. Fletemeyer (1984) reported a direct catch of 600 greens and 300 hawksbills, and an incidental catch of 200 unspecified turtles by other fisheries, in 1981. All of the marine turtle species reported from the BVI are listed in the IUCN Red List of Threatened Species (IUCN, 2004) as either Critically Endangered (leatherback, hawksbill) or Endangered (green, loggerhead). All marine turtles are also protected by inclusion in Appendix I of two Multilateral Environmental Agreements to which the BVI is a party; CITES and the Convention on Migratory Species (CMS). BVI legislation pertaining to marine turtles includes the Turtles Ordinance 1959, the Turtles Protection Amendment Notice 1986, the Fisheries Act 1997, and the Fisheries Regulation 2003. In compliance with CITES, the BVI prohibits international trade of marine turtles and products. It is currently illegal to (1) take leatherback and loggerhead turtles, (2) disturb or harm sea turtle eggs or nesting females, (3) use any turtle capture device within 100 m of shore, (4) fish for turtles from 1 April-30 November, or (5) take green and hawksbill turtles with carapace lengths less than 61 cm (24 inches) and 38 cm (15 inches), respectively. Additional recommendations to amend legislation, including maximum size limits to protect reproductive stocks, establishment of a limited turtle fishing licensing scheme with strict regulations, catch quotas, compulsory biometric reporting prior to slaughter, and increased fines for infringements were proposed by Godley et al. (2004). Although all nesting marine turtles and their eggs have been protected in the BVI since 1986, commercial trade of marine turtles and products is permitted within the BVI. Government-regulated turtle harvest appears to go beyond accommodating ‘the needs of subsistence users’, as provided by the CMS. Godley et al. (2004)
Conservation of amphibians and reptiles in BVI
117
estimated that over 150 green and 50 hawksbill turtles are taken annually, and illegal take is still ongoing as well. Sea-turtle soup and products can still be readily obtained in the BVI, but increased law enforcement, public awareness, and monitoring and conservation activities have allowed sea turtle populations to begin recovering. The Wider Caribbean Sea Turtle Network (WIDECAST) has provided training in marine turtle biology and management and assisted in development of a national sea turtle recovery action plan (Eckert et al., 1992). Leatherback nesting activities have been monitored annually by the Conservation and Fisheries Department since the 1980s (Hasting, 2003; Godley et al., 2004). Most recently, the BVI participated in two UK sponsored projects aimed in whole or in part at marine turtle conservation: Turtles in the Caribbean Overseas Territories (TCOT), from 2001-2004, and the Darwin Initiative Assessment of Coastal Biodiversity in Anegada, from 2003-2006. TCOT-initiated activities in the BVI included training and capacity building, extensive sociological surveys to document trends in the harvest of marine turtles and attitudes toward conservation efforts, aerial and ground surveys of beaches to assess marine turtle nesting activities, and an overall assessment of the status and exploitation of marine turtles in the BVI (Godley et al., 2004). The ongoing biodiversity assessment of Anegada (www.seaturtle.org/mtrg/projects/anegada) initiated an extensive in-water tagging, monitoring, and sampling program for marine turtles. Several hundred green and hawksbill turtles have been marked to date, and an action plan for preserving Anegada’s biodiversity is being produced. As a result of this effort, the outlook for marine turtles in the BVI has improved dramatically in recent years. As many as 65 leatherback nesting attempts per year have been reported for the north-shore beaches of Tortola and adjacent Beef Island (Hasting, 2003; Godley et al., 2004). Populations of other species also appear to be on the rise, but have not rebounded to the extent that leatherbacks have (Godley et al., 2004). The take of marine turtles and their eggs by humans remains the greatest threat to BVI turtle populations. Other threats reported by Godley et al. (2004) include accidental boat strikes; loss of beach nesting habitat from erosion, sand mining, and development; indirect impacts from increased development, including artificial lighting; pollution, including litter at sea and on beaches; and general environmental degradation. In addition, fibropapilloma disease has been observed in green turtles in the BVI (Overing, 1996) and, although undocumented, introduced predators, such as mongoose and dogs, likely prey on turtle eggs in the BVI, as they do in the US Virgin Islands (Platenberg and Boulon, 2006). Livestock, which on some islands (e.g., Anegada) frequent beach areas in large numbers at night, probably also damage nests. To adequately protect marine turtle stocks in the BVI and aid in their recovery, we strongly urge authorities to (1) increase protection of critical nesting and foraging habitats, (2) implement country-wide beach and in-water monitoring programs to better document turtle population trends, and (3) increase oversight of the turtle fishery, including strict enforcement of regulations, detailed documentation of the annual take and evaluation of its impacts, and establishment of
118
G. Perry, G.P. Gerber
size limits that encourage maximum reproduction. Experience has shown that taking primarily large individuals in fish populations results in a reduction in reproductive output, and we urge the government to consider setting both upper and lower limits on size of turtles which can be killed.
Discussion Of the 34 amphibian and reptile species documented in the BVI, five (15%) are common, three (9%) are at risk, eight (23%) are endangered, ten (29%) are data deficient, two (6%) are extinct, and six (18%) are introduced or cryptogenic. There are several causes for alarm in this breakdown. One is that we have little or no information about the population trends of almost a third of the species, a lack that urgently needs to be rectified. A second concern is that another third of the species are already at immediate or low-level risk and an additional number are already extinct. Given the increasing population and development pressure, this is not a good sign for the future. Of especially great concern are the sea turtles, which have traditionally been harvested in the area (Eckert et al., 1992) and remain an exploited resource; the native iguana; and species found on single, tiny, and highly vulnerable islets. However, leatherback nesting activities appear to be on the rise (Hasting, 2003), and both insitu and ex-situ efforts to protect the iguana are having some success (Lazell, 2002; Bradley and Gerber, 2006; Perry et al., 2006). Finally, over a tenth of the herpetofauna of the BVI is already comprised of introduced species, some of which have documented negative impacts on native species. Additional species may have been introduced long enough ago and their origin is hard to ascertain. Primary causes of endangerment and extinction in the BVI include habitat loss and introduction of invasive species such as mongooses, cats, goats, and sheep. Development is an especially large concern for sea turtles, both because of the loss of nesting beaches and the additional night-lights that are detrimental to juvenile post-hatching dispersal (Salmon, 2005). Some work has taken place or is planned for control of invasives. For example, goats were successfully eradicated from Norman Island. However, most invasive species remain common and prospects for eradicating species such as the mongoose in the foreseeable future are minimal. Worse, additional species keep arriving in the BVI, and some taxa that are already in the region, such as Bufo marinus and Eleutherodactylus coqui have great potential for harm should they invade the BVI. Luckily, we have not yet seen signs of chytridiomycosis, a disease implicated in the severe declines of many amphibian populations (Berger et al., 1998), in BVI amphibian samples sent to the United States Geological Survey National Wildlife Health Center in Madison, Wisconsin for analysis (D.E. Green, Pers. Com.). Moreover, most BVI amphibians do not match the profile of especially susceptible taxa identified by Lips et al. (2003). Nonetheless, monitoring of BVI populations must be a high priority, given the broad declines of amphibians identified in Puerto Rico (Burrowes et al., 2004).
Conservation of amphibians and reptiles in BVI
119
For species with single-island distributions, the risk of extinction as a result of stochastic events such as storms remains a major concern. On Puerto Rico, hurricanes are known to affect birds (Wauer and Wunderle, 1992) and boas (Wunderle et al., 2004). Similar effects are likely in the BVI, especially given the prediction that global climate change will result in more frequent and more severe storms (Goldenberg et al., 2001; Emannuel, 2005). Climate change is expected to affect forests in additional ways as well (Dale et al., 2001), and changes in factors such as the frequency of drought are sources for concern. Although extinctions of small isolated populations are a natural event, the increased likelihood caused by human activities may merit efforts to protect such taxa. For example, Carrot Rock may not be facing development but the unique species it contains are nonetheless affected by developments on nearby Peter Island (where the Carrot Rock anole is probably already extinct) and by global climate change, thought to be responsible for increased storm severity and higher sea levels. In the short-term, the conservation status of the BVI herpetofauna appears unlikely to change. However, we are more concerned about the mid-term outlook, which includes increasing impacts from habitat loss and invasive species. To offset these pressures, we recommend the following strategies be adopted: 1. Set aside additional areas for conservation. This is especially true for marine turtle nesting beaches; the proposed National Park on Anegada, which is essential for the survival of C. pinguis; and for expanding the size of the two peak reserves already recognized, Gorda Peak and Sage Mountain, both of which are very small. Islets containing unique taxa, such as Carrot Rock, Carvel Rock, and Great Dog, should also be a high priority for protection. 2. Minimize the impacts of development via better enforcement of existing regulations and improved planning. For example, impacts to sea turtles from beach-side night-lights can be reduced by use of improved lighting technology (Bertolotti and Salmon, 2005). Improved international collaboration on conservation of sea turtles would also benefit the conservation of these animals, which migrate among political units and are therefore subject to variable protection. 3. Establish a baseline for population size of data-deficient species and a longterm program for monitoring all amphibian and reptile species to ensure declines are not occurring. Studies of the molecular systematics of local species should be a high priority, as such work has repeatedly identified the presence of cryptic species. 4. Support the eradication of existing harmful invasives, a process which has become increasingly feasible in recent years (Veitch and Clout, 2001; Krajick, 2005), and enhance prevention of additional invasive species arrivals. New Zealand is a leader in this, and much information is available on their governmental web site (http://www.biosecurity.govt.nz/) and on the IUCN Invasive Species Specialist Group web site (http://www.issg.org/).
120
G. Perry, G.P. Gerber
5. Improve public education about the value of conservation in general and herpetofauna in particular. The motto of the BVI is ‘nature’s little secrets’, but its ability to sell itself as an ecotourism destination is rapidly being eroded by the same processes that are endangering the herpetofauna of the nation. The five strategies we identified above are not unique to the herpetofauna, but will rather provide protection to many species and habitats. We hope that the government of the BVI will continue to show foresight in protecting its natural assets.
Acknowledgements. We thank Kate LeVering, James Lazell, and an anonymous reviewer for useful comments on this manuscript. This review would not have been possible without years of field work in the BVI, supported by (in alphabetical order) the American Zoological Association Conservation Endowment Fund, BVI National Parks Trust, The Conservation Agency via grants from the Falconwood Corporation, the Dallas Zoo, the Fort Worth Zoo, the International Iguana Foundation, IUCN Sir Peter Scott Fund for Conservation Action, Texas Tech University, the UK Foreign and Commonwealth Office, and the Zoological Society of San Diego. This is manuscript T-9-1089 of the College of Agricultural Sciences and Natural Resources, Texas Tech University. References Adams, M.J. (1999): Correlated factors in amphibian decline: Exotic species and habitat change in western Washington. J. Wildl. Manage. 63: 1162-1171. Alberts, A.C. (Ed.) (2000): West Indian Iguanas: Status Survey and Conservation Action Plan. Gland, Switzerland, IUCN — The World Conservation Union. Barbour, T. (1917): Notes on the herpetology of the Virgin Islands. Proc. Biol. Soc. Wash. 30: 99-103. Barbour, T. (1919): A new rock iguana from Porto Rico. Proc. Biol. Soc. Wash. 32: 145-148. Berger, L., Speare, R., Daszak, P., Green, D.E., Cunningham, A.A., Goggin, C.L., Slocombe, R., Ragan, M.A., Hyatt, A.D., McDonald, K.R., Hines, H.B., Lips, K.R., Marantelli, G., Parkes, H. (1998): Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America. Proc. Nat. Acad. Sci. 95: 9031-9036. Bertolotti, L., Salmon, M. (2005): Do embedded roadway lights protect sea turtles? Environ. Manage. 36: 702-710. Blaustein, A.R., Kiesecker, J.M. (2002): Complexity in conservation: lessons from the global decline of amphibian populations. Ecol. Letters 5: 597-608. Brach, V. (1977): Notes on the introduced population of Anolis cristatellus in south Florida. Copeia 1977: 184-185. Bradley, K.A., Gerber, G.P. (2005): Conservation of the Anegada iguana (Cyclura pinguis). Iguana 12: 78-85. Bradley, K.A., Gerber, G.P. (2006): Release of headstarted iguanas in Anegada, British Virgin Islands. Re-introduction News 25: 14-16. Burrowes, P.A., Joglar, R.L., Green, D.E. (2004): Potential causes for amphibian declines in Puerto Rico. Herpetologica 60: 141-154. BVI Government (2005): British Virgin Islands CD Atlas: population (http://www.bvingis.gov. vg/population.htm).
Conservation of amphibians and reptiles in BVI
121
Campbell, H.W., Dodd, C.K., Jr. (1982): Culebra Island giant anole recovery plan. U.S. Fish and Wildlife Service, Atlanta, Georgia (http://ecos.fws.gov/docs/recovery_plans/1983/830128.pdf). Carey, M. (1972): The herpetology of Anegada, British Virgin Islands. Carib. J. Sci. 12: 79-89. Carey, W.M. (1975): The rock iguana, Cyclura pinguis, on Anegada, British Virgin Islands, with notes on Cyclura ricordi and Cyclura cornuta on Hispaniola. Bull. Fla. State Mus. Biol. Sci. 19: 189233. Carlton, J.T. (1996): Biological invasions and cryptogenic species. Ecology 77: 1653-1655. Censky, E.J. (1988): Geochelone carbonaria (Reptilia: Testudines) in the West Indies. Fla. Sci. 50: 108-114. CITES (2005): Appendices I, II, and III to the Convention on International Trade in Endangered Species of Wild Fauna and Flora. United Nations Environment Programme, 47 pp. (http://www.cites.org/eng/app/index.shtml). Chambers, G., Lima, H. (1990): Leatherback turtles disappearing from the BVI. Martine Turtle Newsletter. 49: 4-7. Dale, V.H., Joyce, L.A., McNulty, S., Neilson, R.P., Ayres, M.P., Flannigan, M.D., Hanson, P.J., Irland, L.C., Lugo, A.E., Peterson, C.J., Simberloff, D., Swanson, F.J., Stocks, B.J., Michael, W.B. (2001): Climate change and forest disturbances. BioScience 51: 723-734. Eckert, K.L., Overing, J.A., Lettsome, B.B. (1992): WIDECAST Sea Turtle Recovery Action Plan for the British Virgin Islands. CEP Technical Report No. 15. Kingston, Jamaica, UNEP Caribbean Environment Programme, xv + 116 pp. Eckert, S. (1999): Global Distribution of Juvenile Leatherback Sea Turtles. Hubbs Sea World Research Institute Technical Report 99-294. Emmanuel, K.A. (2005): Increasing destructiveness of tropical cyclones over the past 30 years. Nature 436: 686-688. Fergus, H.A. (2003): A History of Education in the British Leeward Islands, 1838-1945. Kingston, Jamaica, University of the West Indies Press. Fletemeyer, J. (1984): National report for the British Virgin Islands to the western Atlantic Turtle Symposium, 17-22 July 1983, Costa Rica. In: Proceedings of the Western Atlantic Turtle Symposium, p. 70-117, Vol. 3, Bacon, P., et al., Eds, Miami, Florida, University of Miami Press. Gaa, A. (1987): Culebra Giant Anole Status Determination Study. Final Report, Department of Natural Resources, San Juan, Puerto Rico. Gerber, G.P. (2004): An update on the ecology and conservation of Cyclura pinguis on Anegada. Iguana 11: 23-26. Gibbons, J.W., Scott, D.E., Ryan, T.J., Buhlmann, K.A., Tuberville, T.D., Metts, B.S., Greene, J.L., Mills, T., Leiden, Y., Poppy, S., Winne, C.T. (2000): The global decline of reptiles, deja vu amphibians. Bioscience 50: 653-666. Goodyear, N.C., Lazell, J. (1994): Status of a relocated population of endangered Iguana pinguis on Guana Island, British Virgin Islands. Rest. Ecol. 2: 43-50. Godley, B.J., Broderick, A.C., Campbell, L.M., Ranger, S., Richardson, P.B. (2004): An assessment of the status and exploitation of marine turtles in the British Virgin Islands. In: An Assessment of the Status and Exploitation of Marine Turtles in the UK Overseas Territories in the Wider Caribbean, p. 96-123. Final project report for the Department of Environment, Food and rural Affairs and the Foreign and Commonwealth Office (http://www.seaturtle.org/mtrg/projects/tcot/finalreport/). Goldenberg, S.B., Landsea, C.W., Mestas-Núñez, A.M., Gray, W.M. (2001): The recent increase in Atlantic hurricane activity: causes and implications. Science 293: 474-479. Hasting, M. (1992): Survey of Hawksbill/Green Turtle Nesting Sites in 1990 and 1991 in the British Virgin Islands. Technical Report No. 13. Conservation and Fisheries Department, Ministry of Natural Resources and Labour, British Virgin Islands. Hasting, M. (2003): A conservation success: leatherback turtles in the British Virgin Islands. Marine Turtle Newsletter 99: 5-7.
122
G. Perry, G.P. Gerber
Heatwole, H., MacKenzie, F. (1967): Herpetogeography of Puerto Rico. IV: Paleogeography, faunal similarity and endemism. Evolution 21: 429-439. Heatwole, H., Levins, R., Byer, M.D. (1981): Biogeography of the Puerto Rican Bank. Atoll Res. Bul. no. 251. Henderson, R.W. (1992): Consequences of predator introductions and habitat destruction on amphibians and reptiles in the post-Columbus West Indies. Carib. J. Sci. 28: 1-10. IUCN (1996): 1996 IUCN Red List of Threatened Animals. Gland, Switzerland, World Conservation Union. IUCN (2004): 2004 IUCN Red List of Threatened Species — A Global Species Assessment. Gland, Switzerland, World Conservation Union (http://www.iucn.org/themes/ssc/red_list_2004/ summarytables_EN.htm). Jenkins, C.F. (1923): Tortola: a Quaker Experiment of Long Ago in the Tropics. London, Friends’ Bookshop. Krajick, K. (2005): Winning the war against invaders. Science 310: 1410-1413. Lannoo, M.J. (Ed.). (2005): Amphibian Declines: the Conservation Status of United States Species. Berkeley, California, University of California Press. Lazell, J. (1983): Biogeography of the Herpetofauna of the British Virgin Islands, with Description of a New Anole (Sauria: Iguanidae). In: Advances in Herpetology and Evolutionary Biology, p. 99117. Rhodin, A., Miyata, K., Eds, Harvard, Museum of Comparative Zoology. Lazell, J. (1995): Natural Necker. The Conservation Agency Occasional Paper 2: 1-28. Lazell, J. (2002): Restoring vertebrate animals in the British Virgin Islands. Ecol. Rest. 20: 179-185. Lazell, J. (2005): Island: Fact and Theory in Nature. Berkeley, California, University of California Press. Lettsome, B.B. (1989): Subsistence Leatherback Sea Turtle Fishery on Tortola, BVI. BVI Conservation and Fisheries Internal Report. Lips, K.R., Reeve, J.D., Witters, L.R. (2003): Ecological traits predicting amphibian population declines in Central America. Conserv. Bio. 17: 1078-1088. Mayer, G.C., Lazell, J. (1988): Distributional records for reptiles and amphibians from the Puerto Rico Bank. Herp. Rev. 19: 23-24. Mayer, G., Lazell, J. (2000): A new species of Mabuya (Sauria: Scincidae) from the British Virgin Islands. Proc. Biol. Soc. Washington 113: 871-886. MacLean, W.P. (1982): Reptiles and Amphibians of the Virgin Islands. London, MacMillan Caribbean. MacLean, W.P. (1985): Water-loss rates of Sphaerodactylus parthenoprion (Reptilia: Gekkonidae), the smallest amniote vertebrate. Comp. Biochem. Physiol. 82A: 759-761. Miller, T.J. (2005): Husbandry and breeding of the Puerto Rican toad (Peltophryne lemur) with comments on its natural history. Zoo Biol. 4: 281-286. Mitchell, N.C. (1999): Effect of introduced ungulates on density, dietary preferences, home range, and physical condition of the iguana (Cyclura pinguis) on Anegada. Herpetologica 55: 7-17. Muths, E., Corn, P.S., Pessier, A.P., Green, D.E. (2003): Evidence for disease-related amphibian decline in Colorado. Biol. Conserv. 110: 357-365. Nicholson, K.L., Torrence, S.M., Ghioca, D.M., Bhattacharjee, J., Andrei, A.E., Owen, J., Radke, N.J.A., Perry, G. (2005): The influence of temperature and humidity on activity patterns of the lizards Anolis stratulus and Ameiva exsul in the British Virgin Islands. Carib. J. Sci. 41: 870-873. Ovaska, K., Caldbeck, J., Lazell, J. (2000): New records and distributional and ecological notes of leptodactylid frogs, Leptodactylus and Eleutherodactylus, from the British Virgin Islands. Breviora 508: 1-25. Overing, J.A. (1996): Green turtles with fibropapilloma disease in the BVI. Marine Turtle Newsletter 75: 17-18. Owen, J. (2005): The Cuban Tree Frog (Osteopilus septentrionalis): Diet, Reproduction, and Distribution of an Invasive Species in the British Virgin Islands. MS thesis, Texas Tech University.
Conservation of amphibians and reptiles in BVI
123
Owen, J., Perry, G. (2005): Anolis cristatellus wileyae (Virgin Islands Crested Anole). Saurophagy. Herp. Rev. 36: 444. Owen, J., Perry, G., Lazell, J., Egelhoff, J. (2005a): Osteopilus septentrionalis (Cuban tree frog). Distribution. Herp. Rev. 36: 76. Owen, J., Perry, G., Lazell, J., Petrovic, C. (2005b): Pseudemys nelsoni (Florida red-bellied turtle). Distribution. Herp. Rev. 36: 466. Owen, J., Perry, G., Lazell, J., Petrovic, C., Egelhoff, J. (2006): Osteopilus septentrionalis (Cuban tree frog). Colonization of the British Virgin islands. Herp. Rev. 37: 74-75. Perry, G. (1995): The Evolutionary Ecology of Lizard Foraging: a Comparative Study. Ph.D. dissertation, University of Texas, Austin. Perry, G. (2005): The Anolis lizards of Guana Island. In: Island: Fact and Theory in Nature, J. Lazell (Ed.), p. 186-190. Berkeley, California University Press. Perry, G., Lazell, J. (1997): Anolis stratulus (Saddled Anole). Nectivory. Herp. Rev. 28: 150-151. Perry, G., Mitchell, N. (2003): Guana and Necker Island population assessments 2002. Iguana 10: 49. Perry, G., Dmi’el, R., Lazell, J. (2004): Amphisbaena fenestrate (Virgin Islands worm lizard). Evaporative water loss. Herp. Rev. 35: 165-166. Perry, G., Lazell, J., LeVering, K., Mitchell, N. (2006): Reproduction and size in the highly endangered stout iguana, Cyclura pinguis. Carib. J. Sci., in press. Philibosian, R., Yntema, J.A. (1976): Records and status of some reptiles and amphibians in the Virgin Islands. I. 1968-1975. Herpetologica 32: 81-85. Platenberg, R.J., Boulon, R. (2006): Conservation status of reptiles and amphibians in the U.S. Virgin Islands. Appl. Herp. 3: 215-235. Powell, R., Henderson, R.W. (2005): Conservation status of Lesser Antillean reptiles. Iguana 12: 2-17. Powell, R., Henderson, R.W., Parmerlee, J.S., Jr. (2005): The Reptiles and Amphibians of the Dutch Caribbean: St. Eustatius, Saba, and St. Maarten. St. Eustatius, Netherlands Antilles, St. Eustatius National Parks Foundation. Powell, R., Perry, G., Henderson, R.W., Barun, A. (2006): Alsophis portoricensis anegadae (NCN). Aquatic activity. Herp. Rev., in press. Pregill, G. (1981): Late Pleistocene herpetofaunas from Puerto Rico. Univ. Kansas Mus. Nat. Hist. Misc. Pub. 71: 1-72. Pregill, G.K., Olson, S.L. (1981): Zoogeography of West Indian vertebrates in relation to Pleistocene climatic cycles. Ann. Rev. Ecol. Syst. 12: 75-98. Procter, D., Fleming, L.V. (Eds) (1999): Biodiversity: the UK Overseas Territories. Peterborough, Joint Nature Conservation Committee (www.jncc.gov.uk/pdf/OT_BVI.pdf). Rios-López, N. (2004): Anolis stratulus (Saddled Anole). Extrafloral herbivory. Herp. Rev. 35: 386. Reagan, D.P. (1992): Congener species distribution and abundance in a three-dimensional habitat: the rain forest anoles of Puerto Rico. Copeia 1992: 392-403. Rodda, G.H., Perry, G., Rondeau, R.J., Lazell, J. (2001): The densest terrestrial vertebrate. J. Trop. Ecol. 17: 331-338. Rogozinski, J. (1992): A Brief History of the Caribbean. Facts on File, New York. Salmon, M. (2005): Protecting sea turtles from artificial night lighting at Florida’s oceanic beaches. In: Ecological Consequences of Artificial Night Lighting, p. 141-168, Rich C., Longcore, T., Eds, Washington, D.C., Island Press. Schomburgk, R.H. (1832): Remarks on Anegada. J. Royal Geog. Soc. Lond. 2: 152-170. Smith, K.G. (2005): Effects of nonindigenous tadpoles on native tadpoles in Florida: Evidence of competition. Biol. Conserv. 123: 433-441. Stallard, R.F. (2001): Possible Environmental Factors Underlying Amphibian Decline in Eastern Puerto Rico: Analysis of U.S. Government Data Archives. Conserv. Bio. 15: 943-953. Thomas, R. (1999): The Puerto Rico area. In: Caribbean Amphibians and Reptiles, p. 169-179. Crother, B.I., Ed., San Diego, Academic Press.
124
G. Perry, G.P. Gerber
Tolson, P.J. (2005): Reintroduction Evaluation and Habitat Assessments of the Virgin Islands Tree Boa, Epicrates monensis granti, to the U.S. Virgin Islands. Grant T-1. Final report. Division of Fish and Wildlife, St. Thomas, 13 pp. U.S. Fish and Wildlife Service, (1980): Status of Virgin Islands boa clarified. Endangered Species Tech. Bul. 5: 12. U.S. Fish and Wildlife Service, (1999): Endangered and Threatened Wildlife and Plants 50 CFR 17.11 and 17.12. Division of Endangered Species, U.S. Fish and Wildlife Service, Washington, D.C. (http://www.fws.gov/endangered/wildlife.html#Species). Veitch, C.R., Clout, M.N. (Eds) (2002): Turning the Tide: the Eradication of Invasive Species (proceedings of the international conference on eradication of island invasives). Occasional Paper of the IUCN Species Survival Commission No. 27. (http://www.hear.org/articles/turningthetide/turningthetide.pdf). Wauer, R.H., Wunderle, J.M., Jr. (1992): The effect of hurricane Hugo on bird populations on St. Croix, U.S. Virgin Islands. Wilson Bul. 104: 656-673. Wing, E.S. (2001): Native American use of animals in the Caribbean. In: Biogeography of the West Indies, 2nd ed., p. 481-518. Woods, C.A., Sergile, F.E., Eds, Boca Raton, Florida, CRC Press. Wilson, S.M. (2001): The prehistory and early history of the Caribbean. In: Biogeography of the West Indies, 2nd ed., p. 519-527, Woods, C.A., Sergile, F.E., Eds, Boca Raton, Florida, CRC Press. Woods, C.A., Sergile, F.E. (Eds) (2001): Biogeography of the West Indies: Patterns and Perspectives, 2nd ed. Boca Raton, Florida, CRC Press. Wunderle, J.M., Mercado, J.E., Parresol, B., Terranova, E. (2004): Spatial ecology of Puerto Rican boas (Epicrates inornatus) in a hurricane impacted forest. Biotropica 36: 555-571. Accepted: May 29, 2006 (AH). Reprinted from Applied Herpetology 3: 237-256 (2006).
Addendum With few exceptions, the original paper remains accurate and the recommendations remain appropriate and largely un-implemented. However, some changes have occurred in the ensuing years that are worth noting. Eleutherodactylus antillensis — Native to the region, a population was recently intentionally established on Necker by the island’s owners. It is currently limited to the hotel area (C. Petrovic, unpubl. data). Eleutherodactylus johnstonei — The frogs were noted on August 16, 2008 by amateur herpetologist Alejandro Sanchez (pers. comm.), who is very familiar with the regional herpetofauna. He “found several males singing at night on the grounds of a restaurant at sea level” on Tortola and thought that this “seems to point at an introduction in plant produce or the like”. Eleutherodactylus lentus — Until it was reported from Jost Van Dyke (Perry, 2009a), this species was only known from the US Virgin Islands (USVI), where it is at risk because of habitat destruction (Platenberg and Boulon, 2006). The wellestablished population is most likely the result of a recent introduction, but impacts are unknown and the appropriate management response is unclear (Perry, 2009a). Osteopilus septentrionalis — Spread of this ubiquitous, damaging invasive appears to continue (Owen et al., 2006). Despite considerable effort searching (Perry
Conservation of amphibians and reptiles in BVI
125
et al., 2006), only a single individual has been captured on Guana Island (Perry, 2009b). In contrast, Cuban treefrogs can now be found all the way to the top of Sage Mountain on Tortola (G. Perry, unpubl. data). The 2009 drought appears to have slowed the spread of this species, which is not yet found in Jost Van Dyke, Great Camanoe, or Anegada (G. Perry and G. Gerber, unpubl. data). The species is now established on Moskito, however, following arrival within the last two years, probably as stowaways in containers of construction material (C. Petrovic, unpubl. data). Trachemys scripta elegans — Persistent reports of additional turtles in the retention ponds by the Beef Island airport have yet to be confirmed. Cyclura pinguis — Work on both the Anegada and Guana populations continues. Restoration of a self-sustaining population on Anegada remains a priority (IUCN, 2007) and progress toward this goal is being made. In 2006, Island Conservation (islandconservation.org) surveyed Anegada in consultation with the IUCN Iguana Specialist Group and produced a detailed plan for feral mammal removal, funding for which is being sought. In 2008, a proposed National Park on Anegada that includes the core iguana area cleared a major obstacle by passing the BVI Cabinet. Headstarting efforts continue as well and to date 115 headstarted iguanas have been returned to the wild on Anegada with an encouraging survival rate of 79% or higher (G. Gerber and K. Bradley, unpubl. data). A set of polymorphic microsatellite markers has been developed for the species (Lau et al., 2009) and studies of genetic diversity utilizing these markers are underway. Perry et al. (2007) studied reproduction and size, primarily of the Guana population, where animals are in better body condition than those previously reported from Anegada. Anderson et al. (2010) recently reported on the Guana population, which appears to primarily utilize relatively open areas and avoid the eastern part of the island, perhaps because of the noticeable grazing damage caused by invasive feral sheep. The Guana population was estimated in 2009, using mark-recapture and modern estimation techniques, at about 100 adults and 150 hatchlings (B. Bibles, unpubl. data). This estimate is slightly higher than previous estimates of about 100 animals (Perry and Mitchell, 2003), perhaps because of the large difference in methodology and search effort but perhaps showing a slight increase in the population. Unfortunately, many of the objectives identified by the IUCN (2007) and the original paper have yet to be carried out. In late May 2010, at least ten juvenile iguanas caught on Necker were released on Moskito, which is owned by the same person. More releases are apparently planned with the goal to establish a population on Moskito (C. Petrovic, unpubl. data). Iguana iguana — Repeated reports suggest green iguanas are arriving on Tortola via a barge operating between St. Thomas and West End (C. Petrovic, unpubl. data). Those reports suggest that at least some of the introductions may be intentional. There are unrelated regular reports of them throughout Tortola, including small numbers of individuals collected from Road Town, Cane Garden Bay, and East End. These are presumably escaped or released pets. Green iguanas may now be found
126
G. Perry, G.P. Gerber
on Jost Van Dyke, also as a result of an intentional attempt to establish them there (C. Petrovic, unpubl. data). Virgin Gorda populations seem to be thriving, with both adults and juveniles commonly observed at the Bitter End Yacht Club, Biras Creek, Leverick Bay, the Valley, and perhaps other locations. Elaphe guttata — The corn snake was not recorded in the original paper, but is known from the region. Several BVI reports and specimens have materialized since then. A snake was killed at the commercial port (18◦ 25 38.3 N, 64◦ 36 31.2 W) on May 2006 (C. Petrovic, unpubl. data). Two were killed or collected on Peter Island, one in 2008 and one in 2010. As with I. iguana, multiple snakes are arriving on Tortola via a barge operating between St. Thomas and West End (C. Petrovic, unpubl. data). Given the locations of initial sightings the source is likely to be related to commerce, rather than pets. The growing prevalence of Elaphe guttata, a humantolerant species with broad diet and climatic needs, is of great concern. It has the potential of becoming a major predator on native lizards, birds, and mammals, and may be able to compete with the native boa, Epicrates monensis. In addition there are new records of Hemidactylus mabouia (G. Perry, unpubl. data) and Epicrates monensis (Barker et al., 2009) from Great Camanoe. Encouragingly, a population of Sphaerodactylus parthenopion was found on Moskito Island, (C. Petrovic, unpubl. data) bringing the total number of known populations to two. A release of Red-footed Tortoises (Geochelone carbonaria) on Moskito is currently planned by the island’s owners (C. Petrovic, unpubl. data). We are concerned that future additions to the list of invasives in the BVI are likely, especially as much of the material used in “development” projects originates in Puerto Rico, the USVI, and Florida. We therefore recommend additional training of workers at the port and nursery industry to monitor invasive herpetofauna. An informal survey of BVI pet stores (C. Petrovic, unpubl. data) indicates that many people simply bring in their “pets” — often birds or turtles — from Puerto Rico or elsewhere, which makes both control and education efforts especially challenging. Although the global economic downturn has slowed or caused cancellation of some “development” plans, major projects are ongoing on Scrub Island (see http://scrubisland.com/) and Oil Nut Bay on Virgin Gorda (http://www.oilnutbay.com/home). These further decrease the amount of dry tropical forest available, and increase transport of both material and people within the BVI and between them and other locations. We thank Clive Petrovic (Road Town, Tortola) and Nancy K. Woodfield (BVI National Parks Trust) for crucial help with this update. Primary financial assistance came from The Conservation Agency via a grant from the Falconwood Corporation and the Zoological Society of San Diego.
References Anderson, W.M., Sorensen, G.E., Lloyd-Strovas, J.D., Arroyo, R.J., Sosa, J.A., Wulff, S.J., Bibles, B.D., Boal, C.W., Perry, G. (2010): Distribution and habitat use by the critically endangered stout
Conservation of amphibians and reptiles in BVI
127
iguana (Cyclura pinguis) on Guana Island, British Virgin Islands. IRCF Rept. Amphib. 17: 158165. Barker, B.S., Henderson, R.W., Powell, R. (2009): Geographic distribution. Epicrates monensis granti. Herpetol. Rev. 40: 455-456. Lau, J., Alberts, A.C., Chemnick, L.G., Gerber, G.P., Jones, K.C., Mitchell, A.A., Ryder, O.A. (2009): Isolation and characterization of 23 polymorphic microsatellite loci for a West Indian iguana (Cyclura pinguis) from the British Virgin Islands. Molec. Ecol. Res. 9: 1412-1414. Owen, J.L., Perry, G., Lazell, J., Petrovic, C., Egelhoff, J. (2006): Osteopilus septentrionalis: Colonization of the British Virgin Islands. Herpetol. Rev. 37: 74-75. Perry, G. (2009a): First record of the frog Eleutherodactylus lentus in the British Virgin Islands: Conservation implications of native or introduced status. Appl. Herpetol. 6: 185-187. Perry, G. (2009b): First record of Osteopilus septentrionalis on Guana Island, British Virgin Islands. Appl. Herpetol. 6: 191-192. Perry, G., Mitchell, N. (2003): Guana and Necker island population assessments 2002. Iguana 10(2): 49. Perry, G., Powell, R., Watson, H. (2006): Keeping invasive species off Guana Island, British Virgin Islands. Iguana 13: 272-277. Perry, G., Lazell, J., LeVering, K., Mitchell, N. (2007): Reproduction and size in the highly endangered stout iguana, Cyclura pinguis. Carib. J. Sci. 43: 155-159. Platenberg, R.J., Boulon, R.H., Jr. (2006): Conservation status of reptiles and amphibians in the U.S. Virgin Islands. Appl. Herpetol. 3: 215-235.
The amphibians and reptiles of the Cayman Islands: Conservation issues in the face of invasions A. C. Echternacht1,2 , F. J. Burton3 , J. M. Blumenthal4 1 Department of Ecology & Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996-1610, USA 2 Corresponding author; e-mail:
[email protected] 3 Blue Iguana Recovery Programme, P. O. Box 10308, Grand Cayman KY1-1003, Cayman Islands 4 Cayman Islands Department of Environment, P. O. Box 486, Grand Cayman KY1-1106, Cayman Islands
Abstract. The four islands of Cayman Islands are among the most isolated in the West Indies. They support 25 native species of amphibians and reptiles. Fifteen additional species have been deliberately or accidently introduced. The immediate source for 11 of the 15 is the United States. Eight of the 15 have become established. There have been two introductions in which both the source and target islands are in the Cayman Islands, one successful and the other a failure. Eleven native species have been evaluated with respect to CITES and/or IUCN. Nine species have not been evaluated and some of these may be found to warrant listing. Seventeen species, some with multiple subspecies, are endemic to the Cayman Islands. Threats to the native species of the Cayman Islands include habitat modification or destruction, over-exploitation, introduced species, and the effects of anthropogenic global climate change. Conservation actions are discussed, emphasizing marine turtles and Cyclura lewisi, as is legal protection afforded the herpetofauna. Key words: Amphibians; Cayman Islands; conservation; native species; non-native species; reptiles.
Introduction Small islands, isolated from other islands and continents as possible sources of colonists, tend to have low species richness and high endemism (MacArthur and Wilson, 1967). The herpetofauna of the Cayman Islands fits this description well. In addition, the islands are all low with little topographic relief and are fairly uniform with respect to vegetation. Only Grand Cayman has large areas of freshbrackish water. This lack of habitat diversity also contributes to the low richness of amphibians and reptiles. This richness is, however, increasingly enhanced by the deliberate or accidental introduction of non-native amphibians and reptiles, mostly from the United States.
130
A.C. Echternacht et al.
Some of these are native to North America, but others are derived from populations that represent earlier introductions to the United States. The number of introductions to the Cayman Islands, particularly Grand Cayman, is related to the rapid development of the islands since the 1960s and the consequent need to import products from the United States in support of a burgeoning tourism industry and an influx of nonnative colonists of the human kind. The impact of the increasing human population of the Cayman Islands is obvious. The impact of other sorts of biotic introductions, including amphibians and reptiles, is less obvious and much less well-studied. It is the purpose of this paper to (1) summarize the occurrence of non-native amphibians and reptiles on the islands, (2) discuss the conservation status of the native herpetofauna, (3) consider the threats, including non-native species, to the native herpetofauna, and (4) discuss measures being taken by the government of the Cayman Islands and NGOs to mitigate these threats. Special attention will be given to the Blue Iguana Recovery Programme, as an excellent example of a successful species recovery program, and to marine turtles.
The Cayman Islands The Cayman Islands are among the most isolated in the West Indies (Brunt and Davies, 1994). Grand Cayman, the largest of the four islands (area 197 km2 ; maximum elevation 18 m), lies about 300 km from both Cuba and Jamaica. Cayman Brac (38 km2 ; 43 m and Little Cayman (28 km2 ; 12 m) are separated by about 7 km and are 130 km northwest of Grand Cayman. Tiny unpopulated Owen Island (4.25 ha; <3 m) is located on South Hole Sound on the south side of Little Cayman. Grand Cayman, Cayman Brac and Little Cayman are emergent peaks on the eastwest Cayman Ridge, a westward extension of the Sierra Maestra mountains of Cuba (Jones, 1994). The surface of the islands is primarily limestone or coralline, with pockets of soil where the actions of wind and water have created depressions. The shorelines of the islands are, in many areas, comprised of white beach sand. Behind these, or standing alone, are limestone ironshores that have been weathered into razor-sharp formations, often over solution tunnels and pits that when overgrown and hidden by vegetation, make field work an adventure. Cayman Brac differs from the other three islands in topography. From sea level at its west end, it slopes upward to an impressive cliff at the east end. The north and south sides of the uplifted “slab” are increasingly steep as well, with numerous caves opening out toward the sea. The Cayman Islands have a tropical maritime climate characterized by little monthly variation in temperature and seasonal variation in precipitation (Burton, 1994). Seasons are defined by precipitation, with a summer wet season extending from May to November, and a winter dry season from November to April. The mean maximum and minimum January air temperatures are about 28◦ C and 22◦ C, respectively, and for July they are 32◦ C and 25◦ C, respectively. Mean annual rainfall for Cayman Brac is about 1100 mm, and for Little Cayman, it is about 1175 mm. On Grand Cayman, there is a pronounced east-west precipitation gradient, from
Conservation issues in the Cayman Islands
131
about 1100 mm annually in the east to about 1600 mm in the west. There is a less pronounced gradient on Cayman Brac, from about 1050 mm of annual rainfall in the east to 1175 mm in the central part of the island. Generally, March is the driest month and October the wettest. The islands lie within a track along which hurricanes frequently move from east to west during the wet season. The vegetation, described in detail by Burton (2008), is characterized as Dry Forest, Xerophytic Shrubland, Seasonally Flooded Forests and Shrublands, with mangroves prominent on Grand Cayman and, especially, around North Sound, Grand Cayman. The inland vegetation of Little Cayman is dominated by xerophytic shrubland, with mangrove forests concentrated around coastal ponds, especially near the south coast. On Cayman Brac, dry and xerophytic forests dominate the central, elevated plateau, and on low coastal platforms in sheltered areas. Xerophytic shrubland dominates the eastern region and in exposed coastal settings. The vegetation of Grand Cayman reflects the east-west precipitation gradient with xerophytic shrubland in the eastern interior grading to dry forest further west, especially on higher terrain. Cayman Islands census data (Government of the Cayman Islands, 2010; index mundi, 2010) indicate that the human population of the Cayman Islands increased slowly between 1802 (estimated population 933) and 1970 (10,068). It had reached an estimated 39,410 by 1999 and 49,035 by 2009. Most residents live on Grand Cayman. Tourism is the major industry. Most visitors arrive by either air (354,087 in 2000; 271,958 in 2009) or on cruise ships (1,030,857 in 2000; 1,520,372 in 2009). About 90 per cent of imports are from the United States, and many of these goods arrive on container ships. The Herpetofauna There have been two comprehensive accounts of the amphibian and reptile fauna of the Cayman Islands (Grant, 1940; Seidel and Franz, 1994). Since 1994, there have been several taxonomic changes associated with partitioning genera or elevating subspecies to species status (table 1). We have not included individual species Table 1. Classification history of native reptiles of the Cayman Islands comparing that employed by Seigel and Franz (1994) and that used in this paper. Seigel and Franz, 1994
This paper
Cyclura nubila lewisi Anolis sagrei luteosignifer
Cyclura lewisi Anolis luteosignifer
Tropidophis caymanensis caymanensis Tropidophis caymanensis parkeri Tropidophis caymanensis schwartzi Alsophis cantherigerus caymanus Alsophis cantherigerus fuscicauda Alsophis cantherigerus ruttyi
Tropidophis caymanensis Tropidophis parkeri Tropidophis schwartzi Cubophis caymanus Cubophis fuscicauda Cubophis ruttyi
132
A.C. Echternacht et al.
accounts herein, referring the reader instead to Seidel and Franz (1994) and Henderson and Powell (2009). Native amphibians and reptiles The native herpetofauna of the Cayman Islands currently includes 25 species, some represented by multiple subspecies (table 2). The numbers of species known to inhabit each of the four islands are: Grand Cayman 15, Cayman Brac 16, Little Cayman 14, Owen Island 5. Twenty species or subspecies are endemic to the Cayman Islands (table 2). Crocodylus rhombifer is not listed in table 2. The Cayman Islands are believed to have once supported large populations of both C. acutus and C. rhombifer. Subfossil remains of C. rhombifer and associated coproliths occur in abundance throughout Grand Cayman in saturated peat deposits accumulated in sinkholes (Morgan, 1994). Crocodylus acutus is not represented in the fossil record, presumably because its habitat offers fewer opportunities for preservation. Early maps of the Cayman Islands feature crocodilians on and around the coasts, and an April 1586 account of a visit from a vessel in Sir Francis Drake’s fleet speaks of both “alligatos” and “crocadiles” both in sea and on land. Indeed, the name “Cayman Islands” is likely derived from the Spanish, “Caiman” (Craton, 2003). Crocodylus rhombifer is extinct in the Cayman Islands, although oral history suggests that it may have survived until at least the late 19th Century. Many of the fossil sites for this species are in predominately dry land, and it seems inconceivable that crocodiles could occupy these areas in modern times. This suggests that historic climate change may have played a part in the decline of C. rhombifer in the Cayman Islands, though oral history confirms that persecution by humans was also a major factor toward the end. We consider Crocodylus acutus native to the Cayman Islands because, although there are currently no breeding populations in the Caymans, these islands are within the overall geographic range of the species and its absence at this time is almost certainly attributable to human intervention. Rare vagrants, presumably from populations in neighboring Cuba and/or Jamaica, are still sighted from time to time on all of the Cayman Islands (Garman, 1988; Grant, 1940; Morgan, 1994). Recent sightings include an eight foot long C. acutus/C. rhombifer hybrid on Grand Cayman on 30 December 2007 (hybridity was confirmed by genetic analysis), a seven to eight foot crocodile, species unknown, sighted off Little Cayman on 25 November 2008, and a 1.4 m C. acutus observed off Grand Cayman on 26 January 2009 (Cayman Islands Department of Environment [DoE] records, courtesy of M. DaCosta-Cottam and K.D. Godbeer). The crocodiles observed in 2008 and 2009 may have come from either Cuba or Jamaica, but the hybrid must have come from Cuba. It is known that Crocodylus porosus ride surface currents and its wide geographic distribution in the southeast Pacific suggests that some individuals make long oceanic voyages (Campbell et al., 2010). Ocean currents between Cuba and Jamaica would facilitate similar voyages in the Caribbean. Unfortunately, poorly
Conservation issues in the Cayman Islands
133
Table 2. Native amphibians and reptiles currently known to occur in the Cayman Islands. GC = Grand Cayman, CB = Cayman Brac, LC = Little Cayman, OI = Owen Island. N = Not reported. An asterisk indicates a subspecies or species that is endemic to the Cayman Islands. CITES appendices are shown as I or II; IUCN Redlist status (IUCN, 2010) by CR (critically endangered), EN (endangered), NT and LR (lower risk). Crocodiles (Crocodylidae) and sea turtles (Cheloniidae) have been observed or collected in close proximity to the indicated islands. Species
GC
CB
LC
OI
Conservation status CITES
IUCN
AMPHIBIA, Anura Hylidae Leptodactylidae
Osteopilus septentrionalis Eleutherodactylus planirostris
X X
X X
X
– –
LC LC
REPTILIA, Crocodylia Crocodylidae
Crocodylus acutus
X
X
X
I
V
X
X X X
X X
X
X
X
– – – – – I I – – –
– – – – – CR V – – –
– – – –
– – – –
– – – – I I I – –
– – – – – – – – –
I I I
EN EN CR
REPTILIA, Sauria Anguidae Gekkonidae
Iguanidae Leiocephalidae Polychrotidae
REPTILIA, Serpentes Dipsadidae
Tropidophiidae
Typhlopidae REPTILIA, Testudines Cheloniidae
Celestus maculates* Aristelliger praesignis praesignis Sphaerodactylus a. argivus* Sphaerodactylus a. bartschi* Sphaerodactylus a. lewisi* Cyclura lewisi* Cyclura nubila caymanensis* Leiocephalus carinatus granti* Leiocephalus c. varius* Anolis (Norops) conspersus conspersus* Anolis (Norops ) c. lewisi* Anolis (Norops) luteosignifer* Anolis maynardi* Anolis (Norops) sagrei
X X X X
X X
X X X X X X
Cubophis caymanus* Cubophis fuscicauda* Cubophis ruttyi* Tretanorhinus variabilis lewisi* Tropidophis caymanensis* Tropidophis parkeri* Tropidophis schwartzi* Typhlops caymanensis* Typhlops epactius*
X
Caretta caretta Chelonia mydas Eretmochelys imbricata
X X X
X X X X X X X X X X X
X X X
X X X
134
A.C. Echternacht et al.
informed fears for public safety weigh heavily against any chance of the recolonization of the Cayman Islands by C. acutus. The hybrid crocodile mentioned above, a young male, was speared under police direction in shallow coastal waters. Non-native amphibians and reptiles Two amphibian species and 13 reptile species have been introduced to the Cayman Islands, and two reptile introductions have been between islands within the Cayman Island group (table 3). The immediate source of 11 of these was the United States. Of these, five (Rhinella marina, Hemidactylus mabouia, Anolis equestris, Anolis (Norops) sagrei, and Ramphotyphlops braminus) had been introduced to the United States from elsewhere and then secondarily introduced to the Cayman Islands. Anolis maynardi, endemic to Little Cayman, has been successfully introduced on Cayman Brac (Franz et al., 1987), and Cyclura nubila caymanensis from either Cayman Brac or Little Cayman may have been unsuccessfully introduced on Grand Cayman (Grant, 1940). Of the 15 remaining introduced species which have been reported to have arrived from outside of the Cayman Islands, two are anuran species, eight are lizards, three are snakes, and two are turtles. Eight of the 15 species have become established in the Cayman Islands and five have not. One, Anolis equestris, arrived so recently (M. DaCosta-Cottam, K. Godbeer and T. Austin, 2010) that it cannot yet be determined whether the introduction will be successful. The eight successful introductions raise the number of amphibian and reptiles species inhabiting the Cayman Islands to 33 (34 if A. equestris becomes established). On the basis of the absence its fossil remains in peat moss deposits that contain many other vertebrate taxa (Seidel and Franz, 1994), Trachemys decussata is presumed to be introduced, but this has not been confirmed by molecular data. It seems apparent that the large number of tourists who visit the Cayman Islands each year are not the source of these introductions. Rather, introduced species are arriving in ships’ cargo which includes live plants where stowaways can hide. Many of these are foliage plants or trees grown in nurseries in Florida and are destined to beautify homes or resorts in the Cayman Islands. Building materials account for another large fraction of imports, and a substantial part of this is used in the construction of homes and resorts. Therefore, although tourists and immigrants do not actively transport live amphibians or reptiles to the Cayman Islands, the need to provide living quarters for those who stay longer than a single day (i.e., tourists other than cruise ship passengers) has promoted the introduction of non-native species. Conservation status Eleven of the species of amphibians and reptiles inhabiting the Cayman Islands have been evaluated for CITES (UNEP-WCMC, 2010) and/or IUCN (2010) listing, and two of these (both anurans) have an IUCN Redlist status of “Least Concern” (table 2). This is surprising, given the high level of endemism evident in the herpetofauna. Most of the potential candidates for listing, however, have not been
REPTILIA, Testudines Emydidae
Typhlopidae
REPTILIA, Serpentes Colubridae
Polycrotidae
Iguanidae
REPTILIA, Sauria Anguidae Gekkonidae
Species AMPHIBIA, Anura Bufonidae Microhylidae
Trachemys decussata angusta Trachemys scripta
Diadophis p. punctatus Pantherophis guttatus Ramphotyphlops braminus
Ophisaurus ventralis Gonatodes albogularis Hemidactylus mabouia Cyclura nubila caymanensis Iguana iguana Anolis carolinensis Anolis equestris Anolis garmani Anolis maynardi Anolis (Norops) sagrei
Rhinella marina Gastrophryne carolinensis
X X
X X X
X
X X X X X X X X
X X
GC
X
CB
Cuba? U.S.
U.S. U.S. U.S.
U.S. Jamaica? U.S. CB or LC Honduras? U.S. U.S. Jamaica LC U.S.
U.S. U.S.
Source
1 1
2 1 1
2 2 1 2 1 2 ? 2 1 1
2 1
Status
Seidel and Franz, 1994 Lever, 2003
Seidel and Franz, 1994 Franz et al., 1987 Echternacht and Burton, 2003
Seidel and Franz, 1994 Williams, 1964 Echternacht and Burton, 2002 Grant, 1940; Schwartz and Thomas, 1975 Franz and Seidel, 1994 Powell, 2002 M. DaCosta-Cottam, pers. com. Seidel and Franz, 1994 Franz et al., 1987 Minton and Minton, 1984; Kolbe et al., 2004
Burton and Echternacht, 2003 Seidel and Franz, 1994
Documentation
Table 3. Non-native amphibians and reptiles currently known to occur in the Cayman Islands. GC = Grand Cayman, CB = Cayman Brac, LC = Little Cayman, OI = Owen Island. Status: 1 = established: apparent persistent reproducing population(s); the species may or may not be expanding geographic range from site(s) of introduction. 2 = Reported in the wild at least once but no conclusive evidence suggesting that the species has become established or, if it had for a time (e.g., Cyclura nubila), is no longer present (but see text).
Conservation issues in the Cayman Islands 135
136
A.C. Echternacht et al.
evaluated with respect to the criteria employed by CITES and the IUCN so that they can be proposed for listing. For many of these species, even the most basic ecological data are lacking. These include abundance, habitat requirements, and measures of reproductive success. In particular, the two species of blindsnakes endemic to the Cayman Islands, Typhlops caymanensis (Grand Cayman) and T. epactius (Cayman Brac), are burrowers and seldom seen, and their population densities are unknown. They inhabit beach dune areas which are favored by developers (Henderson and Powell, 2009; Seidel and Franz, 1994).
Threats The litany of threats to the species of amphibians and reptiles of the Cayman Islands is heard with respect to the biotas of small islands world-wide. At the top of the list is habitat modification or destruction, often associated with uninformed planning and a lack of awareness, or possibly a lack of caring, about the fate of components of natural (and national) heritage. Coastal beach dune habitats are especially at risk. These environments are in demand for home sites and resorts and are fast disappearing. The economy of the Cayman Islands is based in large part on tourism, and tourists expect suitable housing and entertainment (which may include golf). Often, economics wins out when the difficult decision is made to clear a piece of land which may be prime habitat for a species found in no other habitat (see Typhlops caymanensis and T. epactius below). For some species, over-exploitation is a serious concern, and has led to the loss of a major resource with the collapse of sea turtle populations in the Cayman Islands (see below). Exploitation may also come in the form of illegal poaching of amphibians and reptiles for the pet trade. The accidental or deliberate introduction of non-native species can be a serious threat to native species which have no experience with the newcomers and to which they have had no time to adapt. Such non-native species need not be amphibians or reptiles; rats and mice will eat lizard eggs, for example, and adult rats will attack and eat juvenile lizards. Feral dogs and cats, both non-native in the context of the Cayman Islands, are notorious predators on islands world-wide. Road kills are a threat on Grand Cayman, Cayman Brac, and especially Little Cayman, which has experienced a dramatic increase in road traffic since a power plant was built on the island and the rate of development increased. Anthropogenic climate change resulting in rapid global temperature increase may be expected to lead to higher sea levels, inundating the habitats of species that occupy low-lying coastal areas. Finally, the unthinkable may occur. On the morning of 4 May 2008, a volunteer keeper at the fenced Cyclura lewisi breeding and head-starting facility in Queen Elizabeth II Botanic Park on Grand Cayman discovered that four adult iguanas had been killed, two others left for dead (and subsequently died), and another was missing. This senseless violence, documented by Burton (2010) reduced by 1/3 the adult breeding iguanas population at the facility.
Conservation issues in the Cayman Islands
137
Certain elements of the Cayman herpetofauna may be at greater risk than others and are discussed here. Cyclura lewisi and marine turtles are discussed in greater detail in the next section as well. Cyclura nubila caymanensis. This species, which occurs on Cayman Brac and Little Cayman, is threatened on several fronts. Increased tourism and road improvements, especially on Little Cayman where the species has been relatively abundant, have led to an increase in road kills, and construction behind beaches threatens important nesting areas. An increase in the number of dogs and cats on these islands is also a concern. Cyclura lewisi. Road kills and feral dogs and cats are major threats. The extent to which introduced Iguana iguana are a threat is unknown. Tropidophis caymanensis (Cayman Brac), T. parkeri (Little Cayman) and T. schwartzi (Grand Cayman) are also subject to predation by feral dogs and cats and, should the introduced cane toad (Rhinella marina) have survived flooding associated with Hurricane Ivan, or be successfully re-introduced (two were found by customs officials in a landscaping shipment from Florida in 2003 or 2004; in lit.; Mat DaCosta-Cottam, 25 March 2010), it may pose a threat to T. schwartzi as well. The skin secretions of R. marina are highly toxic and even partial ingestion of the toads has been proven fatal to Death Adders (Acanthophis praelongus; Elapidae) in Australia, where the toad has also been introduced (Hagman et al., 2009), and to Jamaican boas (Epicrates subflavus) in Jamaica (Wilson et al., 2010). Finally, the corn snake (Pantherophis guttatus; Colubridae) has been introduced on Grand Cayman where it is apparently established, though still relatively uncommon. It has a generalized vertebrate diet (Perry et al., 2003) and may compete with T. schwartzi. Typhlops caymanensis and T. epactius. As noted above, these snakes inhabit beach dune areas, and these are often given over to development. Anolis conspersus. There was initial concern that the introduction of Anolis sagrei to Grand Cayman might have negative consequences for the endemic A. conspersus. Anolis conspersus is a trunk-crown anole, meaning that it most often occurs on the trunks or in the crowns of trees, whereas A. sagrei is a trunk-ground anole. In the southeastern United States, the introduction of A. sagrei has led to dramatic population declines in another trunk-crown anole, A. carolinensis. Thus the concern with respect to A. conspersus. The evidence so far, however, suggests that A. sagrei is not negatively impacting A. conspersus (Gerber, 2000). Trachemys decussata. Should molecular data indicate that T. decussata is native, competition with introduced T. scripta should be considered a threat. The two species are ecologically similar as well as closely related (Seidel and Franz, 1994). Of the 30 species of amphibians and terrestrial or freshwater reptiles known to occur in the Cayman Islands, nine (30%) are introduced or assumed to be introduced (tables 1, 2). This assumes that Osteopilus septentrionalis, Eleutherodactylus planirostris are confirmed to be native, and Trachemys decussata is confirmed to be introduced. Of the nine introduced species we consider established, all but one (Anolis maynardi, representing an intraisland introduction within the Cayman Islands)
138
A.C. Echternacht et al.
occur only on Grand Cayman. For purposes of this discussion, Anolis sagrei, which is native to Little Cayman but introduced on Grand Cayman, is included among the nine introduced species. Grand Cayman is about five times larger than Cayman Brac, and seven times larger than Little Cayman but, excluding crocodilians and marine turtles, the number of species of amphibians and reptiles native to each of the three islands is remarkably similar (Grand Cayman = 9, Cayman Brac = 10, Little Cayman = 9). The total count for Grand Cayman, however, rises to 17 with the addition of the eight introduced species which are considered established. This raises the question of the degree to which the terrestrial/freshwater herpetofauna of Grand Cayman is saturated. It is not possible to answer this question at this time. With the possible exception of Trachemys decussata, all of the introductions have almost certainly occurred in the 70 years since Lewis (1940) first documented the entire herpetofauna of the Cayman Islands, and most have been reported since 1983. The populations of several of the established species appear to be small and geographically restricted. Their long-term prospects for survival are unknown. Some species of unknown status (e.g., Anolis equestris) may become established, and additional successful introductions may occur. Cayman Brac and Little Cayman have not experienced the wave of introductions that have impacted Grand Cayman but vigilance is recommended. These islands are undergoing rapid development and the rate of transport of goods from Grand Cayman and elsewhere is increasing. Conservation Actions A first principle of effective conservation efforts is that all stake-holders must be involved. Fortunately, it has been our experience that the people and the government of the Cayman Islands generally support a conservation ethic when it comes to the preservation of elements of their national heritage (but see “Threats” above). Three examples are given below. Illegal trade in wildlife Some forms of exploitation of wildlife are more egregious than others. In 2000, three German men were arrested and charged with a variety of offenses associated with the illegal collecting of animals, mostly reptiles, and plants in the Cayman Islands. When apprehended at the airport as they attempted to depart Grand Cayman, they were found to have in their possession over 1000 live plants and animals, including 930 Anolis conspersus, 112 Leiocephalus carinatus varius, and four Tropidophis caymanensis, all to supply the pet trade and collectors in Europe. Included were species that they had smuggled out of the Bahamas before coming to the Caymans. The investigation leading up to the arrests involved The Cayman Islands National Trust, Department of Agriculture, Customs, Immigration, Department of Environment, and Civil Aviation, but the authorities had been alerted by a concerned local resident. All three were convicted, fined, and deported, but only after spending a couple of months in a prison on Grand Cayman.
Conservation issues in the Cayman Islands
139
The Grand Cayman blue iguana Another example of what can be done when multiple stake-holders work together involves the Critically Endangered Grand Cayman blue iguana, Cyclura lewisi (Burton, 2004). When first described (Grant, 1940), the species was already close to extinction, with local farmers quoted as saying that they had been too scarce to be worth hunting since 1925. A 1988 unpublished report to the Cayman Islands Government by Roger Avery suggested that the species had remained bottlenecked at an extremely low population for over 50 years since the observations by Grant in 1938. Avery saw only two iguanas over two weeks of intensive surveys and interviews in the east interior of Grand Cayman. Avery’s findings stimulated the Cayman Islands Government to ask the newly formed National Trust for the Cayman Islands to launch a conservation initiative for Cyclura lewisi, which commenced with a small-scale captive breeding effort in 1990. This led in turn to a longer-term survey of the wild population in Grand Cayman’s east interior over the years 1992-1993 which showed a population in the range of 100-250 surviving in small isolated clusters amid a mosaic of natural xerophytic shrubland and traditional farms (Burton, 2010). It is unlikely that this represented any increase in population since Avery’s survey in 1988, rather reflecting the far greater duration of the 1992-1993 survey. However, a repeat survey in 2002 revealed a catastrophic new decline, attributable to land use changes, road development, and incursions of free-roaming dogs, in addition to the long-extant predation pressure on hatchlings from a widespread feral cat population. Iguanas were absent from most of the locations which were active in 1992-1993. The surviving wild population was estimated to number between 10 and 25, with indications that the species was at or very near functional extinction. The early efforts of the National Trust for the Cayman Islands gradually evolved into an integrated conservation effort for Cyclura lewisi and its habitat, resulting in the creation, in 2002, of the Blue Iguana Recovery Programme (Burton, 2010). By gathering founders for captive breeding from specimens held captive by members of the community, the captive breeding effort was scaled up at the same time as field research clarified key elements of the ecology of the species, such as habitat use (Goodman et al., 2005a), spatial ecology (Goodman et al., 2005b), and activity patterns and foraging behavior (Goodman, 2007). Pilot releases of captive F1 individuals were carried out in the 26 hectare QE II Botanic Park on Grand Cayman. Many of these iguanas established permanent territories in the Park and began breeding in 2001. By 2004, the free-roaming QE II Botanic Park iguanas were nesting with sufficiently large egg clutches to supplement the production of the captive breeding program, and the numbers available for release into the wild rose rapidly. Starting in 2004, large numbers of two-yearold head-started iguanas from both captive-bred and wild nests were released into dry shrubland habitat within the 253 hectare Salina Reserve, a protected area in northeastern Grand Cayman. By 2010, some 300 young iguanas had been released
140
A.C. Echternacht et al.
into the Salina Reserve, with another 30 permanently settled in the QE II Botanic Park. The Salina Reserve released population began to breed in 2006. The long-term future of Cyclura lewisi now depends as much on protection and management of wild habitat as on the direct conservation actions which are leading to significant recovery. Suitable habitat in the Salina Reserve, only about 14% of the 253 hectares (IRCF 2009), is estimated to be able to support no more than 400 iguanas, while the QE II Botanic Park population is too small to be genetically viable without active management. Fortunately, the government of the Cayman Islands has committed to protecting an additional 81 hectares to the east of the Salina Reserve. This is expected to provide habitat for additional releases such that the total wild population in protected areas may reach ca. 1000 individuals. Assessing the long-term effectiveness of these efforts to restore a self-sustaining wild population of Grand Cayman blue iguanas will require ongoing monitoring. Dispersal of iguanas out of the protected areas, incursion of invasive predatory mammals, and scarcity of nesting habitat remain issues of concern. A high level of community support for the conservation of Cyclura lewisi is being sustained in the Cayman Islands, stimulated by the charismatic “flagship” nature of the iguanas themselves, the ongoing major effort of the Blue Iguana Recovery Programme, and the National Trust, which is devoted to awareness and education. This, together with a strong network of local and international partners, and a commitment to science-directed, results-oriented conservation, are some of the factors that have led to the successes that the Programme has achieved to date. West Indian Rock Iguanas in their own climate zones are relatively easy to breed and head-start, are adaptable to man-modified habitats, and when released from captivity, can adapt to life in the wild without significant pre-conditioning. Work with the Grand Cayman blue iguana suggests that as a group, these iguanas can be highly responsive to well-planned interventions. Marine turtles The Cayman Islands once hosted one of the worlds’ largest marine turtle rookeries (Groombridge, 1982). Historical reports from the 18th century suggest that every summer millions of green turtles (Chelonia mydas) migrated to the Cayman Islands to nest — such that “vessels, which have lost their latitude in hazy weather, have steered entirely by the noise which these creatures make in swimming to attain the Caymana isles” (Long, 1774). In addition to the green turtle rookery, the islands also hosted abundant nesting by loggerhead (Caretta caretta), leatherback (Dermochelys coriacea), and hawksbill (Eretmochelys imbricata) turtles (Lewis, 1940). However, by the early 1800s, massive commercial exploitation had resulted in near-extirpation of Cayman Islands marine turtle rookeries (Lewis, 1940) and by 1900 populations were considered locally extinct (Groombridge, 1982). In 1968, a commercial green turtle farming operation — the Cayman Turtle Farm (CTF) — was established in Grand Cayman with the aim of marketing turtle meat and other turtle products (Wood, 1991) and replenishing wild turtle stocks
Conservation issues in the Cayman Islands
141
through captive breeding (Wood and Wood, 1993). Between 1980 and 2001, CTF released over 30,000 hatchling and yearling green turtles into Cayman waters, of which 80% were tagged with titanium flipper tags and/or “living tags” — created by transplanting a disk of lightly colored plastron into the darker carapace (Wood and Wood, 1993; Bell et al., 2005). Overseas tag returns from farm-released green turtles have been obtained from fisheries and research programs in the Caribbean and Florida (232 returns). Within the Cayman Islands, both locally resident juvenile turtles (154 returns) and sexually dimorphic or reproductively active males and females (6 returns) have been recaptured or observed (Wood and Wood, 1994; Bell et al., 2005). Between 1971 and 1991, ad hoc surveys by the Cayman Turtle Farm detected 79 nests in the wild by green, loggerhead, hawksbill, and leatherback turtles (Wood and Wood, 1994). Detailed monitoring of marine turtle nesting beaches by the Cayman Islands Government Department of Environment (DoE) began in 1998 (Aiken et al., 2001). The first six years of nesting data revealed no leatherback nesting and an annual mean of <1 hawksbill nest, 26 loggerhead nests and 26 green turtle nests (Bell et al., 2007). Since then, hawksbill and loggerhead nesting has remained relatively constant and a considerable increase in green turtle nesting has been observed. More than 100 green turtle nests were recorded for the first time in 2008 (DoE unpublished data). While numbers remain low, fertilization success averages 78% for loggerhead nests and 81% for green turtle nests, showing no reduction in fertility relative to larger populations (Bell et al., 2009). This continued viability may be attributable to behavioral mechanisms enhancing mate-finding, even at low population densities (i.e., natal philopatry and congregation of male and female turtles in breeding areas) and to genetic variation maintained through multiple paternity and mating on migratory routes and foreign foraging grounds (Bell et al., 2009). Indeed, satellite tracking indicates that Cayman Islands loggerhead and green turtle nesting populations are highly migratory, with post-nesting females travelling to foraging grounds in Nicaragua, Mexico, Belize, Guatemala, Honduras, and the Florida Keys (Blumenthal et al., 2006). In addition to supporting green and loggerhead nesting populations, the Cayman Islands host foraging aggregations of juvenile hawksbill and green turtles (Bell et al., 2008; Blumenthal et al., 2009b; Blumenthal et al., 2010). Genetic research has demonstrated that juvenile hawksbills originate from jurisdictions spanning the Caribbean basin (Blumenthal et al., 2009a). Integration of genetic and oceanographic data indicates that ocean currents drive patterns of distribution for Caribbean hawksbill neonates and thus influences connectivity and conservation requirements: while some foraging areas experience high levels of local recruitment, the Cayman Islands are more diverse, complicating management of this stock (Blumenthal et al., 2009a). For green turtles, tag returns from the Cayman Turtle Farm show recruitment of captive-raised individuals to the wild (Wood and Wood, 1993;
142
A.C. Echternacht et al.
Bell et al., 2005; Blumenthal et al., 2010), but a genetic study has not yet been conducted to evaluate the extent of this contribution. For juvenile turtles in the Cayman Islands, a broad size distribution (hawksbills: 20.5-62.6 cm straight carapace length, greens: 32.8-80.7 cm curved carapace length), slow growth rate (hawksbills: 3.0 cm ± 0.9 cm/yr, greens: 4.1 ± 2.2 cm/yr), and multiple local recaptures suggest long-term residence in some individuals (Blumenthal et al., 2009b; Blumenthal et al., in press). Upon nearing maturity, both hawksbills and green turtles appear to undergo a developmental migration to spatially distinct adult foraging habitats — evidenced by an absence of the larger size classes in local capture studies and by the presence of tag returns from overseas (Blumenthal et al., 2009b; DoE unpublished data). Within the Cayman Islands, habitat use by hawksbills includes areas of hardbottom, reef, and reef wall (Blumenthal et al., 2009b). Deployment of time depth recorders (TDRs) shows significant vertical structuring of foraging habitat, with larger turtles diving to greater depths (Blumenthal et al., 2009c). Given the narrow shelf, deep dives (to nearly 100 m) substantially increase available habitat and may buffer against anthropogenic and natural degradation of shallow reefs, as well as create a broad ecological footprint over a range of depths (Blumenthal et al., 2009c). Deployment of ultrasonic tags indicates that, during long term movements, hawksbills cross the boundaries of Cayman Islands marine protected areas (Blumenthal et al., 2009c). Similarly, deployment of TDRs and ultrasonic tags on juvenile green turtles indicates that individuals regularly travel from a shallow seagrass lagoon, where they are protected from a legal marine turtle fishery, to areas outside the reef crest, where they are exposed to legal take (see Legal protection below) (Blumenthal et al., 2010). During their life-cycle, Cayman Islands marine turtles face a wide range of anthropogenic threats. Nesting turtles are threatened by coastal development and illegal take in the Cayman Islands (Bell et al., 2006; Bell et al., 2007) and by directed and incidental take during transboundary reproductive migrations (Blumenthal et al., 2006). Similarly, legal, illegal, and incidental take, entanglement in discarded fishing gear, hurricanes, predation, habitat degradation, and disease (Blumenthal et al., 2009b; Blumenthal et al., 2010; Wood and Wood, 1993) have a cumulative impact on juveniles during the many years they are present on foraging grounds (Blumenthal et al., 2009b). Thus, the continuation and expansion of both local and regional initiatives are necessary to effectively manage migratory Cayman Islands marine turtles. Legal protection Marine turtles and “iguanas” (Cyclura rather than the introduced Iguana iguana) are the only reptiles that are directly protected under domestic legislation in the Cayman Islands. Marine turtles in the Cayman Islands were first protected in 1978, when regulations were put into place prohibiting possession of eggs and banning taking
Conservation issues in the Cayman Islands
143
of nesting females from May through September (Cayman Islands Government, 1978). In 1985, legislation was amended, extending the closed season from May to October and limiting harvesting to those who had traditionally taken turtles in Cayman waters (Cayman Islands Government, 1985). Licensing conditions set a quota of six turtles per licensee, stipulated minimum size limits for legal capture (54.5 kg for green and loggerhead turtles and 36.4 kg for hawksbill turtles) and restricted capture locations to areas outside the reef crest. All captured turtles were inspected by fisheries officers, and the harvest was well monitored (Richardson et al., 2006), but setting of minimum, rather than maximum, size limits allowed rare and reproductively valuable adult turtles to be taken (Bell et al., 2006). In 2008, legislation was amended to extend the closed season from April to November, introduce gear restrictions such as banning set-nets, and institute a maximum size limit to protect subadult and adult turtles. Licensing conditions stipulate size limits of no less than 40 and no more than 60 cm curved carapace length for legal take of green and loggerhead turtles, and prohibit taking of hawksbill turtles (Cayman Islands Government, 2008). Iguanas are protected under the Animals Law (Law 8 of 1976) which states that “iguanas” may not be killed or captured from the wild, nor kept captive. An Exemption Order permits the Cayman Islands National Trust, and by extension, the Blue Iguana Recovery Programme, to conduct conservation work including captive breeding. The Animals Law also provides some protection for birds, but no reptiles other than iguanas are included. An amendment to the Animals Law in 2010 distinguished Cyclura species from the introduced Iguana iguana, so that only Cyclura species remain protected. A new National Conservation Law has been drafted which inter alia would address protection of endemic and endangered species in a modern framework. It has been considered by successive administrations but has yet to be adopted. The Cayman Islands are party to the CITES Convention through the UK, and domestic legislation implementing CITES does place effective controls on international trade in endangered native wildlife, including Appendix I species such as Cyclura and Appendix II species such as Tropidophis. Habitat protection in terrestrial environments is provided for primarily in the National Trust for the Cayman Islands Law, which provides for the Trust to own and protect property, including land in its natural state, in perpetuity. A weaker level of protection is afforded by the Animals Law which provides for the creation of animal sanctuaries. In practice, these have been applied only to brackish ponds of primary importance to wading birds. Marine Parks regulations protect the quite extensive land-sea mangrove interface in Grand Cayman as part of an Environmental Zone which, along with other Marine Park Categories, includes extensive sea turtle feeding habitat. Regulations under the Development and Planning Law require modest setbacks from the sea for coastal construction, but fail to address beach vegetation and lighting concerns that affect nesting marine turtles.
144
A.C. Echternacht et al.
Conclusions The Cayman Islands support a herpetofauna that includes a relatively large number of endemic species and a growing number of introduced species. As humans settled the islands they brought with them, deliberately or accidentally, a number of other animals which threatened the native reptiles. Over the past 40 or so years, since mosquitoes were controlled, the islands have witnessed a spectacular increase in human population, augmented by an increasing number of tourists and other visitors. The combined pressures of human population growth and density, development accompanied by inevitable habitat destruction, and the introduction of non-native species, have the potential of having serious negative consequences for the native herpetofauna, as well as other elements of the native biota. Fortunately, the citizens of the Cayman Islands have demonstrated an admirable conservation ethic and desire to preserve as much as possible of their natural heritage. We hope that they are successful.
Acknowledgements. We would like thank the staffs of the National Trust for the Cayman Islands and the Department of Environment for facilitating our work in the Cayman Islands, and for their efforts on behalf of the flora and fauna of the islands and surrounding waters. We would particularly like to acknowledge Gina Ebanks-Petrie, Director of DoE, for her assistance and support. Mat DaCostaCottam has always been available to answer questions, Kristan Godbeer was kind enough to provide information on recent crocodile sightings, and Jeremy Olynik provided the area of Owens Island. For their assistance in initiating, operating and expanding marine turtle research in the Cayman Islands, we thank Brendan Godley and Annette Broderick at the University of Exeter, the Cayman Islands Department of Environment staff, and numerous volunteers. Marine turtle research was supported by the Darwin Initiative, The National Environment Research Council, the National Fish and Wildlife Foundation, the Turtles in the Caribbean Overseas Territories project, the Wider Caribbean Sea Turtle Conservation Network, and SEATURTLE.ORG. We would also like to thank two anonymous reviewers and the editors for suggestions that substantially improved the manuscript. The senior author would also like to thank John E. Davies who, as Director of the Mosquito Control Unit, antecedent to the DoE, provided early logistical support and encouraged pursuit of research in the Cayman Islands which didn’t involve mosquitoes, mosquito repellant, and pesticides.
References Aiken, J.J., Godley, B.J., Broderick, A.C., Austin, T.J., Ebanks-Petrie, G., Hays, G.C. (2001): Two hundred years after a commercial marine turtle fishery: The current status of marine turtles nesting in the Cayman Islands. Oryx 35: 145-152.
Conservation issues in the Cayman Islands
145
Bell, C., Parsons, J., Austin, T.J., Broderick, A.C., Ebanks-Petrie, G., Godley, B.J. (2005): Some of them came home: The Cayman Turtle Farm headstarting project for the green turtle Chelonia mydas. Oryx 39: 137-148. Bell, C.D., Blumenthal, J.M., Austin, T.J., Solomon, J.L., Ebanks-Petrie, G., Broderick, A.C., Godley, B.J. (2006): Traditional Caymanian fishery may impede local marine turtle population recovery. Endang. Species Res. 2: 63-69. Bell, C., Solomon, J.L., Blumenthal, J.M., Austin, T.J., Ebanks-Petrie, G., Broderick, A.C., Godley, B.J. (2007): Monitoring and conservation of critically reduced marine turtle nesting populations: Lessons from the Cayman Islands. Anim. Conserv. 10: 39-47. Bell, C.D., Blumenthal, J.M., Austin, T.J., Ebanks-Petrie, G., Broderick, A.C., Godley, B.J. (2008): Harnessing recreational divers for the collection of sea turtle data around the Cayman Islands. Tourism Marine Environ. 5: 245-257. Bell, C.D., Blumenthal, J.M., Broderick, A.C., Godley, B.J. (2009): Investigating potential for depensation in marine turtles: How low can you go? Conserv. Biol. 24: 226-235. Blumenthal, J.M., Solomon, J.L., Bell, C.D., Austin, T.J., Ebanks-Petrie, G., Coyne, M.S., Broderick, A.C., Godley, B.J. (2006): Satellite tracking highlights the need for international cooperation in marine turtle management. Endang. Species Res. 2: 51-61. Blumenthal, J.M., Abreu-Grobois, A., Austin, T.J., Broderick, A.C., Bruford, M.W., Coyne, M.S., Ebanks-Petrie, G., Formia, A., Meylan, P.A., Meylan, A.B., Godley, B.J. (2009a): Turtle groups or turtle soup: Patterns of dispersal of hawksbill turtles in the Caribbean. Mol. Ecol. 18: 441-485. Blumenthal, J.M., Austin, T.J., Bell, C.D., Bothwell, J.B., Broderick, A.C., Ebanks-Petrie, G., Gibb, J.A., Luke, K.E., Olynik, J.R., Orr, M.F., Solomon, J.L., Godley, B.J. (2009b): Ecology of hawksbill turtles Eretmochelys imbricata in a western Caribbean foraging area. Chelonian Conserv. Biol. 8: 1-10. Blumenthal, J.M., Austin, T.J., Bothwell, J.B., Broderick, A.C., Ebanks-Petrie, G., Olynik, J.R., Orr, M.F., Solomon, J.L., Witt, M.J., Godley, B.J. (2009c): Diving behaviour and movements of juvenile hawksbill turtles Eretmochelys imbricata on a Caribbean coral reef. Coral Reefs 28: 5565. Blumenthal, J.M., Austin, T.J., Bothwell, J.B., Broderick, A.C., Ebanks-Petrie, G., Olynik, J.R., Orr, M.F., Solomon, J.L., Witt, M.J., Godley, B.J. (2010): Life in (and out of) the lagoon: Insights into movements of green turtles using time depth recorders. Aquatic Biol. 9: 113-121. Brunt, M.A. and Davies, J.E. (Eds) (1994): The Cayman Islands: Natural History and Biogeography, Dordrecht, The Netherlands, Kluwer Academic Publishers. Burton, F.J. (1994): Climate and tides of the Cayman Islands. In: The Cayman Islands: Natural History and Biogeography, p. 51-60. Brunt, M.A., Davies, J.E., Eds, Dordrecht, The Netherlands, Kluwer Academic Publishers. Burton, F.J. (2004): Cyclura lewisi. In: IUCN, 2009. IUCN Red List of Threatened Species. Version 2009.2. http://www.iucnredlist.org Burton, F.J. (2008): Threatened Plants of the Cayman Islands — The Red List. London, Kew Publishers. Burton, F.J. (2010): The Little Blue Book: A Short History of the Grand Cayman Blue Iguana. San Jose, California, USA, International Reptile Conservation Foundation. Burton, F.J., Echternacht, A.C. (2003): Geographic distribution: Bufo marinus (Cane Toad). Herpetol. Rev. 34: 257. Campbell, H.A., Watts, M.E., Sullivan, S., Read, M.A., Choukroun, S., Irwin, S.R. and Franklin, C.E. (2010): Estuarine crocodiles ride surface currents to facilitate long-distance travel. J. Anim. Ecol. 79: 955-964. Cayman Islands Government (1978): Marine Conservation (Turtle Protection) Regulations, 1978. http://faolex.fao.org/docs/pdf/cay24164.pdf Cayman Islands Government (1985): The Marine Conservation (Turtle Protection) (Amendment) Regulations, 1985. http://faolex.fao.org/docs/pdf/cay24166.pdf
146
A.C. Echternacht et al.
Cayman Islands Government (2008): The Marine Conservation (Turtle Protection) (Amendment) Regulations (2008 revision). http://www.gazettes.gov.ky Cayman Islands Government, Economics and Statistics Office (2010): Cayman Islands Popu-lation census 1979. http://www.eso.ky/pages?page=populationandhousingcensus 1999. Craton, M. (2003): Founded Upon the Seas – A History of the Cayman Islands and Their People. Kingston, Jamaica, Ian Randle Publishers. DaCosta-Cottam, M., Godbeer, K., Austin, T. (2010): Knight Anoles (Anois equestris) on Grand Cayman Island. IRCF Rept. Amphib. 17: 122. Echternacht, A.C., Burton, F.J. (2002): Geographic distribution: Hemidactylus mabioua (Amerafrican House Gecko). Herpetol. Rev. 33: 148. Echternacht, A.C., Burton, F.J. (2003): Geographic distribution: Ramphotyphlops braminus (Brahminy Blindsnake). Herpetol. Rev. 34: 265-266. Franz, R., Morgan, G.S., Davies, J.E. (1987): Some recent introductions of reptiles in the Cayman Islands. Herpetol. Rev. 18: 10-11. Garman, S. (1888): Reptiles and batrachians from the Caymans and the Bahamas. Bull. Essex Inst. 20: 101-113. Gerber, G.P. (2000): Interactions between introduced and native Anolis lizards in Florida and Grand Cayman Island. Unpubl. Ph.D. dissertat., Univ. Tennessee, Knoxville, USA. Goodman, R.M. (2007): Activity patterns and foraging behavior of the endangered Grand Cayman blue iguana, Cyclura lewisi. Carib. J. Sci. 43: 73-86. Goodman, R.M., Burton, F.J., Echternacht, A.C. (2005a): Habitat use of the endangered iguana Cyclura lewisi in a human-modified landscape on Grand Cayman. Anim. Conserv. 8: 397-405. Goodman, R.M., Echternacht, A.C., Burton, F.J. (2005b): Spatial ecology of the endangered iguana, Cyclura lewisi, in a disturbed setting on Grand Cayman. J. Herpetol. 39: 402-408. Grant, C. (1940 [1941]): The herpetology of the Cayman Islands. Bull. Inst. Jamaica, Sci. Ser. 2: iv + 65. Groombridge, B. (1982): The IUCN Amphibia-Reptilia Red Databook, Part I, Testudines, Crocodylia, Rhynchocephalia. Gland, Switzerland, IUCN. Hagman, M., Phillips, B.L., Shine, R. (2009): Fatal attraction: Adaptations to prey on native frogs imperil snakes after invasion of toxic toads. Proc. Royal Soc. B 276: 2813-2818. Henderson, R.W., Powell, R. (2009): Natural History of West Indian Reptiles and Amphibians. Gainesville, Univ. Press of Florida. index mundi (2010): Cayman Islands population. http://www.indexmundi.com/cayman_islands/population.html IRCF (International Reptile Conservation Foundation). (2009): New nature reserve for critically endangered blue iguana. Press release, 31 March. IUCN. (2010): IUCN Red List of Threatened Species. Version 2010.1. http://www.iucnredlist.org Jones, B. (1994): Geology of the Cayman Islands. In: The Cayman Islands: Natural History and Biogeography, p. 13-49. Brunt, M.A., Davies, J.E., Eds, Dordrecht, The Netherlands, Kluwer Academic Publishers. Kolbe, J.J., Glor, R.E., Rodriguez Schettino, L., Chamizoi Lara, A., Larson, A., Losos, J.B. (2004): Genetic variation increases during biological invasion by a Cuban lizard. Nature 431: 177-181. Lever, C. (2003): Naturalized Reptiles and Amphibians of the World. Oxford, UK, Oxford Univ. Press. Lewis, C.B. (1940): The Cayman Islands and marine turtle. In: The Herpetology of the Cayman Islands, p. 56-65. Grant, C. Ed., Kingston, Jamaica, Bull. Inst. Jamaica Sci. Ser. 2. Long, E. (1774): History of Jamaica, or General Survey of the Ancient and Modern State of that Island. London, UK, George Metcalf, Frank Cass and Co. MacArthur, R.H., Wilson, E.O. (1967): The Theory of Island Biogeography. Princeton, New Jersey, USA, Princeton Univ. Press. Minton, S.A., Minton, M.R. (1984): Geographic distribution: Anolis sagrei. Herpetol. Rev. 15: 77.
Conservation issues in the Cayman Islands
147
Morgan, G.S. (1994): Late Quaternary fossil vertebrates from the Cayman Islands. In: The Cayman Islands: Natural History and Biogeography, p. 465-508. Brunt, M.A., Davies, J.E., Eds. Dordrecht, The Netherlands, Kluwer Academic Publishers. Perry, G., Pierce, J., Griffin, D., van Buurt, G., Lazell, J. (2003): Elaphe guttata guttata (Corn Snake). Herpetol. Rev. 34: 264. Powell, R. (2002): Geographic distribution: Anolis carolinensis. Herpetol. Rev. 33: 321. Richardson, P., Broderick, A., Campbell, L., Godley, B., Ranger, S. (2006): Marine turtle fisheries in the UK overseas territories of the Caribbean: Domestic legislation and the requirements of multilateral agreements. J. Internat. Wildl. Law Policy 9: 223-246. Seidel, M.E., Franz, R. (1994): Amphibians and reptiles (exclusive of marine turtles) of the Cayman Islands. In: The Cayman Islands: Natural History and Biogeography, p. 407-433. Brunt, M.A., Davies, J.E., Eds, Dordrecht, The Netherlands, Kluwer Academic Publishers. UNEP-WCMC (2010): UNEP-WCMC Species Database: CITES-Listed Species. http://www.unepwcmc.org/isbd/CITES Williams, E.E. (1964): Remarks on the relationships of reptiles and amphibians of the Cayman Islands. Occ. Pap. Mollusk, Mus. Comp. Zool, Harvard Univ. 2: 383-384. Wilson, B.S., Koenig, S.E., van Veen, R., Miersma, E., Rudolph, D.C. (2010): Cane toads a threat to West Indian wildlife: Mortality of Jamaican boas attributable to toad ingestion. Biol. Invasions doi: 10.1007/s10530-010-9787-7. Wood, F.F. (1991): Turtle culture. In: Production of Aquatic Animals, p. 224-234. Nash, C.E., Amsterdam, the Netherlands, Elsevier Science Publishers. Wood, F.F., Wood, J.R. (1993): Release and recapture of captive reared green sea turtle, (Chelonia mydas) in the waters surrounding Grand Cayman. Herpetol. J. 3: 84-89. Wood, F.F., Wood, J.R. (1994): Sea turtles of the Cayman Islands. In: The Cayman Islands: Natural History and Biogeography, p. 229-236. Brunt, M.A., Davies, J.E. Eds, Dordrecht, the Netherlands, Kluwer Academic Publishers.
Accepted: October 19, 2010 (BSW).
A report on the status of the herpetofauna of the Commonwealth of Dominica, West Indies Anita Malhotra1,3 , Roger S. Thorpe1 , Eric Hypolite2 , Arlington James2 1 School
of Biological Sciences, University of Wales Bangor, Gwynedd LL57 2UW, UK Wildlife and Parks Division, Botanic Gardens, Roseau, Commonwealth of Dominica 3 Corresponding author; e-mail:
[email protected] 2 Forestry,
Abstract. We review the status of the herpetofauna of the Commonwealth of Dominica, which is often cited as having the most complete extant herpetofauna of all the Lesser Antillean islands, a region which has suffered much historical extinction. Recent years have seen a number of threats of grave concern to island and regional endemic species, the chief of these being the arrival of chytridiomycosis on this island with negative effects on the mountain chicken Leptodactylus fallax, and the establishment of a non-native Greater Antillean anole, Anolis cristatellus, which has succeeded in displacing the native endemic Anolis oculatus from a part of the island in less than a decade. Key words: Anolis cristatellus; Anolis oculatus; chytridiomycosis; habitat loss; Iguana delicatissima; invasive species; Leptodactylus fallax; Lesser Antilles; mountain chicken.
Introduction: General Ecology of Dominica Dominica is one of the largest of the eastern Caribbean islands. However, by most standards it is a small island, being only 48 km long and 24 km at its widest point. It has a maximum altitude of 1447 m (Morne Diablotin) and several peaks over 1000 m distributed from the extreme northern to the southern tip (fig. 1). It receives an extremely high rainfall (in excess of 10,000 mm on the highest peaks). The spatial and temporal variation in the distribution of rainfall determines the distribution of varying habitats on the island (Lang, 1967). Reptiles form a significant part of its fauna, and it is one of the few Lesser Antillean islands that appears to have retained its original reptile and amphibian fauna over the last 200 years. Xerophytic (or xeric) woodland (often misleadingly referred to as dry scrub woodland) occurs in areas of low rainfall (<2000 mm) with a pronounced dry season, predominantly on the Caribbean (leeward) coast. The vegetation is characterised by deciduous species, which shed their leaves during the dry season (Feb-
150
A. Malhotra et al.
Figure 1. Map of Dominica, showing significant peaks (triangles), protected areas, the three main population centres and other points of interest including those mentioned in the text (squares). The range of the invading Anolis cristatellus as of February 2006 is shown by stippling. Within this range, the native Anolis oculatus is presently absent or very rare.
The herpetofauna of Dominica
151
ruary to May). There are few epiphytes (except in localised areas where a moister microclimate may occur) and the trees, which are generally unbuttressed, may reach a height of 12-15 m. The canopy is fairly complete, and little sunlight reaches the forest floor except during the dry season. Almost all this vegetation type, throughout the Caribbean, has been disturbed at some time, and it is unclear how closely it resembles the original vegetation. There are certainly a large number of introduced species that now flourish. Significant tree species (with their local names) include Lonchocarpus latifolius (savonnèt), Tabebuia heterophylla (white cedar or pòwyé), Pimenta racemosa (bwa denn or bay) and Bursera simaruba (gommier wouj, also known as birch gum, naked indian or turpentine tree). Strangling fig Ficus citrifolia (figuier) is mainly restricted to ruins (e.g. at Cabrits). Shrubby species include croton, Zanthoxylum spinosum or caribaeum (lépini), Leucida leucocephala and Morinda citrifolia (kòwòsòl dyab). Another characteristic feature of xeric woodland is the presence of thorny species, e.g. the introduced logwood Haematoxylon campechianum (kampèch), and shrubs including Acacia and Lantana species. On slopes nearest the sea, the effects of wind and sea spray during occasional storms modify the vegetation somewhat. Species here include white cedar, Indian almond (Terminalia catappa) sea grape (Coccoloba uvifera), seaside mahoe (Thespesia populnea), and manchineel (Hippomane mancinella), although the latter occurs rarely in Dominica (Carrington, 1998). Littoral woodland is a distinct type of vegetation that is found on the exposed eastern or windward (Atlantic) coast of the island, although it contains species that may be found in both xerophytic woodland and rainforest. Much of it has been cleared for agriculture and good examples of this vegetation type only remain in a few locations such as Eden, Pointe Baptiste, and Rosalie Point. The soil on this coast is typically highly weathered and infertile, with poor water penetration. The littoral woodland has a very dense canopy and thus ground vegetation is sparse as are epiphytes and lianas. Most of the species present are hard-leaved evergreens adapted to physiological drought (caused by the drying effects of the sea wind). There is a transition from a hedge-like growth (dense, matted and distorted by the wind, with an almost complete canopy) close to the sea to relatively tall (up to 20 m) evergreen woodland behind. Species present include Coccoloba uvifera, white cedar T. pallida, galba Callophylum calaba, Pimenta racemosa, the overtop palm (locally known as kokoyé and yattahou) Syagrus amara. A species of Clusia also occurs rarely in the littoral hedge most exposed to the effects of the sea. Substantial parts of the island are covered by rainforest. Over 60 species exceeding 10 cm girth at breast height (gbh) have been recorded per 1000 m2 in Dominican rainforests (Lack et al., 1997). Dacryodes excelsea (gommier) is typically the dominant tree species, along with three species of Sloanea (chataignier), although the dominants vary from place to place according to exposure, depth of soil, drainage and other aspects of the site. Other notable tree species here include Amanoa caribaea (karapit), Sterculia caribaea (maho kochon), Licania ternatensis (bwa dyab) and Tapura antillana (bwa kòt). Cephaelis schwartzii, with waxy blue bracts sur-
152
A. Malhotra et al.
rounding small white flowers, is a common ground-layer shrub. Filmy ferns are abundant and tree ferns are also present. Terrestrial and arboreal orchids, lianas, climbers (chiefly aroids) and a variety of epiphytes (e.g. large-leafed anthuriums, Clusia sp.) are abundant. In montane rainforest, the canopy is lower and thinner and the forest less stratified with correspondingly more luxuriant ground vegetation. Common trees in this zone are Sterculia caribaea (Maho kochon), Hibiscus tulipiflorus (Gombo moutayn), Prestoea acuminata (Palmist moutany) and Podocarpus coriaceus (wézinyé moutany), the latter being the only native conifer on the island. The air is extremely humid, with moisture often condensing directly out of the air onto the vegetation. There is usually an abundant layer of vegetation on the ground, and mosses and filmy ferns adorn every available surface. There are many bromeliads growing on (or close to) the ground, and these form important breeding sites for the native Eleutherodactylus frog species. The final major vegetational zone found in Dominica is elfin woodland, found on the most exposed ridges and highest peaks of the island. Sometimes referred to as “dwarf cloud forest”, it is not stratified and the canopy is very low (3-6 m) and thicket-like, with a mass of gnarled, entwined branches. The ground vegetation here often occurs as epiphytes in lower elevation forest. Especially on exposed ridges, the canopy is characteristically shaped by the wind, giving it a “combed” appearance. This vegetation type occurs from about 1000 m (depending on aspect and exposure) up to the summits. The dominant species is Clusia mangle (kaklen), often forming 50% of the trees present and sometimes occurring in pure patches. Another species present in the canopy is the palm Prestoea acuminata, while in the understorey mosses occur in large mats and festoons. Although this vegetation type is not very significant for reptiles as conditions are too cool and cloudy for much of the year (although Anolis oculatus, Liophis juliae, and Sphaerodactylus vincenti have been found at the interface between this and upper montane rainforest), it forms a substantial part of the range of the endemic Eleutherodactylus amplinympha.
The Herpetofauna Amphibia The mountain chicken Leptodactylus fallax is a large frog (females reach 17 cm SVL), which is frequently used for food, and its name derives from the fact that its meat tastes rather like chicken. It is a ground nester, laying twenty or so eggs in a foam nest in burrow half metre long, which is guarded by the female (Lescure, 1979). It has only recently been discovered that the female provisions her young by laying additional unfertilized eggs in the nest over the course of their development (Gibson and Buley, 2004). Prior to 2002, it was widely used as a novelty food by Dominicans and tourists (with annual harvests estimated as between 8,000 to 36,000 individuals). This harvest has been banned since 2002 after the population was confirmed as being infected with chytridiomycosis (see Conservation Issues,
The herpetofauna of Dominica
153
below). While the species is also found on Montserrat, it has been severely affected by the volcanic activity occurring on that island since 1995. On Dominica its natural distribution is from sea level to a maximum of 400 m altitude only on the western side of the island, in natural forest and agricultural areas (Kaiser, 1994). However, introduced populations have been recorded from the east coast (e.g., Governor Estate near Melville Hall, Petite Savanne, La Plaine and Rosalie). It has suffered a large and catastrophic decline since 2002 over all of this former range and is now listed as critically endangered on the IUCN Red List. The smaller whistling frogs, which do not seem to have been affected by chytridiomycosis, include three species of Eleutherodactylus (E. martinicensis, E. johnstonei and E. amplinympha). The latter is the only Dominican endemic (Kaiser et al., 1994). It is most abundant in the transition zone between montane rainforest and elfin woodland, but it co-exists over a broad range of altitudes with the more widespread E. martinicensis. It is listed as endangered in the IUCN Red list, because of its restricted range and probable decline in the extent of its habitat. Kaiser et al. (1994) suggested that E. martinicensis itself might have been introduced by Amerindian or French settlers, as its present distribution in the Lesser Antilles correlates well with the former French colonies. If this is the case, it is possible that the distribution of E. amplinympha may have shrunk in the last few hundred years through competition with this introduced species. However, E. martinicensis is itself listed as Near Threatened on the IUCN Red List as it generally appears to be declining across its very localised range. This may be related to the presence of a competitor, E. johnstonei, which has become widespread throughout the Lesser Antilles (Corke, 1992). Kaiser and Wagenseil (1995) confirmed the presence of E. johnstonei as a relatively recent introduction on Dominica, and recorded its distribution as restricted to the narrow strip on the sea side of the coast road from Fond Colet to Mahaut, and along the edge of the Imperial Road up the Antrim Valley as far as Springfield. It appears to be able to displace E. martinicensis only in open disturbed habitat. Reptilia Testudines. All marine turtles are on CITES Appendix I. Of these, the leatherback turtle (Dermochelys coriacea), have been recorded nesting on Dominica, with recent activity concentrated on the south-east coast beaches, particularly beaches at Rosalie and La Plaine. Loggerhead turtles (Caretta caretta) are also reported (CCA, 1991) from Dominican waters, but not recorded nesting. Green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata), are regularly encountered in Dominican waters and they also nest on the island. Although it is locally known that these turtles nest on beaches on both leeward and windward coasts of the island, efforts are currently being made to document the full extent of the distribution of nesting activity. Anecdotal reports from divers, reinforced by the personal experience of A.M. and R.S.T., suggest that the latter two turtle species are encountered more frequently in recent years. This may be due to the creation of the Soufriere-Scott’s
154
A. Malhotra et al.
Head Marine Reserve, since spear fishermen will take juvenile turtles, or it may be due to extraneous factors. In recent years, sea turtle protection has seen an upsurge in local interest, with beach patrols and tourist excursions being organised. Geochelone carbonaria, the red-footed tortoise, is known from Dominica but rarely seen in the wild. It is probable that it represents an introduced species, perhaps established as long ago as Amerindian settlement of the island but more likely to be relatively recent. Sauria. There are two endemic lizard species, Ameiva fuscata (Teiidae) and Anolis oculatus (Iguanidae). As described by Malhotra and Thorpe (1992a), A. fuscata occurs primarily at lower elevations, and is restricted to coastal woodlands and associated cultivated areas below 300 m elevation. It may be lower in abundance in cultivated areas, but on the other hand it is also spreading to higher altitudes than it would have naturally occupied in areas of rainforest that have been opened up by agriculture. Anolis oculatus is very morphologically variable and was formerly considered to contain four subspecies (Lazell, 1972). However, morphological (Malhotra and Thorpe, 1991a, 1997a, 1997b) and molecular studies (Malhotra and Thorpe, 2000; Stenson et al., 2004) re-examined this variation and concluded that there was no evidence of interruptions to gene flow between the morphologically distinct populations, rather they represented clinal variation in response to selection for geographically varying environmental conditions (Malhotra and Thorpe, 1991b; Thorpe et al., 2005). The last published review of the distribution of this species (Malhotra and Thorpe, 1992b) indicated that they were present in all parts of the island up to c. 900 m elevation, at varying densities. However, recent years have shown a worrying trend towards the extirpation of the species from the southwestern quadrant of the island, which is associated with the establishment of an invasive species of anole from Puerto Rico (Anolis cristatellus) between 1997 and 2002. This invasion is described more fully below. However, there have also been declines noted in recent years in other areas for less obvious reasons, e.g., at Cabrits National Park, where some of the highest densities on the island were recorded in 1991 (Malhotra and Thorpe, 1991b). These declines may be temporary, as recent visits to the Cabrits in January 2007 suggest that the population is returning to its former abundance. The Lesser Antillean iguana is perhaps the lizard species of highest current conservation concern, being listed as Vulnerable by the IUCN Red data book and on CITES Appendix II. The Dominican population of Iguana delicatissima is the largest and most secure of the remaining populations of this species (Day et al., 2000), being one of the few major islands on which the species occurs where its larger congener and competitor I. iguana does not also occur. Until recently thought to be an introduction into the Lesser Antilles, possibly deliberately dispersed as a food source by the first Amerindian settlers, recent genetic studies have suggested that some Lesser Antillean Iguana iguana populations, such as the nearly extinct population on St. Lucia (Alberts, 1999), are genetically distinct from those of the mainland and may therefore be native to some islands. It appears to be able to
The herpetofauna of Dominica
155
outcompete I. delicatissima and may also affect it by genetic introgression (Breuil, 2002). Iguana delicatissima still appears to be common in Dominica, and there are some sites where they are especially abundant (e.g. Canefield, Batalie Valley, Rosalie, Morne Raquette, Hampstead, Woodford Hill). While most abundant and frequently seen in coastal areas, they have been observed in some rainforest areas in fine weather, such as in the Picard Gorge opposite the parrot viewing point on the Syndicate Nature Trail. Geckos include two species of litter or dwarf gecko Sphaerodactylus fantasticus and S. vincenti. Recent evidence suggests that Sphaerodactylus fantasticus is a relatively recent colonizer. Currently found at a few scattered localities along the dry western coast of Dominica, it is also found on the neighbouring islands of Guadeloupe, the Saintes, Marie Galante and Montserrat (Jones, 1999). The Dominican population appears very similar morphologically to the populations from the vicinity of the capital Basse Terre in Guadeloupe, although they were placed in their own subspecies (S. f. fuga) by Thomas (1964). However, molecular studies have shown that they are genetically close to the morphologically similar subspecies from Guadeloupe (R.S. Thorpe and Y. Surget-Groba, unpublished data), suggesting that they are relatively recent colonists of Dominica. Sphaerodactylus vincenti is also found on three islands south of Dominica, although molecular work in progress may lead to nomenclatural changes (R.S. Thorpe and Y. Surget-Groba, unpublished data). It is restricted to rainforest localities, and has been recorded in several parts of the island including Belles, Freshwater Lake, Palmiste Ridge, Syndicate and D’leau Gommier (Schwartz and Henderson, 1991; personal observations). Other gekkonid species whose presence is a result of recent introductions include Thecadactylus rapicauda and the house gecko Hemidactylus mabouia. The former is widespread in Dominica, most abundant in dry forest but also found in relatively pristine rainforest (Bullock and Evans, 1990), and also frequently found in the crevices and roof spaces of houses. The latter is largely restricted to the vicinity of human habitation, and is much less abundant in Dominica. The skink present on Dominica, Mabuya mabouya, was formerly thought to be widespread throughout the Neotropics, but following recent taxonomic revision (Miralles, 2005) M. mabouya sensu stricto is now thought to be a regional endemic, restricted to Dominica, Guadeloupe, Martinique and St. Lucia. This species is now very rare in the Lesser Antilles, except in Dominica, and has probably vanished from Martinique (Cork, 1992). In Dominica, it is still widespread in coastal regions of the island, and may reach relatively high elevations in cultivated areas where it is often found under the corrugated iron roofs of agricultural sheds. It is often confused with the microteiid lizard Gymnophthalmus pleii, which although only officially recorded from Cabrits and Botanic Gardens in Roseau (Brooks, 1983), is almost certainly more widespread. However, there may be more than one species of Gymnophthalmus present (see below), thus the exact distribution of these similar species requires further work.
156
A. Malhotra et al.
Serpentes. The largest snake on Dominica, reaching a length of 4 m, is Boa constrictor. While other subspecies of B. constrictor are listed on CITES Appendix II, due to the substantial trade in live animals and leather of this species, the Dominican subspecies is apparently not considered very attractive and does not feature in the international trade to any extent. It is widely distributed in Dominica in a variety of undisturbed and disturbed forest and agricultural land, though apparently confined to wet ravines in the dryer parts of the island (Lazell, 1964). It can still be considered fairly common in Dominica, although it is possible that larger individuals are becoming less commonly seen. It is vulnerable to persecution and hunting for its fat that is converted into snake oil, a locally prized remedy for low libido and rheumatic pains, as well as accidental killing by vehicles on roads. The species has not been systematically studied since Lazell (1964) described it as a subspecies B. c. nebulosa. Its genetic distinctness from the other Lesser Antillean population in St. Lucia (B. c. orophias), and from mainland populations, needs to be investigated. There are also two medium sized colubrid snakes, Liophis juliae and Alsophis antillensis belonging to endemic subspecies, with additional subspecies being found on other Lesser Antillean islands. However, many of these other populations (such as those on the main islands of the Guadeloupean archipelago, Grande Terre and Basse Terre) are extremely scarce (Breuil, 2002), possibly because of the presence of mongoose on these other islands but not on Dominica (Henderson, 1992). The two colubrid species overlap in their distribution on Dominica to a large extent and either species may be found anywhere on the island except at the highest elevations, but L. juliae is more common at more mesic localities and higher elevations, while A. antillensis reaches highest densities in xeric woodland on the west coast. Both snakes are persecuted out of an innate fear of snakes, though as lizard and amphibian feeders they pose no risk to humans or their animals. Finally, the blind snake Typhlops dominicana, is endemic to Dominica, although some consider T. guadeloupensis to be a subspecies of this species (Schwartz and Henderson, 1991). Erroneous and doubtful records Several checklists of the reptiles of Dominica include two species whose presence on Dominica is unlikely or erroneous. One of these, usually referred to as Clelia clelia (but now shown in fact to represent a different species C. errabunda) is a colubrid that reaches extremely large size (c. 2 m) and is a specialist reptile feeder known from one other Lesser Antillean island, St. Lucia, where it is now extinct. However, Underwood (1993) conclusively demonstrated that the record from Dominica was due to a cataloguing error. Occasional reports of large “black” snakes by foresters are likely to be melanic boas, and even so, juveniles of most Clelia species are not black but reddish with a conspicuous yellow collar. As juveniles will be far more abundant than adults, the total lack of sightings of anything corresponding to this description should be a clear indication that this snake is not present on Dominica.
The herpetofauna of Dominica
157
The other species whose presence on Dominica is in doubt is Sphaerodactylus microlepis. The main range of this species is in St. Lucia, and the record for Dominica rests on a single specimen with no precise locality in the Natural History Museum, London. However, it was catalogued together with some specimens that are clearly from Dominica (G. Underwood, personal comm.) so it cannot be clearly attributed to an error. Its presence in Dominica, however, remains to be verified. Finally, while it has been known for some years that a microteid Gymnophthalmus species is present, the original specimens are very variable (Brooks, 1983) and it is not clear whether more than one species is present. While only the species G. pleii has been officially recorded for Dominica, the taxonomy of Gymnophthalmus species is a matter that requires resolving (Murphy, 1997), so the number of species present on Dominica, and their identity, requires further study.
Conservation Issues Threats to the survival of reptile and amphibian species in the Lesser Antilles include habitat loss, disturbance, unintentional killing, intentional killing, introduced species, disease and natural disasters. These vary greatly in importance. Habitat loss Dominica has a long history of human habitation, with several waves of preColumbian Indian colonisers preceding the Carib Indians whose descendants still inhabit the island. It was given its present name by Columbus himself, who encountered it on his second voyage across the Atlantic. However, the resident Caribs and the rugged terrain deterred both him and subsequent waves of European settlers, and Dominica did not suffer the extensive loss of habitat during the colonial period that other islands experienced. A small population size (71,727 estimated in the 2000 population census) has meant that extensive development and urbanisation has been restricted largely to the south-west coast around the capital Roseau, and other small pockets, especially in the vicinity of the larger settlements of Portsmouth (north-west coast) and Marigot (north-east coast). At least semi-natural vegetation still covers c. 66% of the land surface (Evans, 1986). However, some habitat types have been disproportionately affected by agricultural activities. For example, extensive clearing and associated habitat degradation (e.g. by subsequent erosion) for commercial monocrop agriculture (especially bananas) after the 1940s has left only remnants of littoral woodland. Tropical lowland rainforest, montane rainforest and transitional forest have also been substantially reduced. Relatively little damage has occurred due to commercial wood harvesting. The relatively inaccessible cloud forests do not appear to be perturbed by agriculture but may be vulnerable to natural catastrophes (see below). They have also been affected in some parts of the island, such as Freshwater Lake, by hydro-electric projects which have decreased overall habitat area available by raising water levels in the lake and subsequent
158
A. Malhotra et al.
erosion and landslides along the pipeline route. Change in agricultural practices may also be having an effect e.g. an increase in spraying in banana and other tree crop plantations may extirpate populations of reptiles and amphibians that might otherwise have survived quite well in plantation environments. Species that may be especially vulnerable to such changes and to habitat alteration and fragmentation in general include Iguana delicatissima and Ameiva fuscata. Disturbance and predation by human commensals Some species (e.g. marine turtles) are extremely susceptible to an increase in tourism development along, and increasingly heavy use of beaches, which may prevent them from nesting. However, recently formed conservation groups now control access to known turtle nesting beaches. Other ground nesters, such as iguanas, may also be readily disturbed and the increase in density of potential predators of juveniles such as cats and dogs may also be detrimental. The increased tidiness of grounds that are maintained for tourists, where leaf litter is raked away on a regular basis, may rapidly extirpate even initially dense populations of litterliving dwarf geckos, as has been observed by several of the authors at one site near Batali Beach. Accidental killing Increase in pollution may kill amphibians and reptiles directly as well as destroying their food or habitat. Discarded plastic trash floating in the sea may be mistaken for jellyfish by turtles, with generally fatal results. The amount of trash dumped directly into the sea has declined substantially in the last couple of decades after a garbage collection service was initiated, but unauthorized dump sites can still be seen from the sea. An increase in road traffic may also be affecting some species (e.g., boas, female iguanas crossing coastal roads to find nesting sites, juvenile iguanas dispersing from the nests). It is difficult to assess the impact of road kills. It does not appear to be a major threat but may be locally significant at particular times. Intentional killing This occurs for food, saleable products, “pest” control, and also out of innate fear of snakes. Species that are harvested for local consumption in Dominica include leatherback, green and hawksbill turtles, iguanas (I. delicatissima) and their eggs, and mountain chickens (L. fallax). This may cause local overexploitation of certain populations. Until recently, there was a specialised market for tourists who wanted to sample exotic local specialties such as mountain chicken. This apparently raised the demand to the point that a consignment of frog’s legs were imported into Dominica to meet it, and this is being investigated as a possible source of introduction of disease (see later). Boas are also harvested for their fat bodies, from
The herpetofauna of Dominica
159
which “snake oil” is extracted and sold as a local remedy for arthritic pain, and other afflictions, and frequently killed when they are caught raiding chicken coops. While any amphibian or reptile may be casually killed without good reason, snakes are particularly subject to this through the apparent innate fear of snakes in humans, even though all species present in Dominica are harmless. Introduced species These may have had a devastating effect throughout the Lesser Antilles. Introduced animals may prey on, or compete with, naturally occurring species. More insidiously, they may hybridize with them and irreversibly compromise the purity of their gene pool. Dominica has escaped the introduction of the cane toad and the mongoose, which have been implicated in the extinction of ground-living amphibians and reptiles on other West Indian islands (Henderson, 1992), possibly because the cultivation of sugar cane has never been very important on the island. However, other introductions such as goats, cats and dogs have also been implicated in the decline of iguanas in other islands (Henderson, 1992), but may not be a significant factor in Dominica because of the large amount of remaining relatively unaffected habitat. With the recent increase in attention being given to the mountain chicken, several incidents of domestic cats catching and killing juvenile mountain chickens have been reported. Common iguanas (Iguana iguana) may replace the endemic I. delicatissima or pollute the gene pool by hybridisation as has occurred in Les Saintes (Day and Thorpe, 1996). Although the green iguana has never been recorded in Dominica, it is common on neighbouring islands and the possibility of a future introduction cannot be discounted, especially as it has been shown to be capable of rafting between islands (Censky et al., 1998). Given the importance of the Dominican population, vigilance should be maintained to prevent such an introduction being successful. The whistling frog E. johnstonei has been widely introduced within the Lesser Antilles beyond its presumed natural range e.g., into Anguilla (Censky, 1989) and the Grenadines (Henderson et al., 1992) and may represent a serious conservation threat to the other whistling frogs by competitive replacement (Kaiser and Henderson, 1994). Although it may outcompete naturally occurring species (in Guadeloupe and perhaps Martinique) there is also evidence to suggest that in many cases it is limited to disturbed habitats and is not replacing the local species from undisturbed habitat (e.g., in Grenada and St. Vincent). Nevertheless, ongoing habitat disturbance may facilitate the spread of this frog at the expense of local species. No evidence exists on whether hybridisation between species poses a potential problem. The most recent introduction of concern is that of a Greater Antillean anole Anolis cristatellus, which has established itself in Dominica between 1997 (when an island-wide survey of anoles by A.M. and R.S.T. did not detect it) and 2002 (when Forestry officers’ reports of a non-native anole in the Canefield area of Dominica were followed up by an identification of the species by R.S.T. as A. cristatellus from Puerto Rico and the Virgin Islands). As a medium-sized solitary generalist,
160
A. Malhotra et al.
the native Dominican anole is unlikely to be able to co-exist with a similar sized congener, particularly when the competitor is already very well adapted to withstand competition as it comes from a multi-species assemblage in the Greater Antilles. Anolis cristatellus has also been introduced to Florida and the Dominican Republic and on the latter, it tends to replace the native A. cybotes. This represents a potentially serious conservation issue, not just to Dominica, but also to the other Lesser Antillean endemics if it spreads further. A preliminary survey carried out July/August 2002 across 67 localities found very dense populations of A. cristatellus around Canefield and parts of Morne Daniel (i.e., Canefield Pool). However, it did not reveal any A. cristatellus outside the southwestern coast area. A more detailed survey of the SW coast and Antrim Valley that same year involving an additional 23 localities showed that A. cristatellus was distributed from north of the Belfast River (near the prawn farm at Jimmit) south to Roseau, and up to 150 m elevation along the Imperial road (Interestingly this distribution coincides almost exactly with the distribution of another invasive species, E. johnstonei). Thus, the site of original invasion from which they have spread appears to be Canefield (adjacent to the Airport) and Deep Water Harbour (adjacent to the port) and implies that they may have been introduced accidentally via imported goods. Further surveys in 2003 and subsequently every year (with the latest in February 2006) has shown that the range of the invader has advanced on all fronts, but this advance is relatively slight, ranging from just 100 m further inland along the Imperial road, less than 1 km northwards to Rodney’s Rock, and c. 1.5 km southwards to Anse Bateaux. In the longer-term, the prognosis is that the native anole will be eradicated from large areas of the island, even under the best scenario where environmental conditions in some parts of the island give an advantage to A. oculatus over A. cristatellus. In its native Puerto Rico, A. cristatellus has a widespread distribution including montane habitats, but at higher altitudes it tends to be restricted to more open areas. Therefore, except where hurricanes and agriculture open up the montane rainforest, these areas may not be so vulnerable to invasion. A detailed study of morphological and genetic variation is being carried out by J. Eales and R.S. Thorpe as the presence of appreciable morphological and genetic variation within the invading species has implications for its further spread on the island. It may have the capacity for rapid adaptation to allow it to colonise habitats from which it may otherwise be excluded. The worse case scenario is therefore that it will effectively eradicate A. oculatus across the island (perhaps leaving behind just small surviving pockets) and also spread from the Canefield/Deep Water Harbour area to the docks of other Lesser Antillean islands where it will eradicate other endemic anoles. The situation is being closely monitored and studied. Natural disasters Dominica is subject to several natural catastrophic processes, including hurricanes, storm surges, landslides, earthquakes and volcanic eruptions. Hurricanes can do a
The herpetofauna of Dominica
161
great deal of damage, and while these are naturally occurring, they may prove to be the final deciding factor once other factors have produced a critical situation (e.g., by allowing an introduced species to move into disturbed habitat). Volcanic eruptions have also occurred throughout the geological history of Dominica with some massive eruptions recorded from the geologically recent past. For example, a massive eruption occurred in Dominica c. 28,000 years ago, with the resulting ash deposited on the sea floor up to 150 km to the east, and pyroclastic flows extending 300 km to the south (Sigurdson and Carey, 1981). The signature of these major events has been detected in the patterns of genetic diversity of the native anole, although it has clearly survived these cataclysmic events. Presently, Dominica has eight Pleistocene-Recent volcanic centres concentrated in the southern half of the island. It is widely considered to be one of the most volcanically hazardous countries in the world and the possibility of significant eruptions in the near future is high. It is estimated that there is a 20% chance of a volcanic eruption occurring in the next decade, and that it is extremely likely that a significant eruption will take place in southern Dominica within the current century (UWI, 2000), leading to widespread destruction of habitat and local extinctions putting further pressure on endemic or near-endemic species. Disease On the 3rd December 2002, the outbreak of the fungal disease chytridiomcycosis was first reported in the village of Gallion, in southwest Dominica. Other reports came in rapidly thereafter and dead mountain chickens have since been reported from La Haut, Elmshall, Bagatelle, Coulibistrie, Soufriere, Dublanc valley, Fab, Milton Estate, Tarrou Valley and Carholm (i.e., across the full range of the species). Subsequent surveys (Magin, 2004) indicated the frogs were no longer present at many sites where it was thought that they had previously been common and it was estimated that the population declined by as much as 70% by February 2004. The population size may now (in 2007) be as low as 8,000 individuals and the species is in a critically endangered state. However, the disease does not seem to be affecting Eleutherodactylus species to the same extent, possibly because they do not tend to breed on the ground, but this is continuing to be monitored.
Conservation Legislation and Initiatives Dominica has a strong legal basis for supporting the proper management of its forest and wildlife resources. The government agency responsible for wildlife management and protection in Dominica is the Forestry, Wildlife and Parks Division of the Ministry of Agriculture, Fisheries and Environment, with the primary relevant legislation being the Forestry and Wildlife Act (1976), which makes provision for the protection and management of wild fauna and the management of their forest habitat. For example, this allows for a closed hunting season, which between 1976
162
A. Malhotra et al.
and 1999 extended from 1 March through August 31 each year (CCA, 1991). Since 2000, the closed season has been extended to nine months (i.e., from January to the end of September). Further legislation in 2003 gave full protection to Leptodactylus and banned the import of frogs legs and other amphibian products into Dominica. The National Parks and Protected Areas Act (1975) provides for the establishment of national parks and a protected area system. In 1994, Dominica signed the Convention on Biological Diversity and has prepared and adopted a Biodiversity Strategy and Action Plan. The Pesticide Control Act controls the importation and use of pesticides, and public education has been undertaken in reference to this act. The UN Convention to Combat Desertification was ratified by Dominica on 28th November 1997. Protected areas Over 20% of Dominica is under protective legislation. The reptile and amphibian communities of the island are protected within three National Parks (fig. 1), the newest of which, the Morne Diablotin National Park, was only gazetted in 2000. The smallest, the Cabrits National Park (531 ha), is situated on a small headland in the northwest of the island, including an area of xeric woodland (which however has only developed in the last 100 years, as the headland was virtually treeless during the 18th and 19th century when it was the location of the British-built Fort Shirley) with an adjacent 35 ha wetland, one of the most significant wetlands in Dominica. Despite its small size, the Cabrits supports some of the highest densities of reptiles ever recorded (Bullock and Evans, 1990; Malhotra and Thorpe, 1991b), including populations of most of the reptile species present on the island. There are also low densities of Eleutherodactylus martinicensis (although these may be present in higher numbers in and adjacent to the parts of the wetland that are more protected from salt spray). Only a minority of species (i.e. those that are only found at higher elevations, including Sphaerodactylus vincenti, Eleutherodactylus amplinympha, Leptodactylus fallax) are not found within the boundaries of the Cabrits National Park. However, the Cabrits is unlikely to sustain viable populations of some of the larger or less common reptiles (e.g., Iguana delicatissima, which are not common in any of the currently designated National Parks). The higher altitude forests and communities are protected within the Morne Diablotin National Park (8,242 ha) and the Morne Trois Pitons National Park (6,857 ha). The latter, the first National Park established in Dominica, was designated under the National Parks and Protected Areas Act No. 16 of 1975, and added to the World Heritage List in 1997. Although these two parks encompass a relatively large area and contain a variety of habitats (including forest edge habitats that harbour species not normally expected at high altitudes such as the heliothermic skinks and ground lizards), they are vulnerable to external influences such as increasingly regular occurrence of hurricanes and invasion of disease and alien species. Finally, there are two forest reserves that form an integral element of the country’s natural resource
The herpetofauna of Dominica
163
management; the Central Forest Reserve, established in 1952 (410 ha), and the Northern Forest Reserve, legally established in 1977 (8,903 ha). Ironically it is one of the species that is currently of greatest conservation concern, Leptodactylus fallax, which is not found in any of these protected areas, as its natural range is restricted to intermediate elevations. The full range of genetic diversity within some variable species such as Anolis oculatus is also not adequately protected by the existing protected area system.
Conservation Programs Captive breeding On 1st April 2005, a three-year collaborative project, funded by the Darwin Initiative, was started to protect Dominica’s amphibians from the threat of fungal disease, involving the Forestry and Wildlife Division and the Veterinary Services Division of the Dominican Ministry of Agriculture and Environment, the Zoological Society of London and other international conservation organisations. Captive populations of Leptodactylus fallax (not of Dominican origin) are located in Jersey, Chester and London Zoos in the UK, and one of Dominican origin in St. Louis in the US. There are plans to establish a Dominican mountain chicken population in UK zoos in 2007 and a captive breeding centre in Dominica itself. Captive individuals of Iguana delicatissima from Dominica are currently established at the Jersey Zoo, UK and in San Diego and Memphis Zoos, USA, but have had rather limited breeding success to date, with only nine young having been produced, (one in 1997 and eight in 2000) by Jersey Zoo’s captive pair, eight years after breeding trials had begun (Gibson, 2001). Education No hunting of Leptodactylus fallax on Dominica has been allowed since 2003, and posters and leaflets, targeted at both Dominicans and tourists, have been produced outlining the disease threat and the ways in which people can help (e.g., by obeying the laws which now protect the species and by avoiding touching or moving frogs on the island to reduce chances of inadvertently spreading the disease). A website on the issue was also developed by the Zoological Society of London. A surveillance network is also being created with assistance from the general public and Dominican Hunters Association, inviting all sightings of the species (whether sick, dead or healthy animals) on the island to be reported. A good response was received to this program, with many reports from the public about the location of calling frogs being made by members of the public in 2006. A public education program aimed at reducing turtle poaching has also been undertaken through the Rosalie Sea Turtle Initiative (RoSTI). While some publicity has also taken place about the invading anole, the difficulty of distinguishing the invading species from the native has precluded more active participation of the general public in a monitoring program.
164
A. Malhotra et al.
Monitoring The Darwin funded project has also led to the establishment of molecular diagnostic facilities in Dominica (completed in November 2005 and officially commissioned in 2006) and the training of local personnel in amphibian survey and diagnostic technology, to facilitate the continued monitoring of the spread of chytridiomycosis in Dominica. The expertise developed within Dominica will be made accessible to other Caribbean islands at risk, and a Management Plan will be produced to minimise the risk of spread of the disease. The spread of the invading anole Anolis cristatellus and its interaction with the native endemic species is also being studied by Bangor University (UK), in collaboration with the Forestry, Wildlife and Parks Division. Recommendations Although Anolis oculatus is not yet at risk of extinction, the extent of genetic variation on the island has probably already been greatly affected, since the area affected corresponds to almost the entire range of the South Caribbean ecotype (Malhotra and Thorpe, 2000). It should therefore be a priority to set up captive breeding colonies of this ecotype to preserve as much of the existing genetic diversity of the species as possible. The protected areas of Dominica are generally above the maximum known elevation of Leptodactylus fallax (400 m) and contain few, if any, animals. This species is clearly of high priority for continuing conservation action. However, the effect of the fungus on the endemic Eleutherodactylus species is not entirely known and should be a priority for further study. The danger to currently healthy populations from future introductions should not be underestimated, and vigilance should be exercised so that any such introductions (e.g. of the green iguana) can be caught at an early stage. This could usefully include training of port officials and workers, as they have already assisted in the apprehension of non-native species of frog Osteopilus septentrionalis (native to Cuba) and dwarf gecko Gonatodes vittatus (possibly from Northern Venezuela) in separate incidents at Woodbridge Bay Port in 2006. Genetic studies on the uniqueness of the island’s snakes, currently considered subspecies of more widespread species, should also be encouraged. Finally, further studies on the status and distribution especially of island and regional endemics, and those with restricted or patchy distributions on the island, should be carried out. Acknowledgements. A Rufford Small Grant for Nature conservation funded the monitoring of the spread of Anolis cristatellus and its effect on Anolis oculatus. J. Eales (additionally funded by a NERC CASE studentship and WDNAS) and a number of MSc Ecology students from Bangor University (UK) also assisted with this program and we wish to thank Y. Surget-Groba for information on dwarf geckos.
The herpetofauna of Dominica
165
References Alberts, A. (1999): St Lucia iguana (Iguana iguana). WIISG Newsl. 2 (2): 8. Breuil, M. (2002): Histoire naturelle des amphibiens et reptiles terrestres de l’archipel Guadeloupeen. Guadeloupe, Saint-Martin, Saint-Barthelemy. Patrimoines Naturels. 54: 1-339. Brooks, G.R. (1983): Gymnophthalmus pleei Bocourt: an addition to the lizard fauna of Dominica, West Indies. Herpetol. Rev. 14: 32. Bullock, D.J., Evans, P.G.H. (1990): The distribution, density and biomass of terrestrial reptiles in Dominica, West Indies. J. Zool. 222: 421-443. Carrington, S. (1998): Wild Plants of the Eastern Caribbean. Basingstoke, UK, MacMillan Education. CCA (1991): Dominica. Country Environmental Profile. Caribbean Conservation Agency, St Michael, Barbados. Censky, E.J. (1989): Eleutherodactylus johnstonei (Salientia: Leptodactylidae) from Anguilla, West Indies. Carib. J. Sci. 25: 229-231. Censky, E.J., Hodge, K., Dudley, J. (1998): Evidence of over-water dispersal of lizards due to hurricanes. Nature 395: 556. Corke, D. (1992): The status and conservation needs of the terrestrial herpetofauna of the Windward Islands. Biol. Cons. 62: 47-58. Day, M.L., Thorpe, R.S. (1996): Population differentiation of Iguana delicatissima and Iguana iguana in the Lesser Antilles. In: Contributions to West Indian Herpetology: A Tribute to A. Schwartz, p. 136-137. Powell, R., Henderson, R.W. (Eds). Ithaca, New York, Society for the Study of Amphibians and Reptiles. Day, M.L., Breuil, M., Reichling, S. (2000): Lesser Antillean iguana Iguana delicatissima. In: West Indian Iguanas: Status Survey and Conservation Action Plan, p. 62-67. Alberts, A.C. (Ed.). Gland, Switzerland, IUCN. Evans, P.G.H. (1986): Dominica multiple land-use project. Ambio 15: 82-89. Gibson, R.C. (2001): Dustbins, D3, diet, and determination: how to make baby delicatissima. WIISG Newsl. 4 (1): 6-7. Gibson, R.C., Buley, K.R. (2004): Maternal care and obligatory oophagy in Leptodactylus fallax: A new reproductive mode in frogs. Copeia 2004: 128-135. Henderson, R.W. (1992): Consequences of predator introduction and habitat destruction on amphibians and reptiles in the Post-Columbus West Indies. Carib. J. Sci. 28: 1-10. Henderson, R.W., Daudin, J., Hass, G.T., McCarthy, T.J. (1992): Significant distribution records for some amphibians and reptiles in the Lesser Antilles. Carib. J. Sci. 28: 101-103. Jones, A.G. (1999): The evolutionary history of Sphaerodactylus fantasticus. PhD thesis, University of Wales, Bangor, UK. Kaiser, H. (1994). Leptodactylus fallax. Cat. Am. Rept. Amphib. 583: 2217-2237. Kaiser, H., Green, D.M., Schmidt, M. (1994): Systematics and biogeography of Eastern Caribbean frogs (Leptodactylidae: Eleutherodactylus), with the description of a new species from Dominica. Can. J. Zool. 72: 2217-2237. Kaiser, H., Henderson, R.W. (1994): The conservation status of Lesser Antillean frogs. Herpetol. Nat. Hist. 2: 41-56. Kaiser, H., Wagenseil, R. (1995): Colonisation and distribution of Eleutherodactylus johnstonei Barbour (Anura: Leptodactylidae) on Dominica, West Indies. Carib. J. Sci. 31: 341-344. Lack, A.J., Whitefoord, C., Evans, P.G.H., James, A. (1997): Dominica: Nature Island of the Caribbean. 5: Illustrated Flora. Commonwealth of Dominica, Ministry of Tourism. Lang, D.M. (1967): Soils and land use surveys, No. 21. Dominica. Trinidad, University of the West Indies. Lazell, J.D. (1962): The anoles of the Eastern Caribbean (Sauria: Iguanidae). Part V. Geographic differentiation in Anolis oculatus on Dominica. Bull. Mus. Comp. Zool. 127: 466-475.
166
A. Malhotra et al.
Lazell, J.D. (1964): The Lesser Antillean representatives of Bothrops and Constrictor. Bull. Mus. Comp. Zool. 132: 245-273. Lazell, J.D. (1972): The anoles (Sauria: Iguanidae) of the Lesser Antilles. Bull. Mus. Comp. Zool. 143: 1-115. Lescure, J. (1979): Étude taxonomique et éco-ethologique d’un Amphibien des Petite Antilles: Leptodactylus fallax Müller, 1926 (Leptodactylidae). Bull. Mus. Natl. d’hist. nat., Paris, 4e sér. 1(A): 757-774. Magin, C. (2004): Wildlife Survey Report. Fauna and Flora International, Cambridge, and the Forestry and Wildlife Division, Dominica. Malhotra, A., Thorpe, R.S. (1991a): Microgeographic variation in Anolis oculatus on the Island of Dominica, West Indies. J. Evol. Biol. 4: 321-335. Malhotra, A., Thorpe, R.S. (1991b): Experimental detection of rapid evolutionary response in natural lizard populations. Nature 353: 347-348. Malhotra, A., Thorpe, R.S. (1992a): Ameiva fuscata. Catalog. Am. Rept. Amphib. 606: 1-3. Malhotra, A., Thorpe, R.S. (1992b): Anolis oculatus. Catalog. Am. Rept. Amphib. 540: 1-4. Malhotra, A., Thorpe, R.S. (1997a): Size and shape variation in a Lesser Antillean anole, Anolis oculatus (Sauria; Iguanidae) in relation to habitat. Biol. J. Linn. Soc. 60: 53-72. Malhotra, A., Thorpe, R.S. (1997b): Microgeographic variation in scalation of Anolis oculatus (Dominica, West Indies): a multivariate analysis. Herpetologica 53: 49-62. Malhotra, A., Thorpe, R.S. (2000): The dynamics of natural selection and vicariance in the Dominican anole: patterns of within-island molecular and morphological divergence. Evolution 54: 245-258. Miralles, A. (2005): The identity of Lacertus mabouya Lacepède, 1788, with description of a neotype: an approach toward the taxonomy of new world Mabuya. Herpetologica 61: 46-53. Murphy, J.C. (1997): Amphibians and Reptiles of Trinidad and Tobago. Florida, Krieger publishing company. Schwartz, A., Henderson, R. (1991): The amphibians and reptiles of the West Indies. Miami, University of Florida Press. Sigurdsson, H., Carey, S. (1981): Marine tephrochronology and Quaternary explosive volcanism in the Lesser Antilles arc. In: Tephra studies, p. 255-280. Sparks, R.S.J, Self, S. (Eds). Reidel, Holland, NATO series. Stenson, A.G., Thorpe, R.S., Malhotra, A. (2004): Mitochondrial and nuclear molecular phylogenies of the bimaculatus group anoles (Sauria: Iguanidae) of the northern Lesser Antilles. Mol. Phyl. Evol. 32: 1-10. Thomas, R. (1964): The races of Sphaerodactylus fantasticus Dumeril and Bibron in the Lesser Antilles. Carib. J. Sci. 4: 373-390. Thorpe, R.S., Reardon, J.T., Malhotra, A. (2005): Common garden and natural selection experiments support ecotypic differentiation in the Dominican anole (Anolis oculatus). Amer. Nat. 165: 495504. Underwood, G. (1993): A new snake from St Lucia, West Indies. Bull. Nat. Hist. Mus. (Zool.) 59: 1-9. UWI (2000): Volcano Hazard Report for Southern Dominica: Interpretation of 1998-2000 Earthquakes and Hazard Mapping Results. University of the West Indies. http://dominicapsn.freeyellow.com/ Documents/Final.pdf. Accepted: March 5, 2007 (AH). Reprinted from Applied Herpetology 4: 177-194 (2007).
Conservation of the herpetofauna of the Dominican Republic Robert Powell1 , Sixto J. Incháustegui2 1 Department
of Biology, Avila University, Kansas City, MO 64145, USA Corresponding author; e-mail:
[email protected] 2 Grupo Jaragua, El Vergel 33, El Vergel, Santo Domingo, República Dominicana Abstract. The herpetofauna of the Dominican Republic consists of 39 frogs (two of which are introduced), 110 squamates (one possibly extinct and three or four introduced), one crocodilian, three turtles (one introduced), plus four species of sea turtles. Reflecting the recent “Global Amphibian Assessment,” 32 of 37 (86%) native species of amphibians are included on the IUCN Red List. Reptilian species given formal recognition as being in need of protection include the sea turtles (listed in CITES appendices and the IUCN Red List), the two native species of pond turtles (Trachemys spp.; IUCN, although one as being at “lower risk” of extinction), both species of rock iguanas (Cyclura spp.; CITES and IUCN), two giant galliwasps (Celestus spp., IUCN), three boids (Epicrates spp., CITES), a ground boa (Tropidophis haetianus, CITES), and the American crocodile (Crocodylus acutus; CITES and IUCN). However, at least some additional squamate species appear to meet criteria for inclusion on the IUCN Red List. Four factors largely responsible for the status of these species are: (1) small ranges, habitat specialization, and encroachment by human activities (many amphibians); (2) large size and economic value (turtles, iguanas, crocodile); (3) persecution by people who fear them (galliwasps and snakes); and (4) diurnally active, terrestrial, and vulnerable to predation by mongooses and other introduced mammalian predators (some snakes, Mabuya). Although protection for a few species and for national parks in critical habitats is legislated, enforcement is sporadic and threats, mostly associated with exploitation and development, remain. Specific recommendations for the conservation of the herpetofauna are listed. Key words: Amphibians; conservation; Dominican Republic; Hispaniola; reptiles.
Introduction The Dominican Republic covers the eastern two-thirds of the island of Hispaniola (the western third is the Republic of Haiti). Hispaniola (ca. 76 500 km2 ) is characterized by a rugged topography (fig. 1), which results in a mosaic of mesic highlands and often very xeric lowlands, creating a complex of varied habitats that support a remarkably diverse herpetofauna. Albert Schwartz once described Hispaniola as
168
R. Powell, S.J. Incháustegui
Figure 1. Physiographic features of the Dominican Republic (from Powell, 1999). Numbers correspond to major relief features: 1 = Cordillera Central, 2 = Sierra de Neiba, 3 = Sierra Martín García, 4 = Sierra de Baoruco, 5 = Cordillera Septentrional, 6 = Sierra de Yamasá, 7 = Cordillera Oriental, 8 = Sierra de Samaná.
“an island of islands,” in reference to the myriad pockets of dramatically different habitats often separated by only a few kilometers (Powell et al., 1999). Because conservation issues often are addressed at the political rather than the biogeographic level, we treat the Dominican Republic as an entity independent of Haiti. Physiography of Hispaniola The diversity of the herpetofauna may be attributed primarily to three factors: (1) a rugged and mountainous terrain of which the dominant relief features are parallel ranges that run primarily from the northwest and west in a generally easterly direction (Weil et al., 1982; Lewis and Draper, 1990); (2) satellite islands of varying sizes and exceedingly different topographies and habitats; and (3) the peculiar geological history of the island. The island’s major mountain ranges isolate often extensive intervening valleys, and satellite ranges create narrow and often broken coastal lowlands. A lowland plain covers much of the eastern end of the island. Such structural complexity, composed of high elevations and resultant rainshadows, results in a juxtapositioning of harsh deserts, dry scrub forests, rainforests, cloud forests, and high-elevation pine savannas. Satellite islands, many of which support endemic taxa, range in size from approximately 650 km2 and a maximum elevation > 600 m (Île de la Gonâve;
Conservation of the herpetofauna of the Dominican Republic
169
Schwartz, 1980) to less than 0.02 km2 and only a few meters above sea level (Cayo Muertos in the Cayos Siete Hermanos; Burns et al., 1992). Other satellites of significance on the Dominican side of the island are islas Saona, Catalina, Beata and Alto Velo. Although “Considerable controversy exists over the interpretation of the early tectonic evolution of Hispaniola” (Lewis and Draper, 1990), the peculiar history of the island lies largely in its origin as two paleoislands (Schwartz, 1978, 1980), although as many as four elements may have combined to form the present island. The two major entities joined when the South Paleoisland “caught” the North Paleoisland after the latter collided with the Bahama Platform (Lewis and Draper, 1990), mostly likely during the Miocene (Huebeck and Mann, 1991) and maybe as early as the Eocene (Khudoley and Meyerhoff, 1971); however, as a consequence of rising and falling sea levels, partial or complete separation may have occurred intermittently throughout the Pleistocene. Reef limestones deposited during the Pleistocene are currently exposed in coastal areas and in the former marine channel that separated the paleoislands (Lewis and Draper, 1990). In the herpetological literature (e.g., Williams, 1961), the paleoislands are known as the North and South islands, respectively. The former marine strait is now a barren valley known as the Plaine de Cul-de-Sac in Haiti and the Valle de Neiba in the Dominican Republic. Much of this valley still lies below sea level and it is characterized by four remaining large lakes, two of which are saline. The South Island is the smaller (9500 km2 ) and much less complex of the two paleoislands. The principal relief features are three major mountain ranges that run from the western tip of the Tiburon Peninsula in Haiti east across the Barahona Peninsula in the Dominican Republic. The easternmost range (the Sierra de Baoruco) has a maximum elevation of over 2300 m and lies entirely within the Dominican Republic. The Barahona Peninsula south of the mountains is effectively divided by the Loma Gran Sabana, a limestone ridge with a maximum elevation of about 1100 m and vegetated by dry forest, into an extremely xeric western region and a somewhat less xeric eastern plain. Islas Beata and Alto Velo lie off the southern tip of the peninsula. The larger (67 700 km2 ) and much more complex North Island is dominated by the Cordillera Central, the highest peak of which (Pico Duarte at > 3000 m) is also the highest point in the entire West Indies. Another major range essentially parallels the southern “shore” of the North Island; the portion in the Dominican Republic is the Sierra de Neiba, with a maximum elevation of nearly 2300 m. Paralleling the northern coast is the Cordillera Septentrional, the highest elevation of which is Pico Diego de Campo (1250 m). Smaller, somewhat isolated ranges to the east include the Sierra de Samaná (highest point ∼600 m) on the Samaná Peninsula and the Sierra de Yamasá (>850 m), essentially an eastern isolate of the Cordillera Central that blends into the Cordillera Oriental, which lies south of Samaná Bay and extends into the karst landscape of the Los Haitises region. The Sierra Martín García (>1300 m) is an eastern isolate of the Sierra de Neiba and forms a relatively
170
R. Powell, S.J. Incháustegui
mesic enclave surrounded by desert. Important lowlands of the North Island include the Valle de San Juan between the Cordillera Central and the Sierra de Neiba, the fertile Valle de Cibao north of the Cordillera Central, the northern coastal plain north of the Cordillera Septentrional, the arid Llanos de Azua in the rainshadow of the Cordillera Central, and the moderately mesic Llanura del Este. The Cayos Siete Hermanos is an archipelago of small cays off the northwestern Dominican coast, Isla Saona and the tiny Isla Catalinita lie off the southeastern tip of the island, and Isla Catalina is situated off the southern coast a few kilometers to the west.
Vegetation Vegetative communities are as diverse as the topography. Hedges (1999) provided an overview (paraphrased herein). Characterization of forest types follows SEA/DVS (1990), Hager and Zanoni (1993) and Hedges (1999). Prevailing northeasterly winds carry moisture that typically precipitates on northern and eastern regions, whereas southern areas are usually dry. Vegetation patterns correspond closely to precipitation. Moist forests occur on northern and eastern slopes and dry xerophytic vegetation is found in southern regions and in rainshadows. PreColumbian Hispaniola was largely forested (Hedges, 1999). Lowland forests with high canopies graded into montane rainforests on lower slopes. Cloud forests develop at elevations over 1000 m, and pine forests and elfin woodlands occur at even higher elevations (to 2400 m). Pine forests are relatively dry, whereas elfin woodlands are characterized by windblown tangles of moss-covered trees and shrubs. Karst regions were covered by wet limestone forests with thin soils and relatively low canopies (to 25 m). Dry scrub forests, mostly in coastal areas, have low canopies (∼10 m), thorny shrubs, and many cacti. Essentially all of the lowland forests have been destroyed and were the first to disappear after colonization (Powell and Henderson, 1996a, 1996b; Hedges, 2006). Most other forests are disappearing rapidly, but may still be found in increasingly smaller fragments throughout the island. Wet limestone and dry scrub forests are being destroyed less rapidly than those of other types, mainly because of the difficulty of access and effective exploitation. Even so, many such areas, such as those in the vicinity of Monte Cristi in the northwestern part of the country, have been sufficiently altered, primarily by charcoal burners, that the resulting secondary growth constitutes an impenetrable tangle of cacti and thorny scrub. Montane rainforest remain mainly on steep slopes but, even in areas that appear superficially natural, invasions by cultivated species are rampant (e.g., Lenart et al., 1997). The only remaining extensive upland forests are in the Cordillera Central, but smaller patches persist in other areas. However, “no ‘pristine’ forests [exist anywhere] in the West Indies” (Hedges, 2006).
Conservation of the herpetofauna of the Dominican Republic
171
The Herpetofauna The herpetofauna (table 1) of the Dominican Republic consists of 39 frogs (two of which are introduced), 110 squamates (one possibly extinct and three or four introduced), one crocodilian, three turtles (one introduced), plus four species of sea turtles. The critically endangered and potentially extinct squamate is Alsophis melanichnus, which may never have been common and has probably become the victim of introduced mongooses (Herpestes javanicus). Endemism of terrestrial species is high (Powell et al., 1999; Hedges, 2007). All but one native frog (97%) are Hispaniolan endemics. The exception is Leptodactylus albilabris, which also occurs on Puerto Rico (the Dominican population had been considered distinct at the species level until recently; Hedges and Heinicke, 2007). Of 110 currently recognized squamate species recorded from the Dominican Republic, 101 or 102 (92 or 93%, depending on whether nor not Typhlops sulcatus occurs on Navassa Island; Powell, 1999; Powell et al., 1999) are Hispaniolan endemics and four others (Anolis distichus, Mabuya sloanii, Sphaerodactylus elegans, Epicrates striatus) are West Indian endemics. The one crocodilian (Crocodylus acutus) is endemic to the Western Hemisphere. One of the two native pond turtles (Trachemys decorata) is a Hispaniolan endemic and the other (T. stejnegeri) is endemic to the West Indies. Of the introduced species, Bufo marinus has become widely distributed, invading even very xeric areas that provide breeding sites only intermittently. Rana catesbeiana is widely established in both natural and artificial freshwater systems. Two introduced lizards, Anolis cristatellus from Puerto Rico (Fitch et al., 1989) and A. porcatus from Cuba (Powell et al., 1990), are largely restricted to dramatically altered urban habitats in La Romana and Santo Domingo, respectively. Two other lizards are human commensal “house geckos.” Hemidactylus angulatus (formerly H. haitianus; Weiss and Hedges, 2007), which also occurs on Cuba and Puerto Rico, is a west African species that may have arrived in the western Hemisphere as an unintended consequence of the colonial-era slave trade. The other, possibly introduced, is H. mabouia, which is widely distributed throughout the Neotropics (Powell et al., 1998) and may have arrived on Hispaniola by natural means, but probably was introduced with inadvertent human assistance. The introduced turtle is Trachemys scripta elegans, native to the eastern United States. All but the lizards were presumably imported intentionally, B. marinus for insect control in sugar cane fields, R. catesbeiana for food, and T. scripta via the pet trade. All probably exert a negative influence on native species, although that of the anoles is restricted to highly localized displacement of endemic ecological counterparts in urban areas. Bufo marinus competes with endemic toads in all but the harshest (most xeric) environments and has undoubtedly contributed to their declines. Rana catesbeiana probably preys on hylids and Leptodactylus and their tadpoles and even on Eleutherodactylus that venture too close to water inhabited by these voracious predators that eat anything that will fit in their mouths. Trachemys scripta competes and hybridizes with native turtles (Powell et al., 2000), possibly diluting unique gene pools.
172
R. Powell, S.J. Incháustegui
Table 1. Currently recognized amphibians and reptiles known to occur in the Dominican Republic (adapted from Hedges, 2008). Only those species that have a formally recognized conservation status are listed: CITES appendices are indicated by “I” or “II,” and IUCN Redlist status (IUCN, 2008) by CR (critically endangered), EN (endangered), VU (vulnerable), NT (near-threatened) and LR (lower risk). Species AMPHIBIA, ANURA (frogs and toads) Family Bufonidae (true toads; one genus, four species, one introduced) Bufo fluviaticus Bufo fractus Bufo guentheri Family Hylidae (treefrogs; two genera, four species) Hypsiboas heilprini Osteopilus pulchrilineata Osteopilus vastus Family Leptodactylidae (Neotropical frogs; two genera, 30 species) Eleutherodactylus alcoae Eleutherodactylus armstrongi Eleutherodactylus audanti Eleutherodactylus auriculatoides Eleutherodactylus flavescens Eleutherodactylus fowleri Eleutherodactylus furcyensis Eleutherodactylus haitianus Eleutherodactylus heminota Eleutherodactylus hypostenor Eleutherodactylus jugans Eleutherodactylus leoncei Eleutherodactylus minutus Eleutherodactylus montanus Eleutherodactylus nortoni Eleutherodactylus oxyrhynchus Eleutherodactylus parabates Eleutherodactylus patriciae Eleutherodactylus pictissimus Eleutherodactylus pituinus Eleutherodactylus probolaeus Eleutherodactylus rufifemoralis Eleutherodactylus ruthae Eleutherodactylus schmidti Eleutherodactylus wetmorei Leptodactylus albilabris Family Ranidae (true frogs, one genus, one species, introduced) REPTILIA, CROCODYLIA (crocodilians) Family Crocodylidae (crocodiles, one genus, one species) Crocodylus acutus
Status
CR EN VU VU EN EN EN EN VU EN NT CR CR EN EN EN CR CR EN EN CR CR CR EN VU EN EN CR EN CR VU LC∗
I, VU
Conservation of the herpetofauna of the Dominican Republic
173
Table 1. (Continued). Species REPTILIA, SQUAMATA (scaled reptiles) Family Amphisbaenidae (amphisbaenians; one genus, three species) Family Anguidae (galliwasps; one genus, ten species) Celestus anelpistus Celestus warreni Family Boidae (boas; one genus, three species) Epicrates fordii Epicrates gracilis Epicrates striatus Family Colubridae (common snakes, six genera, 10 species) Family Gekkonidae (geckos, four genera, 28 species, one or two introduced) Family Iguanidae (iguanas; one genus, two species) Cyclura cornuta Cyclura ricordii Family Leiocephalidae (curlytails; one genus, six species) Family Leptotyphlopidae (thread snakes; one genus, three species) Family Polychrotidae (anoles; one genus, 31 species, two introduced) Family Scincidae (skinks; one genus, two species, one possibly introduced) Family Teiidae (ground lizards/whiptails; one genus, three species) Family Tropidophiidae (ground boas; one genus, one species) Tropidophis haetianus Family Typhlopidae (blind snakes; one genus, eight species) REPTILIA, TESTUDINES (turtles) Family Cheloniidae (sea turtles, three genera, three species) Caretta caretta Chelonia mydas Eretmochelys imbricata Family Dermochelidae (leatherback sea turtles, one genus, one species) Dermochelys coriacea Family Emydidae (pond turtles, one genus, three species, one introduced) Trachemys decorata Trachemys stejnegeri
Status
CR CR II II II
I, VU I, CR
II
I, EN I, EN I, CR I, CR VU LR
* Hedges and Heinicke (2007) placed the Hispaniolan ditch frog (Leptodactylus dominicensis) into the synonymy of L. albilabris. The Hispaniolan population had been designated in the IUCN Red List as EN (Hedges et al., 2004).
Conservation Status Insular populations of terrestrial animals often suffer as a consequence of alterations to their habitats by humans (e.g., Wilson et al., 2006 and references therein). Habitat specialists and endemic species that have evolved in the absence of efficient mainland predators and competitors are particularly vulnerable (e.g., Powell and Henderson, 2005 and references therein). Although a few species (sea turtles; e.g., Dutton et al., 2005) and even some genera (e.g., West Indian rock iguanas in the genus Cyclura; e.g., Alberts, 2000; Alberts et al., 2004) have been the focus of
174
R. Powell, S.J. Incháustegui
intensive conservation efforts, populations of many more species are in various stages of decline, and some are in imminent danger of extinction, often with little recognition by the public or even professional conservation biologists (Hedges, 2006). Schubert (1993) noted that data available at that time were inadequate for estimating accurately the number of species lost to human activities. Particularly vulnerable are species with population sizes already reduced dramatically, those that are especially sensitive to human disturbance, those that are naturally “rare” or have very restricted ranges, and those that are actively exploited for economic purposes (Powell et al., 2000). Sadly, we know so little about many other species that we simply cannot draw definitive conclusions about their status, and the lack of timely and accurate data may be the most critical element responsible for our inability to provide more than “educated guesses” regarding the status of many species. Consequently, the species listed in the following paragraphs are not intended to comprise a comprehensive list, but are merely our most recent estimates of those in immediate danger of extirpation or extinction. Formal criteria exist for evaluating the conservation status of species in nature (IUCN, 2001). Application of these critera lead to categories of increasing risk of extinction: CR (critically endangered), EN (endangered), VU (vulnerable), NT (near-threatened) and LR (lower risk). Species for which no reasonable doubt exists that the last individual has died are designated EX (extinct) and those known to survive only in cultivation, captivity, or as naturalized populations outside the historical range of the species are EW (extinct in the wild). Species that have not been evaluated against the criteria are annotated NE (not evaluated) and those for which evaluations have been attempted but for which inadequate information is available are designated DD (data deficient). Evaluations must be based on credible data and include consideration of abundance, areas of occupancy or suitable habitat, actual or potential levels of exploitation, and effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites. An intense effort to assess the conservation status of amphibians worldwide (IUCN et al., 2006; Hedges, 2006) resulted in many species that had previously received little or no attention (e.g., Powell et al., 2000) afforded at least an acknowledgement of their precarious state through inclusion on the IUCN Red List (IUCN, 2008), which assesses specific threats to the ongoing existence of species. Although a comparable effort is being initiated for reptiles (S.B. Hedges, pers. comm.), an obvious inequity currently exists, and we anticipate that many reptilian species will receive a formal acknowledgement of their precarious conservation status once attention is focused on the issue. At this time, when considering only the amphibians and reptiles of the Dominican Republic, 32 of 37 (86%) native species of amphibians known to occur in the country are red-listed (table 1). In stark contrast, only 15 of 108 (14%) native reptilian species are included in the IUCN list (and four of the listed species are sea turtles that are endangered throughout the region and the world).
Conservation of the herpetofauna of the Dominican Republic
175
Among species that are excluded is one snake that may already be extinct (Alsophis melanichnus) and several others that are known to be very rare (A. anomalus and two species in the genus Ialtris). All are diurnally active and terrestrial. The principal threat is undoubtedly predation by introduced mongooses (Herpestes javanicus; Henderson and Sajdak, 1986; Powell and Henderson, 2005). Although red-listing may come too late for some of these snakes (Powell, 2005), we hope that efforts to assess the conservation status of the world’s reptiles succeeds in shedding light on the plight of species for which hope may still exist. A large percentage of Dominican amphibians are habitat specialists that rely on relatively undisturbed forests and often have very small distributions. Almost all of the species afforded formal protective status (table 1) fall into the first category (IUCN et al., 2006; IUCN, 2008), but even those associated with lowland areas have small ranges (e.g., Bufo fractus) or ranges that are becoming increasingly confined by development for social infrastructure, tourism, or agriculture (e.g., B. guentheri). The high percentage of native frogs now known to be threatened with extinction stands in stark contrast to previous lists of endangered Dominican species that listed no amphibians (Aquino, 1983) or only a single species (Osteopilus vastus: IUCN, 1996; Bufo fluviaticus: Powell et al., 2000). Reptiles frequently are the most abundant and obvious naturally occurring vertebrates in the Dominican Republic (Henderson and Powell, 1999, 2001), but overviews of conservation needs have been rare. Although many species are ecological generalists (Henderson and Powell, 1999; Powell and Henderson, 2006) and some thrive in altered habitats, populations of many others are declining at alarming rates. Addressing these concerns for native Dominican reptiles, all sea turtles are listed in CITES Appendix I. Chelonia mydas and Caretta caretta are red-listed as endangered, whereas Eretmochelys imbricata and Dermochelys coriacea are critically endangered. In addition, sea turtles are protected by national and local legislation. Although all turtles are affected by habitat alteration, the sea turtles especially by the development of nesting beaches, the principal threats are due to ongoing exploitation of eggs and adults by humans for food (e.g., Stam and Stam, 1992; Fleming, 2001). Two species of rock iguanas (Cyclura ricordii and C. cornuta), two species of pond turtles (Trachemys decorata and T. stejnegeri vicina), and the one crocodilian (Crocodylus acutus) have been recognized as threatened or endangered for some time (Aquino, 1983; IUCN, 1996; Powell et al., 2000) and additional, recently published information regarding their status is readily available (Cyclura ricordii: Ottenwalder, 2000b; ZOODOM et al., 2002; Bendon and Binns, 2003; Arias et al., 2004; Ramer, 2004a, 2004b: Ramer and Hudson, 2005; Rupp et al., 2005, 2007; C. cornuta: Ottenwalder, 2000a; Ottenwalder and Powell, 2002; Trachemys decorata: Ottenwalder, 1994a, 1994b; Seidel, 1996; T. stejnegeri vicina: Seidel, 1996; Crocodylus acutus: SEA/DVS, 1993; Schubert and Santana, 1996). Three species of boids (Epicrates fordii, E. gracilis, E. striatus) and one tropidophiid (Tropidophis haetianus) are afforded some protection by inclusion of the
176
R. Powell, S.J. Incháustegui
entire families in CITES Appendix II. These snakes remain abundant in some areas, and the CITES listing reflects presumed threats emanating from international trade for the pet industry, which currently are not applicable to these species. Also, spurred in part by recent re-evaluations of taxonomic status (Hallermann and Böhme, 2002; Powell and Henderson, 2003), the conservation status of the giant galliwasps (Celestus anelpistus, C. warreni) has been updated (Powell et al., 2000; Powell and Henderson, 2003; IUCN, 2008). Powell et al. (2000) also addressed the status of four diurnally active terrestrial snakes (Alsophis anomalus, A. melanichnus, Ialtris agyrtes, I. dorsalis) that appear to be particularly vulnerable to predation by introduced mongooses and a single species of dwarf gecko (Sphaerodactylus cochranae) that apparently has been rare for some time and suffers currently from habitat alteration and destruction. The possible extinction of A. melanichnus was mentioned by Schwartz and Henderson (1991) and the status of S. cochranae was addressed in Glor (1999) and Glor et al. (2001). Additional reptilian species (Powell et al., 2000) may be locally abundant, but with very restricted ranges that render them exceedingly vulnerable to stochastic events. Others exhibit highly specialized habitat requirements, often tied to intact forests that are disappearing rapidly. Still others have fragmented ranges, portions of which are sparsely populated. At least some of these taxa undoubtedly meet IUCN Red List criteria (IUCN, 2001). Species in the first category (at times locally abundant, but with restricted ranges) include Anolis altavelensis, A. sheplani, A. strahmi, Celestus marcanoi, Leiocephalus altavelensis, Sphaerodactylus ladae, S. ocoae, S. perissodactylius, S. samanensis, Leptotyphlops asbolepis and L. calypso. Those with specialized habitat requirements tied to mature or structurally intact forests include Anolis bahorucoensis, A. barbouri, giant anoles (A. baleatus, A. barahonae, A. ricordii), and Darlingtonia haetianus. Species with fragmented ranges in at least portions of which population densities are presumably very low include Anolis whitemani, Mabuya lineolata, Phyllodactylus hispaniolae, and Leptotyphlops pyrites. The problem with determining whether or not these species are of concern is that current data regarding abundance and extent of populational distributions are largely lacking, in some instances the situation is aggravated by the small size and secretive habitats of some forms (e.g., some geckos in the genus Sphaerodactylus and the threadsnakes in the genus Leptotyphlops). The intent of including them here is merely to draw attention to conditions that might warrant some acknowledgment of their status or even some form of formal protection. Complicating matters further is the possibility that some populations currently considered to be subspecies (Powell, 1993; Williams, 1999) or others not even recognized at the subspecific level may represent unique gene pools within widely distributed species complexes. Whether these populations warrant recognition as distinct taxa depends largely on the definition of species being applied (see discussion in Powell and Henderson, 2003 and references cited therein). Neverthe-
Conservation of the herpetofauna of the Dominican Republic
177
less, without efforts to survey and analyze especially the isolated populations, they may disappear without any awareness of their unique qualities. Examples include Sphaerodactylus darlingtoni noblei and a subspecifically unassigned population of S. savagei in San Cristóbal Province. Also, ground-dwelling, diurnally active lizards in the genera Ameiva and Leiocephalus are vulnerable to predation by mongooses (e.g., Powell and Henderson, 2005). Although Dominican species in both genera are locally abundant and widespread, isolated populations in areas with relatively little human activity (which presumably reduces mongoose activity) may be vulnerable to extirpation (or extinction, if any such populations warrant recognition as full species; e.g., Gifford, 2005). Examples include an unnamed population of A. lineolata in the extreme eastern Dominican Republic (M.E. Gifford, pers. comm.) or A. taeniura meyerabichi and other isolated populations of A. taeniura that are unassigned to any subspecies in montane areas or the dry lowlands south of Baní.
Threats Like many other island nations in the Caribbean Basin (Harcourt et al., 1996), the Dominican Republic faces multiple threats to biodiversity posed by a growing population, with attendant urban sprawl and the need for increased agricultural productivity, and economic development, much of which is related to the growing tourist industry. The human population of the nation stood at 7.8 million in mid1994 (Harcourt and Ottenwalder, 1996), and population density increased from 48/km2 in 1950 to a projected 177/km2 in 2000 and 203/km2 in 2010 (MacDonald, 1992). Although annual growth rates appear to be slowing from an estimated 2.2% in mid-1994 and 1.9% from 1990-2000 to a projected 1.4% from 2000-2010, the pressure on land use and productivity continues to rise, as do opportunities for additional introductions of exotic species and exploitation of amphibians and reptiles for food or as pets (e.g., Henderson, 1992; Lever, 2003; Powell, 2003). Another substantive threat potentially of greater and more immediate impact on the conservation of amphibians and reptiles results from the increasingly frequent confrontations between tourism or mining development and protected areas. The prevailing model of rampant and unsustainable development, which relies heavily on foreign investment, has encroached already on areas currently within the protected areas system.
Conservation Action No specific legislation addresses the conservation of amphibians and reptiles. However, at present, two laws offer some protection to the herpetofauna, as well as other components of the nation’s flora and fauna. The General Law on Environment and Natural Resources (Law 64-00) was promulgated after reviews of the legal
178
R. Powell, S.J. Incháustegui
and institutional framework for the environmental sector. One consequence was the creation of the Ministry of Environment and Natural Resources (SEMARN, 2000; SEMARN, 2007). Although no specific references are made to the herpetofauna, Chapter IV, under Title IV (Natural Resources) refers to the protection of species of both flora and fauna and the ecosystems where they live. Also, Title II, Chapter III refers to the National System of Protected Areas, which encompasses at least portions of the ranges of many amphibians and reptiles, and, in particular, a large percentage of those facing some degree of endangerment. The General Law on Protected Areas (Law 202-04) addresses and reviews the consideration of areas protected under Law 64-00. The National System of Protected Areas (Hoppe, 1989; Valdez Sierra and Mateo Féliz, 1992; Moya Pons et al., 2004; fig. 2) in 1994 had a ratio of protected area to total surface area of 0.178, which increased in 1995 to 0.311, and in
Figure 2. The Sistema Nacional de Áreas Protegidas (National System of Protected Areas; adapted from Moya Pons, 2004; provided by the Secretaría de Estado de Medio Ambiente y Recursos Naturales). Shaded areas represent scientific reserves (including two marine mammal sanctuaries), national parks (including two submarine parks), natural monuments, wildlife refuges, forestry refuges, panoramic roadways and national recreation areas. Unfortunately, the protected status of many of these areas exists only on paper, enforcing the status of others is lax to nonexistent, and the long-term status of all relies on the often inconsistent support of a legislature with close ties to developers.
Conservation of the herpetofauna of the Dominican Republic
179
2000 to 0.326, the 16th highest ratio of any nation (the ratio of protected area to surface area refers to totally or partially protected areas of at least 1000 ha that are designated as national parks, natural monuments, nature reserves, or wildlife sanctuaries, protected landscapes and seascapes, or scientific reserves with limited public access; the data do not include sites protected under local or provincial law; based on the UN Common Database calculated from UNEP-WCMC; Globalis, 2007). The system currently includes eight scientific reserves (including two marine mammal sanctuaries), 19 national parks (including two submarine parks), 17 natural monuments, 15 wildlife refuges, 15 forestry refuges, nine panoramic roadways, and three national recreation areas (SEMARN, 2007). Of the amphibian species that have a formally recognized conservation status (table 1; 32 species), the ranges of only five (16%) are not included in the national system of protected areas, probably the best protection possible for in situ conservation. Of all the reptilian species listed, the ranges of only two, the galliwasps (Celestus anelpistus, C. warreni) are not in protected areas. The Dominican Republic is party to multilateral environmental agreements that include CITES (www.cites.org), the Convention on Biodiversity (www.biodiv.org/ convention/convention.shtml), and the Cartagena Convention with the SPAW (Specially Protected Areas and Wildlife in the Wider Caribbean Region; www.cep.unep. org/pubs/legislation/spaw.html) Protocol. Within the resultant legal framework, all species of amphibians and reptiles are legally protected. At present, the Secretaría de Estado de Medio Ambiente y Recursos Naturales (SEMARN) is working with international partners to develop a biodiversity law, which will add legal protection at the species level. At the national zoo (ZOODOM), a breeding program of critically endangered Cyclura ricordii has been implemented with support from IUCN’s Iguana Specialist Group as part of the species’ recovery plan (Ramer and Hudson, 2005). Although a number of Dominican NGOs promote environmental conservation, at present, only Grupo Jaragua (www.grupojaragua.org.do) is focusing on the conservation of amphibians and reptiles (Ramer, 2005; Rupp et al., 2005). National and local outreach activities reach thousands of primary and secondary school students and teachers. Synergistic collaborations exist with the Dominican Ministry of Education, one of the main national newspapers, elements in the private sector, and domestic and international NGOs, testament to which is the ongoing research on Cyclura ricordii in the southwestern Dominican Republic (e.g., Arias et al., 2004; Rupp et al., 2005, 2007). This research has been complemented by environmental education initiatives and creation of local governmental protected areas. In addition to ZOODOM, these initiatives are supported by the IUCN Iguana Specialist Group, MacArthur Foundation, Spanish Cooperation Agency, and the Indianapolis Zoo. Concurrent research and educational activities address the conservation of sympatric C. cornuta. Also, in collaboration with the Secretaría de Estado de Agricultura/Departamento de Vida Silvestre (SEA/DVS) and ZOODOM, Grupo
180
R. Powell, S.J. Incháustegui
Jaragua has actively promoted conservation of Crocodylus acutus, although that program is not currently active. Working on baseline data (Ottenwalder, 1982; Ross and Ottenwalder, 1983), since 1996, with staff (C.E. Diez and R. van Dam) from Proyecto Carey in Puerto Rico (Isla Mona) and the Dominican Republic (http://members.seaturtle.org/ proyectocarey/index/htm) and additional support from international agencies, Y.A. León of Grupo Jaragua has conducted population studies of marine turtles, with an emphasis on Eretmochelys imbricata (e.g., León and Diez, 1999; León and Bjorndal, 2002; Diez et al., 2003). Integration of local fishermen and, in particular, the youth of local fishing communities is critical to the success of this effort. Nearly 900 turtles have been captured, tagged, and released in Jaragua National Park. The long-term studies have been supplemented since 2006 by nesting surveys and assessments of incidental take by fishermen. Since 2005, foraging ground surveys have been conducted in Monte Cristi and del Este national parks. An educational campaign focusing on the illegality of the “tortoiseshell” trade was initiated in 2007.
The Future The best and most feasible approach for the conservation of Dominican amphibians and reptiles is the inclusion of at least some of threatened species’ critical habitats and ranges within the protected areas system. Thus, conservation of most amphibians and reptiles in the country depends on the existence and enforcement of a well-established and managed protected areas system. However, Hedges (2006) cautioned that “the existence of protected areas should effectively be ignored in assessing the conservation status of native species, unless there is unambiguous evidence that such a designated area is truly affording protection” (italics in original). The Dominican system of protected areas, although in general having good coverage of main ecosystems, habitats, and species composition, still needs to be revised in order to include the endangered species of amphibians and reptiles with ranges not currently encompassed in protected areas. In particular, special attention should be given to the endemic toads (Bufo fluviaticus and B. fractus) and the giant galliwasps (Celestus warreni and C. anelpistus). Other species, although with ranges included at least in part within protected areas, should be addressed by specific conservation programs. These include the freshwater turtles (Trachemys decorata and T. stejnegeri). The main threats to toads and galliwasps is habitat destruction, and to freshwater turtles, habitat destruction, overfishing, and more recently, hybridization with invasive T. scripta (Powell et al., 2000). A well-established breeding population of the latter is now known to exist in the National Botanical Garden in Santo Domingo. Another group of special concern includes the diurnally active terrestrial snakes (Alsophis spp. and Ialtris spp.). Although inoffensive, snakes are routinely killed by local people who fear them. Special educational efforts should be implemented to address this issue. Regarding marine turtles, greater efforts should be given to abiding by CITES regulations,
Conservation of the herpetofauna of the Dominican Republic
181
including steps to eliminate the sale of marine products at airports and other tourist destinations. In brief, for amphibians and reptiles to be adequately conserved in the Dominican Republic, we recommend the following: (1) The national system of protected areas should be expanded, revised to include ranges of species presently not included, and integrated into current and future plans for local and national development. Assuming adequate levels of enforcement, the conservation needs of a majority of species of special concern would be addressed most effectively in this fashion. (2) A nationwide educational program on amphibians and reptilian conservation must be implemented. This year, for the first time, a private-sector company provided a 2007 calendar with photographs and educational information about amphibians and reptiles. The same company also produced a short video, constituting an excellent resource for environmental education. (3) Support for research must be obtained and used to learn more about the status of endangered species about which we know little (e.g., Eleutherodactylus spp., Celestus spp.). (4) At present, the endangered species receiving too little attention is Crocodylus acutus. The Dominican population is almost exclusively restricted to Lago Enriquillo. Because of the species’ size, potential commercial value, and a reproductive strategy that depends on a peculiar set of local environmental conditions, the threat of adverse effects on the remaining population is great. A program should be reestablished to monitor this species.
Summary Like many other insular nations (and islands throughout the world), the Dominican Republic supports a herpetofauna with a large proportion of endemic species. Portions remain relatively intact; however, the herpetofaunal communities in many areas have suffered immensely from habitat destruction or alteration, much associated with the growing human population and the burgeoning tourist industry, from the introduction of invasive species that compete with or prey on native amphibians and reptiles, from exploitation of some species for economic gain or food, and persecution of others resulting from fear or disgust. Conservation priorities in less damaged regions should focus on preserving relatively natural areas through protection, education, limitations on development, and control of invasive species (those that have already been introduced and those that might be), preferably by inclusion in the national system of protected areas. Priorities in extensively altered areas, already overrun with exotics, must seek to minimize the damage already inflicted and prevent further degradation. Standing in the way of implementing these recommendations are under-funded conservation organizations that rely on the work of too few people, a largely apathetic resident population often resistant to educational programs, lax enforcement of existing legislative measures, and governmental entities with firm commitments to development — a litany of hurdles faced by essentially every conservation organization (governmental, not-for-profit, or private) throughout the region.
182
R. Powell, S.J. Incháustegui
Acknowledgements. Yolanda M. León provided valuable information about the ongoing sea turtle initiative in the Dominican Republic. John S. Parmerlee, Jr. prepared the figures. Robert W. Henderson and S. Blair Hedges commented on earlier drafts of this manuscript. Powell’s fieldwork has been funded by a series of National Science Foundation (NSF) Research Experiences for Undergraduates (REU) site grants.
References Alberts, A., Ed. (2000): West Indian Iguanas. Status Survey and Conservation Action Plan. Gland, Switzerland and Cambridge, United Kingdom, IUCN. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds (2004): Iguanas: Biology and Conservation. Berkeley, University of California Press. Aquino, A.T. (1983): Anfibios y reptiles de la Hispaniola en peligro de extinción. Conf. Rev. Cien. Divul., Mus. Nac. Hist. Nat. 1: 26-30. Arias, Y., Incháustegui, S., Rupp, E. (2004): Cyclura ricordii on the Barahona Peninsula: A preliminary report. Iguana 11: 8-13. Bendon, J., Binns, J. (2003): 2002 Iguana Specialist Group conference. Iguana 10: 3-9. Burns, J.K., Cunningham, C.A., Dupuis, R.A., Trask, M.N., Tulloch, J.S., Powell, R., Parmerlee, J.S., Jr., Kopecky, K.L., Jolley, M.L. (1992): Lizards of the Cayos Siete Hermanos, Dominican Republic, Hispaniola. Bull. Chicago Herpetol. Soc. 27: 225-232. Diez, C.E., Vélez-Zuazo, X., van Dam, R.P. (2003): Hawksbill turtles in seagrass beds. Marine Turtle Newsl. 102: 8-10. Dutton, D.L., Dutton, P.H., Chaloupka, M., Boulon, R.H. (2005): Increase of a Caribbean leatherback turtle Dermochelys coriacea nesting population linked to long-term nest protection. Biol. Cons. 126: 186-194. Fitch, H.S., Henderson, R.W., Guarisco, H. (1989): Aspects of the ecology of an introduced anole: Anolis cristatellus in the Dominican Republic. Amphibia-Reptilia 10: 307-320. Fleming, E.H. (2001): Swimming Against the Tide: Recent Surveys of Exploitation, Trade, and Management of Marine Turtles in the Northern Caribbean. Washington, DC, TRAFFIC North America. Gifford, M.E. (2005): Ecotones and hybrid zones: Implications for conservation illustrated by grounddwelling lizards from Hispaniola. Iguana 12: 234-239. Globalis (2007): Globalis — Dominican Republic (http://globalis.gvu.unu.edu/indicator_detail.cfm? IndicatorID=80&Country=DO). Glor, R.E. (1999): Biodiversity assessment for different land uses: Rare dwarf gecko rediscovered. In: CIFAD (Cornell International Institute for Food, Agriculture and Development) Annual Report 1997-98, p. 14-15. Ithaca, New York, Cornell Univ. Glor, R.E., Flecker, A.S., Benard, M.F., Power, A.G. (2001): Lizard diversity and agricultural disturbance in a Caribbean forest landscape. Biodiversity and Conservation 10: 711-723. Hager, J., Zanoni, T.A. (1993): La vegetación natural de la República Dominicana: Una nueva clasificación. Moscosoa 7: 39-81. Hallermann, J., Böhme, W. (2002): On giant anguids from the West Indies, with special reference to Celestus warreni (Schwartz, 1970) and its relatives from Hispaniola (Reptilia: Squamata: Anguidae). Mitt. Hamb. Zool. Mus. Inst. 99: 169-178. Harcourt, C., Billington, C., Sayer, J. (1996): Introduction. In: The Conservation Atlas of Tropical Forests, The Americas, p. 9-16. Harcourt, C.S., Sayer, J.A., Eds, Gland, Switzerland, IUCN. Harcourt, C., Ottenwalder, J.A. (1996): Hispaniola. In: The Conservation Atlas of Tropical Forests, The Americas, p. 102-111. Harcourt, C.S., Sayer, J.A., Eds, Gland, Switzerland, IUCN.
Conservation of the herpetofauna of the Dominican Republic
183
Hedges, S.B. (1999): Distribution patterns of amphibians in the West Indies. In: Patterns of Distribution of Amphibians: A Global Perspective, p. 211-254. Duellman, W.E., Ed., Baltimore, MD, Johns Hopkins Univ. Press. Hedges, S.B. (2008): Caribherp: West Indian amphibians and reptiles. Island lists: Hispaniola (http://evo.bio.psu.edu/caribherp/lists/hsp-list.htm). Hedges, S.B. (2006): An overview of the evolution and conservation of West Indian amphibians and reptiles. Appl. Herpetol. 3: 281-292. Hedges, S.B. (2008): Caribherp: West Indian amphibians and reptiles. Island lists: Hispaniola (http://evo.bio.psu.edu/caribherp/lists/hsp-list.htm). Hedges, S.B., Heinicke, M.P. (2007): Molecular phylogeny and biogeography of West Indian frogs of the genus Leptodactylus (Anura, Leptodactylidae). Mol. Phylogen. Evol. 44: 308-314. Hedges, S.B., Incháustegui, S., Thomas, R., Powell, R. (2004): Leptodactylus dominicensis. In: IUCN 2006. 2006 IUCN Red List of Threatened Species (www.iucnredlist.org). Henderson, R.W. (1992): Consequences of predator introductions and habitat destruction on amphibians and reptiles in the post-Columbus West Indies. Carib. J. Sci. 28: 1-10. Henderson, R.W., Powell, R. (1999): West Indian herpetoecology. In: Caribbean Amphibians and Reptiles, p. 223-268. Crother, B.I., Ed., San Diego, CA, Academic Press. Henderson, R.W., Powell, R. (2001): Responses by the West Indian herpetofauna to human-influenced resources. Carib. J. Sci. 37: 41-54. Henderson, R.W., Sajdak, R.A. (1986): West Indian racers: A disappearing act or a second chance? Lore 36: 13-18. Hoppe, J. (1989): Los Parques Nacionales de la República Dominicana. The National Parks of the Dominican Republic. Santo Domingo, República Dominicana, privately published. Huebeck, C., Mann, P. (1991): Structural geology and Cenozoic tectonic history of the southeastern termination of the Cordillera Central, Dominican Republic. Geol. Soc. Amer. Spec. Pap. 262: 315336. IUCN (International Union for the Conservation of Nature and Natural Resources). (1996): 1996 IUCN Red List of Threatened Animals. Gland, Switzerland, IUCN. IUCN (International Union for Conservation of Nature and Natural Resources). (2001): 2001 Categories and Criteria (version 3.1) (www.redlist.org/info/categories_criteria2001). IUCN (International Union for the Conservation of Nature and Natural Resources). (2008): 2008 IUCN Red List of Threatened Species (http://www.iucnredlist.org). IUCN (International Union for the Conservation of Nature and Natural Resources), Conservation International, and NatureServe. (2006): Global Amphibian Assessment (http://www. globalamphibians.org). Khudoley, K.M., Meyerhoff, A.A. (1971): Paleogeography and geological history of the Greater Antilles. Geol. Soc. Amer. Memoirs 129: 1-199. Lenart, L.A., Powell, R., Parmerlee, J.S., Jr., Lathrop, A., Smith, D.D. (1997): Anoline diversity in three differentially altered habitats in the Sierra de Baoruco, República Dominicana, Hispaniola. Biotropica 29: 117-123. León, Y.M., Diez, C.E. (1999): Population structure of hawksbill turtles on a foraging ground in the Dominican Republic. Chelon. Conserv. Biol. 3: 230-236. León, Y.M., Bjorndal, K.A. (2002): Selective feeding in the hawksbill turtle, an important predator in coral reef ecosystems. Mar. Ecol. Progr. Ser. 245: 249-258. Lever, C. (2003): Naturalized Reptiles and Amphibians of the World. Oxford, Oxford Univ. Press. Lewis, J.F., Draper, G. (1990): Geology and tectonic evolution of the northern Caribbean margin. In: The Geology of North America. Vol. H. The Caribbean Region, p. 77-140. Dengo, G., Case, J.E., Eds, Boulder, Colorado, Geological Society of America. MacDonald, J.S. (1992): Contemporary size and distribution of population. In: The Cambridge Encyclopedia of Latin America and the Caribbean, 2nd edition, p. 151-157. Collier, S., Skidmore, T.E., Blakemore, H., Eds, New York, Cambridge Univ. Press.
184
R. Powell, S.J. Incháustegui
Moya Pons, F., Ed. (2004): Atlas de los Recursos Naturales de la República Dominicana. Santo Domingo, República Dominicana, Secretaría de Estado de Medio Ambiente y Recursos Naturales. Moya Pons, F., Reynoso, F., Sánchez, R. (2004): Programa Nacional de Valorización de Areas Protegidas. Santo Domingo, República Dominicana, Editora Buho, Secretaría de Estado de Medio Ambiente y Recursos Naturales. Ottenwalder, J.A. (1981): Estudio preliminar sobre el status, distribución y biología reproductiva de las tortugas marinas en la República Dominicana. Santo Domingo, Departamento de Biología, Universidad Autónoma de Santo Domingo. Ottenwalder, J.A. (1994a): Conservation program for the South Hispaniolan Slider Turtle (Trachemys decorata) in the Dominican Republic, 1994. Summary progress report prepared for the 1994 AZA/Chelonian Advisory Group Meeting. New Orleans: International Herpetological Symposium. Ottenwalder, J.A. (1994b): Translocation and monitoring program for the South Hispaniolan Slider Turtle (Trachemys decorata). A proposal for field research submitted to the Columbus Zoo’s AHSSC Committee. Ottenwalder, J.A. (2000a): Taxonomic account: Rhinoceros iguana, Cyclura cornuta cornuta. In: West Indian Iguanas: Status Survey and Conservation Action, p. 22-27. Alberts, A., Ed., Gland, Switzerland and Cambridge, United Kingdom, IUCN. Ottenwalder, J.A. (2000b): Taxonomic account: Ricord’s iguana, Cyclura ricordi. In: West Indian Iguanas: Status Survey and Conservation Action, p. 51-55. Alberts, A., Ed., Gland, Switzerland and Cambridge, United Kingdom, IUCN. Ottenwalder, J.A., Powell, R. (2002): Brief notes on the status of Hispaniolan Rhinoceros Iguanas, Cyclura cornuta. Iguana Times 9: 78. Powell, R. (1993): Comments on the taxonomic arrangement of some Hispaniolan amphibians and reptiles. Herpetol. Rev. 24: 135-137. Powell, R. (1999): Herpetology of Navassa Island, West Indies. Carib. J. Sci. 35: 1-13. Powell, R. (2003): Exploitation of reptiles in the West Indies: A long history. Iguana 10: 67-70. Powell, R. (2005): Editor’s remarks. Iguana 12: 283. Powell, R., Crombie, R.I., Boos, H.E.A. (1998): Hemidactylus mabouia. Cat. Amer. Amphib. Rept. 674: 1-11. Powell, R., Henderson, R.W. (1996a): Introduction. In: Contribution to West Indian Herpetology: A Tribute to Albert Schwartz, p. 11-14. Powell, R., Henderson, R.W., Eds, Ithaca, New York, Society for the Study of Amphibians and Reptiles Contributions to Herpetology, vol. 12. Powell, R., Henderson, R.W. (1996b): A brief history of West Indian herpetology. In: Contribution to West Indian Herpetology: A Tribute to Albert Schwartz, p. 29-50. Powell, R., Henderson, R.W., Eds, Ithaca, New York: Society for the Study of Amphibians and Reptiles Contributions to Herpetology, vol. 12. Powell, R., Henderson, R.W. (2003): Taxonomic and conservation status of giant Hispaniolan Celestus (Reptilia, Anguidae). Carib. J. Sci. 39: 237-240. Powell, R., Henderson, R.W. (2005): Conservation status of Lesser Antillean reptiles. Iguana 12: 6277. Powell, R., Henderson, R.W. (2008): Urban herpetology in the West Indies. In: Urban Herpetology. Herpetological Conservation, vol. 3. Jung, R.E., Mitchell, J.C., Eds, New Haven, Connecticut, Soc. Study Amphib. Rept. Powell, R., Ottenwalder, J.A., Incháustegui, S.J. (1999): The Hispaniolan herpetofauna: Diversity, endemism, and historical perspectives, with comments on Navassa Island. In: Caribbean Amphibians and Reptiles, p. 93-168. Crother, B.I., Ed., San Diego, Academic Press. Powell, R., Ottenwalder, J.A., Incháustegui, S.J., Henderson, R.W., Glor, R.E. (2000): Amphibians and reptiles of the Dominican Republic: Species of special concern. Oryx 34: 118-128. Powell, R., Smith, D.D., Parmerlee, J.S., Jr., Taylor, C.V., Jolley, M.L. (1990): Range expansion by an introduced anole: Anolis porcatus in the Dominican Republic. Amphibia-Reptilia 11: 421-425.
Conservation of the herpetofauna of the Dominican Republic
185
Ramer, J. (2004a): Ricord’s Iguanas, Cyclura ricordii: Isla Cabritos population census, 2003. Iguana 11: 34-35. Ramer, J. (2004b): A survey of Ricord’s Iguanas (Cyclura ricordii) and Rhinoceros Iguanas (Cyclura cornuta cornuta) in Isla Cabritos National Park, Dominican Republic, 2003. Iguana 11: 88-95. Ramer, J. (2005): The faces of Grupo Jaragua. Iguana 12: 252-255. Ramer, J., Hudson, R. (2005): Ricord’s Iguana (Cyclura ricordii): Species recovery plan update. Iguana 12: 27. Ross, J.P., Ottenwalder, J.A. (1983): The leatherback turtle, Dermochelys coriacea, nesting in the Dominican Republic. In: Advances in Herpetology and Evolutionary Biology, p. 706-713. Rhodin, A.G.J., Miyata, K., Eds. Cambridge, Massachusetts: Museum of Comparative Zoology. Rupp, E., Incháustegui, S., Arias, Y. (2005): Conservation of Cyclura ricordii in the southwestern Dominican Republic and a brief history of the Grupo Jaragua. Iguana 12: 222-233. Rupp, E., Incháustegui, S., Arias, Y. (2007): Ricord’s Iguana (Cyclura ricordii) on the southern shore of Lago Enriquillo, Dominican Republic. Iguana 14: 2-7. SEMARN (Secretaría de Estado de Medio Ambiente y Recursos Naturales). (2000): Ley General sobre Medio Ambiente y Recursos Naturales. Santo Domingo, República Dominicana: Publicación Oficial. SEMARN (Secretaría de Estado de Medio Ambiente y Recursos Naturales). (2007): Sistema Nacional de Áreas Protegidas (www.medioambiente.gov.do/cms/index.php). Schubert, A. (1993): Conservation of biological diversity in the Dominican Republic. Oryx 27: 115121. Schubert, A., Santana, G. (1996): Conservation of the American Crocodile (Crocodylus acutus) in the Dominican Republic. In: Contribution to West Indian Herpetology: A Tribute to Albert Schwartz, p. 425-433. Powell, R., Henderson, R.W., Eds. Ithaca, New York: Society for the Study of Amphibians and Reptiles Contributions to Herpetology, vol. 12. Schwartz, A. (1978): Some aspects of the herpetogeography of the West Indies. In: Zoogeography in the Caribbean, The 1975 Leidy Medal Symposium, p. 31-51. Gill, F.B., Ed., Philadelphia: Acad. Nat. Sci. Philadelphia. Spec. Publ. Schwartz, A. (1980): The herpetogeography of Hispaniola, West Indies. Stud. Fauna Curaçao Other Carib. Isl. 61: 86-127. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. Gainesville, Univ. Florida Press. SEA/DVS (Secretaría de Estado de Agricultura/Departamento de Vida Silvestre). (1990): La Diversidad Biológica en la República Dominicana: Reporte Preparado por el Departamento de Vida Silvestre para el Servicio Alemán de Cooperación Social-Tecnica y Fondo Mundial para la Naturaleza (WWF-US). Santo Domingo, Secretaría de Estado de Agricultura, SURENA/DVS. SEA/DVS (Secretaría de Estado de Agricultura/Departamento de Vida Silvestre). (1993): Estudio y Protección de Cocodrilo Americano (Crocodylus acutus) en la República Dominicana. Santo Domingo, Secretaría de Estado de Agricultura, SURENA/DVS. Seidel, M.E. (1996): Current status of the biogeography of the West Indian turtles in the genus Trachemys (Emydidae). In: Contribution to West Indian Herpetology: A Tribute to Albert Schwartz, p. 169-174. Powell, R., Henderson, R.W., Eds, Ithaca, New York: Society for the Study of Amphibians and Reptiles Contributions to Herpetology, vol. 12. Stam, S., Stam, R. (1992): Trouble for sea turtles in the Dominican Republic. Mar. Turtle Newsl. 57: 18-19. Valez Sierra, G., Mateo Féliz, J.M. (1992): Sistema de Áreas Protegidas de República Dominicana. Santo Domingo, República Dominicana, Fondo Pro-naturaleza. Weil, T.E., Black, J.K., Blutstein, H.I., Johnston, K.T., McMorris, D.S., Munson, F.P. (1982): Dominican Republic: A Country Study, 2nd edition. Washington, DC: Department of the Army.
186
R. Powell, S.J. Incháustegui
Weiss, A.J., Hedges, S.B. (2007): Molecular phylogeny and biogeography of the Antillean geckos Phyllodactylus wirshingi, Tarentola americana, and Hemidactylus haitianus (Reptilia, Squamata). Molecular Phylogenetics and Evolution 45: 409-416. Williams, E.E. (1961): Notes on Hispaniolan herpetology 3. The evolution and relationships of the Anolis semilineatus group. Breviora 136: 1-8. Williams, E.E. (1999): Over 300 years of collecting in the Caribbean. In: Caribbean Amphibians and Reptiles, p. 1-30. Crother, B.I., Ed., San Diego, California, Academic Press. Wilson, B.S., Horrocks, J.A., Hailey, A. (2006): Conservation of insular herpetofaunas in the West Indies. Appl. Herpetol. 3: 181-195. ZOODOM (Parque Zoológico Nacional), Grupo Jaragua, IUCN-SSC Iguana Specialist Group, International Iguana Foundation, Durrell Wildlife Conservation Trust. (2002): Ricord’s iguana, Cyclura ricordii: Species recovery plan, 2002-2007. Iguana Ricordi, Cyclura ricordii: Plan de Recuperación de la Especie, 2002-2007. Gland Switzerland, IUCN.
Accepted: April 7, 2008 (BSW). Reprinted from Applied Herpetology 6: 103-122 (2009).
Addendum A number of taxonomic changes have been applied to species of amphibians and reptiles in the Dominican Republic (table A1). Most notable is the partitioning of several genera of snakes in the family Leptotyphlopidae (Adalsteinsson et al., 2009) and others formerly placed in the family Colubridae, but now considered members of the Dipsadidae (Hedges et al., 2009; Zaher et al., 2009). In addition, Hedges et al. (2008) placed all West Indian species of Eleutherodactylus in the family Eleutherodactylidae and Gamble et al. (2007, 2008) recognized the families Phyllodactylidae (genus Phyllodactylus) and Sphaerodactylidae (genera Aristelliger, Gonatodes, and Sphaerodactylus) for geckos previously placed in the family Gekkonidae, which is now restricted to Hispaniolan geckos in the genus Hemidactylus. Frost et al. (2006) resurrected the genus Peltophryne for West Indian toads, and Chapparro et al. (2007) assigned Bufo marinus to the genus Rhinella. Frost et al. (2006) also relegated Rana catesbeiana to the genus Lithobates. Two new introduced lizards have been discovered (Scantlebury et al., 2010). Hemidactylus frenatus (Gekkonidae) is native to southeastern Asia and parts of Africa. It has become widely established in the Western Hemisphere, but had not been previously recorded from the West Indies. Gymnophthalmus underwoodi (Gymnophthalmidae) is a parthenogenetic species native to northeastern South America and presumably some of the southern Lesser Antilles. This is the first record from the Greater Antilles. Three species of Sphaerodactylus are known only from the immediate vicinities of their respective type localities, all of which are in imminent danger from development. Sphaerodactylus epiurus occurs only in isolated karst hills, the western edge of which is an active quarry. Although the type locality of S. perissodactylius is within the Parque Nacional Sierra Martín Garcia, the habitat
Conservation of the herpetofauna of the Dominican Republic
187
Table A1. Taxonomic changes affecting species of amphibians and reptiles in the Dominican Republic. AMPHIBIANS Bufonidae Peltophryne fluviatica (formerly Bufo fluviaticus) Peltophryne fracta (formerly Bufo fractus) Peltophryne guentheri (formerly Bufo guentheri) Rhinella marina (formerly Bufo marinus or Chaunus marinus) Eleutherodactylidae (formerly assigned to the family Leptodactylidae) Eleutherodactylus spp. (all West Indian species in the genus) Ranidae Lithobates catesbeianus (formerly Rana catesbeiana) REPTILES Phyllodactylidae (formerly assigned to the family Gekkonidae) Phyllodactylus spp. (P. hispaniolae and P. sommeri) Sphaerodactylidae (formerly assigned to the family Gekkonidae) Aristelliger spp. (A. expectatus and A. lar) Sphaerodactylus spp. (all species in the genus) Dipsadidae (formerly assigned to the family Colubridae) Haitiophis anomalus (formerly Alsophis anomalus or Ocyophis anomalus) Hypsirhynchus melanichnus (formerly Alsophis melanichnus or Ocyophis melanichnus) Hypsirhynchus parvifrons (formerly Antillophis parvifrons) Ialtris haetianus (formerly Darlingtonia haetianus) Leptotyphlopidae Mitophis asbolepis (formerly Leptotyphlops asbolepis) Mitophis calypso (formerly Leptotyphlops calypso) Mitophis pyrites (formerly Leptotyphlops pyrites)
is threatened by charcoal production. As of August 2010 (D. Scantlebury, pers. comm.), signs of active charcoal production (e.g., log piles and bags of charcoal) were abundant. Sphaerodactylus schuberti might be more widely distributed than the other two species, but the type locality is on private property, and the habitat is severely degraded by overgrazing by goats. In addition, 31 new protected areas were established, expanding the total coverage of protected areas in the Dominican Republic by 13,037.24 km2 .
References Adalsteinsson, S.A., Branch, W.R., Trape, S., Vitt, L.J., Hedges, S.B. (2009): Molecular phylogeny, classification, and biogeography of snakes of the family Leptotyphlopidae (Reptilia, Squamata). Zootaxa 2244: 1-50. Chapparro, J.C., Pramuk, J.B., Gluesenkamp, A.G. (2007): A new species of arboreal Rhinella (Anura: Bufonidae) from cloud forest of southeastern Peru. Herpetologica 63: 203-212. Frost, D.R., Grant, T., Faivovich, J., Bain, R.H., Haas, A., Haddad, C.F.B., de Sá, R.O., Channing, A., Wilkinson, S.C., Donnellan, M., Raxworthy, C.J., Campbell, J.A., Blotto, B.L., Moler, P., Drewes, R.C., Nussbaum, R.A., Lynch, J.D., Green, D.M., Wheeler, W.C. (2006): The amphibian tree of life. Bull. Amer. Mus. Nat. Hist. 297: 1-370.
188
R. Powell, S.J. Incháustegui
Gamble, T., Bauer, A.M., Greenbaum, E., Jackman, T.R. (2007): Evidence for Gondwanan vicariance in an ancient clade of gecko lizards. J. Biogeogr. 35: 88-104. Gamble, T., Bauer, A.M., Greenbaum, E., Jackman, T.R. (2008): Out of the blue: A novel, transAtlantic clade of geckos (Gekkota, Squamata). Zool. Scripta 37: 355-366. Hedges, S.B., Duellman, W.E., Heinicke, M.P. (2008): New World direct-developing frogs (Anura: Terrarana): Molecular phylogeny, classification, biogeography, and conservation. Zootaxa 1737: 1-182. Hedges, S.B., Couloux, A., Vidal, N. (2009): Molecular phylogeny, classification, and biogeography of West Indian racer snakes of the Tribe Alsophiini (Squamata, Dipsadidae, Xenodontinae). Zootaxa 2067: 1-28. Scantlebury, D., Ng, J., Landestoy, M., Glor, R.E. (2010): Hemidactylus frenatus and Gymnophthalmus underwoodi in the Dominican Republic. Rept. Amphib. 17, in press. Zaher, H., Grazziotin, F.G., Cadle, J.E., Murphy, R.W., de Moura-Leite, J.C., Bonatto, S.L. (2009): Molecular phylogeny of advanced snakes (Serpentes, Caenophidia) with an emphasis on South American xenodontines: A revised classification and descriptions of new taxa. Pap. Avul. Zool. 49: 115-153.
Conservation of the herpetofauna on the Dutch Windward Islands: St. Eustatius, Saba, and St. Maarten Robert Powell Department of Biology, Avila University, Kansas City, MO 64145, USA e-mail:
[email protected] Abstract. The Dutch Windward Islands (St. Eustatius, Saba, St. Maarten) support a collective herpetofauna consisting of two frogs (both introduced), six turtles (one introduced, one of uncertain origin, and four sea turtles, of which three are known to nest in the islands), 15 or 16 lizards (depending on whether the iguanas of Saba are a species distinct from Iguana iguana), and three snakes (one introduced). Although politically united, the islands are distinct biogeographic entities and binary similarity indices for the herpetofauna are 0.38 for St. Eustatius/Saba, 0.35 for St. Eustatius/St. Maarten, and 0.20 for Saba/St. Maarten (with values varying only little when the introduced species are included). Only three species, Eleutherodactylus johnstonei, Hemidactylus mabouia, and Thecadactylus rapicauda, are found on all three islands. Species given formal recognition as being in need of protection include the sea turtles (listed in CITES appendices and the IUCN Redlist), Geochelone carbonaria (CITES), Iguana delicatissima (CITES and IUCN), Iguana iguana (CITES), and two species of Alsophis (IUCN). Other species of conservation concern include two species of Ameiva, both of which are restricted to areas of considerable human activity on islands where mongooses (Herpestes javanicus) are established, and Mabuya sp., which may be extirpated on St. Maarten. Three factors largely responsible for the status of these species are: (1) large size and economic value (turtles and iguanas), (2) persecution by people who fear them (snakes), and (3) diurnally active, terrestrial, and vulnerable to predation by mongooses (snakes, Ameiva, Mabuya). Non-governmental organizations on each island are largely responsible for conservation and related educational efforts. Specific recommendations for each island are listed. Key words: Amphibians; conservation; Dutch Windward Islands; reptiles.
Introduction Although part of a political entity (the Netherlands Antilles, which also includes Bonaire and Curaçao, two of the three “Leeward Islands”) and geographically proximate, each of the Dutch Windwards is a distinct biogeographic element (Powell et al., 2005; fig. 1). St. Eustatius (Statia) is part of the St. Christopher (St. Kitts) Bank, which also includes St. Christopher and Nevis. Saba is an isolated
190
R. Powell
Figure 1. An overview of the island banks in the northern Lesser Antilles (from Powell et al., 2005).
seamount volcano separated from the nearby Saba Bank. St. Maarten not only shares an island with St.-Martin, an overseas department of France, but is part of the Anguilla Bank, which includes Anguilla, St.-Barthélemy, and satellites. In addition, islands of the Anguilla Bank are part of the “Limestone Caribees,” also called the outer-arc islands of the Lesser Antilles. These very old islands, originally of volcanic origin, have weathered considerably and have been submerged during periods of high ocean levels. Consequently, limestone deposits of marine origin cover the volcanic core. The Limestone Caribees, due to erosion by wind and water, also lack substantial elevations. The highest peak on St. Maarten/St. Martin is Pic Paradis, with an elevation of about 400 m a.s.l. (above sea level). In stark contrast, Saba and the islands of the St. Kitts Bank (which includes St. Eustatius) belong to the “Volcanic Caribees,” also called the inner-arc islands. These much more recently formed islands are characterized by active or dormant volcanoes, substrates of volcanic origin, and substantial elevations. The highest peak on Saba is Mount Scenery (870 m a.s.l.) and the Quill on St. Eustatius is slightly over 600 m a.s.l. The greater elevations function to “snag” clouds, which results in mesic conditions,
Conservation on the Dutch Windward Islands
191
especially near the tops of peaks and on the higher slopes, and a much greater differential in precipitation with drier lowlands than on the lower outer-arc islands that are more uniformly xeric.
The Herpetofauna of the Islands The herpetofauna of the three islands consists of two amphibians (both frogs and both presumably introduced, at least one by human agency), 15 or 16 lizards (depending on whether or not the green iguana of Saba is a species distinct from Iguana iguana; see discussion in Powell et al., 2005), three snakes (one introduced), and two turtles (at least one introduced), plus three species of sea turtles known to nest in the islands and a fourth that is sometimes seen in surrounding waters (table 1). In addition, strays (populations of species not known to have established breeding populations), all on St. Maarten (Powell et al., 1992, 2005), include two species (Anolis bimaculatus and Alsophis rufiventris) native to other Dutch islands and at least five exotic species of snakes (only two of which are listed in the table because the others represent isolated incidents and are very unlikely to establish self-perpetuating populations). St. Maarten is plagued by introduced exotics to a much greater extent than either Statia or Saba, a situation reflecting that island’s larger size, larger and more transient human population, and the island’s status as a regional shipping center serving the pet trade. Binary indices of similarity (Krebs, 1989) comparing the herpetofaunas of the three islands (Powell et al., 2005; table 2) emphasize the differences that exist despite the islands’ geographic proximity to one another. The greater similarity between St. Eustatius and Saba compared to that for either island and St. Maarten undoubtedly reflects the fact that prevailing currents in the region would facilitate movement of species via overwater dispersal from the St. Kitts Bank to Saba. Notable is the fact that only three species (possibly four, if Geochelone carbonaria was historically present on Statia), other than sea turtles, are common to all three islands. Hemidactylus mabouia commonly functions as a human commensal (Vitt and Zani, 1997; Powell et al., 1998, 2005; Henderson and Powell, 2001; Howard et al., 2001; Hodge et al., 2003) and is likely to appear eventually on any inhabited island in the area. Thecadactylus rapicauda is less frequently and closely allied with humans (Vitt and Zani, 1997; Powell et al., 1998, 2005; Howard et al., 2001; Russell and Bauer, 2002; Hodge et al., 2003), but the occasional associations may facilitate dispersal. Both species, however, also have characteristics (hardiness, ecological versatility, and both adults and eggs that are resistant to exposure; Powell and Henderson, 2006) that render them good candidates for natural dispersal. The third species, Eleutherodactylus johnstonei, is all but ubiquitous in the Lesser Antilles (Kaiser and Hardy, 1994; Henderson and Powell, 2001), testament to its dispersal abilities despite the generalization that amphibians are less capable of overwater movement and colonization than reptiles (Henderson and Powell, 1999; Lever, 2003; Powell and Henderson, 2006).
192
R. Powell
Table 1. The distribution of non-marine reptiles and amphibians on the Dutch Windward Islands (from Powell et al., 2005): Saba (13 km2 ), St. Eustatius (Statia) (20 km2 ), and St. Maarten (includes the French portion of the island known as St.-Martin) (85 km2 ). In addition to taxa listed, three species of sea turtles (green turtle, Chelonia mydas; hawksbill, Eretmochelys imbricata; leatherback, Dermochelys coriacea) are know to nest on all three islands at least occasionally, and another (Caretta caretta) is a vagrant in these waters. Note that green iguanas (Iguana iguana) from Saba may be distinct at the species level from populations of green iguanas found elsewhere. The asterisk (∗) denotes populations that probably are native, but some individuals and possibly even entire populations might be introduced (see text); other symbols: X = extirpated; E = critically endangered; A = abundant (at least at some locations), likely to be encountered within a few minutes of searching in appropriate habitat; R = rare, encountered at most sporadically, even in appropriate habitat; I = introduced; S = stray (one or few individuals introduced, but no population established). The question mark (?) used in combination with the “X” for the slipperyback (Mabuya sp.) indicates uncertainty about the possible extirpation of the population on St. Maarten. The question mark in combination with the “S” for the red-footed tortoise (Geochelone carbonaria) on Statia denotes a situation where we cannot rule out the possibility that the species was once present. Species Lizards Green iguana (Iguana iguana) Lesser Antillean iguana (Iguana delicatissima) Red-faced ground lizard (Ameiva erythrocephala) Anguilla Bank ground lizard (Ameiva plei) Green tree lizard (Anolis bimaculatus) Common tree lizard (Anolis gingivinus) Anguilla Bank bush anole (Anolis pogus) Saba anole (Anolis sabanus) Statia bush anole (Anolis schwartzi) Woodslave (Hemidactylus mabouia) Turnip-tailed gecko (Thecadactylus rapicauda) Little dwarf gecko (Sphaerodactylus parvus) Saba dwarf gecko (Sphaerodactylus sabanus) Island dwarf gecko (Sphaerodactylus sputator) Slipperyback (Mabuya sp.) Snakes Boa constrictor (Boa constrictor) Anguilla Bank racer (Alsophis rijgersmaei) Red-bellied racer (Alsophis rufiventris) Corn snake (Elaphe guttata) Worm snake (Ramphotyphlops braminus)
Saba
Statia
R E A A
St. Maarten RI X A IX A A
A A* R A
A A* R A A
A* R A A X? S E S S RI
A
A
Turtles Red-footed tortoise (Geochelone carbonaria) Red-eared slider (Trachemys scripta)
E*
S?
E* AI
Frogs Johnstone’s whistling frog (Eleutherodactylus johnstonei) Cuban treefrog (Osteopilus septentrionalis)
AI
AI
AI AI
Conservation on the Dutch Windward Islands
193
Table 2. Binary indices of similarity for pairwise comparisons of the herpetofaunal communities on St. Eustatius (Statia), Saba, and St. Maarten. Similarity indices (S) compare the faunas of two entities using the following formula (Krebs, 1989): S = a/(a + b + c), where a = number of species common to both entities, b = number of species found only on one, and c = number of species found only on the other. The native population of iguanas on Saba and the introduced population on St. Maarten are considered conspecific (Iguana iguana) for purposes of these comparisons (but see text) and the extirpated population of Lesser Antillean iguanas (I. delicatissima) is included only for comparisons of endemic and native species. “Introduced” populations are limited to those designated with an “I” (and which are not extirpated) in Table 1. Values differ from those in Powell et al. (2005) because some taxa were assigned to different categories.
Endemic and native species only With introduced species
Saba/Statia
Saba/St. Maarten
Statia/St. Maarten
0.33 0.42
0.20 0.28
0.25 0.24
Conservation Status Animal populations often suffer as a consequence of alterations to their habitats by humans. Insular populations, particularly habitat specialists and endemic species that have evolved in the absence of efficient mainland predators and competitors, are most vulnerable (e.g., Powell and Henderson, 2005; Powell et al., 2005). Declines in amphibian populations throughout the world have been documented in recent years (e.g., IUCN et al., 2004), but comparable surveys of reptilian species have yet to be implemented (but see Gibbons et al., 2000). A few species and even some genera (e.g., West Indian rock iguanas in the genus Cyclura; e.g., Alberts, 2000; Alberts et al., 2004) have been the focus of intensive conservation efforts. Populations of many more species, a large proportion of which are found only on small islands, are in various stages of decline, some in imminent danger of extinction, often with little recognition by the public or even professional conservation biologists. Lesser Antillean reptiles are frequently the most abundant and obvious naturally occurring vertebrates (Henderson and Powell, 1999), but overviews of conservation needs have been rare. Whereas many Lesser Antillean species are ecological generalists (Henderson and Powell, 1999; Powell and Henderson, 2005, 2006) and some thrive in altered habitats, populations of many others are declining at alarming rates. Recent extirpations and even some extinctions have been documented, with a majority of both attributable to human agency. Powell and Henderson (2005) contended that at least 37 of 81 (45.7%) native terrestrial reptiles inhabiting the Lesser Antilles have been affected negatively in some substantive way by human activities. These include species that have become extinct since European arrival and species with at least some populations that have been extirpated or drastically reduced in numbers. Addressing these concerns (table 3) for the native reptiles of the Dutch Windward islands (both amphibians on these islands are introduced and not of concern), all sea turtles are listed in CITES Appendix I. Green (Chelonia mydas) and loggerhead (Caretta caretta) turtles are red-listed as endangered, whereas the
194
R. Powell
Table 3. Formally recognized conservation status of reptilian species in the Dutch Windward Islands: St. Eustatius (Statia), Saba, and St. Maarten. CITES appendices are indicated by “I” or “II,” and IUCN Red List status by CR (critically endangered), EN (endangered), or VU (vulnerable). Species Loggerhead turtle (Caretta caretta) Green turtle (Chelonia mydas) Hawksbill turtle (Eretmochelys imbricata) Leatherback turtle (Dermochelys coriacea) Red-footed tortoises (Geochelone carbonaria)a Lesser Antillean iguana (Iguana delicatissima) Common or green iguana (Iguana iguana)a,c Anguilla Bank racer (Alsophis rijgersmaei) Red-bellied racer (Alsophis rufiventris) a No
Status I, EN I, EN I, CR I, CR II II, VUb II ENd ENe
distinction is made between island and continental populations.
b Status almost certainly needs to be upgraded to EN in light of continuing declines in population sizes
and ongoing threats to habitat and gene pools on nearly all islands where the species occurs. c No distinction is made between native and introduced island populations. d While the population on St. Maarten is functionally extirpated, those elsewhere on the Anguilla Bank are relatively healthy. This situation is very similar to that for Ameiva plei, which remains abundant only locally on St. Maarten, and for Mabuya sp., which may be extirpated on St. Maarten but is apparently widespread but rarely encountered on other Anguilla Bank islands. e Populations on St. Christopher (St. Kitts) and Nevis are extirpated, but snakes remain abundant on St. Eustatius and Saba. Somewhat similarly, populations of Ameiva erythrocephala are greatly restricted on St. Kitts and Nevis, but the species is widespread and abundant on Statia.
hawksbill (Eretmochelys imbricata) and leatherback (Dermochelys coriacea) turtles are critically endangered. Red-footed tortoises (Geochelone carbonaria) are listed in CITES Appendix II. In addition, sea turtles are protected by national and local legislation. Although all turtles are affected by habitat alteration, the sea turtles especially by the development of nesting beaches, the principal threats are due to exploitation by humans for food or, in the case of tortoises, as pets. The original range of the Lesser Antillean iguana (I. delicatissima) extended from Martinique in the south to Anguilla in the north (Powell, 2004; Pasachnik et al., 2006), but several populations, including that on St. Maarten, are extirpated. Along with all iguanas, the species is listed in CITES Appendix II and as “vulnerable” in the IUCN Red List. Like sea turtles, the principal threat is exploitation, although habitat destruction and competition with invasive mammalian herbivores also are major factors. Also like sea turtles, populations are protected by local regulations, although enforcement ranges from non-existent to sporadic. Some Lesser Antillean populations of green iguanas (Iguana iguana) are undoubtedly descendants of ancestors that arrived in the islands by natural (nonhuman-mediated) overwater dispersal. Others may have been introduced by Amerindians (probably for food), established recently as a consequence of escaped pets, or combinations thereof (Powell, 2004). The population on Saba is presumably native (Malone and Davis, 2004; Powell, 2004), whereas that on St. Maarten is known
Conservation on the Dutch Windward Islands
195
to be introduced (Powell et al., 2005). Because of the species’ broad continental range, which extends from México through Central America and across much of northern South America, and a general lack of recognition of genetic variability among populations, protective measures are considerably less stringent than for I. delicatissima. Iguana iguana is listed in CITES Appendix II, but export quotas exist for many countries, primarily for live animals (pet trade) or products (leather goods and meat). No distinction is made for native versus introduced or for continental versus insular populations. Hunting is usually prohibited, but enforcement of laws is often lax. Neither of the two species of Ameiva that occur in the Dutch Windwards is listed. Although some populations have declined dramatically, they remain common in at least some portion of their historic ranges. Ameiva plei is common on Anguilla, some of its satellites, and St.-Barthélemy, but populations on mongoose-infested St. Maarten are localized, and the species is absent from many areas that apparently provide suitable habitat and adequate resources. Similarly, A. erythrocephala is doing quite well on mongoose-free St. Eustatius (Rojer, 1997a; Kerr et al., 2005a,b), but is essentially restricted to heavily trafficked “urban” areas on St. Christopher and Nevis (Barbour, 1930; Westerman, 1953; Malhotra and Thorpe, 1999), where its apparent dependence on humans to deter mongoose activity renders it a human commensal in such situations. Skinks in the genus Mabuya are widely distributed throughout the Lesser Antilles (Schwartz and Henderson, 1991), but they are nowhere abundant. The population on St. Maarten may have been extirpated (Breuil, 2002). Predation by mongooses, cats, and other exotic predators appears to be primarily responsible. The ranks of the common snakes (Family Colubridae), like the ground-dwelling Ameiva lizards, have suffered the greatest number of extirpations, extinctions, or dramatic reductions in geographic ranges in the Lesser Antilles (Henderson, 1992, 2004; Powell and Henderson, 2005). West Indian racers (Alsophis) are, essentially, snake counterparts of Ameiva. They are ground-dwelling, diurnal, fast-moving, oviparous, and apparently susceptible to predation by ground-dwelling, diurnal, fast-moving mongooses. Although some islands harbor healthy racer populations (e.g., Alsophis rijgersmaei on Anguilla and St.-Barthélemy and A. rufiventris on Saba and Statia; Rojer, 1997a, b; Malhotra and Thorpe, 1999; Breuil, 2002; Hodge et al., 2003; Heinz et al., 2004; Henderson, 2004; Maley et al., 2005; Powell and Henderson, 2005; Powell et al., 2005; Savit et al., 2005), populations of the same species are restricted to small, isolated enclaves on St. Maarten (A. rijgersmaei; Powell et al., 1992, 2005; Rojer, 1997c; Breuil, 2002; Powell and Henderson, 2005) and extirpated on St. Christopher and Nevis (A. rufiventris; Barbour, 1930; Sajdak and Henderson, 1991; Henderson, 1992, 2004; Sajdak, 2004; Maley et al., 2005). In each instance, the mongoose appears to be primarily responsible (Henderson, 1992, 2004; Powell and Henderson, 2005; Powell et al., 2005). Both A. rijgersmaei and A. rufiventris are included on the IUCN Red List as endangered.
196
R. Powell
In summary, many Lesser Antillean reptiles and some of those found on the Dutch Windwards are habitat generalists, descendants of effective colonizers, and often adapt well to human-mediated alterations of their environments (Henderson and Powell, 1999; Powell and Henderson, 2005; Powell et al., 2005). The most obvious examples are the many anoles that probably were arboreal historically, but adapt readily to almost any vertical structure. Also apparently doing well are some of the nocturnally active species (e.g., wall geckos, Hemidactylus and Thecadactylus), and those that are small and inconspicuous (e.g., dwarf geckos, Sphaerodactylus; e.g., Hensley et al., 2004). In sharp contrast, many other reptiles have seen populations decline precipitously and even disappear altogether. Particularly vulnerable are species that are associated primarily or solely with pristine habitats that no longer exist on most islands, those that are large and can serve as economic commodities (e.g., sea turtles, tortoises, iguanas), species that inspire fear and are actively persecuted by residents who consider them dangerous (e.g., snakes), or forms that are diurnally active and terrestrial (e.g., Ameiva, Mabuya, Alsophis) — but, in the absence of mongoose introductions, extirpations and dramatic reductions in populations sizes would be far less common (Sajdak and Henderson, 1991; Henderson, 1992, 2004; Henderson and Powell, 1999; Sajdak, 2004; Powell and Henderson, 2005; Powell et al., 2005).
Conservation Action Despite a collective population of fewer than 220,000 people and a total land area of just 800 km2 , and division into two distinct island groups separated by more than 900 km of open water, and linguistic and cultural differences, the conservation efforts of the Netherlands Antilles over the past decades are exemplary for the region. Each island has one or more legally established protected area of significance. All are managed by non-governmental, not-for-profit foundations, which are struggling to protect and make wise use of the natural heritage of their islands. Common threats to these protected areas include limited and at times unreliable governmental support and escalating pressure to develop particularly tourism-related construction. Other problems include entrenched local issues, such as disputes over land tenure, persistent overharvesting of resources, and overgrazing by free-roaming goats, sheep, cattle, and donkeys. The Dutch Caribbean Nature Alliance (DCNA) was established with goals of safeguarding the biodiversity and promoting sustainable management of the islands’ natural resources. The DCNA supports the local conservation organizations on each of the islands, seeks to develop a collective trust fund for nature conservation, and aims to make the rich and varied nature of the islands wider known in the Netherlands and elsewhere. Within the Kingdom of the Netherlands, the islands are the most important “hotspot” of biodiversity. The St. Eustatius National Parks Foundation (STENAPA) is the only environmental organization on St. Eustatius. It was established in 1988 with the primary
Conservation on the Dutch Windward Islands
197
objective of protecting terrestrial and marine areas of ecological, scientific, and cultural significance. In 1996, the island government delegated STENAPA to protect and manage the newly declared Marine Park and, in 1998, the Quill and Boven National Park. Since 2002, staff, interns, and volunteers have been active with day and night patrols during nesting seasons to document, measure, and tag all nesting sea turtles, to protect nests, and ensure that hatchlings reach the sea. The Saba Conservation Foundation (SCF), operational since 1987, has a stated mission of contributing to the sustainable development of Saba through the preservation and sensible use of the island’s natural and cultural resources. The island government has delegated the responsibility of nature management, including management of the Saba National Marine Park to the SCF. The SCF also conducts programs on species protection (particularly for Anolis sabanus, Alsophis rufiventris, and Iguana iguana), has implemented an ongoing and to date somewhat successful effort to reduce the island’s domestic and feral cat population through a tagging, registration, spay-and-neuter program, was instrumental in promoting efforts to reduce populations of free-ranging goats, and conducts occasional animal management and protected species public relations and awareness campaigns. The Nature Foundation of St. Maarten (NAFSXM), established in January 1997, with the objective of enhancing the environment through proper management, education, awareness, and protection of natural resources. St. Maarten recently established a marine park and legislation calling for the protection of beaches, coral reefs, turtles, mangroves, sea grasses, and other protected species are planned. The Nature Foundation also has proposed development of a “hillside park” that will protect the island’s indigenous terrestrial flora and fauna and educational programs to stimulate environmental awareness in the schools are ongoing.
The Future Paralleling the geological and geographic differences between the islands, the probable fates of natural biotic communities on Statia and Saba versus those on St. Maarten differ substantially, as do priorities for conservation. The latter differences are largely attributable to dramatically different states of development, largely related to tourism and attributable to size and ready access via air or cruise ships. I have somewhat presumptuously decided to present my views as lists of priorities for each island. Readers must keep in mind that these are solely opinions that reflect my experiences and herpetological biases and may not accurately represent the policies or priorities of the islands’ governments or conservation organizations. Also important is an awareness that the following recommendations apply solely to terrestrial communities, may not be equally practical or easily implemented, and that my lists of priorities are not meant to be all-inclusive. In addition, I have not separated those priorities currently being addressed with varying degrees of success from those that are not being addressed at all. Finally, readers will note
198
R. Powell
similarities between priorities I have proposed for Saba and Statia, whereas those for St. Maarten differ considerably, with only a few common threads. Saba, due to its stark topography and lack of tourist-friendly beaches, remains the most “natural” of the three Windward Islands. However, an economy increasingly dependent on tourism will inevitably increase pressure to expand related development and accompanying infrastructure to portions of the island less and less suited to accommodate them. Furthermore, proposed expansion of an offshore medical school will increase the human population, number of motor vehicles, and pressure to support them adequately. Priorities for conservation should include: (1) restrictions on development to areas already altered by human presence; (2) fostering and possibly subsidizing eco-friendly development (most tourists to Saba are attracted by the excellent diving or hiking trails and should be open to these sorts of facilities); (3) defending vigorously existing protected areas and supporting initiatives to expand them; (4) continuing efforts to educate residents and visitors regarding the island’s unique and fragile biota (the island’s Sea & Learn program is an outstanding example of an educational partnership between businesses, schools, and the international scientific community; for more information see: www.seaandlearn.org); (5) implementation of stringent regulations restricting introduction of alien species (of particular importance are efforts to preclude importation of exotic plants that might displace the native flora, green iguanas that might interbreed with native iguanas and dilute the population’s gene pool, and non-native predators such as mongooses and exotic snakes with the potential to wreak havoc with native avian and reptilian populations); and (6) ongoing restrictions and efforts to reduce the number of feral cats and free-ranging goats. St. Eustatius, once an international commercial center, is now off the beaten track. Consequently, pressures to develop the island’s remaining relatively natural areas have been minimal in recent years. However, easier access by tourists via air service directly from Puerto Rico, the presence of a medical school with plans for expansion, domination of the local economy by a major petroleum transshipment operation, and inconsistent governmental support of current conservation efforts speak to rapidly changing realities. Priorities for conservation should include: (1) very stringent control of development that might affect existing natural areas (especially important and vulnerable are Zeelandia Beach, where sea turtles nest, and the slopes of the Quill); (2) resolving land-ownership issues in those parts of the Boven Sector not incorporated in the grounds of the refueling station in order that historical and biotic resources in that area might be preserved; (3) fostering and possibly subsidizing eco-friendly development (most tourists to Statia, like those to Saba, are attracted by the excellent diving or hiking trails and should be open to these sorts of facilities); (4) continuing efforts to educate residents and visitors regarding the island’s unique and fragile biota (effective educational collaborations between the island’s schools and the National Parks Foundation are a solid beginning); (5) implementation of stringent regulations restricting introduction of alien species (of particular importance are efforts to preclude importation of
Conservation on the Dutch Windward Islands
199
exotic plants that might displace the native flora, green iguanas that might interbreed with naturally occurring Lesser Antillean iguanas, and non-native predators such as mongooses and exotic snakes with the potential to wreak havoc with native avian and reptilian populations); (6) increased emphasis and funding for efforts to control or even eliminate coralita (or Mexican creeper, Antigonon sp.), which has overrun Statia to a much greater extent than on the many other West Indian islands on which that invasive plant has become established; and (7) implementation of ever more aggressive efforts to reduce the numbers of free-ranging mammalian herbivores, especially goats that have dramatically altered the biotic communities throughout the island. Unlike Saba and Statia, much of St. Maarten has already been developed, primarily for tourism. Essentially all lowland habitats have been altered, and construction is climbing higher and higher onto hillsides. In addition, few relatively natural areas remain and exotic species abound; most notably, the mongoose is firmly established. Consequently, my proposals seek to reflect the status quo, acknowledging the damage already done, and stress the need to conserve the few remaining natural resources present on the island. Priorities for conservation should include: (1) establishment of hillside protected areas and constraints on development of hillsides that can only affect negatively the relict relatively natural areas (a failure to do so will inevitably cause further damage to lowlands and watersheds as a consequence of increased erosion); (2) protection of beaches used by nesting sea turtles and not already developed for tourism; (3) ongoing conservation and reestablishment of coastal mangrove stands that protect low lying areas and support a number of native animals; (4) continuing efforts to educate residents and visitors regarding the island’s fragile biotic communities (complicated by the island’s dual nationality and a relatively large human population that render collaboration with schools much more difficult than on Saba or Statia); and (5) implementation and enforcement of stringent regulations restricting further introductions of alien species.
Summary Like many other West Indian islands (and islands throughout the world), the three Dutch Windward islands support herpetofaunas with large proportions of insular or bank endemics or species found only on adjacent banks. Those on Saba and Statia are relatively intact; however, the herpetofaunal community on St. Maarten has experienced an extirpation (Iguana delicatissima, although the niche has been largely filled by introduced I. iguana), a probable extirpation (Mabuya sp.), and dramatic reductions in population sizes and distribution (one of which, Alsophis rijgersmaei, appears to functionally extirpated). An additional population of one species (Geochelone carbonaria) is of unknown origin and status, and invasive species have become established (Ramphotyphlops braminus and Trachemys scripta) or threaten to do so (Boa constrictor and Elaphe guttata).
200
R. Powell
The differences between St. Maarten and the less-developed islands are almost entirely attributable to varying levels of human influence: development, largely for the tourist industry and introductions of exotic species. Saba and Statia have largely been spared the carnage inflicted on St. Maarten due to smaller island sizes, smaller human populations, and physical characteristics (topography and lack of tourist-friendly beaches) that have retarded development. Consequently, conservation priorities on the two smaller islands deal mainly with preserving relatively natural areas through protection, education, limitations on development, and control of invasive species (those that have been introduced and those that might be). In sharp contrast, extensively developed St. Maarten, already overrun with exotics, has little choice but to minimize the damage already inflicted and prevent further degradation. So, controlling expansion of developed areas onto hillsides, establishing a terrestrial protected area with at least a somewhat natural flora, preventing further invasions by non-native plants and animals, are, along with education, the highest priorities for conservation. Standing in the way of implementing these (and other, largely tied to marine resources) recommendations on any of the islands are under-funded conservation organizations that rely on the work of too few people, a largely apathetic resident population resistant to educational programs, and governmental entities with firm commitments to development that provide only sporadic or even no support of efforts to conserve natural resources — a litany of hurdles faced by essentially every conservation organization (governmental, not-for-profit, or private) throughout the region.
Acknowledgements. Robert W. Henderson and John S. Parmerlee, Jr. have been active collaborators throughout the years during which I’ve been working in the West Indies. John also generated the map (fig. 1). Gerard van Buurt contributed helpful comments on an earlier version of this manuscript. Nicole Esteban, Manager, Gershon Lopes, Assistant Manager, and the staff, interns, and volunteers at the St. Eustatius National Parks Foundation (STENAPA) have been immensely helpful. Andy Caballero, Director, Nature Foundation of St. Maarten (NAFSXM), facilitated our efforts on St. Maarten. James Johnson, The Saba Conservation Foundation (SCF), was an excellent host and guide on Saba. Winfried and Laura Piechutzki, King’s Well Hotel on St. Eustatius, and Oliver and Angelika Hartleib, El Momo Cottages on Saba, were gracious and tolerant. Research and involvement in conservation efforts in the Dutch Windward Islands would not have been possible without the efforts of students in the 2004 Avila University Research Experiences for Undergraduates (REU) program. National Science Foundation (NSF) grants (DBI-9732257 and DBI-0242589) provided funding for fieldwork.
Conservation on the Dutch Windward Islands
201
References Alberts, A., Ed. (2000): West Indian Iguanas. Status Survey and Conservation Action Plan. IUCN, Gland, Switzerland and Cambridge, United Kingdom, IUCN/SSC West Indian Iguana Specialist Group. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds. (2004): Iguanas: Biology and Conservation. Berkeley, University of California Press. Barbour, T. (1930): Some faunistic changes in the Lesser Antilles. Proc. New England Zool. Club 11: 73-85. Breuil, M. (2002): Histoire naturelle des amphibiens et reptiles terrestres de l’archipel Guadeloupéen. Guadeloupe, Saint-Martin, Saint Barthélemy. Patrimoines Naturels, Paris 54: [2] + 339 p. Gibbons, J.W., Scott, D.E., Ryan, T.J., Buhlmann, K.A., Tuberville, T.D., Metts, B.S., Greene, J.L., Mills, T., Leiden, Y., Poppy, S., Winne, C.T. (2000): The global decline of reptiles, déjà vu amphibians. Bioscience 50: 653-666. Heinz, H.M., Maley, A.J., Savit, A.Z., Henderson, R.W., Powell, R. (2004): Behaviour and time allotment in the West Indian snake, Alsophis rufiventris (Colubridae). Herpetol. Bull. 89: 22-25. Henderson, R.W. (1992): Consequences of predator introductions and habitat destruction on amphibians and reptiles in the post-Columbus West Indies. Carib. J. Sci. 28: 1-10. Henderson, R.W. (2004): Lesser Antillean snake faunas: Distribution, ecology, and conservation concerns. Oryx 38: 311-320. Henderson, R.W., Powell, R. (1999): West Indian herpetoecology. In: Caribbean Amphibians and Reptiles, p. 223-268. Crother, B.I., Ed., San Diego, California: Academic Press. Henderson, R.W., Powell, R. (2001): Responses by the West Indian herpetofauna to human-influenced resources. Carib. J. Sci. 37: 41-54. Hensley, R.L., Wissman, S.M., Powell, R., Parmerlee, J.S., Jr. (2004): Habitat preferences and abundance of Dwarf Geckos (Sphaerodactylus) on St. Eustatius, Netherlands Antilles. Carib. J. Sci. 40: 427-429. Hodge, K.V.D., Censky, E.J., Powell, R. (2003): The Reptiles and Amphibians of Anguilla, British West Indies. The Valley, Anguilla, British West Indies, Anguilla National Trust. Howard, K.G., Parmerlee, J.S., Jr., Powell, R. (2001): Natural history of the edificarian geckos Hemidactylus mabouia, Thecadactylus rapicauda, and Sphaerodactylus sputator on Anguilla. Carib. J. Sci. 37: 285-288. IUCN (International Union for the Conservation of Nature), Conservation International, and NatureServe. (2004): Global Amphibian Assessment. (http://www.globalamphibians.org). Kaiser, H., Hardy, J.D., Jr. (1994): Eleutherodactylus johnstonei. Cat. Amer. Amphib. Rept. 581: 1-5. Kerr, A.M., Powell, R., Parmerlee, J.S., Jr. (2005a): Ameiva erythrocephala (Teiidae) on Sint Eustatius, Netherlands Antilles: Baseline data on a small population in a severely altered habitat. Carib. J. Sci. 41: 162-169. Kerr, A.M., Zero, V.H., Powell, R. (2005b): Ameiva erythrocephala. Cat. Amer. Amphib. Rept. 817: 1-4. Krebs, C.J. (1989): Ecological Methodology. New York: Harper & Row, Publ. Lever, C. (2003): Naturalized Reptiles and Amphibians of the World. Oxford, Oxford Univ. Press. Maley, A.J., Savit, A.Z., Heinz, H.M., Powell, R., Henderson, R.W. (2005): Alsophis rufiventris. Cat. Amer. Amphib. Rept. 818: 1-4. Malhotra, A., Thorpe, R.S. (1999): Reptiles & Amphibians of the Eastern Caribbean. London and Oxford, Macmillan Educ., Ltd. Malone, C.L., Davis, S.K. (2004): Genetic contributions to Caribbean iguana conservation. In: Iguanas: Biology and Conservation, p. 45-57. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Berkeley: Univ. California Press. Pasachnik, S.A., Breuil, M., Powell, R. (2006): Iguana delicatissima. Cat. Amer. Amphib. Rept. 811: 1-14.
202
R. Powell
Powell, R. (2004): Conservation of iguanas (Iguana delicatissima and I. iguana) in the Lesser Antilles. Iguana 11: 238-246. Powell, R., Crombie, R.I., Boos, H.E.A. (1998): Hemidactylus mabouia. Cat. Amer. Amphib. Rept. 674: 1-11. Powell, R., Henderson, R.W. (2005): Conservation status of Lesser Antillean reptiles. Iguana 12: 6277. Powell, R., Henderson, R.W. (2006): Urban herpetology in the West Indies. In: Urban Herpetology. Herpetological Conservation, volume 3. Jung, R.E., Mitchell, J.C., Eds, New Haven, Connecticut, Soc. Study Amphib. Rept. Powell, R., Henderson, R.W., Parmerlee, J.S., Jr. (2005): Reptiles and Amphibians of the Dutch Caribbean: St. Eustatius, Saba, and St. Maarten. Gallows Bay, St. Eustatius, Netherlands Antilles, St. Eustatius National Parks Foundation. Powell, R., Passaro, R.J., Henderson, R.W. (1992): Noteworthy herpetological records from Saint [sic] Maarten, Netherlands Antilles. Carib. J. Sci. 28: 234-235. Rojer, A. (1997a): Biological Inventory of Saba. Unpubl. report 96-10. Curaçao, Netherlands Antilles, Carmabi Foundation. Rojer, A. (1997b): Biological Inventory of St. Eustatius. Unpubl. report 96-10. Curaçao, Netherlands Antilles, Carmabi Foundation. Rojer, A. (1997c): Biological Inventory of St. Maarten. Unpubl. report 96-10. Curaçao, Netherlands Antilles, Carmabi Foundation. Russell, A.P., Bauer, A.M. (2002): Thecadactylus, T. rapicauda. Cat. Amer. Amphib. Rept. 753: 1-16. Sajdak, R.A. (2004): Snakes of the Caribbean: An island-by-island look at the 25 snake species of the Lesser Antilles. Reptiles 12(10): 58-65. Sajdak, R.A., Henderson, R.W. (1991): Status of West Indian racers in the Lesser Antilles. Oryx 25: 33-38. Savit, A.Z., Maley, A.J., Heinz, H.M., Henderson, R.W., Powell, R. (2005): Distribution and activity periods of Alsophis rufiventris (Colubridae) on The Quill, St. Eustatius, Netherlands Antilles. Amphibia-Reptilia 26: 418-421. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. Gainesville, Univ. Florida Press. Vitt, L.J., Zani, P.A. (1997): Ecology of the nocturnal lizard Thecadactylus rapicauda (Sauria: Gekkonidae) in the Amazon Region. Herpetologica 53: 165-179. Westerman, J.H. (1953): Nature preservation in the Caribbean: A review of literature on the destruction and preservation of flora and fauna in the Caribbean area; extinct and endangered land reptiles and amphibians. Publ. Found. Sci. Res. Surinam Netherlands Antilles 9: 51-56.
Accepted: July 17, 2006 (AH). Reprinted from Applied Herpetology 3: 293-306 (2006).
Conservation on the Dutch Windward Islands
203
Addendum The Cuban treefrog (Osteopilus septentrionalis), established on St. Maarten for some time, has been documented on Saba (J. Magor, pers. comm.; Powell, 2007). These frogs almost certainly originated on St. Maarten. To date, only individuals have been found and no evidence suggests the presence of a breeding population on Saba. If these large, voracious frogs were to become established, they have great potential to negatively affect native populations of invertebrates and small vertebrates. Smooth-scaled worm lizards (Gymnophthalmus underwoodi) are known to occur on St. Maarten (van Buel and Powell, 2006). This parthenogenetic species, native to northeastern South America, has been documented on a number of West Indian islands. Although some insular populations might be native, those in the northern Lesser Antilles almost certainly represent recent introductions. Cuban brown anoles (Anolis sagrei) have recently been found in and around the Philipsburg harbor in St. Maarten (Fläschendräger, 2010). Although the source of the animals on St. Maarten is unknown, many introduced populations of the species trace their origin to introduced populations in the southeastern United States. In all three instances, founding individuals almost certainly hitchhiked on ornamental plants, building materials, or other goods. Brahminy blind snakes (Ramphotyphlops braminus), previously reported from St. Maarten, are appearing in increasing numbers on St. Eustatius (N. Esteban, St. Eustatius National Parks, in litt., 17 March 2010; photographic voucher Milwaukee Public Museum MPM P747). Local residents have found these tiny parthenogentic snakes in the ground when digging, others were found in a cistern, and Statia Park staff members have observed them in the field. The source of the animals on Statia is probably St. Maarten. The Netherlands Antilles, which includes the Dutch Windward (St. Maarten, Saba, St. Eustatius) and Leeward (Curaçao and Bonaire) islands, is now signatory to the 2001 Inter-American Convention for the Protection and Conservation of Sea Turtles. On St. Eustatius (Statia), the Quill/Boven National Park is in process of being declared a National Park in accordance with Specially Protected Areas and Wildlife (SPAW) Convention criteria in a pilot project of ten National Parks in the Caribbean. The Statia Marine Park was recognized nationally and declared the Statia National Marine Park by the Minister of Public Health and Social Development of the Netherlands Antilles in 2007. The Quill and Boven Sectors of the National Park on Statia, the Saba coastline, and Little Bay Pond, Fresh Pond, Great Salt Pond, Fort Amsterdam, and Pelikan Rock in St. Maarten were each declared as Important Bird Areas (IBA) by Birdlife International (Wege and Anadón-Irizarry, 2008). Although almost half of Caribbean IBAs lack formal protection, such recognition could lead to an increased awareness of the value of biodiversity that will benefit all wildlife in those areas.
204
R. Powell
References Fläschendräger, A. (2010): Cuban brown anoles (Anolis sagrei) in St. Maarten. Rept. Amphib. 17, in press. Powell, R. (2007): Geographic distribution: Osteopilus septentrionalis (Cuban treefrog). Herpetol. Rev. 38: 215. van Buel, H., Powell, R. (2006): Geographic distribution: Gymnophthalmus underwoodi. Herpetol. Rev. 37: 494. Wege, D.C., Anadón-Irizarry, V. (2008): Important Bird Areas in the Caribbean: Key Sites for Conservation. BirdLife Conservation Series No. 15. Cambridge, BirdLife International.
Amphibians and reptiles of the French West Indies: Inventory, threats and conservation Olivier Lorvelec1,4,5 , Michel Pascal1 , Claudie Pavis2,4 , Philippe Feldmann3,4 1 Institut
National de la Recherche Agronomique (INRA), UMR 0985 Écologie et Santé des Écosystèmes, Équipe des Invasions Biologiques, Campus de Beaulieu, 35042 Rennes Cedex, France 2 INRA, UR 1321 AgroSystèmes Tropicaux, Domaine Duclos, 97170 Petit-Bourg, Guadeloupe, FWI 3 Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), TA A-DIR / PS3, 34398 Montpellier Cedex 5, France 4 Association pour l’Etude et la Protection des Vertébrés et Végétaux des Petites Antilles (AEVA), c/ Claudie Pavis, Hauteurs Lézarde, 97170 Petit-Bourg, Guadeloupe, FWI 5 Corresponding author; e-mail:
[email protected] Abstract. At least five marine turtles and 49 terrestrial or freshwater amphibians and reptiles have been listed from the French West Indies since the beginning of human settlement. Among terrestrial or freshwater species, two groups may be distinguished. The first group comprises 35 native species, of which seven are currently extinct or vanished. These species are often endemic to a bank and make up the initial herpetofauna of the French West Indies. Disregarding two species impossible to rule on due to lack of data, the second group includes twelve species that were introduced. Except for marine turtles and some terrestrial species for which the decline was due to human predation, the extinctions primarily involved ground living reptiles of average size and round section body shape. Habitat degradation and mammalian predator introductions have probably contributed to the extinction of these species, in addition to a possible direct impact of man. To better understand the threats to species, we suggest studying the interactions between native herpetofauna and introduced competitors or predators, taking into account the habitat structure. This would help to give the necessary information for successful management measures for conservation or restoration. As an example, the conservation of the Petite Terre (Guadeloupe) Iguana delicatissima population requires identifying both the mechanisms that regulate its population and their relationships to catastrophic climatic events. Key words: Amphibians; biological invasions; conservation; French West Indies; Guadeloupe; Iguana delicatissima; Petite Terre; Reptiles; threats.
Introduction The extensive work devoted to the amphibians and reptiles of the French West Indies during the last 100 years provides a good understanding of the distribution of the
206
O. Lorvelec et al.
majority of the species. It allows estimation of the changes since the first human settlement, despite knowledge gaps for the Amerindian and Colonial Periods. It also allows highlighting the risks of new extinctions related to human activities. One of the major causes of changes to the French West Indies herpetofauna is probably the introduction of alien competitor or predator species. These introductions are globally considered as the second cause of biodiversity losses, preceded only by habitat destruction and fragmentation (Diamond, 1989; Vitousek et al., 1997; Alonso et al., 2001). Insular species are particularly sensitive to introductions (Moors and Atkinson, 1984; Diamond, 1989; Lever, 1994). The commensal Rattus, at the world scale (Atkinson, 1985), and the mongoose Herpestes auropunctatus, in some areas like the French West Indies, belong to the vertebrate species that have had the strongest impact on the native fauna when introduced on islands (Lowe et al., 2000). This is why identifying mechanisms and quantifying interactions between native and introduced species are major stakes for insular ecosystem management and restoration policies. The scope of this paper is to make an inventory of the extinct, vanished (that is, lost from the French West Indies but present elsewhere) or currently present (both native and introduced) species of the French West Indies herpetofauna. It also points out current threats to native species, and proposes steps to identify and quantify mechanisms that endanger native populations, in order to work out relevant conservation or restoration strategies. Geographical area The Lesser Antillean islands belong to banks, as defined by the 160 m isobath limit and by their mutual isolation since emergence. The French West Indies islands belong to five banks: Martinique, Les Saintes, Marie-Galante, Guadeloupe, and Anguilla. We split the Guadeloupe Bank into four subsets: Basse-Terre, GrandeTerre, La Désirade, and Îles de la Petite Terre (or simply Petite Terre). All these banks are wholly under French jurisdiction, except for the Anguilla Bank, of which we only consider the French part, i.e. Saint-Barthélemy and the northern part of Saint-Martin. Powell (2006) considers the other part of the latter island. Nine insular entities are thus included in this paper. The French West Indies are administratively divided into two sets: Martinique alone; and Guadeloupe, which is a discontinuous archipelago including Les Saintes, Marie-Galante, Désirade and Guadeloupe Banks and further north some islands of the Anguilla Bank, i.e. French Saint-Martin and Saint-Barthélemy. Unless specified, in this paper the word Guadeloupe indicates the geographical and not the larger administrative entity. Information concerning biodiversity threats and protection measures were extracted from various monographs, from the synthesis prepared by the French Committee for IUCN (Gargominy, 2003), and is here updated. The legislation on protection of the species has been consulted. In addition, the status established by IUCN, according to the extinction threats under the Red List
Amphibians and reptiles of the French West Indies
207
categories, is specified (IUCN, 2006), and conservation measures already carried out are described.
Herpetofauna Inventory: Methods and Definitions Several species that are sometimes quoted from the French West Indies were not retained, either because their presence is improbable (Gonatodes albogularis and Sphaerodactylus microlepis in Martinique), or because of the lack of conclusive information. Nevertheless, the current or past presence of some species in the second category may be confirmed in future, so we give a summary of available information on some of these species. Mainly on the basis of photographs, Breuil (2002) hypothesised the current presence in Guadeloupe of the piping frog Eleutherodactylus cf. planirostris, and the tortoise Chelonoidis denticulata. In the same publication, he pointed out the capture in Saint-Barthélemy of one just-introduced specimen of the colubrid snake Elaphe guttata. However, there is a lack of evidence concerning the naturalisation of these species in these islands. Breuil (2002) also hypothesized the presence in the past of an extinct Diploglossine lizard in Guadeloupe, on the basis of textual evidence (see also Lorvelec et al., 2000), and of an extinct or vanished colubrid of the genus Clelia on the basis of textual and archaeological evidence. However, the precise archaeological information for the Clelia sp. is absent from the text quoted (Grouard, 2001a). Breuil (2002) also indicated the past presence of an extinct Eleutherodactylus sp. from Saint-Barthélemy and Saint-Martin on the basis of textual evidence. The case of the African tortoises Kinixys homeana and Kinixys erosa is of historical interest. In 1835 Duméril and Bibron included these species in the American fauna because two specimens of the first species were sent to the Paris Museum from Guadeloupe by two French naturalists, L’Herminier father and son. Analysing letters and all specimens from the L’Herminiers stored in the Paris Museum, Breuil (2002, 2003) reached the conclusion that these specimens belong to the two species and came from Africa through Guadeloupe. Presently, these species are absent from Guadeloupe and there is no evidence that feral populations lived in Guadeloupe in the past. In addition, following Fretey and Lescure (1999), we have excluded the marine turtle Lepidochelys kempi as absent from the sea around the Lesser Antilles. Moreover, Anolis bimaculatus, introduced into the Netherlands part of Saint-Martin (Powell et al., 1992) but never recorded from the French part, was also excluded. Other species were retained although their local reproduction has not yet been confirmed. These species are the slider Trachemys scripta, which is presently widely distributed at least in Guadeloupe, two marine turtles, Caretta caretta and Lepidochelys olivacea, which are present in the sea around the French West Indies (Fretey, 1997; Chevalier and Lartiges, 2001), and the parthenogenetic snake, Ramphotyphlops braminus, which was recently introduced in Saint-Barthélemy and
208
O. Lorvelec et al.
Saint-Martin and which is a good candidate for a prompt naturalization (Breuil, 2002; Henderson, 2004). According to Breuil (2002), the extinct Ameiva major would have come from Petite Terre and not from Martinique as previously thought (Baskin and Williams, 1966). However, there is recent information of an undated museum specimen quoted from Martinique (Ineich et al., 2005). The history of this specimen deserves further investigation. Study of the numerous archaeological remains from Petite Terre and Martinique could also provide a definitive validation of Breuil’s hypothesis. Since Schwartz and Henderson (1991), several recent revisions re-established or put at species rank some taxa. We followed Powell and Henderson (2001) putting Anolis pogus Lazell, 1972, and Sphaerodactylus parvus King, 1962, at species rank. We followed Breuil (2002) re-establishing Anolis terraealtae Barbour, 1915, and Alsophis sanctonum Barbour, 1915, at species rank, each one with two subspecies. We followed Breuil (2002) and Henderson (2004) re-establishing Typhlops guadeloupensis Richmond, 1966, at species rank. Lastly, we followed Breuil (2002) and Miralles (2005), for the taxonomic position of the Lesser Antillean Mabuya. In conclusion, we have to keep in mind that the French West Indies species number may increase in the near future, by description of new Eleutherodactylus for Basse-Terre (e.g. Breuil, 2002; Kaiser et al., 2003) and revisions of the genera Gymnophthalmus and Anolis. Thus for Anolis, Roughgarden (1995: 83) elevated to species rank the taxa chrysops, desiradei, kahouannensis, and caryae described by Lazell in 1964 and generally considered as subspecies. Inventories of terrestrial and marine species were then performed for each of the nine insular entities using mainly data from Barbour (1914), King (1962), Lazell (1964, 1972, 1973), Baskin and Williams (1966), Schwartz and Thomas (1975), MacLean et al. (1977), Schwartz et al. (1978), Schwartz and Henderson (1985, 1988, 1991), Powell et al. (1996), Censky and Kaiser (1999), Malhotra and Thorpe (1999) and the recent syntheses of Breuil (2002, 2003, 2004). The endemic species from the Lesser Antilles and from the French West Indies were quoted and the number of subspecies recorded for the French West Indies was recorded for each species (table 1). For the purposes of this study, as for a previous one (Pascal et al., 2005), we defined a biological invasion as an event in which a species increased its distributional area during a specific period of time, whether or not because of human activities, and founded at least one self-perpetuating population in the newly invaded area. In the case of the French West Indies herpetofauna, biological invasions have concerned primarily species introduced, intentionally or not, by man. We chose island as the unit of study, and the period that began with the first Amerindian settlements, about 4000 BP (Pregill et al., 1994), and ended with present as the specific period of time. We considered as native to an island a species that was present on it before the beginning of this period, and as introduced a species that was absent before this period but now present.
Amphibians and reptiles of the French West Indies
209
Six groups of species were distinguished in order to appreciate the French West Indies herpetofauna turnover during the four last millennia (table 1). The first group comprises the marine turtles, the five other groups include terrestrial or freshwater species. The second group includes the native species extinct (vanished from all its distribution area) after the Amerindian settlement or not recorded for several decades (Honegger, 1981). The third group comprises the native species that have vanished from the French West Indies, but are not extinct. The fourth group is native present species, the fifth group is species with dubious status, and the sixth group is introduced species. Such categorization was used in a recently published book devoted to the French vertebrate fauna turnover during the Holocene (Pascal et al., 2006).
Table 1. Inventory and status of the French West Indies amphibians and reptiles. Species
LA FWI ssp MA SA MG BT GT DE PT SB FSM IUCN FL
Marine turtles (5) • Chelonians Cheloniidae Caretta caretta Chelonia mydas Eretmochelys imbricata Lepidochelys olivacea Dermochelyidae Dermochelys coriacea Other species (49) Native and extinct (5) • Lizards Teiidae Ameiva cineracea Ameiva major Tropiduridae Leiocephalus cf. cuneus Leiocephalus herminieri • Snakes Colubridae Liophis cursor Native and vanished (2) • Anurans Leptodactylidae Leptodactylus fallax • Snakes Boidae Boa constrictor
– – – –
(+) +
+ +
+ +
? + +
? ? + (+) + (+) (+) + + + (+) (+) ?
EN EN CR EN
p p p p
–
+
?
(+)
+
+
? (+) (+) (+)
CR
p
+
+
+
+
?
EX EX
?
+
e e
e e
– –
?
e e
e
– –
+
– EX
e
e
–
+
CR
–
+
?
?
?
CR
?
+
?
?
?
NE
e
? ?
p
210
O. Lorvelec et al.
Table 1. Continued. Species Native and currently present (28) • Anurans Aromobatidae Allobates chalcopis Brachycephalidae Eleutherodactylus barlagnei Eleutherodactylus martinicensis Eleutherodactylus pinchoni • Lizards Gekkonidae Sphaerodactylus fantasticus Sphaerodactylus parvus Sphaerodactylus sputator Sphaerodactylus vincenti Thecadactylus rapicauda Gymnophtalmidae Gymnophthalmus pleii Iguanidae Iguana delicatissima Polychrotidae Anolis ferreus Anolis gingivinus Anolis marmoratus Anolis pogus Anolis roquet Anolis terraealtae Scincidae Mabuya mabouya Mabuya sloanii Teiidae Ameiva plei • Snakes Colubridae Alsophis antillensis Alsophis rijgersmaei Alsophis sanctonum Liophis juliae Leptotyphlopidae Leptotyphlops bilineatus Typhlopidae Typhlops annae Typhlops guadeloupensis Viperidae Bothrops lanceolatus
LA FWI ssp MA SA MG BT GT DE PT SB FSM IUCN FL
e
e
–
+
e e e
e ? e
– – –
+
e e e e
VU
+
+
+ + +
+
+
+
+
+
+
+ +
+
+
+ +
+ + +
7 – – 6 –
+ +
+
?
+
+
+ + +
e
1
+
?
?
?
?
?
e
–
+
+
d
+
+
+ + +
+
+
+
?
+
e e e e e e
Ae
e Ae e Ae e e
e
– – 9 – 6 2 – 1
e
Ae
2
e e e e
Ae e
1 – 2 2
e
–
e e
e e
– –
e
e
–
+ +
+
+ +
+ + d?
?
d? d? +
?
+
+
+ ? d? +
+
?
?
+
+
+
+ + d? d? + d? +
+
+
d?
?
?
+ ? +
?
?
?
EN NT EN
p p p
NE NE NE NE NE
p p p p p
NE
p
VU
p
NE NE NE NE NE NE
p p p p p p
NE pG NE p NE
p
NE EN NE NE
p p p p
NE
p
NE NE
p
NE
Amphibians and reptiles of the French West Indies
211
Table 1. Continued. Species
LA FWI ssp MA SA MG BT GT DE PT SB FSM IUCN FL
Dubious status (2) • Lizards Gekkonidae Hemidactylus mabouia Gymnophtalmidae Gymnophthalmus underwoodi Introduced (12) • Anurans Brachycephalidae Eleutherodactylus johnstonei Bufonidae Chaunus marinus Hylidae Osteopilus septentrionalis Scinax cf. ruber Scinax cf. x-signatus • Chelonians Emydidae Trachemys scripta Trachemys stejnegeri Pelomedusidae Pelusios castaneus Testudinidae Chelonoidis carbonaria • Lizards Gekkonidae Gekko gecko Iguanidae Iguana iguana • Snakes Typhlopidae Ramphotyphlops braminus
e
–
+
+
+
+
+
+
–
+
?
+
+
+
+
–
+
+
+
+
+
+
–
+
+
+
– – –
+
+ +
?
+
+
?
+
+
+
1
+
–
+
–
p
NE NE NE
LR/nt LR/nt p
+
– (+) (+) (+) (+) (+) (+) ?
NE NE
1 (+) (+) (+) (+) 1 + + (+) (+) –
NE NE
+ +
+
NE +
+
p
NE
NE +
+
+
+
+
(+) (+)
NE pG
NE
LA. e: Lesser Antilles endemic species. FWI. e: French West Indies endemic species; Ae: Anguilla Bank endemic species; ?: see text. ssp. #: Number of French West Indies sub-species; –: monotypic species or species with dubious sub-species or perhaps species complex. Insular entities. MA: Martinique; SA: Les Saintes; MG: Marie-Galante; BT: Basse-Terre; GT: Grande-Terre; DE: La Désirade; PT: Petite Terre; SB: Saint-Barthélemy; FSM: French Saint-Martin. IUCN. EX: Extinct; CR: Critically Endangered; EN: Endangered; VU: Vulnerable; NT: Near Threatened; LR/nt: Lower Risk, Near Threatened in origin area; NE: Not Evaluated; –: sub-fossil. FL. French legislation. p: Protected species; pG: protected species in the Guadeloupe administrative entity but not in Martinique. Currently nesting (marine turtles). +: regular but sometimes rare; (+): casual or possibly disappeared; ?: potential or not confirmed. Past or current presence (terrestrial or freshwater species). +: known; (+): known but reproduction not confirmed; ?: potential or not confirmed; d: locally disappeared; d?: possibly locally disappeared.
212
O. Lorvelec et al.
Herpetofauna Inventory and Turnover Table 1 summarizes information on the presence of the French West Indies amphibian and reptile species since the beginnings of human settlement. This information will change with improvement of knowledge thanks to new data, particularly for extinct or vanished species. Our inventory contains five marine turtles, all having a transoceanic distribution area, and 49 terrestrial or freshwater species of which 42 are still present. Among terrestrial or freshwater amphibians and reptiles of the French West Indies, most are native species that are often endemic to one bank, and represent the initial herpetofauna. Other species were, with a high probability level, introduced by man; the status of two species, H. mabouia and G. underwoodi, is dubious. Native herpetofauna Thirty-five species (71.5% of the 49 terrestrial or freshwater species) are probably native of the French West Indies. All these native species are endemic of an island or sets of islands of the Lesser Antilles, except: Boa constrictor, which is distributed in South America, Central America and the Lesser Antilles and includes Lesser Antillean subspecies; Thecadactylus rapicauda, which is distributed in Northern South America, Central America and the Lesser Antilles; and Mabuya sloanii which is endemic to the Greater Antilles and the extreme north of the Lesser Antilles. Seven species (20% of the 35 native species) present in the past have now disappeared from the French West Indies. Among these, five are extinct and two are vanished. Leiocephalus cf. cuneus, known from Grande-Terre fossil remains (Pregill et al., 1994), apparently still lived on small islets off Guadeloupe at the beginning of European Colonization (du Tertre, 1667-1671), and became extinct at an unspecified time. The same situation occurs for Leiocephalus herminieri which lived in Martinique (Breuil, 2002, 2003). The species description by Duméril and Bibron, under the name Holotropis Herminieri, goes back to 1837. According to Honegger (1981), Ameiva cineracea became extinct when Grand Îlet off BasseTerre, its last refuge in Guadeloupe, was destroyed by the 1928 hurricane. Ameiva major had been extinct from Martinique (Baskin and Williams, 1966) at an unspecified time or, according to Breuil (2002), from Petite Terre during the 19th or at the beginning of the 20th century. Lastly, Liophis cursor, never recorded since 1962 from Rocher du Diamant (Lazell, 1967), its last refuge in Martinique, was considered as extinct by Honegger (1981). Two other species, Leptodactylus fallax and Boa constrictor, which lived in Martinique (Anonyme de Carpentras, 16181620), from where they vanished after 1796 (Lescure, 1979) and at an unspecified time (Breuil, 2002) respectively, persist outside the French West Indies. Twenty-eight species (80% of the 35 native species) are still present in the French West Indies. Among them, Eleutherodactylus martinicensis has a controversial status. Looking at the present distribution and filling the “endemism gaps”, Censky and Kaiser (1999) considered that Eleutherodactylus johnstonei and E. martinicensis are native from Saint Lucia and Martinique respectively, and introduced every-
Amphibians and reptiles of the French West Indies
213
where else. However, Lescure (2000) proposed the Antigua and Barbuda Bank as the native place for E. johnstonei (see also Kaiser, 1997) and Saint Lucia, Martinique and Dominica for E. martinicensis. In addition, Kaiser (1992) emphasized that the differences in distribution of these species in the Lesser Antilles reflected the respective English and French influences during the Colonial Period. Whatever the theory selected, the statuses of these two species do not change for the French West Indies where only E. martinicensis is native. The arrival time of this species in Les Saintes, Guadeloupe and Marie-Galante Banks is unknown and its native status for these banks is dubious, but its introduction in Saint-Barthélemy (Magras, 1992) and Saint-Martin (Breuil, 2002) took place, according to these authors, at the latest during the beginning of the 1980’s. Kaiser et al. (1994) described Colostethus chalcopis, discovered only in 1990 and recently renamed Allobates chalcopis (see Grant et al., 2006), as endemic of Martinique, rejecting the assumption of an introduction. Nevertheless, these authors emphasized that the occurrence of this species in Martinique constitutes a biogeographic enigma because no member of the superfamily Dendrobatoidea is native to an oceanic island. According to Hedges (1996), the Lesser Antillean populations of the gecko Thecadactylus rapicauda are morphologically close to the continental ones, and would have colonized the Lesser Antilles relatively recently during the Quaternary. However, genetic analysis shows that samples from the Lesser Antilles belong to a monophyletic group (Kronauer et al., 2005). This result suggests that the hypothesis of its introduction by man has to be taken cautiously, and increases the likelihood of native status for T. rapicauda in the Lesser Antilles. Species of dubious status Two species (4% of the 49 terrestrial or freshwater species) have a dubious status. Several authors considered that the synantropic gecko Hemidactylus mabouia was introduced in the American Continent from West Africa during the Triangular Trade (Lescure, 1983). However, Kluge (1969), suggested the hypothesis of a natural dispersal during former time based on Hemidactylus distribution and differentiation in the New World. According to Hedges (1996), Gymnophthalmus underwoodi, a parthenogenetic lizard from Northern South America and Lesser Antilles, would have colonized the Lesser Antilles relatively recently during the Quaternary. According to Kizirian and Cole (1999), this species came from a single hybridization event and the presence of G. underwoodi in the Lesser Antilles seems likely to be a result of dispersal of individuals from the mainland. Was it dispersed by rafts, taking advantage of parthenogenetic reproduction, or was it accidentally introduced in the French West Indies where it was recorded recently for the first time (Schwartz and Thomas, 1975)? These questions remain open. Introduced species Twelve species (24.5% of the 49 terrestrial or freshwater species) that are known today from the French West Indies, were introduced in our view. The introduction
214
O. Lorvelec et al.
history of eight of these species is documented. Eleutherodactylus johnstonei, which can be distinguished from Eleutherodactylus martinicensis only by specialists, is the only one initially endemic of the Lesser Antilles (see above). Its introduction into all the French West Indies is probably recent considering that the 19th century rare descriptions of amphibians for Saint-Barthélemy and Saint-Martin have to be related to an endemic and extinct species of the Anguilla Bank (Breuil, 2002). Barbour (1914) recorded the species for the first time in Saint-Martin as martinicensis before Schwartz (1967) recorded it under its true name. Thereafter, it was recorded in Martinique by Lescure (1968), in Basse-Terre in 1970 by Kaiser (1997) and in Grande-Terre in 1991 by Henderson et al. (1992). It was recorded by Breuil (2002) for the first time in 1989 in Marie-Galante, 1999 in Les Saintes, and 2001 in La Désirade, and its introduction in Saint-Barthélemy goes back to 1995 or 1996 according to this author. The initial distribution area of the seven other introduced species is outside of the Lesser Antilles. Chaunus marinus, until recently named Bufo marinus (see Frost et al., 2006), was intentionally introduced in Martinique before 1844 (Waite, 1901), then in Basse-Terre and Grande-Terre. Osteopilus septentrionalis was recorded for the first time in the Netherlands part of Saint-Martin in 1987 (Powell et al., 1992) and in the French part of SaintMartin and in Saint-Barthélemy in 1996 (Breuil, 2002). Scinax cf. ruber and Scinax cf. x-signatus were recorded respectively for the first time in 1997 in Martinique and 2003 in Basse-Terre and Grande-Terre (Breuil, 2004). The introduction is also documented for a slider, Trachemys scripta, recorded for the first time in BasseTerre and Grande-Terre by Schwartz and Thomas (1975), and also released in Marie-Galante and Martinique according to Breuil (2002). Finally, Gekko gecko was introduced intentionally at the beginning of the 1970’s in Martinique from Indo-China (Henderson et al., 1993) and Ramphotyphlops braminus was introduced unintentionally during the 1990’s in Saint-Barthélemy and Saint-Martin (Breuil, 2002). In our view, the four following species have to be considered as introduced, even if the modalities of these introductions are not yet clearly documented. According to Lescure (1983), an introduction from West Africa during the Triangular Trade is the most probable hypothesis to explain the presence of the terrapin Pelusios castaneus (see also Bour, 1983). According to Breuil (2002), an introduction from Puerto Rico (by Amerindians or more recently), is the most probable assumption to explain the presence of the slider Trachemys stejnegeri (see also Seidel, 1988). However Breuil (2004) favoured a later introduction of these two turtles by L’Herminier father and son during the first half of the 19th century. In the same way, according to Lescure (1983), the tortoise Chelonoidis carbonaria was probably introduced at various times. Thereafter, Censky (1988) and Censky and Kaiser (1999) considered four modalities to explain its presence in the Lesser Antilles: natural dispersion, introduction by Amerindians, introduction by the European colonists, and recent introduction. In the French West Indies, this species is often kept in captivity but seems to currently constitute feral populations only in Saint-Barthélemy (where
Amphibians and reptiles of the French West Indies
215
it was introduced at the end of the Second World War; Breuil, 2004) and in Île Tintamarre off Saint-Martin. If Lazell (1973) recorded Iguana iguana as native in all the Lesser Antilles, Lescure (1983) assumed a combination of spontaneous dispersal and introduction by Amerindians as food resource. Breuil (2002) emphasized the numerous local introductions of this species during the 20th century (e.g. in the 1960’s in Martinique and in the 1990’s in Marie-Galante and Saint-Martin) as well as hybridization and competition between I. iguana and Iguana delicatissima, to refute the assumption of Lazell.
Processes of Extinction and Threats In addition to the disappearance or extinction of at least seven native species, many are becoming rare or are at the fringe of extinction (table 1). According to the IUCN assessments (IUCN, 2006), the five marine turtles are Critically Endangered or Endangered. Among the terrestrial or freshwater species, only the two endemic piping frogs of Basse-Terre (Eleutherodactylus barlagnei and Eleutherodactylus pinchoni), and Alsophis rijgersmaei, the endemic racer of Anguilla Bank, are Endangered (Hedges et al., 2004a,b; Day, 1996). If the last species is currently very rare in Saint-Martin (maybe vanished), it seems present on the whole island of SaintBarthélemy even if rare (Breuil, 2002). In addition, Allobates chalcopis, endemic of Martinique, and Iguana delicatissima, are Vulnerable (Hedges et al., 2004c; Breuil and Day, 1996). This last species, endemic of the northern part of the Lesser Antilles (islands located between Martinique and Anguilla), vanished from several islands including Marie-Galante. Except for populations from Dominica, La Désirade and Petite Terre, this species is currently very rare because of habitat destruction and fragmentation, hunting, human persecution, competition with introduced ungulates, predation by alien carnivores, hybridization and competition with I. iguana (e.g. Breuil and Sastre, 1993; Breuil and Thiébot, 1993; Day and Thorpe, 1996; Day et al., 1999; Breuil, 2002; Pasachnik et al., 2006). According to Breuil (2002), the status of other species needs to be evaluated. Anolis pogus, endemic to Anguilla Bank, still present in Saint-Martin, may have disappeared from Saint-Barthélemy. The skink Mabuya mabouya was observed only twice recently, in Petite Terre (Lorvelec et al., 2000) and in La Désirade (Breuil, 2002). Mabuya sloanii, probably still abundant in Saint-Barthélemy, may have disappeared from Saint-Martin. Typhlops annae, endemic to Saint-Barthélemy, was recently described by Breuil (1999a), and is still not well known. Racers such as Alsophis antillensis and Liophis juliae are now very rare in Basse-Terre and GrandeTerre, and may not be present any more in Marie-Galante. Alsophis sanctonum, endemic of Les Saintes, is still common in Terre-de-Bas but rare in Terre-de-Haut. Lastly Bothrops lanceolatus, endemic to Martinique, is endangered according to Breuil (2004).
216
O. Lorvelec et al.
Threats What are the threats causing extinction or decline of the French West Indies species? Marine turtles were hunted by Amerindians, but their drastic decline has to be related to the over-fishing by Europeans that began during the 16th century (Breton, 1665; du Tertre, 1667-1671). Nowadays, in spite of their protection since the 1990s, threats mainly come from accidental mortality by fishing nets (including the bottom trammel), poaching on beaches (of eggs and females), destruction of feeding and egg-laying habitats, and hunting in some Antillean islands where these species are poorly protected (Chevalier, 2003, and personal observations). Moreover, substantial nest predation by mongooses (Lorvelec et al., 2004a) or dogs is reported from several beaches. Terrestrial or freshwater species are subjected to natural or human threats. Natural threats such as hurricanes or fires increase the extinction probability of species that survive as relict populations in small islands. During the Amerindian Period, man hunted Ameiva sp., Iguana sp. and Anolis sp. (Pregill et al., 1994; Grouard, 2001a,b, 2004), and, maybe, Leptodactylus fallax, Boa constrictor and other species. The predation continued in the following centuries for species such as snakes or iguanas, but Iguana iguana poaching in Saint-Martin (Breuil, 2002) is currently the only significant human direct impact. Indirect human threats are the most important at present. They are the consequences of the socio-economic development and alien species introductions. Martinique and Guadeloupe islands have a dense human population (348 and 260 inhabitants per km2 respectively in 2004), some parts of the territory being more urbanised than others. The increasing urbanisation, of roads (e.g. cars running over gravid Iguana delicatissima in La Désirade), and of agricultural and tourist activities, induces destruction, fragmentation and pollution of natural habitats. Two situations begin to be documented concerning the impact of introduced amphibians and reptiles as competitors of the native ones in the French West Indies. The first deals with the substitution of native Eleutherodactylus species by introduced ones. In Martinique, E. johnstonei has replaced E. martinicensis in terrestrial habitats, but not in arboreal ones (Breuil, 1997a). In Basse-Terre, Kaiser (1997) suspected E. johnstonei to be a competitor of the two endemic piping frogs of this island and, according to Breuil (2002), at least E. pinchoni would be restricted to the most humid forest habitat of this island. Besides, hybridization and competition between I. iguana and I. delicatissima would be responsible for the near disappearance of I. delicatissima from Les Saintes during the second part of the 20th century (e.g. Breuil and Sastre, 1993). Mammal species have the most evident impact when introduced in islands. The native mammal fauna of the Lesser Antilles, restricted (apart from bats and marine species) to Sigmodontine rodents that are now extinct, has probably been completely replaced since human settlement (Morgan and Woods, 1986; Pregill et al., 1994; Lorvelec et al., 2001; Breuil, 2003), as in large Mediterranean islands (Vigne, 1999). In these two cases, the turnover of mammal species has been more important than
Amphibians and reptiles of the French West Indies
217
that of amphibians and reptiles. Amerindians introduced dogs and some neotropical species. Among the latter, an agouti Dasyprocta leporina, a much appreciated game animal, was present at the beginning of the 17th century in the French West Indies (du Tertre, 1667-1671), and an opossum Didelphis marsupialis was introduced in Martinique at an undetermined period. In addition to feral populations of domestic species such as cat, pig, goat, sheep and rabbit (du Tertre, 1667-1671; Pinchon, 1967), six other mammal species were introduced by Europeans (Lorvelec et al., 2001). Three of them are commensal Murine rodents: the ship rat, Rattus rattus, and the house mouse, Mus musculus, introduced a long time ago (du Tertre, 16671671), and the Norway rat, Rattus norvegicus, which would have been introduced at the end of the 18th century (Pinchon, 1967). The fourth species is the small Indian mongoose, Herpestes auropunctatus, introduced in 1870 in Trinidad (Husson, 1960), in 1872 in Jamaica (Espeut, 1882), then in 1888 in Guadeloupe (GrandeTerre and Basse-Terre), and between 1890 and 1891 in Martinique (Pinchon, 1967). Introduced very early in Saint-Martin, it is not present in Les Saintes, Petite Terre, Saint-Barthélemy and La Désirade. The fifth species was previously considered as endemic to Guadeloupe, but is now identified as the raccoon, Procyon lotor (e.g. Pons et al., 1999). Its absence from the archaeological Amerindian sites (Pregill et al., 1994; Grouard, 2001a,b) supports the hypothesis of an introduction that took place after the arrival of Europeans, but at an unknown date. In addition to BasseTerre, Grande-Terre and Marie-Galante, the raccoon was present in Martinique since the middle of the 20th century (Bon Saint Côme and Tanasi, 1994), and has been recently introduced in La Désirade and Saint-Martin (Lorvelec et al., 2001). The sixth species is a squirrel belonging to the Indian subcontinent genus Funambulus, of which one pair, bought in a pet shop in Orlando, Florida, was introduced in 1968 in Guadeloupe (Lorvelec et al., unpublished data). In the French West Indies, if man is the first and major agent of vegetation destruction, goats and sometimes sheep prevented regeneration (Questel, 1941) on different islands including Les Saintes (Terre-de-Haut). In Anegada, in the Greater Antilles, Mitchell (1999a,b) observed the senescence of the iguana Cyclura pinguis population (currently, this species has nearly disappeared everywhere but on this island), due to the degradation of the habitats by ungulates. This senescence was characterised by shift in diet, population density and body weight decrease, and unbalanced sex ratio. The impact of introduced mammal predators in the Antilles is poorly documented. Mongoose, cat and rat impacts have usually been reported without quantitative data. Mongooses were introduced to control rats in sugar cane plantations and venomous snakes such as Bothrops lanceolatus in Martinique (Pinchon, 1967). It was quickly shown that this alien species has a great impact on other animal groups in Jamaica: terrestrial crabs, insects, amphibians, snakes, lizards, ground-nesting birds, mammals and domestic animals (Espeut, 1882; Allen, 1911). According to Barbour (1930), the mongoose H. auropunctatus may have been responsible for major changes in the fauna distribution in the Antilles, leading to extinction of ground-
218
O. Lorvelec et al.
nesting birds and reptiles. According to this author, Bothrops caribbaeus would have become rare in Saint Lucia and B. lanceolatus very rare in Martinique. Among other studies, Seaman (1952) and Seaman and Randall (1962) reported its impact on reptile (Iguana, Ameiva, Alsophis, marine turtle eggs) and bird populations in the US Virgin Islands, Westermann (1953) reported its impact on L. fallax in the Lesser Antilles, and Pimentel (1955) draw similar conclusions on arthropods, amphibians, reptiles and mammals in Puerto Rico. The extinction of Alsophis ater in Jamaica (Powell and Henderson, 1996), of Alsophis sanctaecrucis in Saint Croix, of Liophis cursor in Martinique (Lazell, 1967) and of Liophis ornatus in Saint Lucia were supposed to be due mostly to mongoose predation by Honegger (1981). In 1966, Baskin and Williams described Ameiva vanzoi, today Cnemidophorus vanzoi, a species whose distribution is restricted to the Maria Islands off Saint Lucia, and made the hypothesis that its absence on the main island might be due to mongoose introduction. Besides, these authors underlined that the relation between Ameiva disappearance (C. vanzoi included), and the presence of the mongoose is unclear, because cohabitation occurred in some islands such as Saint-Martin, Saint Christopher and Grenada. Thus Ameiva plei could survive in Saint-Martin disturbed habitats, because these would be less used by mongooses. According to Henderson (1992), most of the extinction or disappearance in amphibians and reptiles in the Lesser Antilles would be a consequence of mongoose, dog and cat introductions, Ameiva, Alsophis and Liophis being the most susceptible genera. Breuil (1997b) reported cat faeces containing remains of juvenile I. delicatissima and Anolis roquet, in Îlet Chancel off Martinique. Concerning threats on iguanas in general, cats are identified as the main cause of Brachylophus population declines in Fiji (Gibbons, 1984), and cats and dogs drove to near disappearance the 5,500 Cyclura carinata carinata population of Pine Cay Island (390 ha) in the Caicos Islands in only three years (Iverson, 1978). According to Henderson (1992, 2004), the mongoose impact would be increased by high human population density, small island area and low physiographic complexity. Besides, the same author indicates that habitat destructions are more likely to have a negative effect on amphibian and reptile populations in the Greater Antilles than in the Lesser Antilles. This would be due to the ability of some generalist species to adapt to disturbed habitats in the Lesser Antilles (see also Henderson and Powell, 2001). In the French West Indies, except for marine turtles (and, maybe, some terrestrial species such as L. fallax, B. constrictor and B. lanceolatus) for which the decline can be mainly related to human predation, extinctions or extinction threats primarily involved I. delicatissima (for several reasons) and ground living reptiles of average size and round section body shape (Leiocephalus, Ameiva, Mabuya, Alsophis, Liophis). In the case of these latest species, without forgetting the possible direct impact of man, our hypothesis is that these morphological characteristics indicate that these species have been more sensitive than others to the introduction of mammal predators.
Amphibians and reptiles of the French West Indies
219
Protection Status and Conservation Management Since the beginning of the 1990s, all the marine turtle species are protected under the French legislation, and some terrestrial or fresh water species of the herpetofauna are protected since 1989 (table 1), although this does not take recent taxonomic revisions into account. Among native species, Allobates chalcopis and Typhlops annae, discovered after the publication of the 1989 texts, and Bothrops lanceolatus, have no protection status. Mabuya mabouya is protected in Guadeloupe but not in Martinique where it is regarded as vanished. The species with dubious status, Hemidactylus mabouia and Gymnophthalmus underwoodi, are not protected. Eleutherodactylus martinicensis is also protected although its native status outside of Martinique is dubious. Lastly, some probably introduced species are protected: Eleutherodactylus johnstonei, Pelusios castaneus, Trachemys stejnegeri and Iguana iguana (in Guadeloupe but not in Martinique where it was introduced recently). Legislation should be revised soon and this should lead to a status change for some species. For the species introduced, or supposed introduced, some cases will be complex. Indeed, if an absence of protected status seems logical for recently introduced species, the loss of protected status for some past introduced species, if it is decided, will have to be accompanied by precautions. It requires, as a preliminary, being able to evaluate the impact that this measure could have on similar native species distinguishable only by specialists (Eleutherodactylus, Iguana). It also requires being able to evaluate the functional role taken by the past introduced species into the current ecosystems which are very different from the originals; about half of the 3200 species inventoried in the Guadeloupe and Martinique Flora have been introduced during the last four centuries (Fournet, 2002). Marine turtle species are on the CITES Annex I. France ratified this convention, so their international trade is forbidden in the French West Indies. Iguana sp. and Chelonoidis carbonaria are on the CITES Annex II, thus their trade is authorised under certain conditions. What about protected areas that allow biodiversity conservation? The central area of the Guadeloupe National Park represents 20% of Basse-Terre. Nature Reserves (NR), that have been created between 1976 and 1998, include two in Martinique (Îlets de Sainte-Anne NR and Presqu’île de la Caravelle NR), both terrestrial reserves, and four in Guadeloupe, three being both marine and terrestrial (Grand cul-de-sac marin NR, Îlets de la Petite Terre NR and Saint-Martin NR) and one marine reserve (Saint-Barthélemy NR). Other areas have a weaker protection status, the largest being the peripheral area of the National Park in Guadeloupe, and the Regional Natural Park in Martinique. In Guadeloupe, a Man and Biosphere Reserve was created in 1992, its area including the National Park and the Grand cul-deSac Marin NR. Besides, egg-laying areas of Iguana delicatissima in Îlet Chancel off Martinique are specially protected, with an increase of their size, following the recommendations of Breuil (1997b).
220
O. Lorvelec et al.
Management and habitat restoration In addition to these legal protections, threatened species require urgent and targetted management, and their habitats need to be restored. In 1998, a strategy on marine turtle conservation and a network of voluntary helpers were initiated in Guadeloupe administrative entity (Pavis et al., 2004). A similar network was reactivated in Martinique in 2003. The results obtained on habitats and threats led to the build up of a restoration programme of the French West Indies marine turtle populations (Chevalier, 2003). Two programs on predator eradication showed a posteriori the negative impact of predators on native species. This was observed following the successful eradication of introduced mammal species in nature reserves of the French West Indies. The first one was carried out in 2001 on Herpestes auropunctatus in the 115 ha Îlet Fajou off Guadeloupe (Lorvelec et al., 2004a). The second one occurred in 2002 and concerned Rattus rattus in the 5.7 ha Îlets de Sainte-Anne off Martinique (Pascal et al., 2004). After the eradications, terrestrial crab and bird populations increased, and in the case of Îlet Fajou, the systematic destruction of the marine turtle Eretmochelys imbricata eggs was stopped. Other eradication attempts were carried out in the Antilles. In the 8.3 ha Great Bird Island off Antigua, R. rattus eradication led in three years to a 100% increase of the Alsophis antiguae population (Varnham et al., 1998). This species had previously disappeared from Antigua (Henderson et al., 1996). In the 14.9 ha White Cay Island in the Bahamas, the eradication of Procyon lotor in 1997, and of R. rattus in 1998, were carried out in order to preserve the Cyclura rileyi cristata population (Day et al., 1998), a sub-species endemic to this island (Hayes, 1999). In the 5.7 ha Sandy Cay Island in the British Virgin Islands, the eradication of R. rattus was successfully performed in 2002 (K. Varnham, pers. comm., October 2003). In the 111 ha Long Cay Island in Caicos Banc, the eradication of cats was carried out in 1999 in the context of Cyclura carinata translocation (Mitchell et al., 2002). Lastly, in the 15 ha Monito Island between Hispanolia and Puerto Rico, the eradication of R. rattus was conducted in 1998 (García et al., 2002) to preserve the gecko Sphaerodactylus micropithecus, endemic of this island (Schwartz and Henderson, 1991). Far from the Antilles, Towns et al. (2001) showed that seven geckos and ten skinks from New Zealand increased their population levels, following the eradication of rats. These authors predicted that these operations may have benefits on 26 rare and micro insular species. Pacific Rats (Rattus exulans) in 1986, then rabbits in 1987, were eradicated from Korapuki in the Mercury Islands, with the view to reintroduce skinks (Towns and Ferreira, 2001). According to Towns et al. (2001), the latter operation led also to a large increase of the skink Oligosoma smithi population, with variations according to habitats, size and sex, indicating selection effects of rats. The quality of refuges may be informative on the rat impact, large rocks (>25 cm length) allowing the skink survival. This hypothesis was confirmed in Mercury and Marotene Islands for another skink species, Oligosoma suteri, which
Amphibians and reptiles of the French West Indies
221
may not coexist with rats if bouldery beaches are not available as refuges (Towns et al., 2003). Introduced amphibian and reptile species may also have a great impact on native species. Henderson and Powell (1999) underlined that Eleutherodactylus johnstonei or Anolis introductions led to changes in other species’ distributions. However, the processes involved seem complex. For instance, according to Cole et al. (2005), when the gecko Hemidactylus frenatus was introduced in islets off Mauritius (Mascarene Islands), the endemic gecko populations decreased drastically (Nactus coindemirensis, Nactus durrelli and Nactus serpensinsula), due to a competition for refuges. One can also wonder which was the role of H. frenatus in the extinction of Nactus sp. populations of Mascarene main islands (Arnold, 2000). In the Bahamas, Schoener et al. (2001) showed that after the 1999 hurricane Floyd, the predatory Leiocephalus carinatus was introduced in the 200 m2 Great Abaco Islets, increasing the probability for Anolis sagrei to become extinct. This was due to a reduction in the amounts of prey, but also to a modification of its life history traits. As a conclusion, we suggest modelling the interactions between native amphibians or reptiles, and introduced competitors or predators, taking into account the habitat structure (absence of refuges for some life history stages for sensitive species), following the approach used in New Zealand. Such studies on mechanisms would provide better understanding of the nature and importance of the threats allowing the best management measures for conservation or restoration.
Case Study: The Petite Terre Iguana delicatissima Population Ecology, history and herpetofauna of Petite Terre The Petite Terre Islands (148.6 ha) are located at 16◦ 11 N and 61◦ 07 W, 12 km south off La Désirade and 7.5 km south-east of Grande-Terre. They comprise two islands; Terre de Bas (117.1 ha, 8 ha of which is salt lagoons, 2.5 × 0.6 km, height < 8 m); and Terre de Haut windward (31.5 ha, 1.1 × 0.3 km, height < 8 m). A shallow channel, approximately 150 m broad at its narrow part, separates them (fig. 1). In the past these islands were subject to significant human impacts: deforestation, fishing and hunting, fields surrounded by dry-stone walls, construction of several sheds, and livestock production. Uninhabited since 1972, at present the channel and its surrounded beaches are subject to tourist activity. Since September 1998, Petite Terre is a terrestrial and marine nature reserve, in particular to protect its Lesser Antillean iguana, Iguana delicatissima (fig. 2a), population. Petite Terre has great ecological interest due to the presence of a large population of I. delicatissima, and other significant species. The Gaïac, Guaiacum officinale, very rare in the French West Indies except in Saint-Barthélemy (Fournet, 2002), is one of the Terre de Bas dry forest tree species. Among invertebrates, the terrestrial crab Gecarcinus ruricola, very rare elsewhere in Guadeloupe, has to be mentioned. Birds such as Sterna antillarum and Mimus gilvus breed, and the four Petite Terre
222
O. Lorvelec et al.
Figure 1. Petite Terre, Guadeloupe. The cairns delimit the line transects used for the adult Iguana delicatissima censuses in the Terre de Bas arborescent bush between 1995 and 2004.
salt lagoons act as one of the two best resting areas in Guadeloupe for about twenty shorebird migratory species (Barré et al., 1997). Petite Terre is also a regular nesting site for few females of the marine turtles Chelonia mydas and Eretmochelys imbricata (Lorvelec et al., 2000), and a former resident reported nesting of two other marine turtles: Dermochelys coriacea very rarely, and possibly Lepidochelys olivacea (Lorvelec et al., 2004c). D. coriacea was then reported to lay eggs in 2004 (Saint-Auret and Dulormne, 2005), but the nesting of L. olivacea is not yet confirmed (this species is not known to breed in the Lesser Antilles). Six terrestrial reptile species have been reported (table 1). In addition to I. delicatissima, three of them are rare or with a restricted distribution: Anolis marmoratus chrysops (fig. 2b), a sub-species endemic to Petite Terre; Sphaerodactylus fantasticus karukera, a subspecies reported only in Terre de Bas and in part of Grande-Terre; and Mabuya mabouya which was recently observed only once in Terre de Bas (Lorvelec et al., 2000). Although Lazell (1973) reported the absence of I. delicatissima in Petite Terre, Lorvelec et al. (2004b) collected credible accounts from former residents, arguing for its presence for a long time. The accounts lead to the conclusion that only the smallest island Terre de Haut had a visible iguana population from the 1920s (or before) to between 1945 and 1960. During this period, iguanas were absent or very rare from Terre de Bas, from where they have been eliminated by man, because of their negative impact on agriculture. About 50 years ago, the present Terre de Bas iguana population built up, starting from some individuals coming from one or
Amphibians and reptiles of the French West Indies
223
Figure 2. Two reptiles from Petite Terre, Guadeloupe which are rare or have restricted distribution: (a) Iguana delicatissima; (b) Anolis marmoratus chrysops, a subspecies endemic to Petite Terre. (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm)
the other of the two islands, a corollary of the decline of agriculture. Besides, the strong 1928 hurricane impact on the Petite Terre herpetofauna is unknown, the sea elevation during this hurricane having caused the disappearance of some islets off Basse-Terre. The status of the Petite Terre iguana population before the 20th century is unknown. It was not mentioned by Breton (1665) and du Tertre (1667-1671) in the 17th century, but this absence of records cannot be conclusive. The Petite Terre resources were exploited over a long time, first by Amerindians, then by European colonists. The relations between these human populations and iguanas are unknown, but the study of the Petite Terre archaeological sites may bring answers.
224
O. Lorvelec et al.
Iguana survey methods We review data from several studies on the dynamics of this iguana population that began in 1995 (Barré et al., 1997; Cabanis, 1998; Lorvelec et al., 2000, 2004b,c), and add unpublished results from 2003 and 2004. The iguana density in the Terre de Bas arborescent bush (27.2 ha) that bears the highest density, was estimated yearly between 1995 and 2004, except 1997, following the assumption that density variations would be more easily estimated in this habitat. Sixteen censuses of live and dead adults and sub-adults were carried out along a 2100 m line transect marked out every 100 m with cairns (fig. 1), following a standard protocol (Barré et al., 1997). The distance between each sighted iguana and the line transect was estimated and each sighting was assigned to one of four virtual bands distributed on both sides of the line transect (0-2 m, 2-5 m, 5-10 m, >10 m). An abundance index was computed; the number of contacts inside the inner band (0-2 m), converted to 1 ha. The method used for density calculation, initially devised to estimate bird densities (Bibby et al., 1992), and later recommended for lizard populations (Hayes and Carter, 1999; Harlow and Biciloa, 2001), was adapted to the Petite Terre iguana population (Barré et al., 1997). This method is based on the determination of the model that describes the detection probability decline when the sighting distance increases. For all the Petite Terre habitats, this model was a negative exponential one. Therefore, the density follows the relation: D=
1 ) −5N loge ( N−N N , LW
where N = total iguanas; N1 = number within W ; W = centre to inner band (m); L = transect length (km); D = density iguanas per ha. In 1995 and 1996, in addition to the Terre de Bas arborescent bush, all the phytoecological habitats (Rousteau, 1995) of the two islands were sampled. The ratios of density and iguana number between Petite Terre and the Terre de Bas arborescent bush were computed. The annual density and the size of the total population were estimated on the basis of these ratios. The Petite Terre iguana population Figure 3 represents the changes in the abundance index in the Terre de Bas arborescent bush between 1995 and 2004. The annual mean densities and numbers of adult iguanas are compiled in table 2, for the Terre de Bas arborescent bush and for both islands respectively. In 1995, the total population was estimated as about 12,300 individuals, of which most (more than 10,500) were in Terre de Bas and more than 1,500 in Terre de Haut (Barré et al., 1997). We use the 1995 population as a reference, because no major climatic event had occurred since the 1989 hurricane Hugo, five and a half years before. We observed a decline of 60% in the population in 1996. The two September 1995 hurricanes played a major role in this decline, though direct impact was not observed just after these climatic events, during the
Amphibians and reptiles of the French West Indies
225
Figure 3. Adult Iguana delicatissima dynamics in the Terre de Bas arborescent bush between 1995 and 2004 (Petite Terre, Guadeloupe). Data are the number of contacts inside the census inner band (0-2 m), converted to 1 ha. Grey: alive; hatched: dead. 1995: April 16, May 13, June 24, September 23; 1996: January 13, March 23; 1998: May 17; May 24; 1999: April 24; 2000: April 15; 2001: April 10, August 27; 2002: February 10, March 24; 2003: May 21; 2004: June 5; (1): September 1995 hurricanes; (2): 1997 lack of data; (3): 2001 drought.
Table 2. Annual estimates of the Iguana delicatissima adult density and population size between 1995 and 2004 (Petite Terre, Guadeloupe). Year 1995 1996 1997 1998 1999 2000 2001 April 2001 August, alive 2001 August, dead 2002 2003 2004
D TBAB
N TBAB
D PT
N PT
184 70 – 143 152 142 174 49 55 91 101 148
5,014 1,920 – 3,891 4,135 3,859 4,745 1,335 1,496 2,489 2,755 4,038
88 34 – 68 73 68 83 23 26 44 48 71
12,283 4,769 – 9,532 10,130 9,454 11,624 3,270 3,665 6,097 6,749 9,892
D: Density (ha−1 ); N: population size; TBAB: Terre de Bas arborescent bush; PT: Petite Terre.
226
O. Lorvelec et al.
census carried out in September 1995 (Barré et al., 1997). As early as 1998, the population level increased and nearly reached the reference level after three years (Lorvelec et al., 2000). A drastic decline was again observed in August 2001, with high mortality occurring between April and August. As the cadavers were quickly eliminated by the terrestrial hermit crab Coenobita clipeatus, the 3,500 dead iguanas counted in August 2001 underestimate the total mortality, which probably reached 8,000 adults corresponding to 70% of the population (Lorvelec et al., 2004b). This estimate is double that of Breuil (2001, 2002). The mortality was linked to the extreme drought which occurred in 2001, which probably led to a water and food deficit for the iguanas. The Petite Terre Iguana delicatissima population is one of the most important in the world, with those of La Désirade and Dominica. In 1993, three and a half years after hurricane Hugo, the number of adults was estimated as ranging from 4,000 to 6,000 (Breuil and Thiébot, 1993; Breuil, 1994). The counting methods used in these studies were not reported precisely, and do not allow comparison with our results. At this period, the population was considered to represent a quarter or a third of the world stock (Breuil, 1994). Our results suggest that the Petite Terre share is even more important, and represents the I. delicatissima population with the highest density in the world. Conclusions and recommendations The Petite Terre vertebrate biomass is dominated by a large vegetarian reptile, a currently rare situation. Similar situations are found only on: Aldabra island (Seychelles) dominated by the tortoise Dipsochelys dussumieri; Galapagos (Ecuador) dominated by the tortoise Chelonoidis nigra and two terrestrial iguanas (Conolophus pallidus and Conolophus subcristatus); the 70 ha uninhabited Yadua Taba island (Fiji) with the last abundant Brachylophus vitiensis population of 6,000 adults (Harlow and Biciloa, 2001); and some Antillean islands with Cyclura species, such as certain Turks and Caicos islands where the C. carinata carinata density can exceed 30 ha−1 (Iverson, 1979). The large size of the healthy Petite Terre Iguana delicatissima population distributed on two islands preserved this species from the main threats. The strong protection status of nature reserve gives to these islands a major role for the conservation and the study of this threatened and protected species. Nevertheless, despite its very high density, this population is perhaps more vulnerable than those of Dominica and La Désirade because of drastic demographic fluctuations related to major hurricanes, intense droughts or possible fires. Nevertheless, in spite of the relatively recent establishment of the species in Terre de Bas and the major impact of climatic events detected in the past, the prompt recovery of the population after crashes suggests that I. delicatissima is a species adapted to strong climatic variations. Genetic studies would be welcome to determine the possible gene-flux and its direction between the two islands and, if extended to other populations, to document the colonization history.
Amphibians and reptiles of the French West Indies
227
Will the demography of this population reach equilibrium in the absence of major climatic disturbances? Answering this question implies exploring the qualitative and quantitative relationships between this species and others hosted by the insular ecosystem to estimate the role played by reproduction, food resources, predation, and invasive species. Such researches will be a major contribution to build up a well-founded management strategy (Lorvelec et al., 2004b,c). The number of nesting areas increased in Terre de Bas with the opening of a management path. This event may induce a decrease of the female density in areas that were utilised in the past. We ignore the impact of this event on the total reproductive success. The female density reduction on nesting areas will decrease the risk of egg loss by excavation, but will also decrease the number of collapsed burrows. The latter effect will tend to increase hermit crab predation because open burrows are easier to enter than collapsed ones (Lorvelec et al., 2000). Lastly, does tourist activity have an unfavourable impact on the use of the nesting areas located behind the channel beaches? Are the local food resources sufficient to allow long term survival of a high iguana density? Rousteau (1995) described the extreme slowness of the Petite Terre vegetation dynamics and Barré et al. (1997) showed the qualitative impact of the iguana on various flora species. As Guaiacum officinale leaves, flowers and fruits are eaten by iguanas, studies must be undertaken to evaluate the impact on this significant tree species (Barré et al., 1997; Monthieux, 2002). Lorvelec et al. (2004c) and Rousteau and Monthieux (2005) synthesized knowledge on the subject. G. officinale is missing in Terre de Haut and only about thirty trees are present in Terre de Bas, the youngest being 50 years old. The in situ seed germination capacity seems sufficient at the beginning of the reproductive season, but there is no local regeneration. The test of various hypotheses to explain this lack of regeneration is in progress: seedling destruction (by rats, iguanas, or hermit crabs), herbivore or pathogen attack, disseminator absence, inbreeding depression, edaphic or climatic restraints (Rousteau and Monthieux, 2005). Although iguana eggs are subject to unquantified hermit crab predation, juveniles and adults are free of native predators, and Rattus rattus impact on eggs and young juveniles is unknown. Rats have been regularly recorded on the two islands since 1998. However, according to Terre de Bas former residents, rats and mice were present in the past (Lorvelec et al., 2004c) and the lack of rat sighting over several years in Terre de Bas has to be related to occasional chemical control (Lorvelec et al., 2000). A 2001 necropsy of a feral cat, present in Terre de Bas since at least 1995, revealed fresh remains of an I. delicatissima adult female or large juvenile (Lorvelec et al., 2004b). A major management measure is to prevent introduction of any alien predator and to consider regulation or eradication of the species already introduced. Another threat is I. iguana, which has a large neotropical distribution. Absent from Petite Terre, it is present in other islands of the Lesser Antilles and competition and hybridization are known in sympatric areas (review in Breuil, 2002). Consequently, preventing the arrival of I. iguana, as recorded in Anguilla, Antigua and
228
O. Lorvelec et al.
Barbuda after the 1995 hurricanes (Censky et al., 1998; Breuil, 1999b), constitutes a management goal for the continuity of the Petite Terre I. delicatissima population. Identifying the mechanisms regulating the Petite Terre I. delicatissima population and their possible relationships with catastrophic climatic events, requires a thorough knowledge of the biology of this population. This will help managers to develop a strategy of conservation in the long-term, which must aim at ensuring the continuity of the population in good balance with the ecosystem and not by an artificial increase of its size. Acknowledgements. Iguana delicatissima data from Petite Terre were collected by AEVA local natural society (Association pour l’Etude et la protection des Vertébrés et végétaux des petites Antilles), contractually (1995-1996 and 20002001) or with authorization of ONF (Office National des Forêts) that is the Nature Reserve manager institution. We thank ONF, AEVA, the Nature Reserve rangers and Ti-Tè association of La Désirade that employs them, and all the naturalists involved in field operations. We thank Damien Fourcy (INRA SCRIBE) for the mapping of Petite Terre (modified from J.M. Neumuller and C. Barneron map, ONF, 1995), and Thierry Frétey (RACINE association) supporting documentation research. We also thank the two referees for their remarks, and Hélène Quinonero (CIRAD Montpellier) and Adrian Hailey who improved the English.
References Allen, G.M. (1911): Mammals of the West Indies. Bull. Mus. Comp. Zoöl. 54: 175-263. Alonso, A., Dallmeier, F., Granek, E., Raven, P. (2001): Biodiversity: Connecting with the Tapestry of Life. Washington, Smithsonian Institution, Monitoring and Assessment of Biodiversity Program and President’s Committee of Advisors on Science and Technology. Anonyme de Carpentras (1618-1620): Un Flibustier Français dans la Mer des Antilles (1618-1620). Paris, Payot & Rivages, presented by Moreau, J.-P., 2002. Arnold, E.N. (2000): Using fossils and phylogenies to understand evolution of reptile communities on islands. In: Isolated Vertebrate Communities in the Tropics, p. 309-323. Rheinwold, G., Ed., Bonn, Bonner Zool. Monogr., Vol. 46. Atkinson, I.A.E. (1985): The spread of commensal species of Rattus to oceanic islands and their effect on island avifaunas. In: Conservation of Island Birds, p. 35-81. Moors, P.J., Ed., Cambridge, International Council for Bird Preservation, Technical Publication No. 3. Barbour, T. (1914): A contribution to the zoögeography of the West Indies, with especial reference to amphibians and reptiles. Mem. Mus. Comp. Zoöl. 44: 209-359. Barbour, T. (1915): Recent notes regarding West Indians reptiles and amphibians. Proc. Biol. Soc. Washington. 28: 71-78. Barbour, T. (1930): Some faunistic changes in the Lesser Antilles. Proc. New England Zoöl. Club. 11: 73-85. Barré, N., Lorvelec, O., Breuil, M. (1997): Les Oiseaux et les Reptiles des Îles de la Petite Terre (Guadeloupe). Bilan d’un Suivi Ecologique d’une Année (Mars 1995 à Mars 1996). Petit-Bourg, Guadeloupe, AEVA, Report No. 16, Conservatoire du Littoral, Office National des Forêts. Baskin, J.N., Williams, E.E. (1966): The Lesser Antillean Ameiva (Sauria, Teiidae). Re-evaluation, zoogeography, and the effects of predation. Stud. Fauna Curaçao Carib. Is. 23: 144-176. Bibby, C.J., Burgess, N.D., Hill, D.A. (1992): Bird Census Techniques. London, Academic Press.
Amphibians and reptiles of the French West Indies
229
Bon Saint Côme, M., Tanasi, M. (1994): Le Raccoon en Martinique. Fort-de-France, Martinique, Report, Office National de la Chasse et de la Faune Sauvage. Bour, R. (1983): Trois populations endémiques du genre Pelusios (Reptilia, Chelonii, Pelomedusidae) aux îles Seychelles; relations avec les espèces africaines et malgaches. Bull. Mus. natn. Hist. nat. Paris, sér. 4A 5: 343-382. Breton, R. (1665): Dictionnaire Caraïbe-Français. Paris, Karthala and IRD, 1999. Breuil, M. (1994): Les iguanes (Iguana delicatissima et Iguana iguana) dans les Antilles françaises et sur les îles de la Petite Terre. In: Dossier de Création de la Réserve Naturelle Terrestre et Marine des Ilets de Petite Terre, p. 27-34. Asmodé, J.-F., Breuil, M., Lecomte, P., Chabin, L., Eds, BasseTerre, Guadeloupe, Report, Direction Régionale de l’Environnement, Office de Génie Écologique. Breuil, M. (1997a): L’Herpétofaune de la Réserve Biologique de la Montagne Peléé (Martinique). Fort-de-France, Martinique, Report, Office national des Forêts, Paris, Association des Amis du Laboratoire des Reptiles et Amphibiens du MNHN. Breuil, M. (1997b): Les Reptiles, les Amphibiens et les Chauves-Souris de l’Îlet Chancel (Martinique). Fort-de-France, Martinique, Report, Direction Régionale de l’Environnement, Paris, Association des Amis du Laboratoire des Reptiles et Amphibiens du MNHN. Breuil, M. (1999a): Nouvelle espèce du genre Typhlops, (Serpentes, Typhlopidae) de l’île de SaintBarthélemy, comparaison avec les autres espèces des Petites Antilles. Bull. Mens. Soc. Linn. Lyon. 68: 30-40. Breuil, M. (1999b): Editorial. West Indian Iguana Specialist Group Newsletter. 2: 4. Breuil, M. (2001): Taxon Reports: Lesser Antilles Iguana delicatissima and Iguana iguana. West Indian Iguana Specialist Group Newsletter. 4: 9-11. Breuil, M. (2002): Histoire Naturelle des Amphibiens et Reptiles Terrestres de l’Archipel Guadeloupéen. Guadeloupe, Saint-Martin, Saint-Barthélemy. Paris, MNHN, Institut d’Écologie et de Gestion de la Biodiversité, Service du Patrimoine Naturel, Patrimoines naturels No. 54. Breuil, M. (2003): In the footsteps of French naturalists, a “battle” of iguanas, and “improvements” in biodiversity. In: Islands and the Sea. Essays on Herpetological Exploration in the West Indies, p. 255-270. Henderson, R.W., Powell, R., Eds, Ithaca, New York, Society for the Study of Amphibians and Reptiles. Breuil, M. (2004): À la Découverte des Amphibiens & Reptiles des Antilles. Le Gosier, Guadeloupe, PLB (Thierry Petit Le Brun) Éditions. Breuil, M., Day, M. (1996): Iguana delicatissima. In: 2006 IUCN Red List of Threatened Species. Gland, Switzerland, IUCN Species Survival Commission. (www.iucnredlist.org). Breuil, M., Sastre, C. (1993): Inventaire Ecologique de l’Archipel des Saintes (Guadeloupe): Végétation et Vertébrés (sauf Oiseaux). Basse-Terre, Guadeloupe, Report, Parc National de la Guadeloupe, Paris, MNHN. Breuil, M., Thiébot, B. (1993): Essai d’Inventaire des Iguanes (Iguana iguana et Iguana delicatissima) dans l’Archipel Guadeloupéen. Petit-Bourg, Guadeloupe, AEVA, Report No. 1, Parc National de la Guadeloupe. Cabanis, L. (1998): Estimation de la Population d’Iguana delicatissima aux Îles de la Petite Terre (Guadeloupe). Petit-Bourg, Guadeloupe, AEVA, Report No. 19, Univ. Antilles Guyane. Censky, E.J. (1988): Geochelone carbonaria (Reptilia: Testudines) in the West Indies. Florida Sci. 50: 108-114. Censky, E.J., Hodge, K., Dudley, J. (1998): Over-water dispersal of lizards due to hurricanes. Nature 395: 556. Censky, E.J., Kaiser, H. (1999): The Lesser Antillean fauna. In: Caribbean Amphibians and Reptiles, p. 181-221. Crother, B.I., Ed., San Diego and London, Academic Press. Chevalier, J. (2003): Plan de Restauration des Tortues Marines des Antilles Françaises. Basse-Terre, Guadeloupe, Report, Office National de la Chasse et de la Faune Sauvage.
230
O. Lorvelec et al.
Chevalier, J., Lartiges, A. (2001): Les Tortues Marines des Antilles. Basse-Terre, Guadeloupe, Report, Office National de la Chasse et de la Faune Sauvage, Direction de l’Environnement de la Guadeloupe, Direction de l’Environnement de la Martinique. Cole, N.C., Jones, C.G., Harris, S. (2005): The need for enemy-free space: the impact of an invasive gecko on island endemics. Biol. Conserv. 125: 467-474. Day, M. (1996): Alsophis rijersmai. In: 2006 IUCN Red List of Threatened Species. Gland, Switzerland, IUCN Species Survival Commission. (www.iucnredlist.org). Day, M.L., Breuil, M., Reichling, S. (1999): Lesser Antillean iguana. Iguana delicatissima. In: West Indian Iguanas: Status Survey and Conservation Action Plan, p. 62-67. Alberts, A., Ed., Gland, Switzerland, IUCN, Species Survival Commission, West Indian Iguana Specialist Group. Day, M., Hayes, W., Varnham, K., Ross, T., Carey, E., Ferguson, T., Monestine, J., Smith, S., Amstrong, C., Buckle, A., Alberts, A., Buckner, S. (1998): Rat eradication to protect the White Cay iguana. Aliens. 8: 22-24. Day, M.L., Thorpe, R.S. (1996): Population differentiation of Iguana delicatissima and I. iguana in the Lesser Antilles. In: Contributions to the West Indian Herpetology. A Tribute to Albert Schwartz, p. 436-437, abstract. Powell, R., Henderson, R.W., Eds, Ithaca, New York, Society for the Study of the Amphibians and Reptiles, Contributions to Herpetology, Vol. 12. Diamond, J. (1989): Overview of recent extinctions. In: Conservation for the Twenty-First Century, p. 37-41. Western, D., Pearl, M.C., Eds, Oxford University Press. Duméril, A.M.C., Bibron, G. (1835): Erpétologie Générale ou Histoire Naturelle Complète des Reptiles. Vol. 2. Paris, Librairie Encyclopédique de Roret. Duméril, A.M.C., Bibron, G. (1837): Erpétologie Générale ou Histoire Naturelle Complète des Reptiles. Vol. 4. Paris, Librairie Encyclopédique de Roret. Espeut, W.B. (1882): On the acclimatization of the Indian mungoos in Jamaica. Proc. Zool. Soc. London. 1882: 712-714. Fournet, J. (2002): Flore Illustrée des Phanérogames de Guadeloupe et de Martinique. Montpellier, France, Gondwana and CIRAD. Fretey, J. (1997): Propositions de Sites de Nidification des Tortues Marines Prioritaires dans les Départements Français d’Amérique. Paris, Report, Ministère de l’Écologie and WWF France. Fretey, J., Lescure, J. (1999): Présence de Lepidochelys olivacea (Eschscholtz, 1829) (Chelonii, Cheloniidae) dans les Antilles françaises. Bull. Soc. Herp. Fr. 90: 41-49. Frost, D.R., Grant, T., Faivovich, J., Bain, R.H., Haas, A., Haddad, C.F.B., De Sá, R.O., Channing, A., Wilkinson, M., Donnellan, S.C., Raxworthy, C.J., Campbell, J.A., Blotto, B.L., Moler, P., Drewes, R.C., Nussbaum, R.A., Lynch, J.D., Green, D.M., Ward, C., Wheeler, W.C. (2006): The amphibian tree of life. Bull. Amer. Mus. Nat. Hist. 297: 1-370. García, M.A., Diez, C.E., Alvarez, A.O. (2002): The eradication of Rattus rattus from Monito Island, West Indies. In: Turning the Tide: the Eradication of Invasive Species, p. 116-119. Veitch, C.R., Clout, M.N., Eds, Auckland Univ., Occasional Paper of the IUCN Species Survival Commission No. 27. Gargominy, O. (Ed.) (2003): Biodiversité et Conservation dans les Collectivités d’Outre-Mer. Paris, French committee of the IUCN. Gibbons, J.R.H. (1984): Iguanas of the South Pacific. Oryx. 18: 82-91. Grant, T., Frost, D.R., Caldwell, J.P., Gagliardo, R., Haddad, C.F.B., Kok, P.J.R., Means, D.B., Noonan, B.P., Schargel, W.E., Wheeler, W.C. (2006): Phylogenetic systematics of dart-poison frogs and their relatives (Amphibi: Athesphatanura, Dendrobatidae). Bull. Amer. Mus. Nat. Hist. 299: 1-262. Grouard, S. (2001a): Subsistance, Systèmes Techniques et Gestion Territoriale en Milieu Insulaire Antillais Précolombien – Exploitation des Vertébrés et des Crustacés aux Époques Saladoïdes et Troumassoïdes de Guadeloupe (400 av. J.-C. à 1500 ap. J.-C.). Thèse de doctorat (3 vol.). Paris, Univ. Paris X-Nanterre.
Amphibians and reptiles of the French West Indies
231
Grouard, S. (2001b): Faunal remains associated with late Saladoïd and post-Saladoïd occupations at Anse à la Gourde, Guadeloupe, West Indies: Preliminary results. Archaeofauna. 10: 71-98. Grouard, S. (2004): Variation des stratégies de subsistance des Précolombiens à Hope Estate, SaintMartin (Petites Antilles), d’après l’analyse des restes des petits vertébrés. In: Petits Animaux et Sociétés Humaines. Du Complément Alimentaire aux Ressources Utilitaires, p. 441-467. Brugal J.-P., Desse, J., Eds, Rencontres Internationales d’Archéologie et d’Histoire d’Antibes No. 23, France. Harlow, P.S., Biciloa, P.N. (2001): Abundance of the Fijian crested iguana (Brachylophus vitiensis) on two islands. Biol. Conserv. 98: 223-231. Hayes, W. (1999): White Cay iguana. Cyclura rileyi cristata. In: West Indian Iguanas: Status Survey and Conservation Action Plan, p. 59-62. Alberts, A., Ed., Gland, Switzerland, IUCN, Species Survival Commission, West Indian Iguana Specialist Group. Hayes, W., Carter, R. (1999): Population monitoring. In: West Indian Iguanas: Status Survey and Conservation Action Plan, p. 79-85. Alberts, A., Ed., Gland, Switzerland, IUCN, Species Survival Commission, West Indian Iguana Specialist Group. Hedges, S.B. (1996): The origin of West Indian amphibians and reptiles. In: Contributions to the West Indian Herpetology. A Tribute to Albert Schwartz, p. 95-128. Powell, R., Henderson, R.W., Eds, Ithaca, New York, Society for the Study of the Amphibians and Reptiles, Contributions to Herpetology, Vol. 12. Hedges, B., Ibéné, B., Breuil, M., Powell, R. (2004a): Eleutherodactylus barlagnei. In: 2006 IUCN Red List of Threatened Species. Gland, Switzerland, IUCN Species Survival Commission. (www.iucnredlist.org). Hedges, B., Ibéné, B., Breuil, M., Powell, R. (2004b): Eleutherodactylus pinchoni. In: 2006 IUCN Red List of Threatened Species. Gland, Switzerland, IUCN Species Survival Commission. (www.iucnredlist.org). Hedges, B., Ibéné, B., Breuil, M., Powell, R. (2004c): Colostethus chalcopis. In: 2006 IUCN Red List of Threatened Species. Gland, Switzerland, IUCN Species Survival Commission. (www.iucnredlist.org). Henderson, R.W. (1992): Consequences of predator introductions and habitat destruction on amphibians and reptiles in the post-Columbus West Indies. Carib. J. Sci. 28: 1-10. Henderson, R.W. (2004): Lesser Antillean snake faunas: distribution, ecology, and conservation concerns. Oryx. 38: 311-320. Henderson, R.W., Daudin, J., Haas, G.T., McCarthy, T.J. (1992): Significant distribution records for some amphibians and reptiles in the Lesser Antilles. Carib. J. Sci. 28: 101-103. Henderson, R.W., Delatte, A., McCarthy, T.J. (1993): Gekko gecko (Sauria: Gekkonidae) established on Martinique, French West Indies. Carib. J. Sc. 29: 128-129. Henderson, R.W., Powell, R. (1999): West Indian herpetoecology. In: Caribbean Amphibians and Reptiles, p. 223-268. Crother, B.I., Ed., San Diego and London, Academic Press. Henderson, R.W., Powell, R. (2001): Responses by the West Indian herpetofauna to human-influenced resources. Carib. J. Sci. 37: 41-54. Henderson, R.W., Powell, R., Daltry, J.C., Day, M.L. (1996): Alsophis antiguae. Cat. Amer. Amphib. Rept. 632: 1-3. Honegger, R.E. (1981): List of amphibians and reptiles either known or thought to have become extinct since 1600. Biol. Conserv. 19: 141-158. Husson, A.M. (1960): Het voorkomen van de mungo in Suriname. Lutra. 2: 12-13. Ineich, I., Martelli, J.-L., Clary, J. (2005): Catalogue des collections de reptiles du Muséum d’Histoire naturelle de Lyon, sixième note: Sauriens (deuxième partie) et Rhynchocéphales. Cahiers scientifiques Mus. Hist. nat. Lyon. 8: 33-66. IUCN (2006): 2006 IUCN Red List of Threatened Species. Gland, Switzerland, IUCN Species Survival Commission. (www.redlist.org).
232
O. Lorvelec et al.
Iverson, J.B. (1978): The impact of feral cats and dogs on populations of the West Indian rock iguana, Cyclura carinata. Biol. Conserv. 14: 63-73. Iverson, J.B. (1979): Behavior and ecology of the rock iguana Cyclura carinata. Bull. Florida State Mus., Biol. Sci. 24: 175-358. Kaiser, H. (1992): The trade-mediated introduction of Eleutherodactylus martinicensis (Anura: Leptodactylidae) on St Barthélémy, French Antilles, and its implication for Lesser Antillean biogeography. J. Herpetol. 26: 264-273. Kaiser, H. (1997): Origins and introductions of the Caribbean frog Eleutherodactylus johnstonei (Leptodactylidae): management and conservation concerns. Biodivers. Conserv. 6: 1391-1407. Kaiser, H., Coloma, L.A., Gray, H.M. (1994): A new species of Colostethus (Anura: Dendrobatidae) from Martinique, French Antilles. Herpetologica. 50: 23-32. Kaiser, H., Murdoch, J.T., Boistel, R., Breuil, M. (2003): Eleutherodactylus pinchoni. Cat. Amer. Amphib. Rept. 765: 1-3. King, W. (1962): Systematics of Lesser Antillean lizards of the genus Sphaerodactylus. Bull. Florida State Mus., Biol. Sci. 7: 1-52. Kizirian, D.A., Cole, C.J. (1999): Origin of the unisexual lizard Gymnophthalmus underwoodi (Gymnophthalmidae) inferred from mitochondrial DNA nucleotide sequences. Mol. Phylogenet. Evol. 11: 394-400. Kluge, A.G. (1969): The evolution and geographical origin of the New World Hemidactylus mabouiabrookii complex (Gekkonidae, Sauria). Misc. Publ. Mus. Zool. Univ. Michigan. 138: 1-78. Kronauer, D.J.C., Bergmann, P.J., Mercer, J.M., Russell, A.P. (2005): A phylogeographically distinct and deep divergence in the widespread Neotropical turnip-tailed gecko, Thecadactylus rapicauda. Mol. Phylogenet. Evol. 34: 431-437. Lazell, J.D., Jr. (1964): The anoles (Sauria, Iguanidae) of the Guadeloupéen archipelago. Bull. Mus. Comp. Zool. 131: 359-401. Lazell, J.D., Jr. (1967): Wiederentdeckung von zwei angeblich ausgestorbenen Schlangenarten der westindischen Inseln. Salamandra. 3: 91-97. Lazell, J.D., Jr. (1972): The anoles (Sauria, Iguanidae) of the Lesser Antilles. Bull. Mus. Comp. Zool. 143: 1-115. Lazell, J.D., Jr. (1973): The lizard genus Iguana in the Lesser Antilles. Bull. Mus. Comp. Zool. 145: 1-28. Lescure, J. (1968): Le comportement social des batraciens. Revue du Comportement Animal. 2: 1-33. Lescure, J. (1979): Singularité et fragilité de la faune en vertébrés des petites Antilles. C.R. Soc. Biogéogr. 48: 93-109. Lescure, J. (1983): Introductions passives et actives de reptiles et d’amphibiens dans les Antilles et les Guyanes. C.R. Soc. Biogéogr. 59: 59-70. Lescure, J. (2000): Répartition passée de Leptodactylus fallax Müller, 1923 et d’Eleutherodactylus johnstonei Barbour, 1914 (Anoures, Leptodactylidés). Bull. Soc. Herp. Fr. 94: 13-23. Lever, C. (1994): Naturalized Animals: the Ecology of Successfully Introduced Species. London, Poyser Natural History. Lorvelec, O., Delloue, X., Pascal, M., Mège, S. (2004a): Impacts des mammifères allochtones sur quelques espèces autochtones de l’îlet Fajou (réserve naturelle du Grand cul-de-sac marin, Guadeloupe), établis à l’issue d’une tentative d’éradication. Rev. Écol. (Terre Vie). 59: 293-307. Lorvelec, O., Levesque, A., Barré, N., Feldmann, P., Leblond, G., Jaffard, M.-È., Pascal, M., Pavis, C. (2004b): Évolution de la densité de population de l’iguane des Petites Antilles (Iguana delicatissima) dans la réserve naturelle des îles de la Petite Terre (Guadeloupe) entre 1995 et 2002. Rev. Écol. (Terre Vie). 59: 331-344. Lorvelec, O., Levesque, A., Leblond, G., Jaffard, M.-E., Barré, N., Feldmann, P., Pascal M., Pavis, C. (2000): Suivi Ecologique des Reptiles, Oiseaux et Mammifères aux Îles de la Petite Terre (Commune de La Désirade, Guadeloupe). Années 1998 et 1999. Petit-Bourg, Guadeloupe, AEVA, Report No. 24.
Amphibians and reptiles of the French West Indies
233
Lorvelec, O., Levesque, A., Saint-Auret, A., Feldmann, P., Rousteau, A., Pavis, C. (2004c): Suivi Ecologique des Reptiles, Oiseaux et Mammifères aux Îles de la Petite Terre (Réserve Naturelle, Commune de La Désirade, Guadeloupe). Années 2000, 2001 et 2002. Petit-Bourg, Guadeloupe, AEVA, Report No. 28, Office National des Forêts. Lorvelec, O., Pascal, M., Pavis, C. (2001): Inventaire et Statut des Mammifères des Antilles françaises (hors Chiroptères et Cétacés). Petit-Bourg, Guadeloupe, AEVA, Report No. 27. Lowe, S., Browne, M., Boudjelas, S., Poorter, M. de (2000): 100 of the World’s Worst Invasive Alien Species. A Selection from the Global Invasive Species Database. Gland, Switzerland, IUCN Invasive Species Specialist Group. MacLean, W.P., Kellner, R., Dennis, H. (1977): Island lists of West Indian amphibians and reptiles. Smithsonian Herpetol. Information Service. 40: 1-47 Magras, M. (1992): La faune de Saint-Barthélemy. The fauna of Saint-Barthélemy. Tropical St Barth. 2: 22-30. Malhotra, A., Thorpe, R.S. (1999): Reptiles & Amphibians of the Eastern Caribbean. London and Oxford, Macmillan Education LTD. Miralles, A. (2005): The identity of Lacertus mabouya Lacepède, 1788, with description of a neotype: an approach toward the taxonomy of new world Mabuya. Herpetologica. 61: 46-53. Mitchell, N.C. (1999a): Anegada Island iguana. Cyclura pinguis. In: West Indian Iguanas: Status Survey and Conservation Action Plan, p. 47-50. Alberts, A., Ed., Gland, Switzerland, IUCN, Species Survival Commission, West Indian Iguana Specialist Group. Mitchell, N.C. (1999b): Effect of introduced ungulates on density, dietary preferences, home range, and physical condition of the iguana (Cyclura pinguis) on Anegada. Herpetologica. 55: 7-17. Mitchell, N., Haeffner, R., Veer, V., Fulford-Gardner, M., Clerveaux, W., Veitch, C.R., Mitchell, G. (2002): Cat eradication and the restoration of endangered iguanas (Cyclura carinata) on Long Cay, Caicos Bank, Turks and Caicos Islands, British West Indies. In: Turning the Tide: the Eradication of Invasive Species, p. 206-212. Veitch, C.R., Clout, M.N., Eds, Auckland Univ., Occasional Paper of the IUCN Species Survival Commission No. 27. Monthieux, A. (2002): Étude de la Floraison et de la Fructification de Guaicum officinale L. sur l’Île de Petite Terre en Guadeloupe. Le Gosier, Guadeloupe, Report, Univ. Antilles Guyane, Conservatoire Botanique des Antilles Françaises. Moors, P.J., Atkinson, I.A.E. (1984): Predation on seabirds by introduced animals, and factors affecting its severity. In: Status and Conservation of the World’s Seabirds, p. 667-690. Croxall, J.P., Evan, P.G.H., Schreiber, R.W., Eds, Cambridge, International Council for Bird Preservation, Technical Publications No. 2. Morgan, G.S., Woods, C.A. (1986): Extinction and the zoogeography of West Indian land mammals. Biol. J. Linn. Soc. London. 28: 167-203. Pasachnik, S.A., Breuil, M., Powell, R. (2006): Iguana delicatissima. Cat. Amer. Amphib. Rept. 811: 1-14. Pascal, M., Brithmer, R., Lorvelec, O., Vénumière, N. (2004): Conséquences sur l’avifaune nicheuse de la réserve naturelle des îlets de Sainte-Anne (Martinique) de la récente invasion du rat noir (Rattus rattus), établies à l’issue d’une tentative d’éradication. Rev. Écol. (Terre Vie). 59: 309318. Pascal, M., Lorvelec, O., Vigne, J.-D. (2005): Holocene turnover of the French vertebrate fauna. Biol. Invasions, 2005. 7: 99-106 (and 8: 395, corrigendum, 2006). Pascal, M., Lorvelec, O., Vigne, J.-D. (2006): Invasions Biologiques et Extinctions: 11 000 Ans d’Histoire des Vertébrés en France. Paris, Belin and Quæ. Pavis, C., Lorvelec, O., Dulormne, M., Chevalier, J., Levesque, A., Legendre, L. (2004): Stratégie de conservation des tortues marines dans l’archipel Guadeloupéen. Rev. Écol. (Terre Vie). 59: 381382, abstract. Pimentel, D. (1955): Biology of the Indian mongoose in Puerto Rico. J. Mamm. 36: 62-68.
234
O. Lorvelec et al.
Pinchon, R. (1967): Quelques Aspects de la Nature aux Antilles. Fort-de-France, Martinique, Caen, France, Imprimerie Ozanne et Cie. Pons, J.-M., Volobouev, V., Ducroz, J.-F., Tillier, A., Reudet, D. (1999): Is the Guadeloupean racoon (Procyon minor) really an endemic species? New insights from molecular and chromosomal analyses. J. Zool. Syst. Evol. Res. 37: 101-108. Powell, R. (2006): Conservation of the herpetofauna on the Dutch Windward Islands: St. Eustatius, Saba, and St. Maarten. Appl. Herpetol. 3: 293-306. Powell, R., Henderson, R.W. (1996): A brief history of West Indian herpetology. In: Contributions to the West Indian Herpetology. A Tribute to Albert Schwartz, p. 29-50. Powell, R., Henderson, R.W., Eds, Ithaca, New York, Society for the Study of the Amphibians and Reptiles, Contributions to Herpetology, Vol. 12. Powell, R., Henderson, R.W. (2001): On the taxonomic status of some Lesser Antillean lizards. Carib. J. Sci. 37: 288-290. Powell, R., Henderson, R.W., Adler, K., Dundee, H.A. (1996): An annotated checklist of West Indian amphibians and reptiles. In: Contributions to the West Indian Herpetology. A Tribute to Albert Schwartz, p. 51-93. Powell, R., Henderson, R.W., Eds. Ithaca, New York, Society for the Study of the Amphibians and Reptiles, Contributions to Herpetology, Vol. 12. Powell, R., Passaro, R.J., Henderson, R.W. (1992): Noteworthy herpetological records from Saint Maarten, Netherlands Antilles. Carib. J. Sci. 28: 234-235. Pregill, G.K., Steadman, D.W., Watters, D.R. (1994): Late Quaternary vertebrate faunas of the Lesser Antilles: historical components of Caribbean biogeography. Bull. Carnegie Mus. Nat. Hist. 30: 1-51. Questel, A. (1941): The Flora of the Island of St-Bartholomew (French West Indies) and its Origin. Paris, Paul Lechevallier. Richmond, N.D. (1966): The blind snakes, Typhlops, of Guadeloupe and Dominica with the description of a new species. Herpetologica. 22: 129-132. Roughgarden, J. (1995): Anolis Lizards of the Caribbean: Ecology, Evolution, and Plate Tectonics. New York and Oxford, Oxford Univ. Press. Rousteau, A. (1995): Petite Terre de La Désirade. Étude Phytoécologique. Basse-Terre, Guadeloupe, Report, Conservatoire du Littoral, Office National des Forêts. Rousteau, A., Monthieux, A. (2005): Le Déficit de Régénération des Gaiäcs de la Petite-Terre. BasseTerre, Guadeloupe, BIOS Report, Office National des Forêts. Saint-Auret, A., Dulormne, M. (2005): Saison de ponte 2004 en chiffre. Petite Terre. L’éko des Kawann (Petit-Bourg, Guadeloupe, AEVA, Bulletin de liaison du Réseau Tortues marines de Guadeloupe). 9: 7. Schoener, T.W., Spiller, D.A., Losos, J.B. (2001): Predators increase the risk of catastrophic extinction of prey populations. Nature. 412: 183-186. Schwartz, A. (1967): Frogs of the genus Eleutherodactylus in the Lesser Antilles. Stud. Fauna Curaçao Carib. Is. 24: 1-62. Schwartz, A., Henderson, R.W. (1985): A Guide to the Identification of the Amphibians and Reptiles of the West Indies Exclusive of Hispaniola. Wisconsin, Milwaukee Public Museum. Schwartz, A., Henderson, R.W. (1988): West Indian amphibians and reptiles: a check-list. Milwaukee Public Mus. Contrib. Biol. Geol. 74: 1-264. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies. Descriptions, Distributions, and Natural History. Gainesville, Florida, Univ. Florida Press. Schwartz, A., Thomas, R. (1975): A check-list of West Indian amphibians and reptiles. Carnegie Mus. Nat. Hist. Spec. Publ. 1: 1-216. Schwartz, A., Thomas, R., Ober, L.D. (1978): First supplement to a check-list of West Indian amphibians and reptiles. Carnegie Mus. Nat. Hist. Spec. Publ. 5: 1-35.
Amphibians and reptiles of the French West Indies
235
Seaman, G.A. (1952): The mongoose and Caribbean wildlife, p. 188-197. Transactions of the Seventeenth North American Wildlife Conference. Quee, E.M., Ed., Washington, Wildlife Management Institute. Seaman, G.A., Randall, J.E. (1962): The mongoose as a predator in the Virgin Islands. J. Mamm. 43: 544-546. Seidel, M.E. (1988): Revision of the West Indian emydid turtles (Testudines). Amer. Mus. Novit. 2918: 1-41. Tertre, J.B. du (1667-1671): Histoire Générale des Antilles Habitées par les François. Horizons Caraïbes, 1973, after the 1667-1671’s Edition. Towns, D.R., Daugherty, C.H., Cree, A. (2001): Raising the prospects for a forgotten fauna: a review of 10 years of conservation effort for New Zealand reptiles. Biol. Conserv. 99: 3-16. Towns, D.R., Ferreira, S.M. (2001): Conservation of New Zealand lizards (Lacertilia: Scincidae) by translocation of small populations. Biol. Conserv. 98: 211-222. Towns, D.R., Parrish, G.R., Westbrooke, I. (2003): Inferring vulnerability to introduced predators without experimental demonstration: case study of Suter’s skink in New Zealand. Conserv. Biol. 17: 1361-1371. Varnham, K., Ross, T., Daltry, J., Day, M., Cooper, G., Lindsay, K. (1998): Recovery of the Antiguan racer. Aliens. 8: 21. Vigne, J.-D. (1999): The large “true” Mediterranean islands as a model for the Holocene human impact on the European vertebrate fauna? Recent data and new reflections. In: The Holocene History of the European Vertebrate Fauna. Modern Aspects of Research, p. 295-322. Benecke, N., Ed., Berlin, Deutsches Archäologisches Institut Eurasien-Abteilung. Vitousek, P.M., Mooney, H.A., Lubchenco, J., Melillo, J.M. (1997): Human domination of earth’s ecosystems. Science. 277: 494-499. Waite, F.C. (1901): Bufo agua in the Bermudas. Science. 13: 342-343. Westermann, J.H. (1953): Natural preservation in the Caribbean. A review of literature on the destruction and preservation of flora and fauna in the Caribbean area. Foundation Sci. Res. Surinam Netherlands Antilles. 9: 1-106.
Accepted: January 19, 2007 (AH). Reprinted from Applied Herpetology 4: 131-161 (2007).
Addendum Saint-Barthélemy and Saint-Martin administrations Until 2007, the island of Saint-Barthélemy and the French portion of the island of Saint-Martin fell under the jurisdiction of Guadeloupe. Now, they are both considered as French Overseas Collectivities, which means that local authorities are responsible for environmental matters. Ecosystem conservation on small islands The boundaries of the Guadeloupe National Park (IUCN Category II) were modified and now include (among other changes) two islets, Tête à l’Anglais (1.5 ha) and îlet à Kahouanne (20 ha), located approximately 3 and 1.5 km to the north of BasseTerre, respectively. Îlet à Kahouanne is of great herpetological interest because of the presence of a hawksbill turtle nesting site; Anolis marmoratus kahouannensis,
236
O. Lorvelec et al.
an endemic sub-species of these islets; and a form of the gecko Sphaerodactylus fantasticus that is not currently linked to any subspecies (see Thomas, 1964). We confirmed the presence of these two lizards and nests of E. imbricata on îlet à Kahouanne in 2008 and 2009, but did not record any reptile or amphibian on Tête à l’Anglais during April 2008. We recorded evidence of predation by the black rat, Rattus rattus, on hatchlings of E. imbricata on îlet à Kahouanne and îlet à Fajou (Guadeloupe National Park), and on Anolis marmoratus chrysops on Terre de Bas and Terre de Haut (îles de la Petite Terre, Nature Reserve). New introduced species records Several species introduced to the French West Indies continue to expand their ranges. Breuil and Ibéné (2008) and Breuil (2009) report Ramphotyphlops braminus on Basse-Terre and Grande-Terre, Gekko gecko on Grande-Terre, and Scinax cf. xsignatus on Marie-Galante and la Désirade. Breuil (2009) reports Gymnophthalmus underwoodi on Saint-Martin and Iguana iguana on Saint-Barthélemy. Breuil et al. (2009a) report Scinax cf. x-signatus on Martinique. Breuil et al. (2009b) report that Trachemys scripta elegans is well established on Saint-Martin and present but not established on Saint-Barthélemy, and that Pelusios castaneus is present on Martinique. Moreover, these authors mention the discovery of specimens of several species on Martinique, Guadeloupe and Saint-Barthélemy that were escaped pets or perhaps introduced with cargo. A large snake (3.5 m length) was recently captured on Basse-Terre (Gilles Pitrou, pers. comm., March 2010). It was probably the specimen whose slough has been previously identified as Morelia amethistina (Breuil and Ibéné, 2008). National Action Plan for Iguana delicatissima populations The IUCN status of Iguana delicatissima has changed from Vulnerable to Endangered (Breuil et al., 2010). In 2006 the French Ministry of Ecology called for a National Action Plan for French West Indies I. delicatissima populations (Maillard and Breuil, 2007a, 2007b; Breuil et al., 2007; Legouez, 2007; see also Legouez et al., 2009). At the end of 2010 the drafting of the plan, led by the ONCFS with assistance from the DIREN of Martinique and Guadeloupe, is complete and the plan is being validated by the French Ministry of Ecology. The aim of this plan is to reduce threats on I. delicatissima, in particular extinction of small populations induced by hybridization and introgression with I. iguana. Breuil et al. (2007) report that there are no more “pure” I. delicatissima populations on îles des Saintes, Grande-Terre and Basse-Terre (see also Breuil, 2009; Breuil and Ibéné, 2008). All these populations include specimens of I. iguana and hybrids. According to these authors, I. delicatissima has not been recorded on Saint-Martin and îles des Saintes in more than ten years and may have disappeared from these localities. In Martinique, a few I. delicatissima individuals were translocated from îlet Chancel to îlet à Ramiers in 2006 as a safeguard against local extinction (Ourly, 2006; Maillard and Breuil, 2007a, 2007b). The success of this translocation has not yet been established. Oth-
Amphibians and reptiles of the French West Indies
237
erwise, nesting areas of I. delicatissima were improved in 2006 on îlet Chancel (Maillard and Breuil, 2007a, 2007b). Since 2005, ONCFS rangers are allowed to kill introduced I. iguana on Martinique (the species is not protected on this island) to limit their proliferation (Maillard and Breuil, 2007a, 2007b). In 2009, the Association AEVA proposed to expand the goals of the genetic part of the National Action Plan for I. delicatissima to include the entire Iguana genus. The revised plan focuses on hybridisation and introgression with I. iguana, including assessment of genetic isolation and interactions between the two species and their island sub-populations, in relation to conservation.
References Breuil, M. (2009): The terrestrial herpetofauna of Martinique: Past, present, future. Appl. Herpetol. 6: 123-149. Breuil, M., Day, M., Knapp, C. (2010): Iguana delicatissima. In: IUCN (2010). IUCN Red List of Threatened Species. www.iucnredlist.org. Breuil, M., Guiougou, F., Ibéné, B. (2007): Taxon Reports: Lesser Antillean iguana (Iguana delicatissima). Iguana Specialist Group Newsl. 10(2): 15-17. Breuil, M., Guiougou, F., Questel, K., Ibéné, B. (2009a): Modification du peuplement herpétologique dans les Antilles françaises. Disparitions et espèces allochtones. 1ère partie : historique - amphibiens. Le Courrier de la Nature, 249: 30-37. Breuil, M., Guiougou, F., Questel, K., Ibéné, B. (2009b): Modification du peuplement herpétologique dans les Antilles françaises. Disparitions et espèces allochtones. 2ème partie : reptiles. Le Courrier de la nature, 251: 36-43. Breuil, M., Ibéné, B. (2008): Les Hylidés envahissants dans les Antilles françaises et le peuplement batrachologique naturel. Bull. Soc. Herp. Fr. 125: 41-67. Legouez, C. (2007): Les Iguanes des Petites Antilles : Étude de la Population de l’Îlet Chancel (Martinique) et Élaboration du Plan de Restauration. Univ. Paul Sabatier, Toulouse 3, Report, Master d’Écologie, 2e année, Mention Gestion de la Biodiversité, Office National de la Chasse et de la Faune Sauvage. Legouez, C., Maillard, J.-F., Arenales Del Campo, V., Breuil, M. (2009): L’iguane des Petites Antilles : une espèce menacée en Martinique. Premières mesures de conservation. Faune Sauvage (technical bulletin of the Office National de la Chasse et de la Faune Sauvage, Saint-Benoist, Yvelines, France) 284: 60-66. Maillard, J.-F., Breuil, M. (2007a): 2006 ISG Annual Meeting. Taxon Report Session: The conservation of Iguana delicatissima in Martinique and a future action plan for the French West Indies. Iguana Specialist Group Newsl. 10(1): 15. Maillard, J.-F., Breuil, M. (2007b): 2006 ISG Meeting Reports: The conservation of Iguana delicatissima in Martinique and a future action plan for the French West Indies. Iguana 14: 245-246. Ourly, L. (2006): Conservation de l’Iguane des Petites Antilles (Iguana delicatissima) en Martinique : Suivi des Populations sur l’Îlet Chancel et Réintroduction sur l’Îlet Ramiers. Univ. Paul Sabatier, Toulouse 3, Report, Master d’Écologie, 2e année, Mention Gestion de la Biodiversité, Office National de la Chasse et de la Faune Sauvage (ONCFS). Thomas, R. (1964): The races of Sphaerodactylus fantasticus Duméril & Bibron in the Lesser Antilles. Carib. J. Sci. 4: 373-390.
The herpetofauna of Grenada and the Grenada Grenadines: Conservation concerns Robert W. Henderson1 , Craig S. Berg2 1 Section of Vertebrate Zoology, Milwaukee Public Museum, 800 W. Wells St., Milwaukee, Wisconsin 53233-1478, USA 2 Milwaukee County Zoo, 10001 W. Blue Mound Rd., Milwaukee, Wisconsin 53226, USA
Abstract. Grenada and the politically associated Grenadines harbor 19 species of terrestrial herpetofauna, and four species of marine turtles either nest on their beaches or forage in the surrounding waters. The islands have a 2000-year history of human activity, but the past five centuries had the most adverse impact on the environment. Although some members of the herpetofauna have responded well to dramatically altered habitats (Anolis spp.), others have not (e.g., Eleutherodactylus euphronides). Similarly, the introductions of alien predators (most notably Herpestes javanicus) have likely impacted some species (e.g., Ameiva ameiva, Mabuya sp.), but not others. Several species appear to be genuinely rare (e.g., Clelia clelia, Typhlops tasymicris), and sharp declines in numbers have been documented for the arboreal boa Corallus grenadensis. The future of marine turtles in the area is threatened by habitat destruction (development of beachfront habitat for the tourist industry), slaughter of adults, and poaching of nests. Eco-tourism may hold the key for protection of forested habitats and the herpetofauna of this important group of islands. Key words: Conservation; frogs; Grenada; mongoose; reptiles.
Introduction The southernmost of the main islands in the Lesser Antilles, Grenada is situated about 135 km off the northern coast of Trinidad and about 140 km off the northern coast of Venezuela. The island has had a long history of human activity with dramatic effects on the ecology of its herpetofauna. For the vast majority of that time, the impact of humans on the herpetofauna has probably been negligible. The past five centuries, however, have witnessed tremendous growth of the human population coupled with widespread habitat destruction or alteration. Studying the ecology of any member of Grenada’s herpetofauna without taking into account the impact of human activity is virtually impossible today (e.g., Germano et al., 2003).
240
R.W. Henderson, C.S. Berg
Our fieldwork in Grenada commenced in 1988, and since then we have witnessed changes to the island’s landscape and to its herpetofauna.
The Setting Grenada is about 34 km long and 19 km wide, and has an area of 311 km2 (fig. 1). It is a moderately eroded volcanic pile, apparently intermediate in age between young St. Vincent and old St. Lucia. The highest peak, Morne St. Catherine (840 m), rises in the northern half of the island as the center of a massif surrounded by lesser peaks and ridges. South of this peak is a low depression, and beyond it the land rises again into a long, curving ridge (or system of ridges), running first to the south and then to the east and northeast. This chain contains numerous peaks and high points (Morne QuaQua 735 m, Mt. Sinai 701 m, and Southeast Mountain 219 m) and embraces several old crater basins, one of which is occupied by the lake Grand Etang. From these central mountains the land descends gradually to the sea. A true coastal plain is missing, but lowlands occur in the northeast at Levera and in the southwest, where a long, low peninsula runs out to Pointe Salines. A large portion of the island has been cleared for cultivation (table 1) due to the small size of the island and the fact that mountain slopes are not excessively steep except at extreme elevations. Orchard crops form the bulk of the cultivations. Because of the gentle topography along most of the coastline, eroded hills covered with thorny scrub are not a common feature except in the extreme south (rough grazing land with Acacia covers most of the Pointe Salines Peninsula). The Grenadine Islands are part of the Grenada Bank (Grenada plus the Grenadines) and are situated between St. Vincent to the north and Grenada to the south, but of the populated islands, only Carriacou and Petit Martinique are politically associated with Grenada; the remainder are governed by St. Vincent. Approximately 120 islands comprise the group, and the composite surface area of the islands is about 130 km2 . According to Howard (1952), if the current sea level was lowered 38 m, all of the islands between Bequia and Carriacou would be united. Europeans have inhabited the Grenadines continuously since 1650, and deforestation, poor farming practices, and rapidly increasing erosion have caused agriculture to deteriorate over the past 200 years (Kingsbury, 1960). The islands were divided into estates, with the smaller islands representing single plantations. The human population on the Grenadines waxed and waned with the sugar economy and the associated slave population. In 1831, the total human population was 9,500, of which 6,000 were slaves, and sugar production was about 25,000 tons. A more-or-less gradual population decline occurred through the remainder of the 19th century, and, by 1859, sugar production was down to 8,000 tons. By 1910, the human population was reported to be 2,500 persons. The 20th century, however, saw a gradual increase in human population on the islands (Howard, 1952), but sugar was grown only for local consumption. With the abolition of slavery and the sugar crisis, cotton became the important crop in the economy of the Grenadines in the latter half of the 19th
The herpetofauna of Grenada and the Grenada Grenadines
241
Figure 1. Map of Grenada indicating most of the localities mentioned in the text. Contour lines are at 120 m, 365 m, and 610 m.
century, and that continues to some degree today. Both sugar and cotton rely on having open, treeless (or nearly treeless) fields, and the impact of this requirement on forest-dependent species is obvious. However, as on Grenada and St. Vincent, cutting of forests on the Grenadines probably increased potential edge habitat used by species such as Corallus grenadensis (or C. cookii on St. Vincent). Howard (1952) presented detailed descriptions of the vegetation for each of the main Grenadine islands and felt that “The forested areas of the Grenadines are secondary formations. At one time practically every possible acre of land has been under cultivation and those not cultivated have been extensively cut back by the
242
R.W. Henderson, C.S. Berg
Table 1. Land use on Grenada in the year 2000. Vegetation category
Area (ha)1
(%)
Foodcrops and vegetables Foodcrops, vegetables, and fruit trees Mixed cultivation Sugarcane Abandoned cultivation Bananas Bananas with cacao and/or nutmeg Cacao Coconut Nutmeg Nutmeg and cacao Moist deciduous and semi-deciduous rainforest Mixed primary and secondary evergreen rainforest Scrub/cactus Mangrove Inland swamp Pastures Urban/suburban Industrial
441 790 10305 224 337 22 1095 575 498 3382 245 4007 5247 1718 172 17 182 1650 44
1.4 2.5 33.1 0.7 1.1 0.1 3.5 1.8 1.6 10.9 0.8 12.9 16.9 5.5 0.6 0.1 0.6 5.3 0.1
1 Based
on data provided December 2005 by the Land Use Division, Ministry of Agriculture.
pressure of [human] population needs”. More than 50 years later, his reference to the pressures of human population needs is just as applicable. Carriacou is the largest of the Grenadines with an area of 32.0 km2 , its highest elevation is 291 m. Annual rainfall is about 1310 mm (Howard, 1952). Carriacou had a long history of sugar cultivation, followed by cotton. Lime trees were also extensively planted. In the remaining woodland areas, the dominant tree species are Bursera simaruba, Pisonia fragrans, Ficus lentiginosa, and Lonchocarpus benthamianus. Beard (1949) encountered woodland of almost pure mahogany (Swietenia mahogani), about 18 m high; he considered it to be a pioneer community on old agricultural land. According to Kingsbury (1960), Carriacou is the longest continually occupied of the Grenadine Islands and, in 1784, it had about 50 estates varying in size from 6.5-223 ha. In the late 1950s, 64% of the island’s area was divided into 2,270 “peasant holdings” — cultivable land amounting to 1700 ha. Lime production was on the increase, and 162 ha were designated as forest reserves (Kingsbury, 1960). More recently, tourists have discovered Carriacou and accommodations for them are proliferating. Petit Martinique has an area of 0.7 km2 and the highest elevation is c. 243 m. We have not been to this island. However, according to Howard (1952), most of Petit Martinique’s area is devoted to crops and pasture for grazing animals, and what few woodlands remain are badly decimated. The dominant and largest tree species is Gumbo Limbo (Bursera simaruba), with lower numbers of Hippomane mancinella, Tabebuia pallida, and Ficus laevigata.
The herpetofauna of Grenada and the Grenada Grenadines
243
Many small (1-28 ha) islands and islets are situated off the coast of Grenada, and additional smaller islands (1-170 ha) comprise part of the Grenada Grenadines. Many of these smaller islands have been surveyed herpetologically and found to support small subsets (e.g., Eleutherodactylus johnstonei, Anolis spp., Gymnophthalmus underwoodi, Ameiva ameiva) of the Grenadian herpetofauna (Lazell, 1972; Corke, 1992; Williamson et al., 2002). Nevertheless, one of the St. Vincent Grenadines was recently found to harbor an endemic species of Gonatodes currently not known to occur anywhere else (Powell and Henderson, 2005b). Unquestionably, additional species will be added to the herpetofaunal lists of many of the Grenadine Islands.
History The impact of humans on the distribution, abundance, and ecology of reptiles (especially on islands) has been well documented in recent years (e.g., Case and Bolger, 1991; Case et al., 1992; Henderson, 1992; Rodda et al., 1997). According to Wilson (2001), a human migration from South America into the Lesser Antilles began about 2000 B.C. Habitat alteration undoubtedly occurred with their arrival in the region. A human population density estimate for the Lesser Antilles at the time of discovery is 500 per 100 km2 (Newson, 1976), but, by the late 1700s, “most aboriginal peoples had been extirpated through warfare, disease, enslavement, and interbreeding. . . ” (Pregill et al., 1994). Whether involved in subsistence hunting or farming, indigenous peoples had the potential of encountering species of amphibians and reptiles on a daily basis, as did the early colonizers from Great Britain and France. Today, several members of Grenada’s herpetofauna have ecologies that are often closely associated with humans: they live in human-disturbed habitats (even entering human dwellings in search of food and shelter), eat prey species introduced into their ranges by humans, and try to avoid predators introduced into their ranges by humans (Henderson and Powell, 2001). The history of agricultural exploitation on Grenada goes back at least 2000 YBP (years before present; Bullen, 1964, 1965). The first attempt to establish a settlement on Grenada by the British in 1609 was a failure. The first successful attempt was by the French in 1650 (Brizan, 1984). The plantation system ushered in the era of mass clearing of forests for sugarcane, and most cultivable areas were cleared of forests. “In the interior [of Grenada], practically all of the land right to the mountain tops was originally sold to estates, and cultivations were pushed to the highest practicable limit in most cases” (Beard, 1949). From 1700-1750, sugar, indigo, cotton, cacao, and coffee were cultivated, with the latter crop the most important. In 1700, only three sugar plantations existed on Grenada, but, by 1763, they numbered 81, in addition to 208 coffee plantations (Brizan, 1984). In 1772, 334 estates were established on Grenada, and 125 of them devoted 12,955 ha to sugarcane (Brizan, 1984). Grenada’s economy, however, did not rely on a monoculture, and, in the last half of the 18th century, it was the leading producer of coffee, cotton, sugar, and
244
R.W. Henderson, C.S. Berg
cacao in the Windward Islands. Therefore, although considerable land was cleared of trees for sugarcane, other land was planted in trees, albeit for other crops. By 1852, only 2,581 ha were planted in sugarcane and, in 2000, 200+ years after sugar had reached its economic apex, only 224 ha were devoted to sugar (M. Mason, in litt.). In the meantime, cacao, bananas, and nutmeg became economically important with 5319 ha devoted to one of the three crops, or some combination of the three, in 2000 (M. Mason, in litt.).
The Herpetofauna and Associated Conservation Concerns Nineteen species of frogs and reptiles comprise the terrestrial herpetofauna on Grenada and its Grenadines, and four species of sea turtles have been known to either nest on the island or to forage in the waters surrounding the island (table 2; Germano et al., 2003). Of the 19 terrestrial species, two are definite introductions (Eleutherodactylus johnstonei and Anolis sagrei), and another (Geochelone carbonaria) is a possible introduction. Four species are CITES-listed (all Appendix II), and only one (E. euphronides) has been Red-listed by the IUCN. Two species are island endemics (E. euphronides and Typhlops tasymicris), three are bank endemics (Anolis aeneus, A. richardii, and Corallus grenadensis), and two are restricted to the Grenada and St. Vincent banks (Leptodactylus validus, Mastigodryas bruesi). The terrestrial herpetofauna is South American in origin (Hedges, 1996; Henderson, 2004; Lescure, 1987), with all genera and several of the species represented on the Neotropical mainland. All of the marine turtles have very broad geographic ranges and are CITES-listed (table 2). Although virtually the entire herpetofauna of Grenada has, to one degree or another, been impacted by human activity, some species have been more adversely affected than others. Herein we single out only those species for which we feel especial concern for their future on Grenada (with the exception of Geochelone carbonaria which is likely already extirpated). We make critical appraisals of their current status, discuss conservation concerns, and offer suggestions for their management. Perhaps not surprisingly, the species discussed below are a combination of taxa with which we have great familiarity, and others whose paths we have yet to cross or rarely cross. Eleutherodactylus euphronides With a remaining range of only 16 km2 (Hedges, 1999), this frog’s status is among the most vulnerable in the West Indies. Restricted to montane forest situations at elevations >300 m, E. euphronides is threatened by habitat alteration and, possibly, by the invasive congener E. johnstonei. At Grand Etang (St. Andrew Parish, c. 525 m), both species have been encountered in the forest calling within close proximity to each other. In February 2004, E. euphronides was encountered at the rate of 6.75/man-hour (mh), while E. johnstonei was encountered at 40.8/mh.
The herpetofauna of Grenada and the Grenada Grenadines
245
Table 2. The herpetofauna of Grenada. Species names followed by (I) are introduced or presumed to be so. Species
Grenada distribution1
West Indian distribution
G G G G
Widespread Grenada endemic Widespread Grenada Bank, St. Vincent
G, C
Widespread
CITES II
Sea turtles Caretta caretta Chelonia mydas Eretmochelys imbricata Dermochelys coriacea
G, C G, C G, C, PM G, C
Widespread Widespread Widespread Widespread
CITES I, EN CITES I, EN CITES I, CR CITES I, CR
Lizards Hemidactylus mabouia Thecadactylus rapicauda Anolis aeneus Anolis sagrei (I) Anolis richardii Iguana iguana Mabuya sp. Bachia heteropa Gymnophthalmus underwoodi
G, C, PM G G, C, PM G G, C G, C G, C G G
CITES II
G
Widespread Widespread Grenada Bank endemic Widespread Grenada Bank endemic Widespread Uncertain Grenada Bank Guadeloupe, Dominica, St. Vincent, Grenada Bank, Barbados Grenada Bank, St. Vincent
G, C, PM G G, C G
Grenada Bank endemic Grenada Grenada Bank, St. Vincent Grenada endemic
Frogs Bufo marinus Eleutherodactylus euphronides Eleutherodactylus johnstonei (I) Leptodactylus validus Land turtles Geochelone carbonaria (I)
Ameiva ameiva Snakes Corallus grenadensis Clelia clelia Mastigodryas bruesi Typhlops tasymicris 1G
Conservation status
EN
CITES II CITES II
= Grenada, C = Carriacou, PM = Petit Martinique.
We are monitoring the impact of Hurricane Ivan on both species at Grand Etang, as much of the shade-providing canopy has been greatly reduced (fig. 2 in Henderson and Berg, 2005). We have found E. euphronides less common on Mt. William (above Providence, St. Andrew Parish; c. 410 m): 3.0/mh and 2.2/mh in February and November 2004, respectively; and at 5.7/mh and 3.4/mh in February 2005 and February 2006, respectively (E. johnstonei was encountered at 42.7/mh, 26.2/mh, 38.6/mh, and 57.0/mh during the same months). In the forest at the Cable and Wireless Station above Blaize (St. Andrew Parish; c. 690 m; fig. 2), E. johnstonei (3.3/mh and 0.7/mh in February 2005 and February 2006, respectively) was absent from the forest interior and E. euphronides was very common (30.7/mh and
246
R.W. Henderson, C.S. Berg
Figure 2. Eleutherodactylus study site at the Cable & Wireless Station above Blaize at 690 m (February 2005). (Colour original — see www.ahailey.fg.co.uk/appliedherpetology/cariherp.htm).
17.3/mh). Eleutherodactylus euphronides, probably more than any other member of the Grenadian terrestrial herpetofauna, needs to be carefully monitored. Geochelone carbonaria It is possible that this species was introduced to Grenada either by indigenous peoples or by colonial Europeans. We have not encountered it during our many
The herpetofauna of Grenada and the Grenada Grenadines
247
visits to the island, and it is now considered extirpated (Ministry of Finance, 2000), likely eliminated by subsistence hunting. The species is not uncommon on some of the Grenadines. Marine turtles Four species of marine turtles nest and/or forage in the area of Grenada and its Grenadines (table 2). On Grenada, leatherbacks (Dermochelys coriacea) are the most frequent nesters (Levera and Bathway are the highest density beaches, with occasional nesting at Grand Anse and Pink Gin beaches; fig. 1), followed by hawksbills (Eretmochelys imbricata). Loggerheads (Caretta caretta) and green turtles (Chelonia mydas) nest only rarely on Grenada (Bräutigam and Eckert, 2006; Carr et al., 1982). Nesting by hawksbills has been documented on Caille and Ronde islands (between Grenada and Carriacou; Bräutigam and Eckert, 2006), whereas leatherbacks and hawksbills are the predominant species around Carriacou (Fastigi, 2002). The history of marine turtle exploitation on and around Grenada is extensive, and recent surveys of local fishermen indicate that fewer turtles are now caught compared to years past, and that total numbers of turtles in Grenada are lower than in the past (Shirley, 2002). Although 2004’s Hurricane Ivan has disrupted nongovernmental organization (NGO) population monitoring and other conservation efforts, the impact on nesting and foraging has not yet been assessed (Bräutigam and Eckert, 2006). Based on their field research in Grenada, Eckert and Eckert (1990) estimated that 25-50% of nesting leatherbacks were killed each year and that at least 50% of the eggs laid were collected by humans. Since February 2001, however, the leatherback is completely protected. Intensive beach monitoring by an NGO at Levera began in 1999. In 2000, fewer than 100 nests were recorded, more than 500 in 2003, and between 300 and 400 in 2005 (Bräutigam and Eckert, 2006). Nevertheless, as elsewhere in the range of marine turtles, poaching and habitat destruction remain constant threats. Iguana iguana Although this species has one of the widest geographic distributions of any reptile in the American tropics, populations have been severely impacted by over-hunting. Iguanas are one of the primary game animals on Grenada, along with opossum (Didelphis marsupialis), armadillo (Dasypus novemcinctus), mona monkey (Cercopithecus mona), and pigeon (Columba squamosa): Ministry of Finance (2000). Informal surveys by the Forestry Department indicate that numbers of I. iguana are dropping, although no reason was provided. Our encounters with iguanas have been few and far between. We occasionally observe sleeping individuals during searches for treeboas (at Levera, Pearls, Beausejour, and Westerhall), and we have seen them captured for food at Pearls. Because this species is exploited as a source of food for human consumption, surveys designed to monitor numbers captured and the status of local populations should be conducted.
248
R.W. Henderson, C.S. Berg
Mabuya sp. Because the taxonomy of Lesser Antillean Mabuya is in a state of flux, we have opted to not assign Grenadian populations to species. We have had but a single encounter with this lizard on Grenada, and that occurred in 1989 on the Point Salines Peninsula. Over a period of 25 days in 1961, Albert Schwartz and associates collected full-time on Grenada and did not encounter Mabuya; they did, however, collect and observe it in the mongoose-free Grenadines (Albert Schwartz, field notes). Although this species will ascend into bushes (M. de Silva, in litt.; pers. obs. on other Lesser Antillean islands), it is largely ground-dwelling and diurnal and, therefore, like species of Ameiva throughout much of the West Indies (Powell and Henderson, 2005a), is vulnerable to mongoose (Herpestes javanicus) predation. It is unlikely that the species has been extirpated from Grenada. However, we believe that the mongoose is likely responsible for its rarity, and that eventual extirpation by this introduced predator is certainly a possibility. Ameiva ameiva Several populations of Lesser Antillean Ameiva have been eliminated from islands in the Lesser Antilles, and Powell and Henderson (2005a) attributed these extirpations to the mongoose (although domestic and feral cats and dogs also prey on them). Ameiva ameiva has a very wide distribution on the Neotropical mainland, and it occurs on several continental and oceanic islands. On Grenada, its distribution now appears to be highly fragmented and restricted to open areas with considerable human activity and minimal mongoose activity (e.g., the grounds of hotels). A study conducted on the grounds of the Rex Grenadian Hotel on the Point Salines Peninsula in June 2002 indicated an adult population size of 23.0±0.2, and a density estimate of 460 adults/ha (Simmons et al., 2005). About two months after Hurricane Ivan hit Grenada (November 2004), Henderson and Berg (2005) found Ameiva of all age and size classes to be very common on the grounds of the Rex Grenadian. At the time, the hotel was closed for repairs and human activity was considerably less than when the hotel was open for guests. This species likely will persist in small, scattered enclaves on Grenada in open situations where mongoose activity is either absent or minimal. Corallus grenadensis The distribution, ecology, and potential conservation concerns regarding this snake species have been described and discussed at length in Henderson (2002). During the past 500 years, original habitat was altered or destroyed, native rodents (rice rats, probably Oryzomys; Lippold, 1991; Pregill et al., 1994) that were probable prey species became extinct, and alien predators were introduced. Treeboas on the Grenada Bank have had to adapt to new habitat (orchard trees), introduced prey species (Rattus rattus and Mus musculus), and new predators (Her-
The herpetofauna of Grenada and the Grenada Grenadines
249
pestes javanicus, Didelphis opossums, humans). Considering the impact of humans on treeboa ecology in Grenada and despite the creation of more edge habitat, that Corallus grenadensis is widespread and locally common is remarkable. We believe that this can be attributed to a number of factors: 1) Arboreal, cryptically colored, compactly coiled on a branch, and sheltered by leafy vegetation, these snakes are inconspicuous during daylight hours. Being arboreal, they are able to avoid non-human predators (e.g., dogs, largely ground-dwelling mongooses). 2) Although they may actively forage at night, without the aid of a light to detect reflection from a boa’s eyes, they remain inconspicuous to humans in their leafy arboreal surroundings. 3) They prey on common vertebrates (some commensal) that occur in high densities, so wide-ranging foraging is not mandatory for locating prey. We have documented decreases in encounter rates of C. grenadensis over the past four years at Pearls, in mangrove (Rhizophora) and Acacia habitats bordering Mt. Hartman Bay (St. George Parish), and at Beausejour and Westerhall in areas of native vegetation and mixed agriculture (Henderson, 2002). Although housing developments at Beausejour and Westerhall may be partially responsible for population declines at those sites, we are at a loss to explain the depressed numbers at Pearls and Mt. Hartman. Mongooses are not uncommon at Mt. Hartman, and they have been observed foraging in trees. Whether they are a significant predator on arboreal boas is unknown, but surely they do occasionally eat them. Opossums (Didelphis marsupialis) are common everywhere on Grenada, are scansorial, and will prey on C. grenadensis (Henderson, 2002). The Pearls site deserves additional attention. It is a site we have visited off and on since 1988. Between 1988 and 2000, treeboa encounter rates ranging from 2.9 ± 0.3 to 8.4 ± 1.8/mh were recorded (Henderson, 2002). In 2002, work was intensified at the site and we began marking snakes with microchips. Between February 2002 and February 2005, the capture rate dropped from 1.5/mh to 0.7/mh, and the encounter rate dropped from 3.3/mh to 0.7/mh (i.e., often more snakes are encountered than we are able to capture). In June 2004, a two-night survey of the study site produced no snakes. Thus, encountering treeboas is now difficult where, five years earlier, two observers could encounter more than 20 C. grenadensis in an hour. In 2005, no large (>950 mm SVL) treeboas were encountered, only young-of-the-year and a single yearling. Likewise, the proportion of treeboas captured in the 700-950 mm SVL size class decreased markedly: in 2002, they represented 32.6% of our sample (n = 46), 20.4% in 2003 (n = 54), and 10.7% in 2004 (n = 28). Pearls was no more developed in 2005 than it was in 1988. If anything, the study site was less developed, human activity was diminished, and wide, previously cleared trails became overgrown through lack of use. As these snakes are conspicuous edge inhabitants, the loss of edge habitat along our transect trails may have contributed to decreased treeboa activity. This explanation, however, is inadequate to explain the dramatic decline in snake numbers, as is the damage wrought by Hurricane Ivan in September 2004 (since we had witnessed declines prior to the hurricane).
250
R.W. Henderson, C.S. Berg
Similarly, at Mt. Hartman Bay, encounter rate dropped from 2.4 ± 0.1/mh in 1994 to 0.2 ± 0.2/mh in 1998 (Henderson, 2002). Again, no evidence of habitat destruction was noted at this site, nor could we document an increase in human activity. Snakes were scale-clipped at this site and, although snakes that are captured once may move out of an area, we are not convinced that this is a plausible explanation for depressed numbers at either Mt. Hartman or Pearls. As adaptable as C. grenadensis appears to be in terms of habitat, habitat loss is undoubtedly the greatest threat it faces. As areas become devoid of trees, or as patches of trees become smaller and smaller, portions of Grenada and the Grenadines will no longer be able to sustain treeboa populations. As a consequence of continued development, C. grenadensis will face at least local extirpations (Henderson, 2002). Clelia clelia Possibly three species of Clelia inhabited the Lesser Antilles at one time: Clelia sp. on Guadeloupe, C. errabunda on St. Lucia, and C. clelia on Grenada. The Guadeloupean and St. Lucian species are extinct; only C. clelia survives and, to the best of our knowledge, it has not been collected or observed by a herpetologist on Grenada since 1964 (Greer, 1965). This large (>2.0 m SVL), diurnal, grounddwelling trophic generalist has a wide geographic distribution on the Neotropical mainland. As noted previously (Henderson, 2004), it seems out of place in the Lesser Antilles where colubrids rarely exceed 1.0 m SVL. Despite its size, it may have been as vulnerable to predation by Herpestes as the smaller Alsophis and Liophis on other islands in the Lesser Antilles — or, as suggested by Henderson (2004), Clelia populations in the West Indies may have, for a variety of reasons, been on a downward trajectory for many hundreds of years. Only three specimens of Clelia are known from Grenada, and only two of those have reliable locality data. Both were collected on the leeward side of the island, one at Beausejour (St. George Parish) and the other in the Duquesne Valley (St. Mark Parish). Both were collected in the morning, and James Lazell (in Greer, 1965) believed the species to be “fairly common” in the wet lowlands. Although we have never encountered this snake despite many months of field work, which has included hundreds of hours driving the roads at all hours of the day and night (including the road where one Clelia was collected), we are not prepared to consider it extirpated. While taking a Coke® break at a small store south of Grenville near the windward coast in November 2004, we entered a conversation with a group of men relaxing outside the store. We explained what we were doing (looking for snakes after the hurricane) and they mentioned cribos (the local name for Clelia). As with virtually everyone we have ever queried about this species, most were familiar with it but had not seen it since they had been children. One man, however, said he had seen one just recently; based on his excellent description, it could not have been anything but Clelia.
The herpetofauna of Grenada and the Grenada Grenadines
251
Mastigodryas bruesi Although fairly widespread on Grenada (Schwartz and Henderson, 1991), we have had only two encounters (the St. Paul’s area in St. David Parish and dead on the road below Birch Grove in St. Andrew Parish) with this species; a third was observed by one of our students at Westerhall (St. David Parish), a fourth in December 2005 (A. Sánchez, in litt.) and a fifth in February 2006 (N. Fleming, pers. comm.), both in the environs of St. George’s. Another was observed on Carriacou. During 25 days of intensive collecting on Grenada in 1961, Schwartz and associates collected three M. bruesi (Albert Schwartz, field notes). This is a diurnal frog and lizard predator that is encountered at ground level and in trees and bushes. Certainly mongooses prey on it, and this may account for its seeming rarity on Grenada. We suspect this species is still fairly widespread on the island, but at low population densities. All indications are that it is still fairly common on several of the Grenadines (RWH, pers. obs.; Albert Schwartz, field notes; M. de Silva, in litt.). Typhlops tasymicris This small secretive snake was first collected near Vincennes (St. David Parish) in 1968 and described in 1974, and only one additional specimen (also collected in 1968 at Pearls, St. Andrew Parish) has been added to scientific collections since then (Wallach, 2000). We have worked extensively near the site where the second specimen was collected, and have described the snake to people involved in agriculture at this site; so far, no one has expressed any familiarity with the species. Whether this species is genuinely rare or if its secretive habits have precluded frequent encounters is unknown. It is not familiar to Grenadians we have queried at several sites on the island.
Discussion Members of Grenada’s terrestrial herpetofauna have demonstrated ecological plasticity in habitat, climatic regimes, and diet. Persistence in human-disturbed habitats is testimony to the adaptability of most reptilian species on the island. Nevertheless, two factors are having a negative impact on frog and reptilian populations: 1) habitat loss or alteration, and 2) introduced species. Neither factor is unique to Grenada, and both are widespread concerns throughout the West Indies and elsewhere in the world. The greatest threats to Grenada’s marine turtles are illegal slaughter, poaching of nest contents, and habitat destruction for development associated with the tourist industry (e.g., hotels, golf courses). Again, none of these threats is unique to Grenada. Although Grenada’s human population growth between the years 2000 and 2010 is estimated to be static (MacDonald, 1992), and land area devoted to forested habitats actually increased between 1981 and 1990 (World Resources Institute, 1994), habitat loss or modification still affects every native species of frog and
252
R.W. Henderson, C.S. Berg
reptile on Grenada. Over 60% of the island’s area is devoted to agriculture or is developed residentially or for industry (table 1), and the island is a mosaic of habitat fragments. Flying over the island on a clear February morning in 2005, we were able to observe the patchwork of human enclaves interspersed with small stands of forest. Houses lined the roads from one end of the island to the other and, seeing this, we were amazed at recalling the numbers of Corallus encountered from time to time in habitats that were intermixed with residential areas (e.g., Beausejour, Pearls). Now, however, we have documented unsettling population declines in C. grenadensis. To identify these declines as the direct result of habitat loss/alteration or part of a natural cycle of waxing and waning numbers is premature. What is a certainty, however, is that some areas that once supported treeboa populations no longer do so, or that treeboa numbers in other areas have been dramatically reduced. The impact of alien species on West Indian herpetofaunas has been ongoing since the arrival of Europeans. Although the introduced rodents Mus musculus and Rattus rattus are now an important source of food for treeboas (and, possibly, C. clelia) on Grenada (and elsewhere), identifying a positive facet of other introductions is difficult. The frog Eleutherodactylus johnstonei has become entrenched on many West Indian islands outside of its native range, and it now occurs on the Neotropical mainland as well. Eleutherodactylus johnstonei may eventually be found everywhere on Grenada and it is likely that nothing can be done to halt its invasion of new habitats. It is uncertain at this time if it is actually displacing the Grenadian endemic E. euphronides. They co-occur at Grand Etang (a National Park and a favorite recreational destination for Grenadians and tourists) where E. johnstonei has invaded the forest, and our encounter rates at this site favor E. johnstonei. However, as pre-johnstonei rates are lacking from the forest interior, we do not know if E. euphronides numbers have been reduced. If they have not, and, if habitat alteration is halted at forested elevations over 300 m, E. euphronides should survive. We are unsure of the long-term impact of 2004’s Hurricane Ivan. In the short-term, E. euphronides seems to be doing well (Henderson and Berg, 2005) and, over the past several thousand years, E. euphronides has undoubtedly withstood many hurricanes, certainly many as powerful and destructive as Ivan. The introduction of Herpestes javanicus into the West Indies is correlated with the disappearance of several species of ground-dwelling lizards, snakes, and birds (Powell and Henderson, 2005a). As with E. johnstonei, eradication of this species on Grenada is unlikely. Ameiva, Mabuya, and, possibly, Clelia, are the reptiles most vulnerable to this efficient predator. The Grenadian herpetofauna has shared the island with Herpestes for over 120 years (Hoagland et al., 1989), and, with the probable exceptions of ground-dwelling snakes, Ameiva ameiva, and Mabuya sp., most members have survived its depredations. All steps must be taken to prevent the accidental introduction of mongooses onto the Grenadines.
The herpetofauna of Grenada and the Grenada Grenadines
253
The Division of Forestry in the Ministry of Agriculture on Grenada is sincere in its efforts to protect wildlife, including amphibians and reptiles. Over many years and many visits to their offices, we have witnessed increasing concerns for the herpetofauna and a growing emphasis on educating the public regarding the island’s natural history. More than half of Grenada’s native herpetofauna has a CITES and/or IUCN listing (table 2), and every effort is made to abide by the CITES designations by the Division of Forestry and the Ministry of Agriculture. Based on personal experience, we are aware of the many layers of paperwork that must accompany any export of herpetofauna, including assurances to Forestry by U.S. Fish and Wildlife personnel that the desired animals are not CITES listed. Grenada is promoting tourism and it is experiencing a growing interest in ecotourism. The Grand Etang Reserve is a favored stop for bus tours on Grenada, and it is often the only site visited by tourists traveling by cruise ship who have only a short time to sightsee on their island-hopping itinerary. Lizards are often the most conspicuous vertebrates on West Indian islands, and may be the only wildlife tourists observe on the manicured grounds of luxury hotels on or near Grand Anse Beach and the Pointe Salines Peninsula. In short, active protection of the island’s native herpetofauna by way of responsible stewardship of its natural resources can only enhance the nature experience for Grenadians and eco-tourists alike.
Acknowledgements. Over the years, the Windway Foundation, the Milwaukee Public Museum, the National Science Foundation (Grant No. DBI-9732257 to R. Powell), the late Albert Schwartz, the late Jack A. Puelicher, Milwaukee County Zoo, the Milwaukee Zoological Society, the J. C. Penney Golden Rule Foundation, and the Robert Bourgeois family have generously funded our fieldwork. Alan Joseph and other Forestry Division personnel on Grenada have been supportive of our fieldwork for many years, and for that we are most appreciative. The Division of Herpetology at the University of Kansas graciously provided copies of the field notes of the late Albert Schwartz. Michael Mason of the Ministry of Agriculture provided data on land use on Grenada. Recent treeboa fieldwork has been facilitated by the enthusiastic participation of Ky Henderson, Rich Sajdak, and Aaron Savit. John Parmerlee provided the map in fig. 1, Karen Eckert provided helpful information regarding the status of sea turtles in Grenada, and James Lazell, Bob Powell, and Peter Tolson reviewed earlier versions of this paper and offered constructive criticisms. We remain grateful to Nigel Fleming, owner of Lazy Lagoon Cottages, for charging us the “herpetologists’ rate” for our living quarters. References Bräutigam, A., Eckert, K.L. (2006): CITES review of exploitation, trade and management of the marine turtles of the Lesser Antilles, Central America, Colombia and Venezuela. CITES, in press. Beard, J.S. (1949): Natural vegetation of the Windward and Leeward islands. Oxford Forestry Mem. 21.
254
R.W. Henderson, C.S. Berg
Brizan, G. (1984): Grenada: Island of Conflict. London, Zed Books Ltd. Bullen, R.P. (1964): The archaeology of Grenada, West Indies. Contrib. Florida State Mus., Soc. Sci. 11: 1-67. Bullen, R.P. (1965): Archaeological chronology of Grenada. American Antiquity 31: 237-241. Carr, A., Meylan, A., Mortimer, J., Bjorndal, K., Carr, T. (1982): Surveys of sea turtle populations and habitats in the Western Atlantic. NOAA Technical Memorandum NMFS-SEFC-91. U.S. Dept. of Commerce. Case, T.J., Bolger, D.T. (1991): The role of introduced species in shaping the distribution and abundance of island reptiles. Evol. Ecol. 5: 272-290. Case, T.J., Bolger, D.T., Richman, A.D. (1992): Reptilian extinctions: The last ten thousand years. In: Conservation Biology: The Theory and Practice of Nature Preservation and Management, p. 91125. Fiedler, P.L., Jain, S.K., Eds. New York, Chapman and Hall. Corke, D. (1992): The status and conservation needs of the terrestrial herpetofauna of the Windward Islands (West Indies). Biol. Conserv. 62: 47-58. Eckert, K.L., Eckert, S.A. (1990): Leatherback sea turtles in Grenada, West Indies: a survey of nesting beaches and socio-economic status. Report to Foundation for Field Research and Fisheries Department, Ministry of Agriculture, Lands, Forestry and Fisheries. July 1990. Fastigi, M. (2002): WIDECAST sea turtle monitoring and tagging programme. Project report: 22 May-21 October 2002. Carriacou, Grenada, KIDO Foundation. Germano, J.M., Sander, J.M., Henderson, R.W., Powell, R. (2003): Herpetofaunal communities on Grenada: A comparison of altered sites, with an annotated checklist of Grenadian amphibians and reptiles. Carib. J. Sci. 39: 68-76. Greer, A.E. (1965): A new subspecies of Clelia clelia (Serpentes: Colubridae) from the island of Grenada. Breviora 223: 1-6. Hedges, S.B. (1996): The origin of West Indian amphibians and reptiles. In: Contributions to West Indian Herpetology: A Tribute to Albert Schwartz, p. 95-128. Powell, R., Henderson, R.W., Eds. Ithaca, New York, Soc. Stud. Amphib. Rept., Contrib. Herpetol., Vol. 12. Hedges, S.B. (1999): Distribution patterns of amphibians in the West Indies. In: Patterns of Distribution of Amphibians, p. 211-254. Duellman, W.E., Ed. Baltimore, Maryland, The Johns Hopkins Univ. Press. Henderson, R.W. (1992): Consequences of predator introductions and habitat destruction on amphibians and reptiles in the post-Columbus West Indies. Carib. J. Sci. 28: 1-10. Henderson, R.W. (2002): Neotropical Treeboas: Natural History of the Corallus hortulanus Complex. Malabar, Florida, Krieger Publ. Co. Henderson, R.W. (2004): Lesser Antillean snake faunas: distribution, ecology, and conservation concerns. Oryx 38: 311-320. Henderson, R.W., Berg, C.S. (2005): A post-Hurricane Ivan assessment of frog and reptile populations on Grenada, West Indies. Herpetol. Bull. 91: 4-9. Henderson, R.W., Powell, R. (2001): Responses by the West Indian herpetofauna to human-influenced resources. Carib. J. Sci. 37: 41-54. Hoagland, D.B., Horst, G.R., Kilpatrick, C.W. (1989): Biogeography and population biology of the mongoose in the West Indies. In: Biogeography of the West Indies: Past, Present, and Future, p. 611-633. Woods, C.A., Ed. Gainesville, Sandhill Crane Press. Howard, R.A. (1952): The vegetation of the Grenadines, Windward Islands, British West Indies. Contrib. Gray Herbarium, Harvard Univ. 174: 1-129. Kingsbury, R.C. (1960): Commercial geography of the Grenadines. Indiana Univ. Dept. Geogr., Tech. Report. 1: iv + 39 p. Lazell, J.D., Jr. (1972): The anoles (Sauria, Iguanidae) of the Lesser Antilles. Bull. Mus. Comp. Zool. 143 (1): 1-115. Lescure, J. (1987): Le peuplement en reptiles et amphibiens des Petites Antilles. Bull. Soc. Zool. France 112: 327-342.
The herpetofauna of Grenada and the Grenada Grenadines
255
Lippold, L.K. (1991): Animal resource utilization by saladoid peoples at Pearls, Grenada, West Indies. In: Proceedings of the 13th International Congress for Caribbean Archeology, p. 264-268. Ayubi, E.N., Haviser, J.B., Eds. Netherlands Antilles, Rept. Archeol.-Anthropol. Inst., No. 9. MacDonald, J.S. (1992): Contemporary size and distribution of population. In: The Cambridge Encyclopedia of Latin America and the Caribbean, 2nd edn, p. 151-157. Collier, S., Skidmore, T.E., Blakemore, H., Eds. New York, Cambridge Univ. Press. Ministry of Finance, Government of Grenada. (2000): Grenada biological diversity strategy and action plan. United Nations Development Programme, Project No. GRN/98/G31/A/99. Newson, L.A. (1976): Aboriginal and Spanish Colonial Trinidad. London, Academic Press. Powell, R., Henderson, R.W. (2005a): Conservation status of Lesser Antillean reptiles. Iguana 12: 3-17. Powell, R., Henderson, R.W. (2005b): A new species of Gonatodes (Squamata: Gekkonidae) from the West Indies. Carib. J. Sci. 41: 709-715. Pregill G.K., Steadman, D.W., Watters, D.R. (1994): Late Quaternary vertebrate faunas of the Lesser Antilles: historical components of Caribbean biogeography. Bull. Carnegie Mus. Nat. Hist. 30: iii, 1-51. Rodda, G.H., Fritts, T.H., Chiszar, D. (1997): The disappearance of Guam’s wildlife. BioScience 47: 565-574. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. Gainesville, Univ. Florida Press. Shirley, C. (ed.) (2002): Turtle Lightening: Sea Turtles and the People of Grenada. Grenada, Ocean Spirits, Inc. Simmons, P.M., Greene, B.T., Williamson, K.E., Powell, R., Parmerlee, J.S., Jr. (2005): Ecological interactions within a lizard community on Grenada. Herpetologica 61: 124-134. Wallach, V. (2000): Typhlops tasymicris. Maximum length and second known specimen. Herpetol. Rev. 31: 180. Williamson, K.E., Poche, A.J., Jr., Greene, B.T., Harris, B.R., Germano, J.M., Simmons, P.M., Yorks, D.T., Powell, R., Parmerlee, J.S., Jr., Henderson, R.W. (2002 [2003]): Herpetofauna of Hog Island, Grenada. Herpetol. Bull. 82: 26-29. Wilson, S.M. (2001): The prehistory and early history of the Caribbean. In: Biogeography of the West Indies: Patterns and Perspectives, p. 519-527. Woods, C.A., Sergile, F.E., Eds. Boca Raton, Florida, CRC Press. World Resources Institute. (1994): World resources 1994-95. New York, Oxford University Press.
Accepted: March 20, 2006 (BSW). Reprinted from Applied Herpetology 3: 197-213 (2006).
Addendum Eleutherodactylus johnstonei Two individuals of this invasive species from Grand Etang tested positive for the fungus Batrachochytrium dendrobatidis (Bd). Leptodactylus validus It is now believed that Lesser Antillean populations of this species were likely transported to the Grenada and St. Vincent banks via human agency from Trinidad
256
R.W. Henderson, C.S. Berg
and Tobago or northern South America (Yanek et al., 2006; Camargo et al., 2009). One specimen from Grand Anse tested positive for Bd (Berg et al., unpubl. data). Eleutherodactylus euphronides Now Pristimantis euphronides (family Strabomantidae) (Hedges et al., 2008). No member of the Grenada herpetofauna has been more adversely impacted in the past five years. We documented changes in the number of P. euphronides at Grand Etang (525 m) and the Cable and Wireless Station above Blaize (690 m). Timed searches were made along the same transects during one or more months each year between 2004 and 2010 (fig. A1). To analyze trends in the P. euphronides encounter rate data, a backwards-stepping general linear model was performed separately for each site in SYSTAT 10.0. Probability was used to determine a predictor variable’s membership in the final model, with an alpha-to-enter of 0.0001, and an alpha-to-remove of 0.051. The encounter rate of P. euphronides was the dependent variable; the encounter rate of E. johnstonei, date, and the interaction of E. johnstonei encounter rate and date were used as independent variables. At each site, we found a significant relationship between at least one of the predictor variables and P. euphronides encounter rate. At Grand Etang, while a positive relationship was found between the encounter rates of P. euphronides and E. johnstonei (t 2,6 = 7.599; multiple R 2 = 0.911; p 0.001), there was also a significant crossed effect of date and the encounter rate of E. johnstonei (t 2,6 = −4.153; multiple R 2 = 0.911; p = 0.006). At Cable and Wireless, the encounter rate of P. euphronides has decreased over the course of our study (t 1,8 = −5.108; multiple R 2 = 0.813; p = 0.002). Because we found a significant crossed effect of date and the encounter rate of E. johnstonei at Grand Etang, it is likely that the persistence of the invasive species at this site over time is contributing to the decline in the numbers of P. euphronides. Besides possible competition from the invasive E. johnstonei, preliminary sampling at these localities indicated the presence of Bd (C.S. Berg et al., unpubl. data). It is likely that declines in P. euphronides numbers can be attributed to a suite of factors: habitat destruction (some via Hurricane Ivan in September 2004), Bd, and competition with E. johnstonei. Furthermore, Grenada has experienced a string of unusually dry years and P. euphronides appears be less tolerant of dry forest floor conditions than E. johnstonei. Monitoring of P. euphronides at Mt. William (410 m) was terminated after our March 2007 observations; by the time of our March 2008 visit the site had been clear-cut for agriculture. Corallus grenadensis We have continued to monitor the Pearls site (St. Andrew Parish). Sixteen visits to the site and more than 50 man-hours of searching during 2004-2010 failed to produce a single adult boa. Henderson et al. (2009) suggested that the most plausible explanation for the boa decline was the reduction in human activity at the site. That led to overgrown trails (= loss of edge habitat) and, likely, a decline in rodent prey. During February 2009, brief searches for C. grenadensis were made at
The herpetofauna of Grenada and the Grenada Grenadines
257
Figure A1. Encounter rates for Pristimantis euphronides and Eleutherodactylus johnstonei at two sites on Grenada. Both sites were dramatically altered during Hurricane Ivan (September 2004), but we had not yet initiated surveys at Cable and Wireless prior to the hurricane. Both sites (but especially Grand Etang) lost shade-producing canopy as a result of Ivan.
several localities that had not been visited in many years and also at new localities; elevations ranged from 10-300 m. Boas were found at all sites and usually included young-of-the-year to large adults (Henderson et al., 2009). A visit to Pearls in February 2010 found much of the remaining forest in the study site gone, replaced by cultivated fields; no boas were encountered. Powell et al. (2007) determined that West Indian Corallus could tolerate a cumulative variety of human-mediated alterations to their habitats, and even function in close proximity to humans, but that certain alterations could not be tolerated. Among those not tolerated is elimination of arboreal habitat. Recently, reports have surfaced that C. grenadensis is being harvested for food and/or use in traditional medicines. If accurate, population declines may be due to unsustainable harvesting methods.
258
R.W. Henderson, C.S. Berg
Clelia clelia In 2009, 500 posters depicting photographs of adult and juvenile C. clelia and requesting information regarding potential Clelia sightings were presented to the Grenada Forestry Department for distribution throughout the island. As of this writing (15 April 2010), no information pertaining to Clelia has been forthcoming. Tantilla melanocephala This small colubrid was recently introduced to Grenada and has been documented from at least three localities on the island (Berg et al., 2009; C. Morrall, in litt.). Although this species is unlikely to have a competitive impact on indigenous snake species, it may compete for invertebrate prey with several lizard species on the Grenada Bank (e.g., Bachia heteropa, Ameiva ameiva, Anolis spp.).
Acknowledgements. We appreciate the enthusiastic participation of Billie Harrison (Racine Zoo) and Shawn Miller (Milwaukee County Zoo) during 2007-2010 boa and frog surveys. M.J. Pauers was instrumental with the Pristimantis data analysis and preparation of the figure. We thank A. Forteau, A. Jeremiah, C. Morrall, and E.M. Rush for various favors and courtesies.
References Berg, C.S., Jeremiah, A., Harrison, B., Henderson, R.W. (2009): New island records for Tantilla melanocephala (Squamata: Colubridae) on the Grenada Bank. Appl. Herpetol. 6: 403-404. Camargo, A., Heyer, W.R., de Sá, R.O. (2009): Phylogeography of the frog Leptodactylus validus (Amphibia: Anura): Patterns and timing of colonization events in the Lesser Antilles. Mol. Phylogen. Evol. 53: 571-579. Hedges, S.B., Duellman, W.E., Heinicke, M.P. (2008): New World direct-developing frogs (Anura: Terrarana): Molecular phylogeny, classification, biogeography, and conservation. Zootaxa 1737: 1-182. Henderson, R.W., Berg, C.S., Harrison, B., Yorks, D.T. (2009): Notes on an unexpected decline of a population of Corallus grenadensis (Squamata: Boidae) in Grenada, West Indies. S. Amer. J. Herpetol. 4: 186-192. Powell, S.D., Treglia, M.L., Henderson, R.W., Powell, R. (2007): Treeboas in the West Indies: Responses of Corallus cookii and C. grenadensis to disturbed habitats. In: Biology of the Boas and Pythons, p. 375-386. Henderson, R.W., Powell, R., Eds, Eagle Mountain, Utah, Eagle Mountain Publ. Yanek (2006): Genetic resolution of the enigmatic Lesser Antillean distribution of the frog Leptodactylus validus (Anura, Leptodactylidae). S. Amer. J. Herpetol. 1: 192-201.
An annotated checklist of the amphibians and terrestrial reptiles of the Grenadines with notes on their local natural history and conservation Jacques Daudin1 , Mark de Silva2,3 1 Union
Island Association for Ecological Protection, Clifton, Union Island Environmental Development Organization, Mayreau 3 Corresponding author; e-mail:
[email protected] 2 Mayreau
Abstract. The Grenadine islands, located on the Grenada Bank, are known to have seventeen species of amphibians and terrestrial reptiles. Of three species of amphibians, two are recent introductions and the third (Leptodactylus validus) may be a native remnant that survived the deforestation that initially transformed these islands in the 18th and 19th centuries. The indigenous reptiles, many of which remain relatively common, may not be able to survive the extensive and unregulated tourism development now taking place on these small islands. Of special interest is the recent discovery of a new species of gecko, Gonatodes daudini, on Union Island. Key words: Amphibians; conservation; Grenadines; reptiles; tourism.
Introduction The Grenadine archipelago (see fig. 1) consists of a string of some fifty small islands and cays and is located between St. Vincent and Grenada near the southern end of the Lesser Antillean chain of islands (N13◦ 00 W61◦ 15 and N12◦ 15 W61◦ 40 ). These islands are emergent portions of an elongated shallow-water platformed ridge that encompasses approximately 3,000 km2 of the Grenada Bank. Most of the islands are geologically older than either St. Vincent or Grenada, and, with their low-lying dry forest habitat, constitute a somewhat unique biological ecosystem. With marked annual wet and dry seasons, rainfall rarely exceeds the annual average of 1000 mm. The almost constant Northeast Trade Winds temper the mean 28◦ C daytime temperatures and average humidity of 75%. Nine islands are inhabited, the two smallest with exclusive hotel resorts, and are in order of size: Carriacou (31.6 km2 ), Bequia (15.6 km2 ), Union (8.4 km2 ), Canouan (7.29 km2 ), Mustique (5.49 km2 ), Petit Martinique (2.02 km2 ), Mayreau (1.76 km2 ),
260
Figure 1. Map of the Grenadines showing the larger islands and cays.
J. Daudin and M. de Silva
Amphibians and terrestrial reptiles of the Grenadines
261
Prune (=Palm) (0.4 km2 ), and Petit St. Vincent (0.38 km2 ). Some of the other significant uninhabited islands include Isle de Ronde (2.54 km2 ), Isle de Quatre (1.49 km2 ), and Balliceaux (1.31 km2 )(Westercamp, 1985). Tourism and fishing are the principal occupations of a total population of about 20,000. Politically, the majority of these islands belong to St. Vincent, with Carriacou, Petit Martinique, and Isle de Ronde falling under the jurisdiction of Grenada. Three species of amphibians and fourteen species of terrestrial reptiles are found in the Grenadines today (Censky and Kaiser, 1999). Two of the three species of amphibians are recent introductions, whereas the third (Leptodactylus validus) appears be native and is found only on the island of Bequia. All of the reptiles are native species, with the possible exceptions of Hemidactylus mabouia, and Geochelone carbonaria. The remaining small populations of Iguana iguana are still hunted for food, and the once abundant Ameiva ameiva is fast disappearing, probably attributable to the rapidly growing domestic/feral cat populations. The greatest threat to these Grenadine islands, however, is the unregulated tourism industry and its overwhelming demand for the remaining land.
Annotated Checklist Much of the herpetofauna in the Grenadines remains undocumented. For instance, only recently was Bachia heteropa recorded from Mustique and Union Island (Henderson and Powell, 2006a) and Battowia, Sphaerodactylus kirbyi found on Mustique (Powell and Henderson, 2006), Mayreau, and Petit Nevis, and Gonatodes daudini discovered on Union Island (Powell and Henderson, 2005). Surveys by resident and international researchers are likely to generate new island records for species known to occur in the region and for others not yet discovered. The following list of the Grenadine terrestrial herpetofauna includes taxonomic authorities, orders and families, indications as to whether a species is endemic, native, or introduced, local name, and approximate size (see also table 1). Not included are three vagrant species. A crocodilian, Caiman crocodilus, was found alive on the windward coast of Carriacou in 1928, and apparently is an occasional vagrant via the floodwaters of the Orinoco River (Groome, 1970). The first frog recorded from Union Island in December 1990 is suspected to be Eleutherodactylus planirostris from the northern Caribbean, but a positive identification could not be made (Henderson, 2003). The thriving yachting industry with its heavy demand on vegetable produce appears to be the cause and/or means of its arrival. A snake, Tantilla melanocephala, was recorded on Mustique in January 2006 (Henderson and Powell, 2006b). This individual might have arrived in the Grenadines by natural over-water dispersal (such as the species’ apparent origin on Tobago), but more likely reflects an accidental introduction with imported materials from South America (e.g., sand for construction from Guyana). Also, the herpetological status of the most southerly uninhabited islands of Isle de Ronde and Isle de Caille are unknown to the authors.
262
J. Daudin and M. de Silva
Table 1. Checklist of amphibians and terrestrial reptiles, and their presence on the various larger Grenadine islands. Abbreviations are: (Bq = Bequia, Iq = Isle de Quatre, Bl = Balliceaux, Mu = Mustique, Cn = Canouan, My = Mayreau, Tc = Tobago Cays, Pr = Prune Island (=Palm Island), Un = Union Island, Pv = Petit St. Vincent, Pm = Petit Martinique, Cr = Carriacou). Bq
Iq
Bl
Mu
Cn
+ +
+ +
My
Frogs Bufo marinus Eleutherodactylus johnstonei Leptodactylus validus
+ +
Land turtle Geochelone carbonaria
+
+
+
+
+
+ + +
+
+ + +
+
+ +
Tc
Pr
Un
Pv
?
+
+
+
+
+
+ + +
Lizards Hemidactylus mabouia Sphaerodactylus kirbyi Thecadactylus rapicauda Gonatodes daudini Anolis aeneus Anolis richardii Iguana iguana Mabuya sp. Ameiva ameiva tobagana Bachia heteropa alleni Gymnophthalmus underwoodi
+ + + + + + +
+
+
+
+
+
+
+
+
+
+ + + + +
+ + + +
+ + +
+
+
Snakes Corallus grenadensis Mastigodryas bruesi
+ +
+ +
+ +
+ +
+ +
+ +
+
+
Pm
Cr + +
+ +
+
+ +
+
+ + + + +
+
+ +
+ +
+
+ + + + +
+ +
+ +
?
Amphibia (frogs) Bufo marinus (Linnaeus, 1758). Anura: Bufonidae. Almost certainly introduced. The cane toad is known locally by the French name “crapaud”. The crapaud (maximum female SVL = 225 mm) is native to South America and was introduced widely in the Caribbean in the last century to control insect pests in the sugarcane fields (Lever, 2003). This toad is a very recent introduction to Carriacou, Mustique and now Canouan. Its means of arrival on Carriacou around 1998 is unknown, but on Mustique it was accidentally transported there in topsoil and plant material, brought from neighboring St. Vincent as recently as six years ago (Paice, 2004). In Mustique it has caused the death of two pet dogs and an officially organized eradication programme has been initiated. Eleutherodactylus johnstonei (Barbour, 1914). Anura: Leptodactylidae. Introduced. The Lesser Antillean whistling frog is also a recent introduction into the Grenadines, where it is now fully established and very common on Bequia, Mustique and Petit St. Vincent, but only now establishing itself on Canouan, Carriacou and Union Island, where they were first reported in the early 1990s (Henderson, 2003). E. johnstonei is a small frog (maximum female SVL = 35 mm) with a loud
Amphibians and terrestrial reptiles of the Grenadines
263
voice and considerable variation in colour and pattern (Sander et al., 2003; Díaz Lameiro et al., in press). At night they can be found on trees and bushes, and they hide under bark and stones by day. They are also commonly found in the dark damp corners of human habitation, particularly bathrooms, drain pipes, and other wet areas. They deposit their eggs in damp areas behind tree bark, under stones, and in the leaf bracts of tree pines (Tillandsia utriculata). A more recently noted phenomenon is their presence high on the vertical walls of dwellings, in the shaded areas under light bulbs, feeding on nocturnal insects. Leptodactylus validus (Garman, 1887). Anura: Leptodactylidae. Native. The smooth-skinned ditch frog is medium-sized (maximum female SVL = 78 mm). This species is a Lesser Antillian endemic from the St. Vincent and Grenada banks that has been recorded only from Bequia in the Grenadines. Its population on Bequia may be a remnant from the pre-colonial era, when the islands were heavily wooded and water was more available. Its present status on Bequia is unknown. Reptilia: Testudines (turtles) Geochelone carbonaria (Spix, 1824). Testudines: Testudinidae. Possibly introduced. The red-footed tortoise (maximum carapace length = 512 mm) is found throughout tropical South America and the West Indies. This tortoise often is thought to have been introduced into our islands by early Amerindian peoples (see Treglia, 2006). This “land turtle”, as it is locally called, will eat almost everything from fruit, flowers, leaves, and even carrion and faeces. It is this offal diet that has somewhat protected it, as the local people scorn them as food. Their numbers in the Grenadines dwindled somewhat in the 1960s and 1970s, when they were shipped to Trinidad and Martinique for food, and to the latter for cleaning up the faeces in chicken farms. Today, their populations have rebounded on Canouan, and on Mustique where they are officially protected. Isle de Large (immediately south of Carriacou) is a relatively small island (0.58 km2 ), but it probably has one of the highest concentrations of these tortoises found anywhere in the region. Courtship and mating is quite a vocal grunting affair, and four or five fragile eggs are laid in an excavated hole in the ground, the young emerging about five months later. Reptilia: Squamata (lizards) Sphaerodactylus kirbyi (Lazell, 1994). Squamata: Gekkonidae. Endemic. The Bequia dwarf gecko is the smallest of the Grenadine reptiles (maximum SVL = 25 mm). This species was thought to be endemic to Bequia only (Lazell, 1994), but was recently recorded from Mustique (Powell and Henderson, 2006), and even more recently from Petit Nevis, a small islet (0.29 km2 ) immediately off the southern coast of Bequia, and on Mayreau, the southernmost known extent of its range (fig. 2a). It is a lizard of the leaf-litter, where it apparently feeds on small arthropods. On Mustique, it is very common in windward coastal areas, but can
264
J. Daudin and M. de Silva
also be found somewhat inland on the leeward side of that island. S. kirbyi is a dull dark-brown with a relatively thick rust-coloured tail. Recent studies suggest that Grenadine populations may merely represent additional populations of S. vincenti (F. Providence, pers. comm.), but until results of that work are published, we continue to recognize S. kirbyi. Hemidactylus mabouia (Moreau de Jonnés, 1818). Squamata: Gekkonidae. Possibly introduced. The house gecko or “woodslave” (maximum male SVL = 68 mm), as it is locally called, is a very common occupant of every Grenadine home, where they are commonly seen around nightlights feeding on insects. In the Grenadines, they are found on all of the inhabited islands and on some of the uninhabited ones (e.g., Petit Nevis, Balliceaux, Savan, and the Tobago Cays). Their colonizing success appears to be linked to their adaptability to human habitation. Thecadactylus rapicauda (Houttuyn, 1782). Squamata: Gekkonidae. Native. The turnip-tailed gecko, which has no local name, is the largest of our geckos (maximum SVL = 121 mm). It is common on Mustique and hides behind tree bark, in stone piles, and in the dry palm-frond bracts of coconut palms. Its status on the other Grenadine islands remains unknown, but it has been recorded on Bequia and Carriacou (Schwartz and Henderson, 1991), and is probably present, but much less common, on the other large islands. This species is not usually found around houses. Gonatodes daudini (Powell and Henderson, 2005). Squamata: Gekkonidae. Endemic. The Union Island decorated gecko (maximum male SVL = 30 mm) has no official common or local name. This beautifully coloured lizard was discovered on Union Island in 2005 in one of the very few remaining stands of true secondary dry forest habitat in the Grenadines (fig. 2b). This small ground-dwelling gecko is a lizard of the leaf-litter and was found in close proximity to the lizard Bachia heteropa. No previously known species of Gonatodes is endemic to the West Indies or is known from the Lesser Antilles. Females have not yet been found. Anolis aeneus (Gray, 1840). Squamata: Polychrotidae. Native. The Grenadine tree lizard (maximum male SVL = 77 mm) is endemic to the Grenada Bank and can be found on almost every Grenadine island, even the very small uninhabited islets. Although it is an important food source for the two local snakes (Corallus grenadensis and Mastigodryas bruesi), the blackbird (Quiscalus lugubris), and the cattle egret (Bubulcus ibis), neither predation nor development has noticeably diminished their numbers. Anolis richardii (Duméril and Bibron, 1837). Squamata: Polychrotidae. Native. This large anole (maximum male SVL = 125 mm) goes by the strange and nondescriptive Bequia name of “whistler”. It is endemic to the Grenada Bank, but can
Amphibians and terrestrial reptiles of the Grenadines
265
be found only on Bequia, Carriacou and Mabouya Island (immediately west of Carriacou) in the Grenadines. It is locally very common on those islands, apparently preferring the trunks of the larger forest trees. Iguana iguana (Linnaeus, 1758). Squamata: Iguanidae. Native. The green iguana is the largest of our land reptiles and can achieve a total length (body and tail) to 1.2 m. This lizard is found on most of the Grenadine islands, including the smaller uninhabited cays. They lay clutches of up to 45 eggs in excavated nests dug in loose soil (Malhotra and Thorpe, 1999) and beach sand. Adult iguanas are still hunted by locals, who appear to be its only predator. Wherever iguanas are protected, their population rebounds, for example on Prune (=Palm) Island, where Forestry officials relocated some 260 iguanas in 2005 because their large numbers were causing significant damage to the flower gardens of this exclusive resort. Uninhabited islands like Balliceaux have large populations, and visiting hunters from St. Vincent and Bequia regularly carry away dozens of these large animals. Mabuya sp. Squamata: Scincidae. Native. These “slippery backs” or “shine lizards”, as they are locally called, are skinks (maximum female SVL = 93 mm), and are found on all of the larger Grenadines. These populations have been identified in the past as M. mabouya, M. bistriata, and most recently as M. nigropunctata (Quesnel, 2005). Because of the uncertainty regarding its taxonomic status, Mayer and Lazell (2000) recommended that all Lesser Antillean populations be referred to as the “M. sloanii complex” until definitive data exist. In the Grenadines, this shy and elusive lizard is more unseen than rare. It usually is found on the ground in woody underbrush and between cacti, but is capable of climbing onto the large pads of prickly-pear cacti (Opuntia dillenii) and dry tree trunks, where it hides in holes. It also appears to frequent areas with garbage and vegetable trash and can be quite at home near human habitation. The shine lizard, still fairly common throughout the Grenadines, is probably extinct on the main island of St. Vincent due to the presence of the mongoose and feral cats. Ameiva ameiva tobagana (Cope, 1879). Squamata: Teiidae. Native. The Neotropical ground lizard (maximum male SVL = 149 mm) or “zaggada”, as it is locally called, is the common Grenadine lizard often heard noisily running through leaflitter or seen quietly basking in the early morning sunlight. These lizards have long claws that they use to dig for food or for excavating nocturnal burrows. The species ranges from St. Vincent into South America. Three years ago this lizard was encountered literally everywhere throughout the village on Mayreau and was a natural part of village life. With the arrival of domestic cats in almost every home, the lizards have disappeared completely, even from the fringes of the village. Today, as more of these cats become wild on Mayreau, the Zaggada population is seriously threatened. This situation now occurs throughout the Grenadines, with only Mustique realizing the danger and implementing a cat control programme. These lizards have a var-
266
J. Daudin and M. de Silva
(a)
(b)
(c) Figure 2. Some notable lizards of the Grenadines: (a) Sphaerodactylus kirbyi, on Mayreau; (b) Gonatodes daudini, on Union Island; (c) Bachia heteropa alleni, on Mustique. (Colour originals – see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm)
Amphibians and terrestrial reptiles of the Grenadines
267
ied diet and are quite resilient, and with some protection, populations could recover even on St. Vincent, where they are now reported from the Ratho Mill/Villa area (M. Baisden and R. Young, pers. comm.). Gymnophthalmus underwoodi (Grant, 1958). Squamata: Gymnophthalmidae. Native. The smooth-scaled worm lizard (maximum SVL = 43 mm) or “snake servant”, the local name that refers to these lizards’ shiny snake-like appearance, is a fairly common species on Bequia, Mustique, and Union Island. It is, however, rarely seen because of its elusive and rapid movements in grass and leaf-litter. This species appears to favor the sandy coastal areas, but can also be found higher at more forested sites. Bachia heteropa alleni (Barbour, 1914). Squamata: Gymnophthalmidae. Native. The earless worm lizard is a microteiid with no local name. This unusual darkcoloured species (maximum SVL = 64 mm) has a very long tail that can be as much as 1.5 times as long as its body. Its long tail and short stubby legs gives it a worm-like appearance. This lizard was until very recently recorded as being present only on Bequia and Canouan in the Grenadines, but is now recorded from Mustique (fig. 2c) and Union Island (Henderson and Powell, 2006a), Battowia, and possibly Petit St. Vincent, where an unconfirmed report exists. In the dry season, when the ground is hard, it can be seen frantically wriggling into the cracked earth as it endeavors to hide itself when disturbed. It is indeed a locally common species, but because of its habit of burrowing into the cracked or soft earth under rotting logs and leaf-litter, it remains an unknown, unseen, and inconspicuous Grenadine reptile. Reptilia: Squamata (snakes) Corallus grenadensis (Barbour, 1914). Squamata: Boidae. Native. The Grenadine treeboa (maximum SVL 1200 mm) or “Congo snake”, as it is locally called, is found throughout the Grenada Bank. The Congo snake is nocturnal and is usually encountered by day with its head hidden by its tightly coiled body while sleeping high in trees, amidst the dry basal fronds of tree pines (Tillandsia utriculata), or in holes on tree trunks. Occasionally, snakes are encountered by local people, with much unnecessary hysteria, near homes and outdoor toilets, where it has wandered in search of mice and rats. These snakes vary in colour and appear to differ from island to island. Mustique and Union Island Congo snakes are predominantly grayish; on Canouan they are predominantly brown; on Mayreau they are of a beautiful orange; and, on Bequia, Union Island, and Grenada, a yellow variety has been recorded (Henderson, 2002). Congo snakes do have a strong, unpleasant odor that might serve to discourage would-be predators. On Mayreau, these snakes remain common, but recent sightings are less frequent and may reflect effects of the substantial feral cat population or the recently introduced “manicou” (Didelphis mar-
268
J. Daudin and M. de Silva
supialis insularis). On Mustique where wildlife is officially protected, an overpopulation of manicous may be the cause for increasingly infrequent sightings of Congo snakes. Mastigodryas bruesi (Barbour, 1914). Squamata: Colubridae. Native. The Windward racer (maximum SVL = 830 mm) or “white snake”, as it is locally called, is the common daytime snake of the Grenadines. This small snake with its greybrown dorsum and pale underside is known only from the St. Vincent and Grenada banks, but a population has been established recently on Barbados (Underwood et al., 1999). This snake is still encountered on all of the larger Grenadine islands and many of the large uninhabited cays, occasionally passing through homes and gardens, on the ground or through the trees. The white snake feeds primarily on small lizards and frogs, and is currently threatened by the growth of feral cat populations.
Conservation The need for serious conservation of the herpetofaunal biodiversity in the Grenadines is urgent. The general situation is so desperate that even the most deliberate conservation efforts will probably amount to salvage operations. The Grenadines have become a victim of the exquisite natural beauty for which they are internationally famous. Many conservation-focused concerns face these islands. They include (1) chytrid fungus, that is already decimating the frog populations throughout Central America (e.g., Lips, 1999), reaching our shores; (2) the growth of the existing domestic/feral cat populations; (3) the iguana still being hunted for food; (4) snakes that continue to be the recipients of instant death by stone and cutlass; and (5) invasives arriving from South America and elsewhere in the unchecked building materials and construction sand that are regularly imported. All these concerns, however, pale into insignificance when compared to the effects of the massive unregulated tourism development that is currently taking place in the area. Two entire islands have been recently sold for hotel resorts and four others (Petit Nevis, Balliceaux, Isle de Ronde, and Isle de Caille) are now for sale. Most of Canouan, for example, is a mere 0.6 km wide, yet it supports an eighteen-hole golf course, a casino, a 200-room resort, and a soon-to-be-extended 1,900 m jetport runway. Land in the Grenadines is high-priced real estate, so almost all of the remaining public “crown” land on Bequia is being sold to finance the purchase of land for the construction of an international airport on mainland St. Vincent. The large mangrove lagoon at Ashton in Union Island, which was once inundated for construction of a marina and resort, was stopped, but is again being prepared for development. Up-to-date statistics are hard to acquire, but cruise ship passengers on Mayreau (pop. 280) alone, amounted to about 40,000 last season, and the resident Grenadine population has about doubled in the past ten years. These increases place a tremendous burden on the remaining available land.
Amphibians and terrestrial reptiles of the Grenadines
269
Legislation is already in place, but public awareness and enforcement are sadly lacking. Under the Wildlife Protection Act of 1987, for example, snakes receive “total protection”. Protected areas and Grenadine “reserves” also exist, but they are simply part of the paper legacy left by past colonial powers that present-day cash-strapped governments reverse with a simple parliamentary decision. If the St. Vincent government could attempt to hand over the control and management of the only national marine park in this region to Palm Island Resorts, Ltd., then the Grenada government can also justify an attempt to sell one of their few national parks to the Four Seasons Hotel chain. Ecotourism is growing very slowly, generates little money, and is not taken very seriously by the government. How can one, for example, promote the beautiful and rare endemic Gonatodes daudini as part of Union Island’s tourism product when its tiny remaining habitat will soon be sandwiched between the planned garbage dump/incinerator (the road is already constructed) and the new hotel developments earmarked for the Chatham Bay area? Presently, Grenadine conservation activities are largely restricted to Mustique, where an active environmental committee is an official instrument of the Mustique Co. Ltd., the island’s de facto local government. Mustique, after many years of environmental neglect, has finally, on its own initiative, made the connection between a healthy natural environment and the sustainability of its exclusive tourism investment, something that the more recently established island resorts have yet to understand. One recent initiative has been a guide to the biodiversity of the island with the objective of increasing public awareness (de Silva and Wilson, 2006). Partly because of the competition with other Caribbean islands for foreign investment, the governments of St. Vincent and the Grenadines, and Grenada do not insist on comprehensive environmental impact assessments, and, if these are conducted, investors are not required to comply with recommendations. Environmental education has, however, begun among the few fledgling Grenadine NGO’s, and this awareness is now growing with the assistance of the University of the West Indies (CERMES) Sustainable Grenadines project led by the Centre for Resource Management and Environmental Studies of the University of the West Indies (Barbados). Five thousand years ago, when the first Amerindians arrived, they saw the Grenadines in its virginal splendour. Three hundred and fifty years ago, when the first Europeans arrived, they met the Grenadines still in its natural glory. What took millions of years to create, however, was about to be destroyed almost overnight. The French and then the English, using slave labour, systematically deforested these low-lying accessible dry-forests for timber, for burning lime, and then for planting indigo. The land was again deforested for sugarcane, and again for planting cotton. During those early plantation estate years, and also during later colonial times, the same small stands of forests were cut for housing, boatbuilding, and fuel (charcoal). The remaining Grenadine forests that we see today are therefore well beyond tertiary forest. One can only imagine the abundance of wildlife and plant species that once existed on these islands and in the surrounding waters. In spite of
270
J. Daudin and M. de Silva
this well-documented history, we struggle today to convince our governments and our people of the necessity to preserve the small remnant of our natural heritage that remains.
Acknowledgements. We acknowledge the original assistance and guidance given to us by Dr. Robert Henderson of the Milwaukee Public Museum, and also his most recent help. We also acknowledge the recent motivation and support given by Prof. Julia Horrocks of UWI Cave Hill, and thank all those who assisted in our present research, particularly Mr. Morison Baisden, Mr. Robert Young, and Mr. Vidal Browne of St. Vincent; Ms. Charmine Simmons and Mr. Leroy Thomas of Canouan; Mr. Matthew Harvey of Union Island; Dr. Patrick Chevailler of Palm Island Resort; Rick Chinsley of Petit St. Vincent; and Bro. Robert Fanovich of Grenada.
References Censky, E.J., Kaiser, H. (1999): The Lesser Antillean fauna. In: Caribbean Amphibians and Reptiles, p. 181-221. Crother, B.I. (Ed.). San Diego, California, Academic Press. de Silva, M., Wilson, D. (2006): A Natural History of Mustique. Mustique Island, St. Vincent and the Grenadines, The Mustique Company Ltd. Díaz-Lameiro, A.M., Powell, R., Berg, C.S. (2007): Colour and pattern polymorphism in Eleutherodactylus shrevei and Eleutherodactylus johnstonei (Leptodactylidae) on St. Vincent, West Indies. Herpetol. Bull. 101: in press. Groome, J.R. (1970): A Natural History of the Island of Grenada, W.I. Trinidad, Caribbean Printers Ltd. Henderson, R.W. (2002): Neotropical Treeboas: Natural History of the Corallus hortulanus Complex. Krieger Publ. Co., Malabar, Florida. Henderson, R.W. (2003): Amphibians and reptiles on Union Island. In: A Natural History Monograph of Union Island, p. 148-151. Daudin, J. (Ed.). Union Island, St. Vincent and the Grenadines. Henderson, R.W., Powell, R. (2006a): Geographic distribution: Bachia heteropa alleni. Herpetol. Rev. 37: 360. Henderson, R.W., Powell, R. (2006b): Geographic distribution: Tantilla melanocephala. Herpetol. Rev. 37: 501. Lazell, J. (1994): A new Sphaerodactylus (Sauria: Gekkonidae) from Bequia, Grenada Bank, Lesser Antilles. Breviora 496: 1-20. Lever, C. (2003): Naturalized Reptiles and Amphibians of the World. Oxford, Oxford University Press. Lips, K.R. (1999): Mass mortality and population declines of anurans at an upland site in western Panama. Conserv. Biol. 13: 117-125. Malhotra, A., Thorpe, R.S. (1999): Reptiles and Amphibians of the Eastern Caribbean. London and Oxford, MacMillan Education Ltd. Mayer, G.C., Lazell, J. (2000): A new species of Mabuya (Sauria: Scincidae) from the British Virgin Islands. Proc. Biol. Soc. Washington 113: 871-886. Paice, M.R. (2005): Geographic Distribution. Bufo marinus. Herpetol. Rev 36: 331-332. Powell, R., Henderson, R.W. (2005): A new species of Gonatodes (Squamata: Gekkonidae) from the West Indies. Carib. J. Sci. 41: 709-715.
Amphibians and terrestrial reptiles of the Grenadines
271
Powell, R., Henderson, R.W. (2006): Geographic distribution: Sphaerodactylus kirbyi. Herpetol. Rev. 37: 495-496. Quesnel, V.C. (2005): Mating behaviour of the Neotropical skink Mabuya nigropunctata (Spix) in Trinidad, West Indies. Living World, Field Naturalists’ Club 2005: 53-55. Sander, J.M., Germano, J.M., Powell, R., Henderson, R.W. (2003): Colour and pattern polymorphism in Eleutherodactylus johnstonei on Grenada. Herpetol. Bull. 83: 22-25. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. Gainesville, Univ. Florida Press. Treglia, M.L. (2006): An annotated checklist of the amphibians and reptiles of St. Vincent, West Indies. Iguana 13: 252-263. Underwood, G., Horrocks, J.A., Daltry, J.C. (1999): A new snake from Barbados. J. Barbados Mus. Hist. Soc. 45: 67-75. Westercamp, D. (1985): Geology of the Grenadine Archipelago (Southern Lesser Antilles). Bureau of Research, National Geologic Service, France.
Accepted: March 2, 2007 (JAH). Reprinted from Applied Herpetology 4: 163-175 (2007).
Conservation of Jamaican amphibians and reptiles Byron S. Wilson Department of Life Sciences, University of the West Indies, Mona, Kingston 7, Jamaica E-mail:
[email protected] Abstract. Jamaica’s modern terrestrial herpetofauna includes 66 described species distributed among four amphibian and 10 reptile families. Inclusion of the American crocodile and four species of sea turtle bring Jamaica’s total to 71 species, of which 64 are native. Four amphibian and three reptile species are presumed to be non-native, having become established on the island following obvious or likely transport by human agency. Up to six native species may have become extinct in the past 150 years, and the status of many others is presently uncertain. Thirty-three of the island’s 37 native reptile species are endemic (89%); of the remaining four native taxa, several, perhaps all, will eventually be described as endemic species (or species complexes). Jamaica’s native amphibian fauna consists of 21 described species representing two genera; all of them are endemic and most (81%) are considered Threatened based on IUCN Red List criteria. Worryingly, six species have not been documented in over 20 years, and at least one is probably extinct (Eleutherodactylus orcutti). Continuing loss and degradation of remaining primary forests is undoubtedly the single greatest threat to the persistence of most threatened species, and less than 10% of such habitat remains. Sea turtle populations have been reduced to mere remnants due to centuries of over-exploitation; and now the beaches that serve as nesting sites for the remaining populations, and for nesting American crocodiles, are under severe threat from tourism development. Another major concern is the likely presence of Batrachochytrium dendrobatidis, a fungal parasite that has been implicated in the extirpation or extinction of amphibians worldwide. Protection of four important forested areas (Blue and John Crow Mountains National Park, The Cockpit Country, Dolphin Head Mountain and adjacent forests, and the Hellshire Hills) would confer protection to all amphibian species and nearly all endemic reptile species. These areas currently fall under or are partially covered by protected areas legislation, but actual protection has been elusive. All of these areas are threatened by continued habitat loss and degradation, primarily from tree cutting. Halting the rampant cutting of trees in these areas, and effecting a moratorium on coastal development in sea turtle and crocodile nesting habitat are conservation priorities. Key words: Amphibian; biodiversity; Celestus; conservation; endemic; herpetofauna; iguana; Jamaica; protected areas; reptile.
274
B.S. Wilson
Introduction At just over 11,500 km2 , Jamaica is the third largest island in the Greater Antilles, smaller than Cuba and Hispaniola, and larger than Puerto Rico. Resting on the Caribbean tectonic plate, Jamaica is believed to have emerged from the sea some 14 MYA, making it considerably younger than the other Greater Antillean islands. Jamaica’s biota is therefore the product of a shorter history of colonization and subsequent evolutionary diversification than are those of the other Greater Antillean islands. Nevertheless, Jamaica boasts a highly diverse and endemic biota — owing in part to its wide altitudinal gradient (sea level to 2256 m), and diversity of microclimates. For example, Jamaica is ranked 5th in the world in terms of endemic plant diversity on islands (Davis et al., 1997), supports the highest density of endemic bird species found on any island in the West Indies, and harbors a highly endemic land snail fauna that is as diverse as any in the world (Rosenberg and Muratov, 2006). In terms of its herpetofauna, Jamaica contains a moderately diverse assemblage, but one that is characterized by high levels of endemism that resulted from several notable radiations. Because the Caribbean is considered to be one of the “hottest hot spots” on the planet (Myers et al., 2000; Mittermeirer et al., 2005), Jamaica represents a hotspot within a hotspot — its herpetofauna is as notable for its high level of endemism as it is for its highly threatened status. The first humans to colonize Jamaica were Amerindians who are believed to have arrived from Central America. The oldest evidence of human occupation dates back only to around AD 650, and represents the Jamaican Redware culture; the better known Tainos arrived about 200 years later (Rampersad, 2009). Thus, compared to many other islands in the region, Jamaica’s pre-Columbian history was relatively short, though future discoveries are likely to push back the date of first occupation (Wilson, 2007). Discovery of Jamaica by Europeans 500 years ago, and the subsequent waves of immigration that followed, resulted in the establishment of diverse ethnic populations. Altogether, the peopling of Jamaica has had a dramatic impact on the island’s amphibian and reptile species, and this impact has not been positive. As was the case elsewhere in the Caribbean, early herpetological work in Jamaica focused on taxonomic considerations, with studies of ecology and general biology emerging later, and with conservation only recently becoming a focus of research attention (Williams, 1999; Henderson and Powell, 2009). Indeed, the island has a long history of descriptive work based on the collections of locally-based natural historians, foreign-based museum taxonomists, and a few resident herpetologists (e.g., Sloane, 1725; Gosse, 1851; Grant, 1940; Lynn and Grant, 1940; Lewis, 1944; Cousens, 1956; Underwood, 1959; Underwood and Williams, 1959). More recent taxonomic studies have been conducted primarily by visiting herpetologists from the United States (e.g., Schwartz, 1971; Crombie, 1977, 1985, 1999; Hedges, 1989, 2010; Hedges and Burnell, 1990).
Conservation of Jamaican amphibians and reptiles
275
Aside from largely descriptive, taxonomic efforts, few detailed studies have been conducted on Jamaica’s amphibians and reptiles; as a consequence, most of what we know about the ecology and behavior of the island’s herpetofauna is based on field notes describing collecting localities, and the examination of museum specimens (e.g., dietary analyses, reproductive parameters). Essentially nothing is known about the ecology of most of the island’s amphibian and reptile species, but exceptions do exist. Several Anolis species have been subjected to intensive ecological and behavioral study (e.g., Lazell, 1966; Rand, 1967; Trivers, 1976; Floyd and Jenssen, 1983), and the Jamaican iguana has been the subject of detailed, conservationfocused research (Vogel, 1994; Vogel et al., 1996; Wilson et al., 2004a, 2004b; Lewis et al., 2008). In addition, various aspects of frog reproductive and community ecology have been elucidated (e.g., Stewart, 1977; Lannoo et al., 1987; Diesel et al., 1995; Thompson, 1996). On the whole, however, Jamaica’s amphibians and reptiles remain notably understudied. In the words of Crombie (1999): “. . .in general, data on the distribution, systematics, and natural history of Jamaican amphibians and reptiles remain so basic that very few ‘definitive’ statements can be made”.
Taxonomic Overview of Jamaica’s Herpetofauna Jamaica’s modern terrestrial herpetofauna includes 66 described species distributed among four amphibian and 10 reptile families (table 1). Inclusion of the American crocodile (Crocodylus acutus) and four species of sea turtle bring the total to 71 species, of which 64 are native. Six native species have probably gone extinct in the past 150 years, and the status of many others is presently uncertain. In addition, four amphibian and three non-native reptile species have become established on the island following obvious or likely transport by human agency. Table 1. Amphibian and reptile species of Jamaica, exclusive of sea turtles. IUCN Red List categories are indicated where available; note that most reptiles have not been comprehensively assessed for Red List status. “Big 4” refers to the island’s four most important remaining forested areas: the Blue and John Crow Mountains National Park (B), The Cockpit Country (C), Dolphin Head Mountain and adjacent forested areas (D), and Hellshire Hills (H). NA = not applicable. Native
Endemic
AMPHIBIANS Bufonidae Bufo marinus Hylidae Osteopilus brunneus Osteopilus crucialis Osteopilus marianae Osteopilus wilderi Osteopilus Sp.?
X X X X X
Introduced
“Big 4”
Status and Threat Category
X
NA
LC
B, C, D B, C C B, C C
LC EN EN EN
276
B.S. Wilson
Table 1. (Continued). Native Eleutherodacylidae Eleutherodactylus alticola Eleutherodactylus andrewsi Eleutherodactylus cavernicola Eleutherodactylus cundalli Eleutherodactylus fuscus Eleutherodactylus glaucoreius Eleutherodactylus gossei Eleutherodactylus grabhami Eleutherodactylus griphus Eleutherodactylus jamaicensiss Eleutherodactylus johnstonei Eleutherodactylus junori Eleutherodactylus luteolus Eleutherodactylus nubicola Eleutherodactylus orcutti Eleutherodactylus pantoni Eleutherodactylus pentasyringos Eleutherodactylus planirostris Eleutherodactylus sisyphodemus
Endemic
X X X X X X X X X X X X X X X X X X X
Ranidae Rana catesbeiana REPTILES Anguidae Celestus barbouri Celestus crusculus Celestus duquesneyi Celestus fowleri Celestus hewardii Celestus microblepharis Celestus molesworthi Celestus occiduus
Introduced
X
X
X ? X X X X X X
Gekkonidae Hemidactylus mabouia
“Big 4”
Status and Threat Category
B B H C, D C, D B B, C C, D C B, C NA C C, D B B B, C, D B NA C
CR EN CR VU CR NT LC EN CR EN LC CR EN EN CR (poss. extinct) NT VU LC CR
NA
LC
C B, C, D, H H C B, C B (?) C (?) X
NA
Iguanidae Cyclura collei
X
H
Phyllodactylidae Tarentola albertschwartzi
X
?
Scincidae Mabuya sloanii
X
EX
H
CR
Conservation of Jamaican amphibians and reptiles
277
Table 1. (Continued).
Sphaerodactylidae Aristelliger praesignis Gonatodes albogularis Sphaerodactylus argus Sphaerodactylus dacnicolor Sphaerodactylus gilvitorques Sphaerodactylus goniorhynchus Sphaerodactylus oxyrhinus Sphaerodactylus parkeri Sphaerodactylus richardsoni Sphaerodactylus semasiops Polychrotidae Anolis garmani Anolis grahami Anolis lineatopus Anolis opalinus Anolis reconditus Anolis sagrei Anolis valencienni
Native
Endemic
X ? X
?
Introduced
? X X X X X X X X X X X X
?
? X
“Big 4”
Status and Threat Category
B, C, D, H NA B, C, D, H B ? B, C, D, H C, D H C C B, C, D B, C, D, H B, C, D, H B, C, D, H B NA B, C, D, H
Teiidae Ameiva dorsalis
X
Boidae Epicrates subflavus
X
B, C, D, H
VU
Dipsadidae Hypsirhynchus ater Hypsirhynchus callilaemum Hypsirhynchus funereum Hypsirhynchus polylepis
X X X X
B, C (?) B, C, H C, D B
CR (prob. extinct)
Tropidophiidae Tropidophis jamaicensis Tropidophis stejnegeri Tropidophis stullae Tropidophis Sp.
X X X X
B C H C
Typhlopidae Typhlops jamaicensis
X
B, C, D, H
Emydidae Trachemys terrapen
X
C, H
VU
H
VU
Crocodylidae Crocodylus acutus
X
278
B.S. Wilson
Jamaica’s native terrestrial reptile fauna contains 37 species representing five lizard families, four snake families, and the fresh water turtle family Emydidae, which contains the endemic slider (Trachemys terrapen). Thirty-three of these 37 native reptile species are endemic to the island (89%); of the remaining four native taxa, several, perhaps all, will eventually be reclassified as endemic species. Therefore, potentially all of Jamaica’s native terrestrial reptile fauna is endemic — and the final list is likely to grow as currently recognized subspecies are accorded full species status (see Crombie, 1999). The island’s native amphibian fauna consists of 21 described species representing two genera, and all of them are endemic to the island. Several species were not described until the 1970’s, so there is ample potential for additional species discoveries (Crombie, 1999). Thus, future and ongoing taxonomic work will inevitably elucidate an even richer and more fully endemic herpetofauna. As is the case for many tropical islands, lizards are the most conspicuous component of Jamaica’s herpetofauna — a feature that was noted early by visiting naturalists who remarked on the abundance and ubiquity of this group (Gosse, 1851). A total of 30 modern lizard species are listed for Jamaica, representing five families and 10 genera (table 1). All but two or three species are native, of which 23 are endemic to the island. Jamaica has, or until recently had, nine snake species, all of which are endemic. A 10th endemic species, a Tropidophis, will be described in the near future (Hedges, pers. comm.).
Threats to Jamaica’s Herpetofauna Habitat loss The most severe threat facing Jamaica’s herpetofauna is loss or degradation of habitats (Hedges, 2006; Wilson et al., 2006). Once almost covered by dry, moist, and wet tropical forests, remaining areas of relatively intact (primary) forests represent less than 10% of the surface area of Jamaica (Hedges and Woods, 1993). Few coastal and lowland habitats retain any semblance of naturalness, and high-quality primary forest probably covers less than 5% of the island. With the possible exception of a few remote forested areas located on steep slopes, Jamaica has retained no truly pristine habitat. Large scale land conversion associated with agriculture (primarily sugar cane), together with timber extraction (for lumber and fuel) decimated the island’s lowland forests in the centuries following European colonization. Subsequent population expansion and the attending explosion of commercial, residential, and urban development further contracted the island’s natural habitats. Today, primary forest habitat is largely restricted to rugged inland areas that are not accessible by road. Nevertheless, those areas are under assault from small-scale agriculture, bauxite (aluminum hydroxides) mining, limestone quarrying, road construction, and squatting (i.e., illegal settlements). Coastal habitats, including what few undeveloped white
Conservation of Jamaican amphibians and reptiles
279
sand beaches remain, are at risk of being extirpated by the latest economic boom: tourism development. Invasive alien species (IAS) Non-native species transported to Jamaica by humans have greatly altered the island environment. Most conspicuous have been mammalian predators such as the cat and mongoose (Herpestes auropunctatus), the latter of which has been implicated in the extinction or near extinction of at least four reptile and two bird species in Jamaica. Dietary studies in the Hellshire Hills have confirmed that the mongoose is a highly efficient predator of diurnal ground reptiles; the remains of 14 individual lizards were found in the stomach of a single mongoose (Lewis, pers. comm.; and see Lewis, 2002). Cats represent a more insidious threat, and are known to consume various endemic reptile species, including the Critically Endangered Jamaican iguana and the more recently “re-discovered” blue-tailed galliwasp (Celestus duquesneyi). Dogs, first brought to Jamaica by the Tainos, are the only predator capable of killing adult iguanas, and they also represent a threat to nesting sea turtles and their nests. Introduced herbivores such as goats have had a marked effect on the vegetation of tropical islands, although this appears to be important in Jamaica only on the Goat Islands — two small offshore cays located west of the Hellshire Hills. Pigs represent a threat to the nests of large reptiles such as iguanas, sea turtles, and crocodiles; they also consume a variety of small vertebrates, and degrade habitats through their rooting behavior. European rodents (Rattus spp. and Mus musculus) are present in both disturbed and natural areas, but their impact on amphibian and reptile populations in Jamaica is unknown. Rattus norvegicus is probably a threat to diverse taxa at, below, or near ground level; R. rattus, being more arboreal, is also a threat to bromeliad-inhabiting species (Hedges and Diaz, this volume). Introduced invertebrates (e.g., Solenopsis) probably also negatively impact the island’s native herpetofauna but this has not been documented (cf. Epperson and Allen, 2010). Similarly, introduced plants have significantly altered many habitats, but the impact on amphibian and reptile populations has not been examined. Nevertheless, exotic plants such as giant bamboo (Bambusa vulgaris) and Asian ferns (Nephroolepis spp.) are widespread in Jamaica, and are transforming natural habitats to the extent that they have undoubtedly rendered some areas unsuitable for the amphibians and reptiles that historically occurred there. Jamaica’s non-native herpetofauna includes four amphibian species, and two, perhaps three reptile species. Two Eleutherodactylus are established and widespread: E. johnstonei from the Leeward Islands and E. planirostris from Cuba. Both species occur primarily in open, disturbed habitats, and Stewart (1977) concluded that they do not compete with native species. The main concern is that continued degradation of natural forests will facilitate the expansion of E. johnstonei into degraded areas that may otherwise be physically suitable for native species. Competition between native Eleutherodactylus and E. johnstonei for food and shelter sites is certainly
280
B.S. Wilson
a possibility; however, a possibly greater impact may come from acoustic interference with mating calls (Hedges, 1993). Jamaica’s native Eleutherodactylus lack vocal sacs, and their calls are comparatively diminutive. On the other hand, E. johnstonei possesses vocal sacs, produces loud calls, and can seemingly dominate the auditory landscape where they occur. In addition, E. johnstonei may be a vector for the introduction or spread of the fungal pathogen Batrachochytrium dendrobatidis (Bd) (Henderson and Berg, this volume). The cane toad (Bufo marinus) was introduced to Jamaica in 1855 (Lewis, 1949) to contain pests on sugar cane plantations, and now occurs throughout the island at lower and mid-elevations. Ranked among the world’s 100 worst invasive species (Lowe et al., 2000), B. marinus almost certainly impacts native amphibian and reptile species through predation and competition, and recent evidence indicates that snakes such as the endemic Jamaican boa (Epicrates subflavus) can succumb to bufotoxin during predation attempts (Wilson et al., 2010). Another consideration is the possible role of B. marinus as a vector for the spread of Bd (cf. Diaz et al., 2007) or ranavirus (see Zupanovic et al., 1998). The American Bullfrog (Rana catesbeiana) was introduced to Jamaica in 1967 (Mahon and Aiken, 1977), though reports of earlier introductions exist (Crombie, 1999). From its reported introduction site in the Black River area of St. Elizabeth, the species has spread east at least as far as the parish of St. Catherine (pers. obs.), probably facilitated by incidental transfer with aquaculture products such as fingerling Tilapia (Oreochromis spp.). Rana catesbeiana is also listed among the world’s 100 worst invasive species (Lowe et al., 2000), and is assumed to negatively impact Jamaica’s native fauna, primarily through predation. This species is also known to carry Bd (e.g., Schloegel et al., 2009), and may well have been the original source of suspected introduction to Jamaica; R. catesbeiana is also a known carrier of ranavirus (e.g., Schloegel et al., 2009). The island’s introduced reptile fauna includes one gekkonid (the pantropical Hemidactylus mabouia), one sphaerodactylid (the neotropical Gonatodes albogularis), and the Cuban anole, Anolis sagrei. Hemidactylus mabouia is an edificarian species confined to highly disturbed, essentially urban habitats, and would not appear to be a competitor of native species occurring in natural habitats. Gonatodes albogularis is likewise restricted to disturbed coastal areas in the vicinity of human settlements, and probably also represents a recent, human-mediated introduction (Crombie, 1999). Anolis sagrei also appears to be restricted to disturbed coastal areas and is considered to represent an anthropogenic introduction (e.g., Stewart, 1977; Crombie, 1999). Future introductions would appear to be inevitable. Several avenues in particular, seem likely to result in the eventual introduction of additional species that could become problematic for the island’s amphibians and reptiles. A recent proliferation of private zoos and pet stores could lead to the introduction of species that could compete with, depredate, hybridize with, or transfer diseases to native species. Given the vulnerability of insular faunas to the threat of invasive species, these
Conservation of Jamaican amphibians and reptiles
281
“backyard” menageries and the trade in exotic animal species should both be banned. Illegal importation and the accidental introduction of organisms through international trade will be more difficult to curtail. Exploitation A number of larger species were exploited by the island’s pre-Columbian inhabitants — first by the Jamaican Redware culture, and later by the Tainos (Atkinson, 2006; Allsworth-Jones, 2008; Rampersad, 2009). In addition to sea turtles, the endemic freshwater slider turtle, the endemic iguana, and crocodiles, the Tainos apparently consumed snakes and medium-sized lizards (Atkinson, 2006; Carlson, pers. comm.). Although the history of Amerindian occupation of Jamaica was comparatively brief, and population densities may have been only modest, the island’s early inhabitants clearly over-exploited marine resources (Hardt, 2009; and see Blick, 2007). Nevertheless, many potentially exploitable natural resources awaited the arrival of Columbus (see Fitzpatrick and Keegan, 2007). Commercial exploitation in the centuries following European colonization had an enormous impact on Jamaica’s large reptile fauna. A major local and export trade in sea turtles decimated nesting populations during the 17th and 18th centuries (Sutton et al., 2008). Crocodiles were also over-exploited (probably in part for food) during the colonial period, and extensive harvesting for skins proceeded into the mid 1900’s. Protective legislation and export restrictions all but eliminated commercial exploitation by the 1970’s. However, recent reports and evidence (pers. obs.) indicate that the illegal harvest and consumption of crocodile meat has emerged as an important threat to remaining populations. Perhaps rising food prices, particularly for beef and other meat products, have lowered the threshold for exploiting alternative protein sources. The Jamaican iguana supplied a local specialty market demand up until the mid 1600’s, but loss of habitat and predation by non-native mammals probably played a much greater role in the population reductions and extirpations of this species (Vogel et al., 1996). And, whereas iguanas are consumed enthusiastically on other West Indian islands, the notion of eating a lizard would repulse most contemporary Jamaicans. A disturbing threat to Jamaica’s herpetofauna has emerged in the form of recent Asian immigrants who reportedly are purchasing threatened reptile species for consumption. Reliably reported incidents include: offers extended to locals to collect the endemic slider turtle, the endemic Jamaican boa, and the American crocodile; the theft of captive Jamaican boas and the edible parts of a crocodile from a nature facility, reportedly for culinary purposes; Chinese construction workers purchasing crocodile meat; and Chinese shop owners purchasing illegally killed boas and slider turtles (S. Koenig, pers. comm.). The recent construction of a large, new Chinese Embassy and the expansion of Chinese investment (and associated immigration) are therefore worrisome conservation indicators; the potential for an illegal harvest of threatened wildlife species to meet an ethnic Asian market demand is a legitimate conservation concern.
282
B.S. Wilson
Persecution To say that modern Jamaicans are not a particularly amphibian — or reptile-friendly people would be a gross understatement — in spite of the absence of venomous snake species on the island, and the obvious economic and human health benefits provided by rat-eating snakes such as the boa. Crocodiles, because of their real or perceived threat to human life, or to pets and livestock, are also killed, and this trend is reportedly on the increase. For example, human-crocodile conflicts have recently been reported from Parottee (St. Elizabeth), where residential encroachment has resulted in the loss of crocodile habitat and movement corridors between the sea and coastal ponds (A. Oberli, pers. comm.). Lizards, particularly Celestus, are regarded as dangerous, and even Anolis lizards can be the subjects of fear-generated persecution. However, owing to their selection of household habitats, it is geckos such as Aristelliger praesignis, and the introduced Hemidactylus, that are the most frequent victims. Local pest control companies even advertise their ability to target these “pests” — especially the dreaded Aristelliger, known locally as the “croaker”, or “croaking lizard”. Pollution As elsewhere in the region, the negative impact of pollution on amphibian and reptile populations remains essentially unstudied (Young et al., 2004; Wilson et al., 2006; Henderson and Powell, 2009). Aside from toxic waste products associated with bauxite processing and water borne pollutants from obvious sources (e.g., human and animal waste), there have been recurrent reports of chemical pollution and associated fish die-offs in the Black River; but environmental contamination does not appear to be a major threat in the island’s remaining terrestrial habitats. Pollution associated with agricultural production is no doubt considerable, but that impact is generally restricted to highly disturbed lowland habitats. One exception may be the unregulated use of herbicides and pesticides associated with high elevation coffee production (Haynes et al., 1989), but the deforestation caused by this industry is a more immediate threat to local amphibian and reptile populations than is the threat of chemical pollution. Disease There has been no confirmation of disease impacting Jamaican amphibians or reptiles; however, two pathogens in particular are either likely or suspected to be present. Fibropapillomatosis, a viral disease that affects green sea turtles, is known from the Caribbean and likely affects those in Jamaican waters. Chytridiomycosis, caused by the fungal parasite Batrachochytrium dendrobatidis (Bd), has been implicated in the extirpation or extinction of anurans in the Caribbean and elsewhere (Burrowes et al., 2004; Young et al., 2004; Lips et al., 2006; Pounds et al., 2006), and the current “Global Amphibian Crisis” is considered to be due largely to the impact of this pathogen (Stuart et al., 2004). To date, no research on Bd has been
Conservation of Jamaican amphibians and reptiles
283
conducted in Jamaica. However, the probable extinction of E. orcutti is notable; this is an aquatic species that occurs at high altitude — the suite of ecological traits that are highly correlated with vulnerability to Bd (Stuart et al., 2004). A high priority objective is therefore to conduct surveys aimed at determining whether Bd occurs in Jamaica, and if so, investigate its geographical range, host specificity, and conservation implications. Those investigations are scheduled to begin during 20102011. Mining Aside from the direct loss of habitat due to mining and quarrying activities, not to mention the potential for toxic contamination, mining operations fragment forest patches both through the direct actions of open-pit mining, and through the construction of road networks to access ore bodies. The most recent threat to The Cockpit Country was the issuing of bauxite prospecting licenses in 2004, with subsequent renewal in 2005 and 2006; in December 2006 one license was surrendered back to Government, and a second license was suspended following intense public outcry. Prospecting alone could potentially damage remaining forest patches through further fragmentation, and by creating trails or roads that would facilitate access for tree cutting (and other damaging practices). Access networks can also serve as corridors for invasive species such as B. marinus. For now (August 2010), those prospecting plans are on hold until disputes over the boundary delineation of The Cockpit Country are resolved. Global climate change The apparently inevitable, deleterious impact of global climate change will have severe consequences for Jamaica’s herpetofauna (Malcolm et al., 2006). Critical coastal habitats, such as sea turtle and crocodile nesting areas, may be lost to rising sea levels. Changes in temperature and precipitation regimes could have negative consequences for essentially every species, and are likely to be especially disastrous for the island’s amphibians. A possible synergistic role of climate change in precipitating Bd outbreaks is also of concern (Pounds and Crump, 1994; and see Daszak et al., 2005), as is alteration in the sex ratios of species showing Temperature Dependent Sex Determination (e.g., crocodiles, turtles; see Gibbons et al., 2000). Even heat-loving lizards appear to be vulnerable to population loss associated with climate change (Sinervo et al., 2010), so essentially the entire herpetofauna will be (or is being) negatively impacted by the current global warming trend.
General Conservation of the Herpetofauna Short- and long-term goals Given the high percentage of threatened amphibian and reptile species in Jamaica, urgent attention will be required to avert additional extirpations or extinctions.
284
B.S. Wilson
The most immediate conservation goal is therefore to ensure the persistence of the island’s extant herpetofauna, in its entirety. But that is a crisis-driven activity aimed solely at averting extinctions; it ignores the important community and ecosystem roles played by healthy amphibian and reptile populations. Accordingly, the ultimate goal is the restoration of natural levels of abundance, such that the island’s herpetofaunal species can play their historical roles in ecosystem function, and thus in the provision of ecosystem services (Thayer et al., 1984; Jackson, 1997; Bjorndahl and Bolten, 2003). Obvious candidates for demographic restoration include the endemic iguana and sea turtle populations. The iguana is an important seed disperser and may therefore be critical to the maintenance of tree species diversity and forest structure (Alberts, 2000; Hartley et al., 2000). Further, historical levels of iguana reproduction would have constituted a major energetic contribution to the dry forest food web. Similarly, historical sea turtle nesting levels would have represented a significant energetic input to the dynamics of coastal food webs (Bjorndahl and Bolten, 2003). In addition, historical levels of foraging by green and hawksbill turtles probably maintained the natural state of sea grass beds, and sponge diversity on coral reefs (Thayer et al., 1984; Jackson, 1997, 2001; McClenachan et al., 2006; Hardt, 2009). Of course, even small, seemingly inconsequential species may play crucial ecological roles; this is especially true for tropical islands, where amphibians or reptiles are often the numerically dominant vertebrates. So, for example, a small but abundant Eleutherodactylus or Anolis species may serve as prey for larger species and act as a natural control of insect populations. Experimental studies have confirmed that Anolis can influence vegetation structure on Caribbean islands (Spiller and Schoener, 1990). Protective legislation The earliest law conferring protection to an amphibian or reptile species in Jamaica was fisheries legislation aimed at regulating the sea turtle industry. This came in 1711, and was aimed at controlling the take of sea turtle eggs; two centuries later, in 1907, the Morant and Pedro Cays Act regulated the take of sea turtles (and eggs) from those offshore areas. Further protection for sea turtles and other wildlife species came in 1945, with the introduction of the Wild Life Protection Act (WLPA); a 1982 amendment to the Third Schedule conferred legal protection to all life stages of five sea turtle species. Unfortunately, these more recent amendments highlight a major legislative flaw: the maximum fine for poaching or possessing a listed sea turtle is ca U.S. $110 — what amounts to a modest licensing fee, given the low probability of prosecution and the potentially high financial rewards of poaching. And, although the amendment also includes a provision for the seizure of equipment (including boats), that law has apparently never been enforced (Sutton et al., 2008). Today, only a handful of Jamaica’s reptile species enjoy special protected status at the national level and, not surprisingly, all of these are relatively large species with
Conservation of Jamaican amphibians and reptiles
285
histories of human exploitation or persecution. In addition to the sea turtles, full protection has been accorded by the WLPA and 1982 amendment to the American crocodile, the Jamaican boa, and the Jamaican iguana. In many cases, the protection of these species follows regional or international legislation (e.g., crocodile, sea turtles). In addition to the WLPA, various other laws confer protection to wildlife species occurring in protected areas such as national parks, forest reserves, game preserves, and sanctuaries. Because so many of the island’s amphibian and reptile species occur in such protected areas, nearly all species have some form of legal protection in part or all of their range. Unfortunately, none of these laws are presently enforced effectively. Sea turtles, for example, continue to be harvested illegally, as do their eggs, and crocodiles continue to suffer from persecution and are now also subjected to poaching for an illicit trade in their meat. Overall, enforcement ranges from inadequate to nonexistent, but this is not a scenario unique to Jamaica. Corruption at the government level, and indeed at all levels of society (see Boxill et al., 2007), has severely hampered attempts to enforce legislation aimed at protecting species and habitats. Especially troubling is the potential for governments, and by extension individuals in government, to contravene established designations and sanction development projects in “protected” areas. A related problem is the manner in which Environmental Impact Assessments (EIAs) are now used in Jamaica as rubber stamps of approval for destroying the island’s diminishing store of wildlife habitat. Five conservation hotspots Jamaica contains five discrete natural areas that are obvious priorities for biodiversity conservation, and hence are clear targets for effective protected areas management programmes. Indeed, delimiting critical areas for amphibian and reptile conservation in Jamaica is straightforward: the protection and management of these five areas alone would confer protection to nearly 100% of the island’s extant, endemic herpetofauna. All of these areas are considered to be Important Bird Areas (IBAs) (BirdLife International, 2008) and are considered high priority sites for conservation by the Critical Ecosystem Partnership Fund (CEPF, 2010). Black River Lower Morass (BRLM). Declared a wetland of international importance in 1997 through the Ramsar Convention, the BRLM includes Jamaica’s largest freshwater wetland. Altogether, this complex wetland area includes mangrove forests, raised limestone islands, remnant patches of swamp forest, and several types of herbaceous wetland habitat. The area is not known to contain any site endemic amphibian or reptile species, but it is an important habitat for the American crocodile, and also supports a population of the endemic slider turtle. Unfortunately, the BRLM has been severely degraded, first by extensive timber harvesting, mostly during the colonial era, and more recently by drainage perturbations associated with sugar cane production, and by extensive loss and degradation of natural habitats for marijuana (Cannabis sativa) cultivation. Another major problem is the proliferation
286
B.S. Wilson
of non-native plant and animal species, which is currently transforming the entire ecosystem. Nevertheless, the area’s conservation importance is likely to grow as Jamaica’s other wetland habitats continue to be lost or degraded. The island’s coastal habitats are under a major assault from development interests. The presence of a profitable ecotourism business focused on the crocodile, and based in Black River, together with the BRLM’s Ramsar status, probably render this the most secure (from development) crocodile habitat on the island. On the other hand, Ramsar status does not in itself confer any protection, and may lead to complacency. In the case of the BRLM, no comprehensive monitoring system or management plan has been developed, much less implemented since the Ramsar designation — in contravention to both the spirit and obligations of the agreement. Many in Jamaica are under the impression that the BRLM is actually being managed and protected — a paper park indeed. Given the scant attention directed at the BRLM by herpetologists (Crombie, 1999), this is also an area that is clearly deserving of additional inventory effort. Of special interest are the remaining patches of swamp forest — one of the most endangered habitats in Jamaica and elsewhere in the region. Blue and John Crow Mountains National Park (BJCMNP). Established in 1989, the BJCMNP was the first terrestrial National Park designated in Jamaica, and remains the only non-marine National Park in the country. The park encompasses 78,000 ha, and supports amphibian and reptile species found nowhere else on the island. The more eastern John Crow Mountains are a limestone formation ranging to 1140 m in elevation, whereas the Blue Mountains are of shale, igneous rocks, and minor limestones, and rise to 2256 m. The two mountain ranges are separated by the Rio Grande and its valley, an area that receives up to 5 m of rainfall annually — the highest recorded for the island. Both ranges contain (or contained) primarily moist and wet tropical forest, although the Blue Mountains also contain high elevation elfin woodland and cloud forest. Despite its fully “protected” National Park status, the BJCMNP continues to suffer from heavy anthropogenic impacts. Inadequate management capacity has permitted continued degradation due to illegal agricultural and timber operations. A recent analysis of change in forest cover suggests that rates of habitat loss may have increased after the national park was designated (Chai et al., 2009). That study, however, as well as those that might paint a more positive picture, misses a major point: old growth primary forest is biologically distinct, but the distinction is not readily discernable from the analysis of remotely sensed images (see Evelyn and Camirand, 2003). In other words, a forest can be in steady qualitative decline, but in the absence of extensive ground-truthing, might appear to be recovering or even healthy. In 2009 a large scale illegal logging operation was uncovered in the BJCNP; together with other less publicized selective timber operations, one can only assume that species diversity and forest structure have been greatly altered — even in this fully protected area.
Conservation of Jamaican amphibians and reptiles
287
The Cockpit Country. A large, uplifted plateau of white limestone, where the chemical and physical actions of rain have resulted in its characteristic polygonal karst topography. The area has sustained centuries of human encroachment and timber removal, but nevertheless contains the island’s largest contiguous expanse of moist and wet broadleaf forest, and the highest concentration of endemic amphibian and reptile species. The area contains a large (22,344 ha) Forest Reserve, much of which is a single contiguous patch of forest that has been identified as being of special conservation value (Newman et al., 2010). The Cockpit Country supports 14 endemic amphibians and 21 endemic reptiles, two of each being site endemics (table 1). Current threats to The Cockpit Country include land conversion for small-scale agriculture, illegal timber harvesting, and the removal of young trees, especially for the production of “yam sticks”. A recent and overriding threat is the government’s plans to mine the area for bauxite. In fact, prospecting licenses issued in 2004 and renewed annually through 2006, permitted prospecting in 75% of The Cockpit Country Conservation Area. Those licenses were suspended amid opposition from the local and international conservation communities; a formal delineation of what actually constitutes “The Cockpit Country” is still pending. Preventing development in the area’s remaining intact forest is critical, and this includes the construction of the roads and trails that invariably lead to increased levels of resource extraction and habitat degradation. Tabled discussions of The Cockpit Country for consideration as a World Heritage Site are encouraging, and should continue. However, because the Mining Act (1947) has precedence over all other environmental protection Acts, a ministerial decree declaring the area “Closed to Mining” will be the only legally recognized protection. Dolphin Head Mountain and adjacent forests. An isolated, western feature of white limestone that boasts the island’s highest level of site specific plant endemism (32.5%). The area contains several forest reserves, and is an Important Bird Area that encompasses 7301 ha (BirdLife International, 2009). Although the number of site endemic amphibians and reptiles is small (table 1), the area’s isolation suggests that it probably contains a higher level of site endemism than is currently recognized, especially since the area is relatively understudied with respect to amphibians and reptiles. Unfortunately, the unique forests of this area were ravaged during the colonial days, primarily for lumber, and for fuel to support sugar cane and lime industries. Extensive re-growth occurred (see Evelyn and Camirand, 2003), and substantial stands of moist tropical forest remained up until recent decades. Current threats to the remaining forests of this area include lumber removal (both legal and illegal) and slash and burn agriculture focused on the cultivation of marijuana. Loss of habitat to marijuana production increased dramatically in the 1970’s, in concert with large scale tourism development in nearby coastal areas, and to meet an expanding export market. Growers also release cats into their fields to control seed pests such as rats and birds; so in addition to the direct loss of habitat, marijuana
288
B.S. Wilson
production results in the insertion of an insidious non-native predator deep into the remaining habitat of threatened wildlife species. In short, the marijuana industry is a major threat to native wildlife, but it is also a major source of income in a region characterized by chronically high un- and under-employment. As a consequence, the illegal cultivation of marijuana is a complicated sociological issue that will not be easy to resolve (Koenig, 2001; St. Vincent MHE, 2010). One obvious option is to legalize cultivation, which would potentially reduce or remove the pressures now being exerted on the remote forested areas that now serve as sites for illicit growing operations. Hellshire Hills. An uplifted dome of white limestone fringed by mangrove wetlands, beaches, and rocky coastline. At ca 114 km2 , the area contains one of the finest remaining examples of dry tropical forest in the insular Caribbean (fig. 1a). The area supports the only known population of the Jamaican iguana, and is a critically important refuge for a number of the island’s other threatened amphibian and reptile species (table 1). The Hellshire Hills also represent an Important Bird Area (IBA), and are listed by the Alliance for Zero Extinction as a globally important site facing an imminent extinction (see Ricketts et al., 2005). The Hellshire Hills, and essentially all of their remaining primary forests, are owned and managed by the Government of Jamaica. In addition to lying within the Portland Bight Protected Area (PBPA), a large government-owned portion of the area falls within the protected category of Forest Reserve. It is strictly illegal to cut trees in Hellshire, or to damage the habitat in any other manner. Unfortunately, as elsewhere in Jamaica, lack of effective management has permitted rampant habitat loss, in Hellshire primarily for the production of charcoal (fig. 1b). Large development projects, some dating back to the 1960s, are reported as shelved by the government, but nevertheless continue to be referenced on occasion; worryingly, the potential economic gains associated with tourism, together with the government’s mandate to provide housing for Jamaica’s increasing population, represent disturbing reminders that priorities can change.
Conservation of Amphibian Taxa Jamaica’s native amphibian fauna consists of 21 described frog species, all of which are endemic to the island. A 22nd species (Osteopilus sp.) was independently discovered by R. Crombie and B. Hedges, and will soon be formally described (B. Hedges, pers. comm.). Of the 21 described species, 17 (81%) are considered to be threatened with extinction by the IUCN — giving Jamaica the dubious claim of harboring one of the world’s most endangered amphibian faunas (IUCN, 2009). One species, E. orcutti, disappeared from formerly reliable collection localities in the mid 1980s, and other species have not been documented in 10-25 years (Hedges and Diaz, this volume). Should Bd be detected in Jamaica, emergency measures such as the establishment of captive populations may be warranted. Indeed, Jamaica
Conservation of Jamaican amphibians and reptiles
289
Figure 1. (a) View of Hellshire Hills and adjacent coastline, looking south. This area contains what is arguably the most intact example of dry tropical forest remaining in the Caribbean. (b) Charcoal kiln deep in the Hellshire Hills. Although Hellshire is protected on paper, illegal tree cutting to produce charcoal is a serious threat to the remaining sectors of primary forest. Photos courtesy of the Jamaican Iguana Recovery Group. (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm.)
is already under consideration as a site to host an “Amphibian Ark”. Aside from Bd infection, the continued loss and degradation of habitat represents the most serious threat to anurans, identified for 16 of the 17 species. Because the threatened species are dependent on mature, closed canopy broadleaf forests, even modest disturbance such as selective logging may be incompatible with persistence. Accordingly, saving most of Jamaica’s endemic frog species will be a matter of maintaining the integrity of remaining tracts of primary forest. As part of the Global Amphibian Assessment (GAA), all of Jamaica’s frog species were evaluated using Red List criteria in 2004; the current Red List (IUCN, 2009) reflects those assessments, and includes detailed
290
B.S. Wilson
Figure 2. (a) Osteopilus wilderi is an Endangered species that requires mature wet or moist broadleaf forest habitat for its survival. (b) Eleutherodactylus orcutti is Red Listed as Critically Endangered but is feared extinct, a potential casualty of the chytrid fungus. Photos courtesy of S.B. Hedges. (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm.)
information on ecology, threat status, and distribution. Some general patterns, emerging issues, and conservation priorities are highlighted below. Hylidae Of the four described Jamaican Osteopilus species, only O. brunneus can tolerate significant levels of habitat disturbance, and indeed, the species can occur in highly modified environments, including human structures. The other three species require mature forest habitats that contain large trees and tank bromeliads (e.g., O. wilderi, see fig. 2a). All three species are Red Listed as Endangered. A notable conservation consideration for this genus is the pending description of a fifth species (B. Hedges, pers. comm.), and its subsequent Red List assessment. Eleutherodactylidae Of the island’s 17 endemic Eleutherodactylus species, 82% (14) are considered to be threatened with extinction (IUCN, 2009), and 71% (12) are ranked as either Endangered (EN) or Critically Endangered (CR). Six of these threatened species have not been recorded in over 20 years, one of which (E. orcutti) is probably extinct; all others are threatened by continued loss and degradation of their mature, closed canopy forest habitat. Given the sensitivity of these species to ongoing habitat degradation, climate change, and Bd, among other threat processes, the threatened Eleutherodactylus species represent the island’s most conspicuous but underappreciated conservation concern. What follows is a brief overview of problems related to particular CR species, and recommended activities that should be initiated with haste. E. alticola. Has a very restricted range near Blue Mountain Peak, and was last known to be extant in 1986 (Hedges and Diaz, 2010). Survey efforts aimed at verifying persistence and delineating full distribution are conservation priorities.
Conservation of Jamaican amphibians and reptiles
291
E. cavernicola. Historically known from only two caves on Portland Ridge, but was more recently discovered in the Hellshire Hills. However, the species has not been documented in a decade, and continued human intrusion into the Portland Ridge caves probably represents a continuing threat to those populations (IUCN, 2009). The species’ range and abundance in the Hellshire Hills are unknown. Accordingly, this species is a prime candidate for additional survey and population assessment activities. E. fuscus. Has not been documented in 25 years; hence, surveys to determine status and area of occurrence are urgently warranted. E. griphus. Not described until the mid 1970’s, and last documented in 1985. This rare species is a range-restricted Cockpit Country endemic known from only three locations (IUCN, 2009), and is recognized by the Alliance for Zero Extinction (AZE). Surveys to verify species persistence and to delineate full area of occurrence are priorities, as is protection of its remaining habitat. E. junori. Abundance appears to have declined markedly in the last 40 years (IUCN, 2009). Although the species was heard calling in the late 1990s, it has not been collected since the 1980s (Hedges, pers. comm.). Assessing the conservation status of this species is a high priority. E. orcutti. The current Red List now considers this species to be CR but “possibly extinct”, probably due to the chytrid (Bd) fungus (IUCN, 2009) (fig. 2b). The species was abundant at some localities until 1985, and then disappeared abruptly. Future survey efforts should aim to examine the most pristine and remote portions of the Blue and John Crow Mountains. Should a relictual population be located, and assuming Bd is shown to be present in much of the species’ historic range, E. orcutti would be an appropriate candidate for captive propagation. E. sisyphodemus. Known only from the type locality, and not documented since 1984 (Hedges and Diaz, this volume), this is a second Cockpit Country endemic. Surveys to verify the species’ persistence, including locations other than the type locality, and an assessment of threats to its remaining habitat, are key conservation priorities.
Conservation of Sea Turtles Sea turtles were historically common in Jamaican waters, and four species were known to nest on the island’s beaches: the green (Chelonia mydas), hawksbill (Eretmochelys imbricata), leatherback (Dermochelys coriacea), and loggerhead (Caretta caretta). Habitat alteration and overexploitation have decimated local sea turtle populations, especially in the last several centuries. Only the hawksbill now nests in Jamaica with any regularity — and it is Critically Endangered
292
B.S. Wilson
(IUCN, 2009). Overall, recent estimates suggest that Caribbean stocks of the green and hawksbill turtles have been reduced by 99.7% of historical abundance (McClenachan et al., 2006); Jamaica is probably on the high side of this regional average, with both species now being commercially and ecologically extinct. All of the current threats impacting sea turtles in Jamaica are anthropogenic in origin, and some vary in importance as a function of geographical location. Geographical variation in threat processes is especially pronounced in a comparison of mainland beaches and off-shore cays within the PBPA. On the PB cays the primary threat is the illegal harvesting of turtles and eggs. Evidence of illegal poaching was observed even on smaller, unoccupied cays that were probably visited specifically for that purpose. Despite the obvious and unacceptably high toll from illegal harvesting of turtles and nests on these cays, nesting success was even lower on mainland beaches. On isolated beaches along the Hellshire coast, introduced mammalian predators (mongooses and pigs) exacted heavy losses during a 20062007 study, perhaps accounting for nest failure rates approaching 90% (Harker and Wilson, unpubl. data). Recent survey efforts (2008-2010) in the PBPA have confirmed the severely depleted status of the nesting hawksbill population, and documented the persistent problems of illegal harvesting and predation by non-native mammals. Because these land-based threats are of such great magnitude on mainland beaches, the island’s offshore cays are considered to be the most important remaining nesting habitats. However, and in spite of adequate legislation protecting both the turtles and the cays, the lack of enforcement has rendered even these nesting hawksbill populations relictual, and in danger of extirpation. No published reports confirm that any of the other three species still nest on Jamaican beaches. Given the long maturation time of sea turtles it may be decades before nesting of those species ceases altogether; but they are already commercially and functionally extinct. Current threats Illegal harvesting. In spite of their full legal protection, sea turtles continue to be harvested. Nesting females and eggs are poached as intensively as their low numbers permit, and turtles are also taken opportunistically at sea. Not surprisingly, fishers pose the primary (direct) anthropogenic threat to sea turtles in Jamaica. Aside from providing meat protein, sea turtle eggs and body parts (especially the penis) are reputed to have aphrodisiac qualities or to enhance sexual performance — a deadly combination for a threatened species if those beliefs are culturally entrenched. Loss or degradation of nesting beaches. Most of Jamaica’s major beaches on the north and southwest coasts have already been rendered unsuitable or greatly diminished for sea turtle nesting. Essentially all mainland beaches are vulnerable to future development or exploitation for tourism, or for settlements and commerce. Destruction of foraging habitats. Jamaica’s coastal (aquatic) habitats have also been severely degraded. The island’s once impressive coral reefs are now in
Conservation of Jamaican amphibians and reptiles
293
deplorable condition, with live coral cover having been reduced to 5% in recent decades (Hughes, 1994). Jamaica’s fisheries are among the most depleted in the world, a factor that has contributed to loss of coral cover, as have damaging practices such as bottom trawling and dynamiting, and land borne pollution and siltation associated with coastal development (Jackson, 2008). In addition, sea grass beds are removed in some tourist areas, thus degrading the quality of green turtle foraging habitats. Invasive predators. Loss of nests to land-based IAS predators is a serious problem, especially on mainland beaches. Beaches in closer proximity to human settlements appear to suffer high rates of predation by dogs and mongooses; the impacts of Rattus, and feral and domestic cats, have not been ascertained, but are probably considerable. Dogs carried by fishers to offshore cays represent a threat to both nesting females and nests, perhaps resulting in a complete loss of nesting success on affected cays. Conservation recommendations Recovering Jamaica’s sea turtle populations is no longer an option, given the loss of historical nesting beaches to development. However, hope remains for the protection of some nesting beaches, as well as for the management of turtles using offshore waters and cays. Recommendations for recovering populations have been outlined in the Sea Turtle Recovery and Action Plan (STRAP) for Jamaica (Sutton et al., 2008). Unfortunately, the effort and resources required for habitat protection and targeted interventions are considerable. This underscores the imperative that scarce conservation resources be used wisely, and be deployed where the potential conservation benefits are likely to be greatest. The recommendation of the Jamaican STRAP that the PBPA be a priority site for sea turtle conservation is therefore endorsed fully. Specific recommendations are as follows: Public education. Changing the attitudes of the island’s current generation of fishers and turtle consumers is probably not possible. Jamaica is a poor country, and a sea turtle represents a valuable resource. So, while a general public education campaign is warranted, efforts should focus on school-aged children. Sea turtles should be portrayed as unique and spectacular animals in danger of both local and global extinction. Debunking the myth that sea turtle consumption confers strength in carnal pursuits would also be useful. Enforcement of existing legislation. Many laws in Jamaica are essentially ignored, in large part because they are not enforced. Moreover, problems of serious crime and unemployment push conservation-related enforcement to the back burner. But increased enforcement is precisely what is needed, and a few well publicized arrests would be a good start (Sutton et al., 2008). If fishers (and others) are aware that the illegal take of sea turtles or sea turtle eggs will result in a significant fine, confiscation of equipment (e.g., boats), and imprisonment, this could act as a strong
294
B.S. Wilson
deterrent. Otherwise, illegal exploitation will likely continue until the last turtle has been harvested. Protection of any remaining nesting beaches. The current construction activities on beaches and associated coastal habitats must be stopped. Unfortunately, the quick financial rewards derived from tourism, particularly in the form of direct foreign investment, are an overwhelming temptation; protecting the island’s few remaining undeveloped beaches will be a formidable task. Nevertheless, several environmental breaches by high profile, often foreign (e.g., Spanish-owned) mega-hotel developments have recently brought attention to the pitfalls of runaway tourism development. Advocacy by environmentalists may become critical, and one can only hope that the government will not mortgage the island’s future through unsustainable tourism development. Protection of offshore cays. Because of land-based threats to sea turtles nesting on mainland beaches, the island’s offshore cays are now considered to be the most important areas for sea turtle nesting. Increased patrols by the Jamaica Defense Force Coast Guard, and vigilance in preventing squatting and use by fishers, would have a major, positive impact. Protection of foraging grounds. Jamaica’s coral reefs are in deplorable condition and the factors that have degraded the island’s once rich reef systems are numerous (e.g., overfishing, use of dynamite, pollution, sediment runoff, climate change, etc.). Curtailing coastal development and minimizing land born contaminants should be a goal of the overall coastal areas management plan that the government will need to implement if the complete loss of coral reefs is to be averted. In addition, rampant over fishing contributes to the loss of corals through removal of algal grazing fishes, and this issue should be addressed with urgency. Investigate potential for other interventions. First, selected beaches along the Hellshire coast and isolated beaches elsewhere could be protected by predatorproof fencing — a technique that has proven to be highly effective elsewhere in the Caribbean (e.g., Mona Island — see NMFS and USFWS, 1993, and included references). Second, if beaches can be afforded protection from non-native mammalian predators and human poaching, then potential restocking with eggs from other beaches could be a recovery strategy worthy of consideration.
Conservation of Other Reptile Taxa Jamaican slider turtle (Trachemys terrapen) This endemic turtle historically occurred in suitable freshwater habitats across the island, but has now apparently been extirpated or greatly diminished at many localities (Tuberville et al., 2005). Overharvesting appears to be the primary activity
Conservation of Jamaican amphibians and reptiles
295
responsible for population reductions and extirpations. The species is CITES Appendix III, is ranked as Vulnerable on the IUCN’s Red List, and is listed as Endangered by the United States Fish & Wildlife Service (USFWS, 2008). However, T. terrapen is not covered by protective legislation in Jamaica. As a consequence, the harvest and sale of this species is legal on the island. Because its meat is reputed to contain “strong back” properties (i.e., an enhancer of male sexual performance), T. terrapen is at special risk, and is taken both opportunistically and through focused fishing effort. Reports of slider turtles being sold in the main Kingston market are disturbing, because source populations cannot sustain such a commercial demand. Perhaps more worrisome are reports of a new demand posed by recent Asian immigrants. Another threat is the potential for invasion by the redeared slider (T. scripta elegans), and resulting competition or hybridization. Redeared sliders are commonly sold in Jamaican pet stores, so such an introduction appears to be inevitable rather than possible. To date however, survey efforts in the western third of the island have not detected any established populations of T. s. elegans, nor has on-going genetic work revealed any evidence of hybridization (Parham et al., unpubl. data). The island-wide status of T. terrapen is unknown, but on-going survey efforts initiated in 2007 (Parham et al., unpubl. data) will remedy this deficiency in the near future. In addition, Tuberville et al. (2005) suggested the existence of distinct northern and southern forms, and this possibility is now under investigation (Parham, pers. comm.). Resolving this taxonomic issue is a high priority objective, and will be a key driver of future conservation planning. In addition to the completion of survey and taxonomic studies aimed at establishing distribution and status, the endemic slider should be added to the list of species protected by the WLPA. Based on a request from this author, NEPA recently (2009) began the consultation and evaluation process that should lead to T. terrapen being afforded full legal protection. A moratorium on the import and sale of T. s. elegans would reduce the potential for invasion, and public education initiatives might serve to reduce the probability of current captives being released or escaping into the wild. American crocodile (Crocodylus acutus) This wide-ranging species occurs from southern Florida to northern South America, and on the Greater Antillean islands of Cuba, Hispaniola, and Jamaica. In Jamaica, the species inhabits estuarine habitats, primarily along the south coast. Although the species’ distribution is relatively well known on Jamaica, the current size and status of the population are not. The species is fully protected in Jamaica by the WLPA, and is listed as an Endangered species by the USFWS. Internationally, C. acutus is ranked as Vulnerable by the current IUCN Red List, and is a CITES Appendix I species. Continued habitat loss, persecution, and an undetermined level of harvesting represent the primary threats to the species in Jamaica. Survey efforts should seek to establish the status of C. acutus populations across the island, and in particular, to identify critical nesting and nursery habitats.
296
B.S. Wilson
The most important conservation objective is the protection of remaining coastal habitats. In particular, the removal of mangroves and the loss of nesting beaches to tourism development should be curtailed, especially given the recent large scale loss of such habitats. Anguidae In Jamaica this family is represented by a single genus, Celestus, that has radiated to produce at least seven endemic species; an 8th native species, C. crusculus, also occurs on the Cayman Islands. This radiation is exceptional for the genus, given Jamaica’s relatively small size and geological youth, and is arguably the most distinctive feature of the island’s reptile fauna. The conservation status of the genus is also distinctive in its uncertainty: one species has not been documented in over a century, and several others were described from only single or a few specimens — and have not been recorded since. Given the biogeographical interest and conservation importance of this group, I will discuss each Celestus species separately. C. barbouri. Relatively widespread, but is considered to be uncommon, perhaps in large part due to the secretive nature of Celestus species generally. This species occurs widely throughout The Cockpit Country; primary threats therefore include deforestation and the prospect of bauxite mining. Protection of The Cockpit Country should ensure the persistence of this species, and no other conservations actions should be necessary. C. crusculus. Currently recognized as having three subspecies, one on the Cayman Islands and two in Jamaica, this is the most common and widespread Celestus; the species is locally abundant in natural areas, and also occurs in highly disturbed habitats such as backyards. Therefore, as presently described, the taxon is neither endemic to Jamaica nor of special conservation concern. However, this taxon is in need of revision. One former subspecies, C. c. molesworthi, has recently been recognized as a full species (Hedges, 2010; Henderson and Powell, 2009), but may have disappeared before this was appreciated (below).The priority objective is to establish the taxonomic and conservation status of this probable species complex. C. duquesneyi. Described from only a few specimens collected in the late 1930s at Portland Ridge (Parish of Clarendon), the species went unrecorded for half a century — in spite of collection efforts by experts searching in the type locality. Then, in 1997, survey work in the central Hellshire Hills (Parish of St. Catherine), ca 25 km east of Portland Ridge, confirmed the extant status of the species and extended its known geographical distribution (Wilson and Vogel, 2000; fig. 3). The persistence of the species at Portland Ridge remains unknown, but the availability of suitable habitat suggests that it probably still occurs there. C. duquesneyi should be considered threatened due to limited range, on-going habitat loss, and the impacts of
Conservation of Jamaican amphibians and reptiles
297
Figure 3. (a) The Jamaican iguana (Cyclura collei) was thought to be extinct for half a century until its “re-discovery” in the remote Hellshire Hills. (b) The Blue-tailed Galliwasp (Celestus duquesneyi) was also considered to be possibly extinct, until the species was similarly re-discovered in the Hellshire Hills in 1997. Photos courtesy of the Jamaican Iguana Recovery Group. (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm.)
IAS. Nevertheless, the species appears to be more common than previously thought, at least in the remaining primary forest of the Hellshire Hills. Protecting the Hellshire Hills and expanding existing IAS control efforts are the conservation priorities for this species. In addition, Portland Ridge should be surveyed to ascertain the species’ status in its type locality. Portland Ridge supports two bird shooting clubs that have erected gates and actively discourage tree cutting; these habitat conservation activities should be continued. Finally, C. duquesneyi would be an excellent candidate for re-introduction onto an IAS-free biodiversity reserve on the Goat Islands, which lie just west of the Hellshire peninsula and to the east of Portland Ridge (assuming the species does not already occur there).
298
B.S. Wilson
C. fowleri. Being a bromeliad specialist, C. fowleri well exemplifies the breadth of ecological diversification shown by this genus in Jamaica. Described in 1971 from a single specimen (Schwartz, 1971), the species has only been recorded a few times since, and always near the type locality. The species’ rarity in herpetological collections may reflect its cryptic occupation of bromeliads, and a limited range in what remains of The Cockpit Country’s forest. Conserving The Cockpit Country forest is the most critical, and perhaps the only conservation activity required to secure the persistence of this species. Ecological studies clarifying distribution and precise habitat requirements would enhance efforts to generate an overall conservation plan. C. hewardii. Has a wide distribution and appears to be relatively abundant in some localities, including disturbed habitats associated with human occupation. C. hewardii would probably be best described as vulnerable, and is probably second only to C. crusculus as the least threatened member of the genus. However, the species is widespread and appears to vary geographically; hence, additional taxonomic studies, especially genetic analyses, could have conservation significance. Moreover, no population estimates are available, so the species could well be persisting at levels far below those of historical times. C. microblepharis. Described from a single specimen (Underwood, 1959) and not recorded since. Although the species obviously existed in altered coastal habitat at the time of its discovery, subsequent tourism development has probably eliminated even its most marginal habitat. The species has been searched for repeatedly but unsuccessfully in recent decades (Hedges, pers. comm.); nevertheless, conducting additional surveys in and around the type locality is a conservation priority. For now the species must be regarded as possibly extinct, and its habitat probably lost altogether as well. C. molesworthi. Formerly considered to be a subspecies of C. crusculus, the status of C. molesworthi is currently unknown. The species has presumably lost most of its historical forest habitat along the northeast coast, and suffered from predation by mongooses and cats. Additional surveys aimed at delineating distribution and abundance are clearly warranted for this species. C. occiduus. Due to its large size, curious but poorly documented ecology, unclear historical distribution, and apparent rapid extinction in the 19th century, this is the most enigmatic member of the taxon. Known only from mostly anecdotal accounts and a handful of museum specimens, there is no evidence to confirm the persistence of C. occiduus beyond the date of the last cataloged museum specimen — collected around 1860 (Henderson, 1992). The extinction of C. occiduus has been attributed to the introduction of the mongoose in 1872, but other factors may have been important (e.g., habitat degradation). The only published natural history notes on C. occiduus reported that it lived in swamps and fed on fish and fruit — an unusual but not inconceivable diet
Conservation of Jamaican amphibians and reptiles
299
for a lizard (see Schwartz and Henderson, 1991). Most of the species’ likely historical habitat has been either eliminated or severely degraded. Recent habitat surveys focused on visiting former collection localities revealed that most of these areas are severely degraded and presumably unsuitable for C. occiduus (e.g., Black River Upper Morass, Bluefields) (McGinnity and Wilson, unpublished). And, while some interview information obtained from local residents and fishers is suggestive, recent survey and interview efforts have failed to uncover any compelling evidence that C. occiduus has persisted. Interestingly, Pregil et al. (1992) reported finding numerous C. occiduus bones in a Cockpit Country cave; the age of these bones was not reported, and the habitat, were the bones contemporary, is not consistent with the species’ documented habitat. Another possibility is that a second “giant” species occurred, but if we conservatively recognize only the swampinhabiting C. occiduus, both the species and its historical habitat appear to have perished. Additional surveys focused on historical localities, especially the Black River morass, are warranted. One contemporary report of a large “black-headed” galliwasp in the hills adjacent to the morass is encouraging, as this matches earlier descriptions of this unique species (McGinnity, pers. comm.). Iguanidae The endemic Jamaican iguana (Cyclura collei) is the island’s largest native land animal (fig. 3). Once considered to be extinct, C. collei was re-discovered in 1970, and again in 1990, in the same remote central portion of the Hellshire Hills (Woodley, 1971, 1980; Alberts, 1993). The 1970 “re-discovery” — the retrieval of a carcass from a pig hunter’s dog — generated surprisingly little international interest; but perhaps of more consequence, there was no resident herpetologist in Jamaica at the time. The 1990 re-discovery was different. This time a live (though mortally wounded) specimen was brought in to the Hope Zoo in Kingston, and this time Jamaica did have a resident herpetologist in the late Peter Vogel, at the University of the West Indies, Mona, to whom this paper is dedicated. Together with Rhema Kerr, then Curator of the Hope Zoo, Peter formed the Jamaican Iguana Research and Conservation Group (JIRCG) which embarked on a conservation crusade that is continuing today (Vogel et al., 1996; Wilson et al., 2004a, 2004b; Lewis et al., 2008). Current conservation activities focus on population monitoring, studies of the species’ ecology, invasive predator control, and advocacy for habitat protection. Ex situ activities include a multi-zoo captive breeding initiative and a headstart-release programme based on wild-caught hatchlings and operated out of the Hope Zoo. To date, over 100 headstarters have been repatriated into Hellshire, and these animals have demonstrated high survival rates and have integrated into the wild breeding population. Captive breeding was documented at the Hope Zoo in 2004, and at the Indianapolis Zoo (USA) in 2006. Foreign-born progeny will be used to establish a viable U.S.-based captive population that can serve as a hedge against local extinction in Jamaica; only animals born and raised in Jamaica are used in repatriation efforts.
300
B.S. Wilson
Conservation status. C. collei is listed as Critically Endangered by the IUCN (Red List), as an endangered species by the USFWS, and is a CITES Appendix 1 species. In Jamaica, the species is fully protected by the WLPA. The remnant population persists at low density in undisturbed sectors of the Hellshire Hills, especially in the south-central region. Overall population size is unknown, but published estimates suggest that only 50-200 adults may survive in the wild, perhaps fewer — and this assessment is consistent with the results of on-going population surveys (Wilson et al., unpubl. data). Primary threats include predation on young iguanas by cats and mongooses, predation on adults by dogs, and habitat loss resulting from charcoal production. Additional threats include the potential for large scale limestone mining and development projects. Most worrisome is the potential for residential or tourism development along the coast bordering the iguana’s remaining habitat; the construction of access roads into this isolated region would lead to further habitat degradation and increased penetration by non-native predators, and would likely lead to the extinction of the iguana (cf. Iverson, 1978). Conservation recommendations. At present, this species appears to be “conservation dependent”. In the absence of on-going predator control and captive management efforts, C. collei would probably decline to extinction in the present century. An international workshop to revise the Species Recovery Plan (SRP) for C. collei was held in July 2006. A seminal goal in the SRP is the restoration of the Goat Islands through invasive species eradications, and the subsequent re-introduction of the iguana. Indeed, the re-establishment of an iguana population on these isolated off-shore cays is arguably the most decisive single action that can be taken to safeguard the species from extinction. Once carrying capacity is reached on the Goat Islands, this population can be used to supplement the existing headstart programme by providing individuals for translocation back into the Hellshire Hills. In conjunction with enhanced predator control efforts this expanded re-introduction programme will be aimed at restoring natural iguana densities throughout the Hellshire Hills. Of course, this will only be possible if the remaining Hellshire forest is protected from charcoal burning and further development. The actualization of habitat protection in the Hellshire Hills and the restoration of the Goat Islands will be determined largely by issues of a political nature. Phyllodactylidae Another member of Jamaica’s “probably extinct” herpetofauna, the Jamaican giant gecko, Tarentola albertschwartzi, was not described until 1998 when a specimen collected in the 1800s surfaced at the National Museums of Scotland (Sprackland and Swinney, 1998). Known only from this type specimen, and with no specific locality data, T. albertschwartzi remains an enigma. However, unlike the small and secretive Sphaerodactylus species, T. albertschwartzi was a large lizard that should not have escaped detection for over a century if in fact it was extant. Moreover, although we know nothing of the species’ ecology, its large size would certainly
Conservation of Jamaican amphibians and reptiles
301
predispose it to becoming fodder for introduced mammalian predators. For now, this species must be considered as likely extinct. Polychrotidae Jamaica’s Anolis assemblage consists of six island endemics that resulted from adaptive radiation following a single colonization event (Hedges and Burnell, 1990). A 7th species, A. sagrei, is likely a more recent addition that arrived from Cuba as a human-mediated introduction (Stewart, 1977; Crombie, 1999). Five of the six endemics are widespread, and to varying degrees, take advantage of human-altered habitats (including buildings and yards). Some of these species reach high densities, and none of them are considered threatened. The sixth endemic, A. reconditus, is a high altitude species with a restricted range in the Blue Mountains (Underwood and Williams, 1959). This species can also co-exist in association with human occupation, which is a desirable characteristic for persisting in altered habitats, but should still be considered threatened. Overall then, members of this genus, as elsewhere in West Indies, seem to do well — perhaps even benefit from — some forms of human-mediated habitat alteration (Henderson and Powell, 2001). Habitat alteration may, however, diminish microhabitat separation and potentially encourage hybridization (see Jenssen, 1977). Scincidae The taxonomic status of the Greater Antillean skink (Mabuya sloanii) is now being re-evaluated using molecular techniques, and the Jamaican form will likely be recognized as a full species endemic to the island (Hedges, pers. comm.). Like the iguana, the skink probably occurred historically over much of the island’s southern dry forest belt. Today, the Hellshire Hills are regarded as the skink’s last stronghold (Vogel et al., 1996), although it occurs on Portland Ridge and perhaps in other, albeit disturbed, dry forest locations (e.g., Brazilletto Mountains). Although reasonably common in the Hellshire Hills, the species is subject to high rates of predation by the mongoose and feral cats, and its population densities are probably well below historical levels. The completion of taxonomic work is a conservation priority, as is the protection of the Hellshire Hills. In addition, should the Goat Islands be restored through the eradication of invasive mammals, the skink would be another ideal candidate for re-introduction onto such a protected, offshore biodiversity reserve. As with C. duquesneyi, the skink is assumed to have occurred on the Goat Islands in historical times; if not, establishment of a population on the Goat Islands would constitute a conservation introduction — an intentional introduction designed to safeguard the species because of habitat loss and IAS on the mainland of Jamaica. Sphaerodactylidae Aristelliger praesignis. Widespread and occurs commonly in both natural and altered habitats. In natural habitats the species’ persistence is of little conservation
302
B.S. Wilson
concern; in human-altered habitats it may experience competition with the ubiquitous non-native gecko Hemidactylus mabouia. As presently recognized, A. praesignis is not of conservation concern, and the species also occurs on the Cayman and Swan Islands. However, on-going molecular studies suggest that it represents a complex of species endemic to Jamaica (Hedges, pers. comm.). The over-riding conservation issue involving this taxon is genetic resolution, followed by status assessments of unique and range-restricted taxa. Sphaerodactylus species. There are eight described species of Sphaerodactylus from Jamaica, seven of which are endemic to the island. The non-endemic S. argus also occurs naturally in Cuba, and has been introduced to the Florida Keys and to the Yucatan peninsula (Krysko and Sheehy, 2005). In Jamaica the species is widespread and tolerant of high levels of disturbance; hence, it is not of special conservation concern. On the other hand, the endemic members of the genus are of conservation interest. S. goniorhynchus is a widespread taxon that displays considerable geographic variation. Because it may represent a “super species”, additional taxonomic work could reveal both new species and new conservation concerns; such additional studies are highly warranted. S. gilvitorques is a major “question mark” species, because its description was based on the only known specimen, which was collected in the middle of the 19th century. Unfortunately, the locality of that specimen was recorded only as “Jamaica”, which precludes the potential for site-focused survey effort. However, given the secretive nature of Sphaerodactylus generally, it may be premature to assume that the species is no longer extant. The remaining five endemic species are all range restricted and should be considered threatened (Hedges, pers. comm.). Teiidae Ameiva dorsalis has a wide but disjunct distribution around the island, with its main population being concentrated along portions of the South Coast. The species also occurs on a number of the Port Royal and Portland Bight cays, as well as in developed areas such as Port Royal and parts of Kingston. Given the species’ relatively wide distribution, occurrence on multiple offshore cays, and ability to persist even in highly disturbed habitats, it is not considered threatened. Because the species occurs in moderately to severely disturbed situations on the mainland (including Kingston backyards), no specific habitat conservation actions can be envisioned. Its occurrence on offshore cays should serve as a hedge against mainland population loss(es), and the cays should be protected to ensure the persistence of those subpopulations. Given the potential for genetic isolation, particularly on offshore cays, this species is also a candidate for molecular taxonomic studies.
Conservation of Jamaican amphibians and reptiles
303
Boidae The endemic Jamaican boa (Epicrates subflavus) occurs widely but discontinuously across Jamaica, and is absent from high elevations (Tzika et al., 2008). The species is protected by the WLPA, it is a CITES Appendix 1 species, it is listed as Vulnerable by the IUCN (2009), and it is considered Endangered by the USFWS. The boa is Jamaica’s largest terrestrial predator, and is known to consume threatened Amazona parrots (Koenig et al., 2007), and also the Critically Endangered Jamaican iguana (Wilson and van Veen, 2006). However, the boa is also a predator of the nonnative cane toad, and can succumb to the toxic assault resulting from toad ingestion, or attempts at same (Wilson et al., 2010). Crucially, the boa is helpless against the machete, and its population has no doubt suffered from centuries of persecution and habitat loss. No quantitative data on the boa population are available. Across the island it is considered uncommon to rare, but in areas recognized as its stronghold, such as Cockpit Country, it can be described as “locally common” in suitable habitat (S. Koenig, unpubl. data). However, it is threatened wherever it occurs. Aside from habitat loss and the impacts of IAS predators, persecution by humans is probably the greatest threat (Tzika et al., 2008). On the other hand, introduced European rodents may provide an alternate food source, though exploitation of this resource may put boas at risk of interacting with humans (Prior and Gibson, 1997). Current conservation initiatives include a public education campaign based out of the Windsor Research Centre in The Cockpit Country, where a mark-recapture and radio telemetry study is underway (S. Koenig, pers. comm.). Dipsadidae Jamaica historically supported four members of the genus Hypsirhynchus (formerly Alsophis or Arrhyton — see Hedges et al., 2009). Hypsirhynchus ater is (or was) the largest member of the taxon, and was a relatively common inhabitant that apparently ranged over much of the island (Gosse, 1851). Given the species’ ecology (diurnal, active foraging), it is perhaps unsurprising that it seems to have disappeared shortly after the introduction of the mongoose in 1872. The last museum specimens were collected around 1920-1930, and there have been no credible reports since that time (Henderson, 1992). Although the species is listed as Critically Endangered on the most recent Red List (IUCN, 2009), in all likelihood it is now extinct (Henderson and Powell, 2009). The other three members of this genus were formerly in the genus Arrhyton, and all are smaller than H. ater. Both H. callilaemum and H. funereum are fairly widespread and not uncommon in some areas. In spite of their reported diurnal activity patterns (Schwartz and Henderson, 1991), these two species were apparently less vulnerable to the mongoose than was H. ater, and neither species appears to be of serious conservation concern. H. callilaemum is rarely surface active during the day, and is therefore comparatively inconspicuous and immune to mongoose predation; furthermore, the species occurs in backyards debris, so it can
304
B.S. Wilson
clearly persist in highly modified habitats. The species has also been documented annually in pitfall traps in the Hellshire Hills up to 2010. Notably however, I have only once in over 14 years of field work encountered a surface active individual; again, the species’ cryptic behavior may have rendered it less vulnerable to predation by the mongoose or by other IAS predators (e.g., cats). On the other hand, genuine rarity cannot be ruled out due to the absence of population estimates. Hypsirhynchus funereum also appears to be reasonably abundant in some areas, and like H. callilaemum, may have avoided heavy losses to the mongoose due to its secretive ecology and behavior. Or, perhaps, selection imposed by the mongoose and other IAS predators has resulted in more wary and secretive behavior, or enhanced predator avoidance mechanisms. Hypsirhynchus polylepis has a more restricted range, and anecdotal evidence (e.g., interviews) suggests that it is less abundant than either H. callilaemum or H. funereum. Additional information on the distribution and abundance of H. polylepis would be useful, as this species appears to warrant conservation attention. Tropidophidae Formerly considered to be subspecies of the Hispaniolan Tropidophis haetianus (Schwartz, 1975; Schwartz and Henderson, 1991), there are three recognized Tropidophis species in Jamaica, all of which are endemic (Henderson and Powell, 2009). Two species, T. jamaicensis and T. stejnegeri, have relatively wide ranges on the south and north of the island (respectively), and can be locally abundant in appropriate habitat. The third species, T. stullae, appears to be restricted to the Portland Ridge and Hellshire Hills areas, and should be considered endangered due to range limitation and uncertainty regarding population status. A fourth taxon has recently been discovered in The Cockpit Country, and will be described as a full (new) species based on morphological and genetic distinctiveness (S.B. Hedges, pers. comm.). All members of the family Tropidophiidae are on CITES Appendix II, so Jamaica’s species are protected by international trade agreements; they otherwise enjoy no national level protection aside from that which is conferred to populations occurring in protected areas. Typhlopidae The Jamaican blind snake (Typhlops jamaicensis) occurs islandwide in both natural and disturbed habitats. The species’ fossorial and nocturnal habits probably render it largely protected from the mongoose, and it does not appear to be of conservation concern. But as with other widespread species, additional taxonomic work could well reveal the existence of cryptic species within the taxon.
Conservation of Jamaican amphibians and reptiles
305
Concluding Comments A disturbing but unifying theme in the endangerment of insular Caribbean biota is that human populations and their associated anthropogenic impacts are expanding and intensifying. Haiti represents a worst case scenario, where deterioration of the physical environment has precipitated an extinction crisis of as yet unknown proportions (Hedges and Woods, 1993). Although significant differences between Haiti and Jamaica are evident (e.g., island size, physical and cultural histories), Haiti nevertheless represents a realistic if depressing model of the likely fate of Jamaica’s natural habitats and inhabitants. The solution is as simple as its implementation is complicated: contain population growth, reduce consumption, and stop cutting down trees. The latter is worth repeating: stop cutting down trees.
Acknowledgements. This paper is dedicated to the late Peter Vogel, who was murdered in Jamaica in 2007. Peter was a pioneer in promoting the conservation of the island’s terrestrial species and habitats, and he gave many students an opportunity and encouragement (including me). Peter’s most important contribution was establishing the Jamaican Iguana Research and Conservation Group; had he not been in Jamaica at the time of the 1990 “re-discovery”, the species might well be extinct. Peter: more iguanas are nesting in central Hellshire these days, and all indications suggest that the species would be extinct if not for the efforts of our group. Walk good. I thank all who contributed their experience and insights to improving the manuscript, especially S.B. Hedges, R. Henderson, C. Levy, K. McLaren, and J. Parham, and an anonymous reviewer. Thanks also, to the many who have helped with my conservation projects in Jamaica, particularly the Hellshire Dream Team of Rick, Leego, Booms, and Killa. Much gratitude goes to the funders of this work, including Conservation International, the Disney Worldwide Conservation Fund, the Environmental Foundation of Jamaica, the International Iguana Foundation, several anonymous donors, and our international partners at the Fort Worth Zoo (particularly Rick Hudson and Nancy Lung), the Milwaukee County Zoo (Dawn Fleuchaus), and the Zoological Society of San Diego (Tandora Grant). Finally, I thank my son Adam, who enjoys the field work even more than I do, and inspires me to continue doing it.
References Alberts, A.C. (1993): The most endangered lizard in the world: The Jamaican iguana, Cyclura collei. Vivarium 5: 12-14. Alberts, A.C., Ed. (2000): West Indian Iguanas: Status Survey and Conservation Action Plan. IUCN — the World Conservation Union, Gland, Switzerland. Allsworth-Jones, P. (2008): Pre-Columbian Jamaica. The University of Alabama Press, Tuscaloosa.
306
B.S. Wilson
Atkinson, L., Ed. (2006): The earliest inhabitants: The dynamics of the Jamaican Taino. University of the West Indies Press, Kingston. Birdlife International (2008): Important Bird Areas in the Caribbean: Key sites for conservation. Wege, D.C., Anadon-Irizarry, A., Eds, Birdlife Conservation Series No. 15. Birdlife International (2009): Important Bird Area factsheet: Dolphin Head, Jamaica. Downloaded from the Data Zone at http://www.birdlife.org on 13/6/2010. Bjorndahl, K.A., Bolten, A.B. (2003): From ghosts to key species: Restoring sea turtle populations to fulfill their ecological roles. Sea Turtle Newsl. 100: 16-21. Blick, J.P. (2007): Pre-Columbian impact on terrestrial, intertidal, and marine resources, San Salvador, Bahamas (A.D. 950-1500). J. Nature Cons. 15: 174-183. Boxill, I., Lewis, R., Russell, A., Bailey, A. (2007): Political culture of democracy in Jamaica: 2006. LAPOP, Vanderbilt University, USA. Burrowes, P.A., Joglar, R.L., Green, D.E. (2004): Potential causes for amphibian declines in Puerto Rico. Herpetologica 60: 141-154. Cousens, P.N. (1956): Notes on the Jamaican and Cayman Island lizards of the genus Celestus. Brevoria 56: 1-6. Crombie, R.I. (1977): A new species of frog of the genus Eleutherodactylus (Amphibia: Leptodactylidae) from the Cockpit Country of Jamaica. Proc. Biol. Soc. Washington 90: 194-204. Crombie, R.I. (1985): Another new forest-dwelling frog (Leptodactylidae: Eleutherodactylus) from the Cockpit Country of Jamaica. Trans. San Diego Soc. Nat. Hist. 21: 145-153. Crombie, R.I. (1999): Jamaica. In: Caribbean Amphibians and Reptiles, p. 63-92. Crother, B.L., Ed., Academic Press, San Diego. Daszak, P., Scott, D.E., Kilpatrick, A.M., Faggioni, C., Gibbons, J.W., Porter, D. (2005): Amphibian population declines at savannah river site are linked to climate, not chytridiomycosis. Ecology 86: 3232-3237. Davis, S.D., Heywood, V.H., Herrera-MacBryde, O., Villa-Lobos, J., Hamilton, A.C., Eds. (1997): Centres of plant diversity: A guide and strategy for their conservation (Volume 3. The Americas). Cambridge, U.K.: WWF-World Wide Fund for Nature and IUCN-The World Conservation Union. IUCN. IUCN Publications Unit. Díaz, L.M., Cádiz, A., Chong, A., Silva, A. (2007): First report of chytridiomycosis in a dying toad (Anura: Bufonidae) from Cuba: A new conservation challenge for the island. EcoHealth 4: 172175. Diesel, R., Baurle, G., Vogel, P. (1995): Cave breeding and froglet transport — a novel pattern of anuran brood care in the Jamaican frog, Eleutherodactylus cundalli. Copeia 1995: 354-360. Epperson, D.M., Allen, C.R. (2010): Red imported fire ant impacts on upland arthropods in southern Mississippi. Am. Midl. Nat. 163: 54-63. Evelyn, O.B., Camirand, R. (2003): Forest cover and deforestation in Jamaica: An analysis of forest cover estimates over time. Int. Forestry Rev. 5: 354-362. Fitzpatrick, S.M., Keegan, W.F. (2007): Human impacts and adaptations in the Caribbean Islands: An historical ecology approach. Earth Envir. Sci. Trans. Roy. Soc. Edinburgh 98: 29-45. Floyd, H.B., Jenssen, T.A. (1983): Food habits of the Jamaican lizard, Anolis opalinus: Resource partitioning and season effects examined. Copeia 1983: 319-331. Gibbons, J.W., Scott, D.E., Ryan, T.J., Buhlmann, K.A., Tuberville, T.D., Metts, B.S., Greene, J.L., Mills, T., Leiden, Y., Poppy, S., Winne, C.T. (2000): The global decline of reptiles, déjà vu amphibians. Bioscience 50: 653-666. Gosse, P.H. (1851): A Naturalist’s Sojourn in Jamaica. Longman, Brown, Green, & Longmans, London. Grant, C. (1940): The herpetology of Jamaica II: The reptiles. Bull. Inst. Jamaica Sci. Ser. 1: 61-148. Hardt, M.J. (2009): Lessons from the past: The collapse of Jamaican coral reefs. Fish Fisheries 10: 143-158.
Conservation of Jamaican amphibians and reptiles
307
Hartley, L.M., Glor, R.E., Sproston, A.L., Powell, R., Parmerlee, J.S., Jr. (2000): Germination rates of seeds consumed by two species of Rock Iguanas (Cyclura spp.) in the Dominican Republic. Carib. J. Sci. 36: 149-151. Haynes, A.M., Sutton, R.L., Harvey, K.D. (1989): Conservation trends, and the threats to endemic birds in Jamaica, p. 827-838. In: Biogeography of the West Indies, Woods, C.A., Ed., Sandhill Crane Press, Inc., Gainesville Florida. Hedges, S.B. (1989): An island radiation: Allozyme variation in the Jamaican frogs of the genus Eleutherodactylus (Anura: Leptodactylidae). Carib. J. Sci. 25: 123-147. Hedges, S.B. (1993): Global amphibian declines: A perspective from the Caribbean. Biodivers. Conserv. 2: 290-303. Hedges, S.B. (2006): An overview of the evolution and conservation of West Indian amphibians and reptiles. Appl. Herpetol. 3: 281-292. Hedges, S.B. (2010): Caribherp: West Indian amphibians and reptiles (http://www.caribherp.net/). Pennsylvania State University, University Park, Pennsylvania. Accessed 21 March 2010. Hedges, S.B., Burnell, K.L. (1990): The Jamaican radiation of Anolis (Sauria: Iguanidae): An analysis of relationships and biogeography using sequential electrophoresis. Carib. J. Sci. 26: 31-44. Hedges, S.B., Couloux, A., Vidal, N. (2009): Molecular phylogeny, classification, and biogeography of West Indian racer snakes of the Tribe Alsophiini (Squamata, Dipsadidae, Xenodeninae). Zootaxa 2067: 1-28. Hedges, S.B., Diaz, L.M. (2011): The conservation status of amphibians in the West Indies. This volume. Hedges, S.B., Woods, C.A. (1993): Caribbean hot spot. Nature 364: 375. Henderson, R.W. (1992): Consequences of predator introductions and habitat destruction on amphibians and reptiles in the post-Columbus West Indies. Carib. J. Sci. 28: 1-10. Henderson, R.W., Berg, C.S. (2011): The herpetofauna of Grenada and the Grenada Grenadines: Conservation concerns. This volume. Henderson, R.W., Powell, R. (2001): Responses by the West Indian herpetofauna to human-influenced resources. Carib. J. Sci. 37: 41-54. Henderson, R.W., Powell, R. (2009): Natural history of West Indian reptiles and amphibians. University Press of Florida, Gainesville. Hughes, T.P. (1994): Catastrophes, phase shifts, and largescale degradation of a Caribbean coral reef. Science 265: 1547-1551. IUCN (2009): IUCN Red List of Threatened Species. Version 2009.2 (www.iucnredlist.org). Downloaded on 9 March 2010. Iverson, J.B. (1978): The impact of feral cats and dogs on populations of the West Indian rock iguana, Cyclura carinata. Biol. Cons. 14: 63-73. Jackson, J.B.C. (1997): Reefs since Columbus. Coral Reefs 16: S23-S33. Jackson, J.B.C. (2001): What was natural in the coastal oceans? PNAS 98: 5411-5418. Jackson, J.B.C. (2008): Ecological extinction and evolution in the brave new ocean. PNAS 105: 11458-11465. Jenssen, T.A. (1977): Morphological, behavioral and electrophoretic evidence of hybridization between the lizards, Anolis grahami and Anolis lineatopus necheri, on Jamaica. Copeia 1977: 270-276. Koenig, S.E. (2001): The fauna of Dolphin Head, Jamaica: A report on the status of wildlife diversity and the effects of habitat modifications on ecological communities. Unpub. Report to Dolphin Head Trust and UNDP. Koenig, S.E., Wunderle, J.M., Jr., Enkerlin-Hoeflich, E.C. (2007): Vines and canopy contact: A route for snake predation on parrot nests. Bird Conserv. Internat. 17: 79-91. Krysko, K.L., Sheehy, C.M. III (2005): Ecological status of the Ocellated Gecko, Sphaerodactylus argus argus Gosse 1850, in Florida, with additional notes from the Florida Keys. Carib. J. Sci. 41: 169-172.
308
B.S. Wilson
Lannoo, M.J., Townsend, D.S., Wassersug, R.J. (1987): Larval life in the leaves: Arboreal tadpole types, with special attention to the morphology, ecology and behavior of the oophagous Osteopilus brunneus (Hylidae) larvsae. Fieldiana Zool. 38: iv + 31. Lazell, J.D., Jr. (1966): Contributions to the herpetology of Jamaica — studies on Anolis reconditus Underwood and Williams. Bull. Inst. Jamaica Sci. Ser. 18: 5-15. Lewis, C.B. (1944): Notes on Cyclura. Herpetologica 2: 93-98. Lewis, C.B., Ed. (1949): Glimpses of Jamaican Natural History, Vol. 1. Institute of Jamaica, Kingston. Lewis, D.S. (2002): Contributions to the conservation of the Hellshire Hills herpetofauna: An analysis of mongoose diet, and radio-telemetry of head-started Jamaican iguanas. M.Phil. Thesis, University of the West Indies, Mona. St. Andrew, Jamaica. Lewis, D.S., Vogel, P., Wilson, B.S. (2008): Survival, dispersal, and home range of headstarted Jamaican iguanas, Cyclura collei. Carib. J. Sci. 44: 423-425. Lips, K.R., Brem, F., Brenes, R., Reeve, J.D., Alford, R.A., Voyles, J., Carey, C., Livo, L., Pessier, A.P., Collins, J.P. (2006): Emerging infectious disease and the loss of biodiversity in a Neotropical amphibian community. Proc. Natl. Acad. Sci. USA 103: 3165-3170. Lowe S., Browne M., Boudjelas S., De Poorter, M. (2000): 100 of the World’s Worst Invasive Alien Species: A selection from the Global Invasive Species Database. Published by The Invasive Species Specialist Group (ISSG) a specialist group of the Species Survival Commission (SSC) of the World Conservation Union (IUCN), 12pp. First published as special lift-out in Aliens 12, December 2000. Updated and reprinted version: November 2004. Lynn, W.G., Grant, C. (1940): The herpetology of Jamaica. Bull. Inst. Jamaica Sci. Ser. 1: 1-148. Mahon, R., Aiken, K. (1977): The establishment of the North American bullfrog, Rana catesbeiana (Amphibia, Anura, Ranidae) in Jamaica. J. Herpetol. 11: 197-199. Malcolm, J.R., Lie, C.R., Neilson, R.P., Hansen, L., Hannah, L. (2006): Global warming and extinctions of endemic species from biodiversity hotspots. Cons. Biol. 20: 538-548. McClenachan, L., Jackson, J.B.C., Newman, M.J.H. (2006): Conservation implications of historic sea turtle nesting beach loss. Front. Ecol. Environ. 4: 290-296. Mittermeirer, R.A., Gil, P.R., Hoffmann, M., Pilgrim, M., Brooks, T., Mittermeirer, C.G., Lamoreux, J., da Fonseca, G.A., Eds. (2005): Hotspots revisited: Earth’s biologically rishest and most endangered terrestrial ecoregions. Mexico City, CEMEX. Myers, N., Mittermeier, R.A., Mittermeier, C.G., da Fonseca, G.A.B., Kent, J. (2000): Biodiversity hotspots for conservation priorities. Nature 403: 853-858. National Marine Fisheries Service and U.S. Fish and Wildlife Service (1993): Recovery plan for Hawksbill turtles in the U.S. Caribbean Sea, Atlantic Ocean, and Gulf of Mexico. National Fisheries Service, St. Petersburg, Florida. Newman, M.E., McLaren, K.P., Wilson, B.S. (2010): Use of object-oriented classification and fragmentation analysis (1985-2008) to identify important areas for conservation in Cockpit Country, Jamaica. Envion. Monit. Assess., in press. Pounds, J.A., Bustamante, M.R., Coloma, L.A., Consuegra, J.A., Fogden, M.P.L., Foster, P.N., La Marca, E., Masters, K.L., Merino-Viteri, A., Puschendorf, R., Ron, S.R., Sanchez-Azofeifa, G.A., Still, C.J., Young, B.E. (2006): Widespread amphibian extinctions from epidemic disease driven by global warming. Nature 439: 161-167. Pounds, J.A., Crump, M.L. (1994): Amphibian declines and climate disturbance — the case of the Golden Toad and the Harlequin Frog. Cons. Biol. 8: 72-85. Powell, R., Inchaustegui, S.J. (2009): Conservation of the herpetofauna of the Dominican Republic. Appl. Herpetol. 6: 103-122. Pregil, G.K., Crombie, R.I., Steadman, D.W., Gordon, L.K., Davis, F.W., Hilgartner, W.B. (1992): Living and late Holocene fossil vertebrates, and the vegetation of the Cockpit Country, Jamaica. Atoll. Res. Bull. 353: 1-19. Prior, K.A., Gibson, R.C. (1997): Observations on the foraging behavior of the Jamaican Boa, Epicrates subflavus. Herpetol. Rev. 28: 72-73.
Conservation of Jamaican amphibians and reptiles
309
Rampersad, S.R. (2009): Targeting the Jamaican Ostionoid: The Blue Marlin Archaeological Project. Caribb. Q. 55: 23-41. Rand, A.S. (1967): Ecology and social organization in the iguanid lizard Anolis lineatopus. Proc. U.S. Nat. Mus. 122: 1-79. Ricketts, T.H., Dinerstein, E., Boucher, T. et al. (2005): Pinpointing and preventing imminent extinctions. PNAS 102: 18497-18501. Rosenberg, G., Muratov, I.V. (2006): Status report on the terrestrial Mollusca of Jamaica. Proceedings of the Academy of Natural Sciences of Philadelphia 155: 117-161. Schloegel, L.M., Picco, A.M., Kilpatrick, A.M., Davies, A.J., Hyatt, A.D., Daszak, P. (2009): Magnitude of the US trade in amphibians and presence of Batrachochytrium dendrobatidis and ranavirus infection in imported North American bullfrogs (Rana catesbeiana). Biol. Cons. 142: 1420-1426. Schwartz, A. (1971): A new species of bromeliad-inhabiting galliwasp (Sauria, Anguidae) from Jamaica. Brevoria, Mus. Comp. Zool. 371: 1-10. Schwartz, A. (1975): Variation in the Antillean Boid snake Tropidophis haetianus Cope. J. Herpetol. 9: 303-311. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. University of Florida Press, Gainesville, Florida. 720 p. Sloane, H. (1725): A voyage to the islands Madera, Barbados, Nieves, St. Christophers, and Jamaica; with the natural history. . . of the last of these islands. London. Sprackland, R.G., Swinney, G.N. (1998): A new species of giant gecko of the genus Tarentola (Reptilia: Squamata: Gekkonidae) from Jamaica. J. Zool., Lond. 245: 73-78. Spiller, D.A., Schoener, T.W. (1990): A terrestrial field experiment showing the impact of eliminating top predators on foliage damage. Nature 347: 469-472. St. Vincent MHE (2010): The fourth National Biodiversity Report of St. Vincent and the Grenadines to the UNCBD. Kingstown, Ministry of Health and the Environment, The Government of St. Vincent and the Grenadines. Stewart, M.M. (1977): The role of introduced species in a Jamaican frog community. Act. Symp. Int. Ecol. Trop. 1: 111-146. Stuart, S.N., Chanson, J.S., Cox, N.A., Yound, B.E., Rodrigues, A.S.L., Fischman, D.L., Waller, R.W. (2004): Status and trends of amphibian declines and extinctions worldwide. Science 306: 17831786. Sutton, A.H., Kerr, R., Donaldson, A. (2008): Draft WIDECAST Sea Turtle Recovery Action Plan for Jamaica, Eckert, K.L., Ed., CEP Technical Report, UNEP Caribbean Environment Programme, Kingston, Jamaica. 102 pp. Thayer, G.W., Bjorndahl, K.A., Ogden, J.C., Williams, S.L., Zieman, J.C. (1984): Role of larger herbivores in seagrass communities. Estuaries 7: 523-532. Thompson, R.L. (1996): Larval habitat, ecology, and parental investment of Osteopilus brunneus (Hylidae). In: Contributions to West Indian Herpetology: A tribute to Albert Schwrtz, p. 259269. Powell, R., Henderson, R.W. Eds, Society for the Study of Amphibians and Reptiles, Ithaca, New York. Trivers, R.L. (1976): Sexual selection and resource-accruing abilities in Anolis garmani. Evolution 30: 253-269. Tuberville, T.D., Buhlmann, K.A., Bjorkland, R.K., Booher, D. (2005): Ecology of the Jamaican slider turtle (Trachemys terrapen), with implications for conservation and management. Chelonian Conserv. Biol. 4: 908-915. Tzika, A.C., Koenig, S., Miller, R., Garcia, G., Remy, C., Milinkovitch, C. (2008): Population structure of an endemic vulnerable species, the Jamaican boa (Epicrates subflavus). Mol. Ecol. 17: 533-544. Underwood, G. (1959): A new Jamaican galliwasp (Sauria, Anguidae). Brevoria, Mus. Comp. Zool. 102: 1-13.
310
B.S. Wilson
Underwood, G., Williams, E. (1959): The anoline lizards of Jamaica. Bull. Inst. Jamaica Sci. Ser. 9: 1-48. USFWS (United States Fish & Wildlife Service) (2008): Species Information Threatened and Endangered Animals and Plants (www.fws.gov/endangered/wildlife.html). Vogel, P. (1994): Evidence of reproduction in a remnant population of the endangered Jamaican Iguana, Cyclura collei (Lacertilia, Iguanidae). Carib. J. Sci. 30: 234-241. Vogel, P., Nelson, R., Kerr, R. (1996): Conservation strategy for the Jamaican iguana, Cyclura collei. In: Contributions to West Indian Herpetology: A Tribute to Albert Schwartz, p. 395-406. Powell, R., Henderson, R.W., Eds, Society for the Study of Amphibians and Reptiles, Ithaca, New York. Williams, E.E. (1999): Over 300 years of collecting in the Caribbean, p. 1-30. Crother, B.L., Ed., Academic Press, San Diego. Wilson, B.S., Alberts, A.C., Graham, K., Hudson, R., Kerr, R., Lewis, D., Lung, N., Nelson, R., Thompson, N., Kunna, J.L., Vogel, P. (2004a): Survival and reproduction of repatriated Jamaican Iguanas: Headstarting as a viable conservation strategy. In: Iguanas: Biology and Conservation, p. 220-231. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Berkeley and Los Angeles, University of California Press. Wilson, B.S., Horrocks, J.A., Hailey, A. (2006): Conservation of insular herpetofaunas in the West Indies. Appl. Herpetol. 3: 181-195. Wilson, B.S., Koenig, S.E., van Veen, R., Miersma, E., Rudolph, D.C. (2011): Cane toads a threat to West Indian wildlife: Mortality of Jamaican boas attributable to toad ingestion. Biol. Invasions 13: 55-60. Wilson, B.S., Robinson, O.F., Vogel, P. (2004b): Status of the Jamaican Iguana (Cyclura collei): Assessing 15 years of conservation effort. Iguana 11: 224-231. Wilson, B.S., van Veen, R. (2006): Jamaican Iguana Recovery Project. Iguana 13: 119-120. Wilson, B.S., Vogel, P. (2000): A survey of the herpetofauna of the Hellshire Hills, Jamaica, including the rediscovery of the Blue-tailed Galliwasp (Celestus duquesneyi Grant). Carib. J. Sci. 36: 244249. Wilson, S.M. (2007): The archaeology of the Caribbean. Cambridge University Press, Cambridge, U.K. Woodley, J.D. (1971): Hellshire Hills Scientific Survey, 1970. Sci. Rep. Univ. West Indies, Kingston. Woodley, J.D. (1980): Survival of the Jamaican iguana, Cyclura collei. J. Herpetol. 14: 45-49. Young, B.E., Stuart, S.N., Chanson, J.S., Cox, N.A., Boucher, T.M. (2004): Disappearing Jewels: The Status of New World Amphibians. NaureServe, Arlington, Virginia. Zupanovic, Z., Musso, C., Lopez, G., Louriero, C.L., Hyatt, A.D., Hengstberger, S., Robinson, A.J. (1998): Isolation and characterization of iridoviruses from the giant toad Bufo marinus in Venezuela. Dis. Aquatic Org. 33: 1-9.
Accepted: August 16, 2010 (AH).
The terrestrial herpetofauna of Martinique: Past, present, future Michel Breuil Département Systématique et Évolution, Taxonomie et Collections, UMS 602, Amphibiens-Reptiles, Muséum National d’Histoire Naturelle, 25 rue Cuvier, 75005 Paris, France e-mail:
[email protected] Abstract. I present an up-to-date annotated list of the herpetofauna of Martinique, and try to explain the causes responsible for the eradication of species such as Leptodactylus fallax, Boa sp. and Leiocephalus herminieri. Mabuya mabouya and Liophis cursor have not been seen for decades and may have been extirpated. It cannot be established that the mongoose was responsible; Didelphis marsupialis, of recent introduction, may have played an important role. Introduced and invasive species are numerous in Martinique: Chaunus marinus, Scinax ruber, Eleutherodactylus johnstonei, Gymnophthalmus underwoodi, Iguana iguana, Gekko gecko, Hemidactylus mabouia, without considering escaped pets and the dubious case of Allobates chalcopis as an endemic species. I also present the restoration plan for Iguana delicatissima in the French West Indies and the conservation work for this species in Martinique; increase of nesting areas, translocation, creation of numerous protected areas, and control of I. iguana. Of a total of 13 endemic and indigenous species from Martinique, three are definitely and a further two are probably eradicated. Including Guadeloupe, the French West Indies have the highest loss of herpetological biodiversity among all the islands in the West Indies. Key words: Amphibians; Chancel Islet; conservation; French West Indies; Iguana delicatissima; invasive species; Martinique; reptiles; restoration plan; threats.
Introduction The book of Schwartz and Henderson (1991) was the first attempt to realise, at the Caribbean level, an account of the distribution of all the species of amphibians and reptiles. Only a few islands have been worked in depth with thorough field work, to produce an atlas with precise distribution ranges for all the herpetofauna. The Guadeloupe islands with Saint-Barthélemy and Saint-Martin (Breuil, 2002) and now Martinique are the islands where the herpetofauna is the best known, but there are many species that must still be worked out in detail. If we have a good understanding of the distribution of the amphibians and reptiles in the French West Indies (FWI), I do not share the opinion of Lorvelec et al. (2007: 132) that we
312
M. Breuil
have accurate distribution ranges for the majority of species at the island and islet levels. As an example, the precise altitudinal distribution is not known for most reptiles species. Moreover, the small French islets are poorly known as shown by the recent discovery of Alsophis sanctonum sanctonum on Ilet à Cabrit or Hemidactylus mabouia and Thecadactylus rapicauda on Ilet Kahouanne (Guadeloupe). This present paper brings the description of the situation on Martinique up to date, including all the recent changes that occurred since the last published works on species distribution. I worked on Martinique since 1994 with field and historical approaches (Breuil, 2003), and also made field trips to Dominica, Saint Lucia and Antigua with colleagues from the Durrell Wildlife Conservation Trust (DWCT, Jersey) to compare the herpetofauna of islands that were less disrupted by human activities. Much of the resulting data are unpublished, and a companion volume to Breuil (2002) on Guadeloupe is planned for Martinique. At the time of writing, I have more than 3000 personal species-localities for Martinique, which have been given to offices such as PNRM or DIREN for distribution maps (full titles of local organizations are given in the Acknowledgements). With the help of old naturalists’data, museum collections, biogeographical and geological analysis, published literature and the results of more than 50 weeks in the field looking for amphibians and reptiles in Martinique, I present in this paper more details and newer information than in Breuil (2002, 2003, 2004) on the herpetological community of this island before European arrival (Past), its recent situation (Present) and current and likely changes (Future). I consider that we are now in this future period with respect to extinction and the arrival of invasive herpetofauna species. I describe in this paper the herpetofauna of Martinique as it was probably at the beginning of European colonization; what I call the Past period. I might have chosen the date of arrival of the first Amerindians to define this first period, but as there are few reptile bones in the archaeological remains in Martinique, it is impossible to evaluate any impact for that first human colonization. This first period may conveniently end in the middle of the 19th century with the death of François-Joseph L’Herminier in 1866, who sent a lot of animals to the Paris museum (MNHN) at a time where there were not too many changes in the FWI (Breuil, 2002). The second period is from that time to the beginning of the 1980s; this period is considered as the Present. This period is marked by an increase in the destruction of habitats and the importation and subsequent proliferation of mongoose and raccoon. Cats, dogs, rats, and pigs were present from the start of colonization (Du Tertre, 1667) and became more and more abundant during this period. For example, British soldiers had Manx cats with them when they were in Marie-Galante during the Napoleonic wars, and it is sometimes possible to see offspring of these tailless cats there. This period was also characterised by massive destruction of Bothrops lanceolatus (Pinchon, 1967). The third period, the Future, has the same characteristics as the second period at the level of the FWI, but its origin is marked by the arrival of many amphibian and
The terrestrial herpetofauna of Martinique: Past, present, future
313
reptile species from South America, North America, other Caribbean islands, and indeed from other parts of the world as escaped pets or waifs. Some of these animals may have great impact on the local fauna. I analyse the status of each species that reproduces or was known to reproduce in Martinique, and some others, and divide the herpetofauna into eight groups according to their status and Antillean geographical ranges: • Vanished species that are no longer present in Martinique even if there are close relatives on other Caribbean islands: Leptodactylus fallax (Leptodactylidae), Boa sp. (Boidae), Leiocephalus herminieri (Tropiduridae). • Nearly-vanished species that may survive in some remote parts such as tiny islets: Mabuya mabouya (Scincidae), Liophis cursor (Colubridae). • Endemic species, with respect to current taxonomic opinion, that are only present in Martinique: Bothrops lanceolatus (Viperidae), Anolis roquet (Polychrotidae), Sphaerodactylus vincenti (Gekkonidae). • Indigenous Lesser Antilles species that are considered as endemic from the Caribbean region: Eleutherodactylus martinicensis (Brachycephalidae), Gymnophthalmus pleii (Gymnophthalmidae), Iguana delicatissima (Iguanidae), Thecadactylus rapicauda (Gekkonidae), Leptotyphlops bilineatus (Leptotyphlopidae). • Deliberately-introduced species, that are definitely attributable to human transport: Chaunus marinus (Bufonidae), Iguana iguana (Iguanidae), Gekko gecko (Gekkonidae), Chelonoidis carbonaria (Testudinidae). • Involuntarily-introduced invasive species, that were not known in the Past or are far away from their original geographical range: Eleutherodactylus johnstonei (Brachycephalidae), Scinax ruber (Hylidae), Hemidactylus mabouia (Gekkonidae), Gymnophthalmus underwoodi (Gymnophthalmidae). • Species escaped from captivity and waifs that have not yet become established: various species. • Species with dubious status or wrong geographical attribution: Allobates chalcopis (Aromobatidae), Ameiva major (Teiidae).
Vanished Species Leptodactylus fallax The presence of Leptodactylus fallax in Martinique is well documented by numerous old texts (Anonyme de Carpentras, 1620; Bouton, 1640; Du Tertre, 1654, 1667; Breton, 1666; Labat, 1724; Thibault de Chanvalon, 1756; Leblond, 1813; Moreau de Jonnès, 1818a, 1858; Plée, 1820). A specimen caught by Moreau de Jonnès has always been in the Paris collection (MNHN.4487) but the locality is simply mentioned as Antilles, so I cannot affirm that this was from Martinique. Du Tertre (1667) was the first to provide a description of the foam nest of this species. To Du Tertre this frog was 14 inches long, whereas it was one foot long for Labat (1724). L. fal-
314
M. Breuil
lax from Montserrat and Dominica seem to be smaller than the Martinique frogs, perhaps because they were heavily hunted by man for food (Daltry, 2002; McIntyre, 2003). To Plée, they seemed to be identical between Dominica and Martinique. Recently Hedges and Heinicke (2007) were surprised by the absence of divergence between the two extant populations of L. fallax in Montserrat and Dominica, and suggested that this situation arose by human introductions. If this is true, it is possible that the species was introduced by Amerindians in some islands and that the population in Martinique was the same. The genetic homogeneity of Iguana delicatissima is similarly interpreted in terms of recent introductions by Mallone and Davis (2004). This frog was hunted by Europeans (Bouton, 1640; Labat, 1724; Thibault de Chanvalon, 1756; Leblond, 1813; Plée, 1820) and by Amerindians. Hunting by Amerindians should have been low because this species is still present in Dominica which they inhabited for a long time. The only precise old localities in Martinique are in Macouba (Labat, 1724), the vicinity of Saint-Pierre, Pitons du Carbet (Leblond, 1813), and Lamentin (Plée, 1820). The species is reported by the different authors to be very abundant. The last testimonies of the presence of L. fallax in Martinique are those of Plée (1820). In Martinique, there are enough pristine areas suitable for this species to exclude habitat destruction as the main cause of extinction. For example, Leblond (1813) hunted L. fallax between the Pitons du Carbet, that has always been a very wild place. Hunting by Europeans (Du Tertre, 1667) may be one of the major causes of the decline, as in Dominica where until recently between 18,000 and 36,000 mountain chickens were killed each year for human consumption (McIntyre, 2003). As the manicou (Didelphis marsupialis) is very abundant in Martinique (Breuil, pers. obs.), and as this species seems to have been introduced in the 18th century (Breuil, 2003), it is also possible that this nocturnal marsupial hunted L. fallax to extinction. The manicou is fully protected in Martinique where it was until recently thought to be a local endemic. The manicou is reported to hunt along the banks of streams and rivers (Daltry, 2002), so as they frequent the same habitat it is easy for the manicou to feed on the frog. It is noteworthy that Daltry (2002) reported of L. fallax that their “naivety when approached is typical of an animal that has evolved in the absence of. . . large predators. Frog species from other tropical continental areas, on the other hand, tend to have. . . more advanced avoidance or defence behaviours”. This is one more argument to consider that the manicou is a recent comer to Martinique that has modified the original herpetofauna. The manicou (and the raccoon) were not considered as important predators in the FWI because, as they were described as endemic subspecies or species, it was believed that the indigenous fauna had adapted to their presence. Classical introduced predators (cats, mongooses, rats, dogs) and feral pigs may have also contributed to the extinction of L. fallax in Martinique but there are no data to support this hypothesis for Martinique. Barbour (1930) and Westerman (1953) suggested the impact of the mongoose on L. fallax, but without precise arguments.
The terrestrial herpetofauna of Martinique: Past, present, future
315
The mongoose is strictly diurnal whereas L. fallax is strictly nocturnal. Other external causes may include the volcanic activity of Montagne Pelée, as for the activity of the Soufrière Hills in Montserrat that deposited acidic ash and decreased the area of suitable habitat. The causes of extinction of this frog are thus not established in Martinique, but the causes of the drastic decrease of the populations of Dominica and Montserrat are now known (Daltry, 2002; McIntyre, 2003). I work on a project with the DWCT to breed this species in Martinique (Breuil, 2007). Leiocephalus herminieri Leiocephalus herminieri is known in France as holotropide de l’Herminier (Breuil, 2002). According to Duméril and Bibron (1837), the specimens were sent to the Paris museum from Martinique by Plée and Guyon, and from Ile de la Trinité (Trinidad) by L’Herminier. This kind of erroneous localization corresponds to the harbour from where the boat carrying the collections left the Lesser Antilles or South America (Breuil, 2002, 2003). Roger Bour (pers. comm., 2003) subsequently studied the herpetological collection of the Bordeaux Museum of Natural History, and found a Leiocephalus herminieri labelled Guadeloupe. So, we have three different origins for this species: Trinidad, Martinique and Guadeloupe, but as I have already demonstrated beyond any doubt (Breuil 2002, 2003), L. herminieri lived in Martinique. The causes of extinction of this lizard are not established; it seems to have been abundant in the 18th century (Breuil, 2003), but its range could also have been very restricted. L. herminieri may have been a beach dweller, as are other species in the genus, and if so tsunami waves may have destroyed its last littoral habitats in Martinique. The 1843 earthquake in Guadeloupe produced waves that may have submerged its habitats, as a 1-2 m increase of sea level was detected hundreds of kilometres from the epicentre. Lorvelec et al. (2007) suggest that this species possesses morphological characteristics that make it vulnerable to the mongoose. As there is a gap of more than 50 years between the last sighting of this lizard and the introduction of the mongoose, this is an unlikely cause of extinction. Boa sp. The first citation of Boa in Martinique is said by Lorvelec et al. (2007) to date back to Anonyme de Carpentras (1620), but it is impossible to affirm that this refers specially to Martinique. The presence in Martinique is first reliably reported by Labat (1724) when he described in 1699 in the vicinity of Macouba “une couleuvre qui poursuivait une grenouille, . . . l’animal paraissait avoir 10 pieds de long” (a snake that ran after a frog, . . .the animal seemed to be 10 feet long). Labat wrote that this snake is non poisonous and that it is well known to eat frogs. Moreover, he said that this couleuvre is an enemy of Bothrops and as a consequence people do not kill it. This citation of Labat is the only text that refers to a huge snake in Martinique. Bonny (2007) placed the boas from Saint Lucia (Boa orophias) and
316
M. Breuil
Dominica (Boa nebulosa) into separate species. If this point of view is correct then the boa from Martinique may have belonged to another endemic species. The extinction of the boa in Martinique seems to be quite ancient. Thibault de Chanvalon (1756), Plée (1820), and Moreau de Jonnès (1816, 1818a, 1818b, 1821, 1822, 1858) never mentioned this snake although these three naturalists were very often in the field collecting specimens for the Paris museum (Breuil, 2002, 2003). So, at the beginning of the 19th century this species was very rare to the point where it could not be found by naturalists. Saint Lucia is inhabited by the mongoose and the manicou, yet Boa orophias is still present, so that these mammals are unlikely to have caused the extinction of the boa in Martinique. Perhaps it was killed because it was mistaken for a lancehead or because it killed poultry.
Nearly-Vanished Species Mabuya mabouya Mabuya mabouya (see Breuil, 2002 and Miralles, 2005 for the taxonomic problems concerning this species) is the rarest lizard in the FWI. The type of this species (now lost) that was used by Lacepède was probably sent to Paris by Thibault de Chanvalon with other reptiles from Martinique (Breuil, 2002). Plée (1820) also collected some specimens in Martinique (Breuil, 2002) and Miralles (2005) chose one of these specimens, which have the same geographical origin as the type, as a neotype. When the situation of this species in Dominica, Saint Lucia, Guadeloupe and Martinique is compared, it is easy to see that in all the islands with the mongoose, there is no Mabuya sp. In Guadeloupe, M. mabouya is only present in three mongoose-free islands (Petite Terre, Désirade, Ilet à Cochons; Breuil, 2002). This species may thus have been a victim of the mongoose, but there is no direct evidence of this, only correlation. When it is at low density, as in Petite Terre and la Désirade, it is not easy to spot this lizard. I did not see this species in Martinique, but optimism makes me hope that M. mabouya is still present in some remote islet. Liophis cursor Liophis cursor was well known in the 18th and 19th centuries (Moreau de Jonnès, 1818a). The Paris museum has 14 specimens of this species determined by Dixon (1981), but all except three are labelled with wrong or imprecise geographical origins (Brazil, Chile, India, French Guiana, undetermined); this shows once again that it is difficult to give credit to some historical labels. Toulouse Natural History Museum possesses two specimens (Dubois and Bour, 1992). To the best of my knowledge there are no 20th century published observations of this species in Martinique main island, but Père Pinchon caught a specimen of this species in 1965 in the vicinity of Fort-de-France which was given at the beginning of the 1990s to a Kansas museum. There are several records of its presence in the 1970s. The latest
The terrestrial herpetofauna of Martinique: Past, present, future
317
published observations were made in Rocher du Diamant in 1962 by Lazell (1967) and two specimens were collected by Père Pinchon and Marcel Bon-Saint-Côme in 1964 and 1968 (these specimens are in the MPP), so the comment of Lorvelec et al. (2007: 138) concerning this species is inaccurate. With Mark Day, I searched the Rocher du Diamant in dry season 1997, but we did not observe this snake, although fishermen reported it basking on rocks. As an elusive species, the Martinique racer could survive in some places, as was shown recently for Alsophis antillensis in Basse-Terre and Grande-Terre (Béatrice Ibéné, pers. comm., 2003) and on Ilet à Cabrit (new locality for Les Saintes as Alsophis sanctonum sanctonum) despite the presence of cats, mongooses, rats, and humans that kill all snakes. In Martinique, the confusion between the racer and the lancehead may be an important cause of the decline and perhaps eradication of this species, but other predators may also have played a part.
Endemic Species Bothrops lanceolatus Bothrops lanceolatus is the most famous endemic species in Martinique, with Saint Lucia the only two oceanic islands in the West Indies to be inhabited by a lancehead. At the time of colonization, Martinique was infested by this snake (Du Tertre, 1654) which was said to be an obstacle to the settlement of the island. An old legend reported by Du Tertre (1667) tries to explain the origin of Bothrops in Saint Lucia and in Martinique as the result of biological warfare between Amerindian groups; Arawaks were supposed to have imported these snakes from South America to make war on Caribs. Wüster et al. (2002) performed a genetic analysis of the two insular Bothrops species with respect to their South-American relatives (B. atrox — B. asper complex). They found that the two species belong to the same clade that may have diverged from their parental continental species some 4.2-8.9 Mya. To them, the first step of the colonization was Saint Lucia, then by dispersion on floatsam to Martinique between 3.1-6.5 Mya. This analysis used only one specimen of B. lanceolatus and two for B. caribbaeus. Nevertheless, taking into account the supposed time of divergence, we should expect to find some genetic variation within each species. I provided R. Thorpe and W. Wüster more than 20 tissue samples of B. lanceolatus from northern Martinique, but they did not find any polymorphism for the gene studied (cytochrome c). As the anti-venom serum producted for B. lanceolatus some 40 years ago is not as efficient as before, local authorities decided in 2007 to produce a new one. This was the opportunity to catch Bothrops that will be also used to study their genetic and morphometric differentiation. The native Caribbean name for Martinique is Ioüanacaera and for Saint Lucia it is Ioüanalao (Breton, 1666). The first name means the island with iguanas and the second the place (island) where iguanas are found. Breuil (2002, 2003) proposed a hypothesis to explain this denomination. Here, I propose another non-exclusive
318
M. Breuil
interpretation for these names. For the guyano-amazonian populations and for rural people in Martinique it is very dangerous to call the Bothrops by its real name, “serpent”. Numerous expressions are used in Martinique to name it: bête longue, cravate, ennemie, vipère. It is possible that Amerindians used the name Ioüana instead of snake (Ahoüa, Ioulia, Iouiliati, Iuanna) as a stratagem to name these islands without fearing the snake’s vengeance. This interpretation is supported by the fact that Ilet Chevallier (south Martinique) is also called Ilet à Lézards but was inhabited by B. lanceolatus (Rufz de Lavison, 1859). Barbour (1930) supposed that the mongoose was responsible of the decline of Bothrops in Martinique and Saint Lucia, De Lalung (1934) thought that both man and mongoose were responsible, and Lorvelec et al. (2007) proposed that the decline of Bothrops may be related to human predation. The situation is not as simple as these suggestions. Pinchon (1967) reported the number of bounties paid for the destruction of the snake in the 1960s. These figures do not give the real number of lanceheads killed each year because people conserved the heads in salt or rum, waiting for the authorities to have the money to pay the bounty. Moreover, among the heads of snakes there are heads of toads and anoles which are in such poor condition that they were thought by the authorities to be parts of real snakes (Lescure, pers. comm., 1997)! Nevertheless, these figures give an approximate rate of 5-10 snakes killed per year per km2 . Thus, we cannot consider that Bothrops was rare in the 1960s. Today, the lancehead’s main prey seems to be rodents and birds. In Martinique, a lot of pesticides (chlordecone) are used against pests in banana fields; these pesticides are ingested by rats and birds, and in turn are accumulated in the snakes. Dead rats are often found in rural places, and such poisoned prey may be lethal or physiologically damaging to snakes. The destruction and fragmentation of habitats, the use of more and more pesticides, the killing of the snake for bounty (about $20 in 1992) are all factors that combined to cause the decline of this species. In summer 2007, a huge catching operation was organised to collect snakes with the help of firemen, local snake hunters, etc.; less than 20 lanceheads were caught alive in three weeks. Anolis roquet Anolis roquet is the most common lizard in Martinique, present on all the mountains: Mont Conil, Morne Jacob, Montagne Pelée, Pitons du Carbet, Montagne du Vauclin. Its range is thus from sea level to the top of the island in undisturbed habitats (Breuil, unpubl. data). Its highest altitude is not 920 m as supposed by Schwartz and Henderson (1991) and Thorpe and Stenson (2003); I found it on Plateau du Palmiste (1200 m asl) and inside the caldeira of Montagne Pelée (1370 m asl), where its presence is obviously a recent colonization event after the 1902 eruption. Lazell (1972) described six subspecies from colour patterns and scalation. For 10 years Roger Thorpe’s team studied A. roquet in Martinique with genetic and morphometric analysis, and constructed its phylogeny in relation to the geological history of the island.
The terrestrial herpetofauna of Martinique: Past, present, future
319
Martinique was formed by agglomeration of old volcanic islands (fig. 1), as described by Andreieff et al. (1976, 1988), Bouysse and Westercamp (1988) and Westercamp et al. (1989). The history of Martinique began with the emergence of the peninsulas of Caravelle (east) and Sainte-Anne (south). These two parts were independent islands since about 22 Mya (Oligocene), when dry vegetation grew on them. During the Miocene, the Vauclin-Pitault submarine chain (16-12 Mya) connected them and later emerged. Volcanic activity then began to construct the south-western peninsula (Presqu’île des Trois-Ilets; 12-9 Mya), and continued in the west to develop the Baie de Fort-de France (8-6.5 Mya) which is a graben, later filled by the sea. This depression was formed after the last volcanic event as shown by the sedimentary rocks on its bottom; the north of this graben was also an old island. Morne Jacob volcano developed (5.5-4 Mya as submarine activity, then 2.7-2.25 Mya as aerial activity) as an independent island that progressively connected itself with the older parts to the south. From 2-0.8 Mya, Pitons du Carbet formed on its west flank. Earlier (3.5-2.5 Mya), an independent island formed at the extremity of the south-west peninsula (Presqu’île des Trois Ilets) that progressively connected itself with the older parts of Martinique. Mont Conil, a new island, formed north of Morne Jacob 0.5 Mya, connected to Morne Jacob and Pitons du Carbet by the birth of Montagne Pelée 0.2 Mya. Lastly, eustatic variation and sedimentation were responsible for the recent coastline and the presence of offshore islets. From this geological sketch, it is easy to see that there were numerous protoislands that were entry points for the flora and the fauna. Thorpe and Stenson (2003) did not use these geological data. A calibration of the molecular clock with local geological history might be useful for the sake of comparison, assuming that colonization of proto-islands is a rapid event after their formation. I agree with Thorpe and Stenson (2003) that for this kind of study it is insufficient to sample populations according to recognized subspecies and it is necessary to sample along transects. But to me, it is also necessary to sample in all areas according to the supposed geological history. Their genetic data lead to the assumption that one of the proto-islands (Péninsule de Sainte-Anne) was not colonized by anoles for some 12-15 My. Palaeontological data show that there is dry forest with Gayacum, Tabebuia and Aiphanes on this old island (Pons, 1987 in Westercamp et al., 1989). This forest was destroyed by ash from volcanic eruptions that date back to 22-20 Mya. Since that time, the south of Martinique emerged and there was no volcanic eruption after 18 Mya. So Sainte-Anne and Caravelle, that have the same age, are the two old islands that were stepping stones for colonization. It seems difficult to believe that these two islands were not colonized by anoles for some 15 My. Sphaerodactylus vincenti Due to its biology, Sphaerodactylus vincenti seems to be a more interesting phylogeograhical model than Anolis. I discovered more than 250 localities where this species is present, compared with the 15 localities mentioned by Schwartz
Figure 1. Geological map of Martinique (modified from Westercamp et al., 1989). (Colour original — see www.ahailey.f9.co.uk/appliedherpetology/ cariherp.htm.)
320 M. Breuil
The terrestrial herpetofauna of Martinique: Past, present, future
321
and Henderson (1991). This species is quite abundant, sometimes at very high density (one per m2 in the litter of dry forest) to very low density at high altitude on the Plateau du Palmiste (1200 m asl) on Montagne Pelée or on the summit of Morne Jacob and Montagne du Vauclin. In these moist forests, numerous individuals are found in bromeliads Glomeropitcairnia penduliflora at 1-3 m above soil level. As this species is more selective in its habitats, and moves less than Anolis, its differentiation is probably more representative of the geological history of Martinique. Schwartz (1965) described six S. vincenti subspecies. My researches show that the situation is more complex, with probably two clades present in Martinique (fig. 2). One clade is in the south, where the Sphaerodactylus are small with no ocelli on the back, the other is in the north, containing subspecies that are bigger and have ocelli on the back. A comparison of morphology of northern and southern populations shows so many differences that it would be easy to place them in two separate
(a)
(b)
(c)
(d)
(e) Figure 2. Sphaerodactylus vincenti from (a) Rocher de Diamant; (b) South Peninsula (SainteAnne); (c) Montagne Pelée; (d) Ajoupa Bouillon; (e) Mont Conil. (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm.)
322
M. Breuil
lineages, one that originates in the Sainte-Anne Peninsula, the other in Caravelle (figs 1 and 2). The morphological characteristics of the Sphaerodactylus populations fit well with the history of Martinique as proposed by Westercamp et al. (1989). Each part of Martinique that was an independent island has its own type of Sphaerodactylus (Sainte-Anne, Caravelle, Péninsule des Trois-Ilets, Rocher du Diamant, Pitons du Carbet, Morne Jacob, Mont Conil, Montagne du Vauclin), but in some places there are intermediate phenotypes. The destruction of dry forest and its replacement by pastures, canefields and banana fields, and the use of many pesticides, are the main causes of the decline of Sphaerodactylus in the lowlands. The last hurricane (Dean, that impacted Martinique on 17 August 2007) nearly destroyed the south coastal populations of this species (as well as Gymnophthalmus underwoodi) by blowing away the leaf litter.
Indigenous Lesser Antilles Species Eleutherodactylus martinicensis The only indigenous species of whistling frog in Martinique is Eleutherodactylus martinicensis (more than 280 localities). Plée first collected this species, probably on Pitons du Carbet. The type series in the MNHN contains females from Martinique and a male probably from Saint-Barth that could belong to an extinct Eleutherodactylus species endemic to that bank (Breuil, 2002). E. martinicensis is mainly present north of a line from Fort-de-France to Robert (fig. 3). Some populations remain in the moistest parts of the south such as Montagne du Vauclin (504 m asl) or in Rivière Pilote. It is probable that this patchy distribution is the consequence of the extension of E. johnstonei (more than 660 localities); E. martinicensis becomes rare.
(a)
(b)
Figure 3. Eleutherodactylus martinicensis from (a) Saint-Joseph (centre of Martinique) and (b) from north-east Martinique. (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/ cariherp.htm.)
The terrestrial herpetofauna of Martinique: Past, present, future
323
Gymnophthalmus pleii Gymnophthalmus pleii is widespread in Martinique; it is found mainly in littoral dry forests but also at greater altitude (400 m asl) along roadsides (more than 100 localities). For a long time it was considered to be the only Gymnophthalmus in Martinique (Schwartz and Henderson, 1991). For example, Pascal et al. (2004) saw a Gymnophthalmus sp. on Hardy islet in Sainte-Anne (south Martinique) and thought that this species was G. pleii. I made a herpetological inventory of these islets before them in 2001 and identified G. pleii, but G. underwoodi was also present on the nearby shore. Barbour (1930) considered that G. pleii was extinct in Martinique and Saint Lucia, and suspected that the mongoose was the cause. Nevertheless, it is easy to see that the two Gymnophthalmus species are very abundant even in mongoose-infested islands. G. pleii is so abundant in Martinique that it is obvious that the mongoose is not a problem for this species; even poultry does not seem to affect it, as seen in Chancel. A comparison of G. pleii from Saint Lucia, Martinique and Dominica shows some differences in the coloration of each island population. It is possible that there is genetic differentiation that may warrant a specific status for these populations. There are about ten localities in Martinique where the two Gymnophthalmus species are present together. G. pleii decreased with respect to G. underwoodi in one of them that I followed since 1997 (Breuil, unpubl. data). These preliminary observations suggest that G. underwoodi becomes more widely distributed and abundant in Martinique and that G. pleii could be threatened as a result. Thecadactylus rapicauda and Leptotyphlops bilineatus Thecadactylus rapicauda and Leptotyphlops bilineatus are the two least known species in Martinique; their distribution range is poorly known because of their secretive habits. Thecadactylus is found in dry and moist forest from sea level to more than 700 m asl (Rocher du Diamant, Mont Conil, Montagne du Vauclin, Ilet Chancel). Kronauer et al. (2005) and Bergmann and Russell (2007) recognized a cryptic species, Thecadactylus solimoensis, in South America that is different from the Lesser Antillean T. rapicauda. Leptotyphlops bilineatus is also very widespread but not easy to find. It occurs in dry forest, gardens, fields and moist forest from south to north. It is also present on Ilet Chancel but now very rare there. A study of the systematics of this latter species is needed. Iguana delicatissima The study of Iguana delicatissima and I. iguana began in the FWI in 1992 (Breuil et al., 1994), the first time that the opinion of Lazell (1973) concerning the relationships between the two iguanas species was challenged. Day and Thorpe (1996) confirmed the hybridization hypothesis between the two species and Breuil
324
M. Breuil
(2000c, 2001, 2002; Breuil et al., 2007) published some pictures of the hybrids. Day et al. (1999) wrote the action plan for I. delicatissima, and a synthesis of all the works devoted to is in Breuil (2002, 2003) and Pasachnik et al. (2006). Iguana delicatissima is now very localized in Martinique. There are some individuals in the moist forest around Montagne Pelée (Pinchon, 1967; Lazell, 1973; pers. obs., fig. 4a). We know nearly nothing about these populations which are very difficult to study. A small population lives in the vicinity of Anse Couleuvre (north) with iguanas nesting on the black sand beaches (Jean-François Maillard, ONCFS and SEPANMAR, pers. comm., 2005, 2007). The most important I. delicatissima population in Martinique lives on Ilet Chancel (Baie du Robert, Atlantic Coast, fig. 4b). I studied this population since 1993, with the collaboration of ONF, DIREN, ONCFS, AOMA, the municipality of Le Robert and the owners of the island (Breuil, 2000a, 2000b, 2001, 2002, 2003; Ourly, 2006; Legouez, 2007; Maillard and Breuil, 2007). A comparison of the population of Chancel with that of Petite Terre (Guadeloupe) shows two important differences; the iguanas are at lower density and have smaller body size in Chancel (Breuil, 2002). From 1993 to 2005, I tagged iguanas with a metallic tag on the dewlap, and since 2006 they are tagged with PIT (Ourly, 2006; Legouez, 2007). Capture-recapture methods (Hayes and Carter, 1999) allow study of the growth and movements of the animals and estimation of the size of the population. Up to now more than 320 iguanas were ‘pitted’ in addition to 140 tagged on the dewlap. Chancel covers 70 ha and Petite Terre 129 ha; the density difference between the two populations is ten-fold although the habitats are similar (dry forest and patches of mangrove). The soil is, however, different; limestone and sand in Petite Terre, and difficult-to-dig volcanic rocks and clay in Chancel. One reason for the small population in Chancel is a nesting limitation, as females migrate to a few colonial nesting sites. A comparison of the iguanas in Chancel from 1997 to 2006 reveals some increase of length (Breuil, 2002; Ourly, 2006; Legouez, 2007), but in ten years the growth was not very high. The small size produces another effect; as the number of eggs laid by a female is related to body size, the small size of the females makes them lay fewer eggs than their counterparts on Petite Terre.
Deliberately-Introduced Species Chaunus marinus Bufo marinus, now Chaunus marinus (Frost et al., 2006) was introduced to fight the sugar cane beetle hence its name of cane toad (review in Breuil, 2002). This toad was introduced in Martinique early in the 19th century, and is now present everywhere at low and medium altitude (more than 340 localities). It is also present in some islets with temporary ponds where it breeds: Chancel, Lavigne. It is more abundant in cultivated areas (mainly in banana fields), but it is also present in littoral dry forests. It is absent on the volcano summits of Montagne Pelée, Pitons du Carbet, and Morne
The terrestrial herpetofauna of Martinique: Past, present, future
(a)
325
(b)
(c) Figure 4. (a) Iguana delicatissima, Anse Céron, Martinique; (b) Ilet Chancel, Baie du Robert, Martinique; (c) Ilet à Ramiers, Baie de Fort-de-France, Martinique. (b), (c): photo DIREN Martinique. (Colour originals — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm.)
Jacob, but it can be found along the roadsides between these mountains at an altitude of more than 470 m asl. It is unlikely that the cane toad contributed to the extinction
326
M. Breuil
of the mountain chicken since the introduction of C. marinus was more than 60 years after the last recorded observation of L. fallax. There are also differences in diet (Lescure, 1979) and breeding site between these two large anurans, and C. marinus is absent from some areas where L. fallax was known to occur (Pitons du Carbet). Gekko gecko The tokay (Gekko gecko) was introduced in Martinique in the 1970s from Indochina (Henderson et al., 1993). This species was reported to live in the lower parts of Martinique between Lamentin and Le Robert-Trinité where it is very abundant (10 localities) and easy to locate at night from its barking call. With its sticky eggs (Breuil, 2004) it is easily carried from place to place and now it is found at Sainte Luce, Le François (south) and Sainte Marie (north east). I have no data on the impact of this species on the local fauna. Nevertheless as a big predator (I saw it eating bats Molossus molossus and Tadarida brasiliensis, and other nocturnal lizards) its impact in a house is of the same type as the presence of a cat. Iguana iguana Iguana iguana is not indigenous in Martinique. The green or common iguanas that are now present were introduced from Les Saintes by Père Pinchon (Breuil, 2003) in the middle of the 1960s. Some may also have been brought to this island by the sailors of the warship Jeanne d’Arc. Since the end of the 1960s they were freed in Fort Saint-Louis and they proliferate in this quiet place which has many trees to hide, food from the army kitchen, and nesting sites. From less than ten individuals in the 1960s the population increased and I estimated its size in 1994 at about 500 adults and subadults (Breuil, 2000a). The number dropped ten-fold at the beginning of the 21st century, as policy towards the iguanas changed (no food supplies; cutting of the trees; cats and dogs running free) and they began to move outside the fort. Iguanas now walk in the public garden close to the fort and people carry them to other places in Martinique. Since the end of the 1990s, there are each year new records of iguanas in different parts of Martinique (Trinité, Le Robert, Saint-François, Le Vauclin, Le Diamant, Trois-Ilets, Schoelcher, Terreville, Le Gallion; the last three places are in the suburbs of Fort-de-France), but there is no proof of the reproduction of this species away from Fort Saint-Louis. I. iguana is now in the vicinity of Chancel and there is the danger that somebody will translocate them there or that they will swim to the islet. In Martinique, ONCFS, DIREN and ONF consider that I. iguana is an invasive species that must be eliminated to prevent the loss of I. delicatissima. Chelonoidis carbonaria Chelonoidis carbonaria is found in Martinique in gardens, where it reproduces. I have no information on the presence of C. denticulata in Martinique, although there
The terrestrial herpetofauna of Martinique: Past, present, future
327
is a carapace with no data in the MPP, whereas I have proof of the existence of this species in Guadeloupe but with an unknown status (Breuil, 2002). I already discussed the origin of C. carbonaria in Guadeloupe and the same hypothesis holds for Martinique. Although some waif C. carbonaria are sometimes found in the wild, I do not think that there are feral populations in Martinique.
Involuntarily-Introduced Invasive Species Scinax ruber I found the first Scinax ruber in 1997 in a house in the town of Le Robert. Since then, I discovered more than 25 populations in Martinique, south of a line Fort-deFrance to Le Robert, but this is an underestimation of its true abundance (Breuil and Ibéné, 2008). This species was found in the extreme north of Martinique in March 2007 (Catzefis, pers. comm.). It inhabits pastures, orchards, banana fields and gardens, and can also be found in buildings in Fort-de-France (Francis Deknuydt, pers. comm., July 2005), and reproduces in tanks, barrels, and ponds. It is more abundant in the south because there are many ponds in the fields for cattle. At night, it hunts on walls and trees; in the day it hides in bricks, pipes, and other construction materials so that it is easily transported from place to place. During the wet season, this species is also able to rapidly colonize new areas on its own. Saint Lucia is the only other Lesser Antillean island where this species is known, but it is not common (Matthew Morton, pers. comm., 2005 and pers. obs.). It is possible that S. ruber arrived in Martinique from Saint Lucia, but its low abundance there makes this less probable than a direct arrival from French Guiana (Breuil and Ibéné, 2008). Eleutherodactylus johnstonei Eleutherodactylus johnstonei is the most widespread Eleutherodactylus in the FWI. It is very abundant in Martinique everywhere from dry forest to the top of the volcanoes (Pitons du Carbet) where it is often found in bromeliads. It replaces E. martinicensis in the south of Martinique. In the moist forest of the north, E. johnstonei is abundant on the ground whereas E. martinicensis is mainly in trees. Hemidactylus mabouia Hemidactylus mabouia is very widespread in Martinique from sea level to the electric transformer of Aileron (880 m asl) on Montagne Pelée (more than 180 localities). This species is also abundant on very small islets off south Martinique (Aigrette, Hardy, Percé); Hemidactylus hides in and under rocks in such places with nearly no trees. The presence of this gecko is explained by its ability to stick eggs on fishing boats, as I observed many times. This species was probably introduced with the slave trade at the beginning of colonization (Breuil, 2002) and was not dispersed by rafting from Africa as suggested by Kluge (1969). The genetic analyses
328
M. Breuil
of amphisbaena by Vidal et al. (2008) and of geckos by Weiss and Hedges (2007) show that transatlantic colonization of the Americas from Africa did occur in the past. But there is nearly no genetic variation in Greater Antilles populations of H. haitianus and H. brooki, and these species clustered with one population of H. angulatus from Equatorial Guinea. So according to Weiss and Hedges (2007) these two species must be referred to H. angulatus and are the descendants of historically introduced individuals. In this context, H. mabouia is also a good candidate for human transportation during the slave trade; genetic analysis is necessary to test this hypothesis. It is worth remembering that, at the beginning of colonization, only one gecko species was known by Du Tertre (1654, 1667); presumably T. rapicauda (Breuil, 2002). Gymnophthalmus underwoodi Breuil (2002) presented the problems concerning the distribution of the two Gymnophthalmus species and how the first G. underwoodi found in Martinique were determined as G. pleii. I now know more than 25 places where this species is present, and among them 10 are also inhabited by G. pleii. G. underwoodi is a newcomer in Martinique; it probably arrived at the beginning of the 1990s. Replacement of G. pleii by G. underwoodi is already known in some places in Martinique. The question is whether this parthenogenetic species arrived in the West Indies once from South America and then colonized other islands from this unknown stepping point, or if it was introduced several times. Genetic analysis must be performed to study the modality of colonization of this invasive species.
Species Escaped from Captivity The oldest waif I discovered is an agamid found alive (1968) on the boat Le Mont Blanc from Marseille that stopped in Fort-de-France. This lizard (probably Laudakia stellio) lives in Greece and is now in the MPP. In Martinique, since the beginning of the 21st century, the following species have been found in the wild as waifs or escaped pets: Graptemys pseudogeographica, Terrapene carolina, Trachemys scripta elegans, Geochelone sulcata, Pantherophis guttatus, Natrix natrix, Epicrates cenchria, Boa constrictor, Python regius and an undetermined caiman from Guiana some 25 years ago. The first Trachemys scripta elegans found in the FWI was discovered by Père Pinchon in Guadeloupe (Breuil, 2002). These historical specimens are in the collection of the MPP in Martinique. Trachemys scripta elegans is now found in artificial ponds but also in rivers and swamps all over Martinique. As the males are very rare because the sex is determined by the incubation temperature, and professional breeders produce only females, it is possible that this species does not reproduce in Martinique. Some specimens of Pantherophis guttatus have been found in the field in Martinique (PNRM, ONCFS, pers. comm., 2005, 2006). Moreover, in
The terrestrial herpetofauna of Martinique: Past, present, future
329
June 2007, two Natrix natrix were found as road kills in the harbour in Martinique by Jean-François Maillard (ONCFS), probably coming in with European cars.
Species of Dubious Status or Wrong Geographical Attribution Allobates chalcopis Colostethus chalcopis was described as an endemic taxon from Martinique by Kaiser et al. (1994). At the time of its description, C. chalcopis was considered to be a dendrobatid, but the supposed presence of such a family on an oceanic island was quite strange. Grant et al. (2006) placed this species in another family (Aromobatidae), in a new subfamily (Allobatinae), and in the genus Allobates. As with the Dendrobatinae, the sub-family Allobatinae does not have any other representative on oceanic islands. The lack of naturally-occurring anurans with totally aquatic development in the Lesser Antilles, even in the southern oceanic islands of the West Indies, suggests that frogs (i.e. metamorphosed anurans) are unable to survive for days on a raft in the sea (Breuil and Ibéné, 2008). The only indigenous Lesser Antillean anurans are Leptodactylidae (Leptodactylus) and Brachycephalidae (Eleutherodactylus) that may have arrived as eggs or in foam nests that can be considered as more resistant stages for survival on a raft. If anurans were able to colonize the Lesser Antilles as frogs, it is curious why there are no indigenous representatives of Hylidae, Centrolenidae, Dendrobatidae and Bufonidae in these islands. I know cases where frogs from Venezuela were carried to Martinique with plants for a botanical garden (Jardin de Balata), and plants from this place have been used in a garden within the distribution area of A. chalcopis. To me, its endemicity is dubious but as I have no stronger arguments, it must at present be considered as a local endemic that should be protected. Ameiva major Since the work of Baskin and Williams (1966), Ameiva major was considered to be a lost Ameiva from Martinique. Nevertheless, I showed beyond any doubt that this species lived in Petite Terre in the Guadeloupean Archipelago (Breuil, 2002). My biogeographical analysis (Breuil, 2003) suggested that the probability of the existence of an Ameiva species in Martinique in historical times was low. There are neither texts nor fossil remains that suggest the presence of an Ameiva species in Martinique. Ineich et al. (2005) mentioned the presence of a specimen of Ameiva major, labelled Martinique, in the Museum of Natural History of Lyon. This is probably one of the specimens used by Duméril and Bibron (1839) for the description of the taxon and labelled Martinique with reference to the MNHN specimens. Such specimens were thereafter given to local and foreign museums (Breuil, 2002). This citation therefore does not modify my conclusions on the
330
M. Breuil
localization of Ameiva major. It is probable that Martinique did not have an Ameiva species in historical times.
Conservation Measures The indigenous species of amphibian and reptile are fully protected in Martinique since 1989. The official list contains many mistakes, including three species that do not live in Martinique. The following species are fully protected by this text: Gymnophthalmus pleii, Anolis roquet, Iguana delicatissima, Sphaerodactylus vincenti, Thecadactylus rapicauda, Liophis cursor, Leptotyphlops bilineatus, Eleutherodactylus johnstonei and E. martinicensis. Mabuya mabouya is not protected because it was thought that it had vanished. An updated list of protected species is in preparation for Guadeloupe and Martinique. Conservation of Iguana delicatissima Iguana iguana is protected only in Guadeloupe where it was thought, on the basis of Lazell’s (1973) work, that it is naturally present; this species is now eliminating I. delicatissima by competition and hybridization. Breuil (2002) gave many arguments that show that I. iguana is a newcomer in Guadeloupe, and its recent expansion there dates back to the 1980s. It is worth noting that in the newspaper France-Antilles (14 June 2008), a man tells of bringing iguanas from Les Saintes to Basse-Terre at the end of the 1950s. Since 1993, I informed local administrations of the situation but it became worse and worse and nothing was done in Guadeloupe to limit the extension of this invasive species (Breuil, 2003). Field work conducted in summer 2007 showed that all the known I. delicatissima populations in Basse-Terre and GrandeTerre are now invaded by I. iguana with the production of many hybrids (Breuil et al., 2007). This dramatic situation in Guadeloupe was understood in Martinique and local authorities tried to prevent such a situation occurring there. Lorvelec et al. (2004, 2007) now consider that I. iguana is a species which causes great threats to I. delicatissima in Guadeloupe, although this threat was not recognised earlier (Lorvelec and Pavis, 1999). It is hoped that a consensus will be found in the FWI and that the local administrations and the Ministry of Ecology and Sustainable Development will take the decision to consider I. iguana as an invasive species in the FWI and withdraw it from the list of protected species in Guadeloupe. In Martinique, since 2005 an official text authorizes agents from ONCFS to kill I. iguana to prevent its extension in the island. The Ministry of Ecology and Sustainable Development in April 2005 requested a restoration plan for I. delicatissima for the FWI. This plan is nearly ready for Martinique (Legouez, 2007) but it is not the case in Guadeloupe where the situation is more complex (Breuil et al., 2007). Iguana iguana is now found in MarieGalante, probably coming from Les Saintes (Fortuné Guiougou, pers. comm., April 2008). Worse, I. iguana is seen regulary in Saint-Barth since 2007 and hybrids were
The terrestrial herpetofauna of Martinique: Past, present, future
331
discovered that suggest an I. iguana arrival already some years ago. These I. iguana are from St Maarten and are waifs or escaped pets (Karl Questel, Franciane Le Quellec, Michel Magras, in litt., April 2008). The causes of the small size of the I. delicatissima population on Chancel are known (Breuil, 2000a, 2000b, 2001c). In 2000 one of the two known colonial nesting sites there was improved to prevent excavation of eggs by females, to increase the population size which is low with respect to the island’s carrying capacity (Breuil, 2000a, 2000b, 2001c). This programme was necessary to balance the negative impact of thousands of tourists that walk on the nesting site, destroying eggs. This island is a tourist hot spot with 50-200 daily visitors all year round; visits to the ruins (old factory, lime kiln) and the sighting of iguanas have a great economic value for the town of Le Robert. This improvement of the nesting site was a success and there were an increase of the adult population and a decrease of egg loss in the following years (Ourly, 2006; Legouez, 2007). The vegetation of Ilet Chancel has changed since the 1950s, as shown by aerial photographs; there was a small landing place for light aircraft on the top of the hill that may have been a nesting site some decades ago, but which is now covered with trees. With the population’s increase in the last two years, new nesting sites were dug by iguanas in places without trees. As a result of the increase of the Chancel population, the ONCFS, DIREN and the MNHN proposed in 2006 to the French Ministry of Ecology and Sustainable Development to translocate some iguanas to Ilet à Ramiers (Baie of Fort de France, fig. 4c). This action was necessary because there is the chance that I. iguana will invade Chancel. This project was accepted because it was documented along Biological Conservation Rules. In 2005, an Arrêté de Protection de Biotope (Local Habitat Protection Law) was published for Ilet Chancel and Ilet à Ramiers; the latter is owned by Marine Nationale and nobody is allowed to get there without permission. The translocation followed the protocol of Knapp and Hudson (2004) for Cyclura, and occurred in July 2006 (Ourly, 2006). Some of the iguanas were equipped with radiotransmitters and all of them were PIT tagged. I went to Ilet à Ramiers in April 2008 with ONCFS. We discovered a 2007 nest at the place we recognized before the translocation as a suitable nesting site and where in summer 2007 we saw signs of nesting activity. We dug the nest and collected 14 eggs, among which 12 hatched. Other islets are currently under study for the PNRM to evaluate their capacity to support an I. delicatissima population. Other species of terrestrial herpetofauna The Rocher du Diamant, supposed to be the last place where Liophis cursor lives, now has full protection status (Arrêté de Protection de Biotope, 2005). It was fitted with videocameras to observe the birds and I hope that we will soon get pictures of L. cursor. It is amazing that this very small place that was inhabited by the English, the French and rats during the Napoleonic wars could still perhaps possess this snake. The persistence of a small population of a racer on a tiny islet calls to mind
332
M. Breuil
the survival of other racer species on Maria Islands (Saint Lucia), on Great Bird Island (Antigua), or in Les Saintes. An important (2300 ha) Reserve Biologique Intégrale, a status recognized by IUCN, was also created in 2007 around Montagne Pelée after years of study, and another is in preparation around Pitons du Carbet (4000 ha) by ONF. Another area, west of the reserve of Montagne Pelée, also has special protection status to preserve the important biodiversity in that sector. These reserves protect the habitat of the last I. delicatissima in moist forest, B. lanceolatus and other herpetofauna, and a beautiful endemic spider, Avicularia versicolor. There are also two nature reserves in Martinique. The older one is the east part of Péninsule de la Caravelle that protects mangrove and dry littoral forest inhabited by Anolis roquet caracoli, Sphaerodactylus vincenti ronaldi, Thecadactylus rapicauda, Gymnophthalmus pleii, Leptotyphlops bilineatus, and Eleutherodactylus martinicensis. The second, La Réserve Naturelle des Ilets de Sainte-Anne, is devoted to birds. Among these islets Hardy is inhabited by G. pleii, Anolis roquet salinei and H. mabouia. The presence of G. pleii in Hardy as well as on other offshore islets (Gros Ilet, Chancel, etc.) is of interest with the colonization of Martinique by G. underwoodi. The FWI possess the worst situation in the Lesser Antilles with respect to the preservation of the original herpetofauna. These islands lost the highest number of amphibian and reptile species and they gained the highest number of introduced and invasive herpetofauna that begin to spread to other islands (Breuil, 2002, 2003; Breuil and Ibéné, 2008). The situation is more problematic in Guadeloupe, SaintMartin and Saint-Barthélemy than in Martinique. As I wrote (Breuil, 2003) there is always something new to discover in the FWI. Since then, Guadeloupe has the additional reproducing species: Ramphotyphlops braminus (Basse-Terre, GrandeTerre), Scinax cf. x-signatus (Basse-Terre, Grande-Terre, Marie-Galante, La Désirade), G. gecko (Grande-Terre), G. underwoodi (Saint-Martin), I. iguana (MarieGalante, Saint-Barthélemy) (Breuil, 2004; Fortuné Guiougou, Béatrice Ibéné, Karl Questel, Franciane Le Quellec, Maxime Louis, Michel Magras, Fred Martail, Éric Dubois-Millot, pers. comm.). Moreover, Scinax ruber, G. gecko, G. underwoodi and I. iguana are expanding in Martinique. The exchanges of introduced species within the FWI, as already shown by G. gecko, will soon occur on an even greater scale with the increase of commercial links between Guadeloupe and Martinique. L’ASFA recently edited a leaflet on the problem of invasive frogs, and a poster on endemic vertebrate species. Other posters and leaflets were also produced by DIREN Martinique on the terrestrial herpetofauna, on iguanas, and marine turtles, to promote knowledge and protection. A stamp picturing I. delicatissima was issued by the French Post Office in 2007, but unfortunately also one picturing the raccoon!
Acknowledgements. I would like to acknowledge the administrations of Martinique and their personnel for their help in the study of the herpetofauna of Martinique: Office National des Forêts (ONF), Office National de la Chasse et de
The terrestrial herpetofauna of Martinique: Past, present, future
333
la Faune Sauvage (ONCFS), Direction Régionale de l’Environnement (DIREN), Parc Naturel Régional (PNRM), Conseil Regional, Musée Père Pinchon (MPP, Fort-de-France), and local associations such as Association Ornithologique Martiniquaise (AOMA), Société pour l’Étude, la Protection et l’Aménagement de la Nature en Martinique (SEPANMAR), Le Gaïac (Iguana group of Guadeloupe) and l’Association pour la Sauvegarde et la Réabilitation de la Faune des Antilles (L’ASFA). Thanks also to Dr Béatrice Ibéné (L’ASFA) and the members of this association for her information concerning the recent herpetological data for Guadeloupe and to the naturalists that send me pictures for identification. I would like also to thank Adrian Hailey and three anonymous referees that made pertinent remarks and improved the text.
References Andreieff, P., Bellon, H., Westercamp, D. (1976): Chronométrie et stratigraphie comparée des édifices volcaniques et formations sédimentaires de la Martinique (Antilles françaises). Bull. BRGM (2), IV, 4: 335-346. Andreieff, P., Baubron, J.-C., Westercamp, D. (1988): Histoire géologique de la Martinique, (Petites Antilles): biostratigraphie (foraminifères), radiochronologie (potassium-argon), évolution volcano-structurale. Géologie de la France 2/3: 39-70. Anonyme de Carpentras (1620): Un Flibustier Français dans la Mer des Antilles (1618-1620). Paris, Payot & Rivages, presented by Moreau, J.-P., 2002. Barbour, T. (1930): Some faunistic changes in the Lesser Antilles. Proc. New England Zoöl. Club. 11: 73-85. Baskin, J.N., Williams, E.E. (1966): The Lesser Antillean Ameiva (Sauria, Teiidae). Re-evaluation, zoogeography, and the effects of predation. Stud. Fauna Curaçao Carib. Is. 23: 144-176. Bergmann, P.J., Russell, A.P. (2007): Systematics and biogeography of the widespread Neotropical gekkonid genus Thecadactylus (Squamata), with the description of a new cryptic species. Zoological Journal of the Linnean Society 149: 339-370. Bonny, K. (2007): Die Gattung Boa. Taxonomie und Fortpflanzung. Kus-Verlag, Rheinstetten, Germany. Bouysse, P., Westercamp, D. (1988): Effets de la subduction de rides océaniques sur l’évolution d’un arc insulaire : l’exemple des Petites Antilles. Géologie de la France 2/3: 2-38. Bouton, J. (1640): Relation de l’Etablissement des Français depuis l’an 1635 en l’Isle de la Martinique, l’une des Antilles de l’Amérique, des moeurs des Sauvages de la situation et des autres singularités de l’Isle. Paris, Sébastien Cramoisy. Breton, R. (1666): Dictionnaire caraïbe françois-Dictionnaire françois caraïbe meslé de quantité de remarques historiques pour l’éclaircissement de la langue. Grammaire caraïbe. Gilles Bouquet, Auxerre. Breuil, M. (2000a): Taxon Reports: Lesser Antilles Iguana delicatissima and Iguana iguana. West Indian Iguana Specialist Group Newsletter 3(1): 4-5. Breuil, M. (2000b): Taxon Reports: Lesser Antilles Iguana delicatissima and Iguana iguana. West Indian Iguana Specialist Group Newsletter 3(2): 11-13. Breuil, M. (2000c): Taxon Reports: Hybridization in the Guadeloupean Archipelago. West Indian Iguana Specialist Group Newsletter 4(2): 13-15. Breuil, M. (2001): Taxon Reports: Lesser Antilles Iguana delicatissima and Iguana iguana. West Indian Iguana Specialist Group Newsletter 4(2): 9-11.
334
M. Breuil
Breuil, M. (2002): Histoire Naturelle des Amphibiens et Reptiles Terrestres de l’Archipel Guadeloupéen. Guadeloupe, Saint-Martin, Saint-Barthélemy. Paris, MNHN, Institut d’Écologie et de Gestion de la Biodiversité, Service du Patrimoine Naturel, Patrimoines naturels No 54. Breuil, M. (2003): In the footsteps of French naturalists, a “battle” of iguanas, and “improvements” in biodiversity. In: Islands and the Sea. Essays on Herpetological Exploration in the West Indies, p. 255-270. Henderson, R.W., Powell, R., Eds, Ithaca, New York, Society for the Study of Amphibians and Reptiles. Breuil, M. (2004): À la Découverte des Amphibiens & Reptiles des Antilles. Le Gosier, Guadeloupe, PLB (Thierry Petit Le Brun) Éditions. Breuil, M. (2007): Projet de reintroduction à la Martinique du crapaud de la Dominique Leptodactylus fallax. Report ONCFS-DIREN Martinique. Breuil, M., Day, M., Thiébot, B. (1994): L’iguane antillais (Iguana delicatissima), une espèce en voie de regression. Le Courrier de la Nature, 143: 16-17. Breuil, M., Guiougou, F., Ibéné, B. (2007): Lesser Antillean Iguana (Iguana delicatissima). West Indian Iguana Specialist Group Newsletter 10(2): 15-17. Breuil, M., Ibéné, B. (2008): Les Hylidés envahissants dans les Antilles françaises et le peuplement batrachologique naturel. Bull. Soc. Herp. Fr. 125: 41-67. Daltry, J.C. (2002): Mountain Chicken Monitoring Manual. First Draft. Fauna & Flora International, Cambridge, and the Forestry and Wildlife Division, Dominica. Day, M.L., Thorpe, R.S. (1996): Population differentiation of Iguana delicatissima and I. iguana in the Lesser Antilles. In: Contributions to the West Indian Herpetology. A Tribute to Albert Schwartz, p. 436-437, abstract. Powell, R., Henderson, R.W., Eds, Ithaca, New York, Society for the Study of the Amphibians and Reptiles, Contributions to Herpetology, Vol. 12. Day, M.L., Breuil, M., Reichling, S. (1999): Lesser Antillean iguana. Iguana delicatissima. In: West Indian Iguanas: Status Survey and Conservation Action Plan, p. 62-67. Alberts, A., Ed., Gland, Switzerland, IUCN, Species Survival Commission, West Indian Iguana Specialist Group. De Lalung, H. (1934): Le Serpent de la Martinique. Sa légende, ses mœurs, ses ennemis. Comment les Caraïbes et les Nègres soignaient ses piqûres. Essai de médecine rétrospective. Laboratoire Corbières, Paris. Dixon, J.R. (1981): The Neotropical Snake genus Liophis: The Eastern Caribbean complex. Copeia 1981: 296-304. Dubois, A., Bour, R. (1992): Inventaire des collections herpétologiques (Amphibiens et reptiles) du Muséum d’Histoire naturelle de Toulouse. Report. Laboratoire des Reptiles et Amphibiens, MNHN. Duméril, A.M.C., Bibron, G. (1837): Erpétologie Générale ou Histoire Naturelle Complète des Reptiles. Vol. 4. Paris, Librairie Encyclopédique de Roret. Duméril, A.M.C., Bibron, G. (1839): Erpétologie Générale ou Histoire Naturelle Complète des Reptiles. Vol. 5. Paris, Librairie Encyclopédique de Roret. Du Tertre, J.-B. (1654): Histoire générale des isles de Saint-Christophe, de la Guadeloupe, de la Martinique et autres de l’Amérique où l’on verra l’établissement des colonies françaises dans ces isles, leurs guerres civiles et étrangères et tout ce qui se passe dans le voyage et retour des Indes. Paris, J. et E. Langlois. Du Tertre, J.-B. (1667): Histoire générale des Antilles habitées par les François. T.1 contenant tout ce qui s’est passé dans l’établissement des colonies françaises. T. 2 contenant l’histoire naturelle. Paris, Thomas Jolly. Frost, D.R., Grant, T., Faivovich, J., Bain, R.H., Haas, A., Haddad, C.F.B., De Sá, R.O., Channing, A., Wilkinson, M., Donnellan, S.C., Raxworthy, C.J., Campbell, J.A., Blotto, B.L., Moler, P., Drewes, R.C., Nussbaum, R.A., Lynch, J.D., Green, D.M., Ward, C., Wheeler, W.C. (2006): The amphibian tree of life. Bull. Amer. Mus. Nat. Hist. 297: 1-370. Grant, T., Frost, D.R., Caldwell, J.P., Gagliardo, R., Haddad, C.F.B., Kok, P.J.R., Means, D.B., Noonan, B.P., Schargel, W.E., Wheeler, W.C. (2006): Phylogenetic systematics of dart-poison
The terrestrial herpetofauna of Martinique: Past, present, future
335
frogs and their relatives (Amphibi: Athesphatanura, Dendrobatidae). Bull. Amer. Mus. Nat. Hist. 299: 1-262. Hayes, W., Carter, R. (1999): Population monitoring. In: West Indian Iguanas: Status Survey and Conservation Action Plan, p. 79-85. Alberts, A., Ed., Gland, Switzerland, IUCN, Species Survival Commission, West Indian Iguana Specialist Group. Hedges, S.B., Heinicke, M.P. (2007): Molecular phylogeny and biogeography of West Indian frogs of the genus Leptodactylus (Anura, Leptodactylidae). Molecular Phylogenetics and Evolution. 44: 308-314. Henderson, R.W., Delatte, A., McCarthy, T.J. (1993): Gekko gecko (Sauria: Gekkonidae) established on Martinique, French West Indies. Carib. J. Sc. 29: 128-129. Ineich, I., Martelli, J.-L., Clary, J. (2005): Catalogue des collections de reptiles du Muséum d’Histoire naturelle de Lyon, sixième note: Sauriens (deuxième partie) et Rhynchocéphales. Cahiers scientifiques Mus. Hist. Nat. Lyon. 8: 33-66. Kaiser, H., Coloma, L.A., Gray, H.M. (1994): A new species of Colostethus (Anura Dendrobatidae) from Martinique, French Antilles. Herpetologica 50: 23-32. Kluge, A.G. (1969): The evolution and geographical origin of the New World Hemidactylus mabouiabrookii complex (Gekkonidae, Sauria). Misc. Publ. Mus. Zool., Univ. Michigan. 138: 1-78. Knapp, C.R., Hudson, R.D. (2004): Translocations strategies as a conservation tool for West Indian iguanas: Evaluations and Recomendations. In: Iguanas Biology and Conservation, p. 199-219. Alberts, A., Carter, R., Hayes, W., Martins, E., Eds, Iguanas Biology and Conservation. Univ. California Press. Kronauer, D.J.C., Bergmann, P.J., Mercer, J.M., Russell, A.P. (2005): A phylogeographically distinct and deep divergence in the widespread Neotropical turnip-tailed gecko, Thecadactylus rapicauda. Mol. Phylogenet. Evol. 34: 431-437. Labat, J.-B. (1724): Voyage du Père Labat, aux isles de l’Amérique contenant: une exacte description de toutes ces isles; des arbres, plantes, fleurs et fruits qu’elles produisent; des animaux, oiseaux, reptiles et poissons qu’on y trouve; des habitants, de leurs mœurs et coutûmes, des manufactures et du commerce qu’on y fait etc. La Haye, P. Lusson et al. (éd. en 2 volumes de l’édition de 1722 en 6 volumes). Lazell, J.D., Jr. (1967): Wiederentdeckung von zwei angeblich ausgestorbenen Schlangenarten der westindischen Inseln. Salamandra 3: 91-97. Lazell, J.D. (1972): The anoles (Sauria, Iguanidae) of the Lesser Antilles. Bull. Mus. Comp. Zool. 143: 1-115. Lazell, J.D. (1973): The Lizard Genus Iguana in the Lesser Antilles. Bull. Mus. Comp. Zool. 145: 1-28. Leblond, J.-B. (1813): Voyage aux Antilles. D’île en île, de la Martinique à Trinidad (1767-1773). Karthala, (2000) Paris. Legouez, C. (2007): Les iguanes des Petites Antilles: étude de la population de l’îlet Chancel (Martinique) et elaboration du plan de restauration. Master II, Ecologie, Gestion de la Biodiversité. Toulouse. Lescure, J. (1979): Étude taxinomique et éco-éthologique d’un Amphibien des Petites Antilles: Leptodactylus fallax Müller, 1926 (Leptodactylidae). Bull. Mus. Nat. Hist. Nat. Paris 4e sér., 1. Sect. A, no 3: 757-774. Lorvelec, O., Pavis, C. (1999): L’iguane des Petites Antilles. Poster DIREN-AEVA. Lorvelec, O., Levesque, A., Barré, N., Feldmann, P., Leblond, G., Jaffard, M.-É., Pascal, M., Pavis, C. (2004): Évolution de la densité de population de l’iguane des Petites Antilles (Iguana delicatissima) dans la réserve naturelle des îles de la Petite Terre (Guadeloupe) entre 1995 et 2002. Rev. Écol. (Terre Vie). 59: 331-344. Lorvelec, O., Pascal, M., Pavis, C., Feldmann, P. (2007): Amphibians and reptiles of the French West Indies: Inventories, Threats and Conservation. Appl. Herpetol. 4: 131-161.
336
M. Breuil
Maillard, J.-F., Breuil, M. (2007): The conservation of iguana delicatissima in Martinique and a Future Action Plan for the French West Indies. West Indian Iguana Specialist Group Newsletter. 10(1): 15. Mallone, C., Davis, S.K. (2004): Genetic contributions to caribbean iguana conservation. In: Iguanas Biology and Conservation, p. 45-57. Alberts, A., Carter, R., Hayes, W., Martins, E., Eds, Iguanas Biology and Conservation. Univ. California Press. McIntyre, S. (2003): The Current Status of the Mountain Chicken Leptodactylus fallax on Dominica, Eastern Caribbean; an Amphibian in Decline. Masters dissertation, University East Anglia. Miralles, A. (2005): The identity of Lacertus mabouya Lacepède, 1788, with description of a neotype: an approach toward the taxonomy of new world Mabuya. Herpetologica 61: 46-53. Moreau de Jonnès, A. (1816): Monographie du trigonocéphale des Antilles ou grande vipère Fer-deLance de la Martinique. Jour. Méd. 36: 324-365. Moreau de Jonnès, A. (1818a): Monographie de la Couleuvre couresse des Antilles Coluber cursor de Lacépède. Journal de Physique 87: 193-200. Moreau de Jonnès, A. (1818b): Monographie du Mabouia des murailles, ou Gecko mabouia des Antilles. Bull. Sci. Soc. philom. Paris, sér. 3: 138-139. Moreau de Jonnès, A. (1821): Monographie du Gecko mabouia des Antilles. Journal de Physique 20: 1-16. Moreau de Jonnès, A. (1822): Histoire physique des Antilles françaises; savoir: la Martinique et les îles de la Guadeloupe. Migneret, Paris, 1-560. Moreau de Jonnès, A. (1858): Aventures de guerre au temps de la République et du Consulat. Tome second. Pagnerre, Paris. Ourly, L. (2006): Conservation de l’iguane des Petites Antilles (Iguana delicatissima) en Martinique. Suivi des populations de l’îlet Chancel et réintroduction sur l’îlet à ramiers. Report Université Paul Sabatier-Office National de la Chasse et de la Faune Sauvage. Pasachnik, S.A., Breuil, M., Powell, R. (2006): Iguana delicatissima. Cat. Amer. Amphib. Rept. 811: 1-14. Pascal, M., Brithmer, R., Lorvelec, O., Vénumière, N. (2004): Conséquences sur l’avifaune nicheuse de la réserve naturelle des îlets de Sainte-Anne (Martinique) de la récente invasion du rat noir (Rattus rattus), établies à l’issue d’une tentative d’éradication. Rev. Écol. (Terre Vie). 59: 309318. Pinchon, R. (1967): Quelques Aspects de la Nature aux Antilles. Fort-de-France, Martinique, Caen, France, Imprimerie Ozanne et Cie. Plée, A. (1820): MS 71. Catalogue des divers objets qui composent mon premier envoi au Muséum d’Histoire naturelle (Fort Royal, île de Martinique) avec un supplément, BMNHN. Rufz de Lavison, D. (1859): Enquête sur le serpent de la Martinique. Germer Baillière, Paris. Schwartz, A. (1965): A review of Sphaerodactylus vincenti on the southern Windward Islands. Carib. J. Sci. 4: 391-409. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies. Descriptions, Distributions and Natural History. Gainesville, University of Florida Press. Thibault de Chanvalon, J.-B.M. (1756): Voyage à la Martinique contenant diverses observations sur la physique, l’histoire naturelle, l’agriculture, les mœurs et les usages de cette île. Manuscript MS 690 MNHN edited by Karthala, Paris (2004). Thorpe, R.S., Stenson, A.G. (2003): Phylogeny, paraphyly and ecological adaptation of the colour and pattern in the Anolis roquet complex on Martinique. Molecular Ecology 12: 117-132. Underwood, G. (1959): Reptiles of the Eastern Caribbean. Caribbean Affaires, NS 1: 1-192. Vidal, N., Azvolinsly, A., Cruaud, C., Hedges, S.B. (2008): Origin of tropical American burrowing reptiles by transatlantic rafting. Biol. Letters 4: 115-118. Weiss, A.J., Hedges, S.B. (2007): Molecular phylogeny and biogeography of the Antillean geckos Phyllodactylus wirshingi, Tarentola americana and Hemidactylus haitianus. Mol. Phyl. Evol. 45: 409-416.
The terrestrial herpetofauna of Martinique: Past, present, future
337
Westermann, J.H. (1953): Nature Preservation in the Caribbean. Foundation for Scientific Research in Surinam and the Netherlands Antilles, Utrecht 9: 1-106. Westercamp, D., Andreieff, P., Bouysse, P., Cottez, S., Battistini, R. (1989): Carte géologique de la France (1: 50 000), feuille Martinique. Notice explicative. Bureau de Recherches Géologiques et Minières, Orléans. Wüster, W., Thorpe, R.S., Salamao, M.G., Thomas, L., Puorto, G., Theakson, R.D.G., Warell, D.A. (2002): Origin and phylogenetic position of the Lesser Antillean species of Bothrops (Serpentes: Viperidae): biogeographical and medical implications. Bull. Nat. Hist. Mus. (Zoology), Lond. 68: 101-106.
Accepted: June 2, 2008 (AH). Reprinted from Applied Herpetology 6: 123-149 (2009).
Addendum Prospecting conducted by ONCFS on Rocher du Diamant in 2009 failed to observe Liophis cursor but discovered Gymnophthalmus pleii. During a brief stay in early March 2010, I discovered eight Scinax cf. x-signatus at Le Vauclin in the south, the first observation in Martinique. The frogs were in a new bungalow built three years ago from a kit in a container imported directly from Brazil, and first appeared during construction; the owner had never seen them before. This is the first documented case of the mechanism by which Scinax from South America arrived in the FWI, and perhaps in other islands. The import of manufactured wood from Brazil and French Guyana in containers that are not checked is a great threat to the biodiversity of the Caribbean. It is urgent that information concerning this problem is given to the customs in Caribbean islands and also to exporters to prevent further introductions. Inspection of houses in the FWI built with such kits is of interest to discover new arrivals (Breuil et al., 2010a). During this stay I had the opportunity to visit two sites where Trachemys scripta elegans (all observed were females) and Trachemys stejnegeri, respectively, were kept in captivity. In another place I found another Astrochelys sulcata and numerous Chelonoidis carbonaria (but no C. denticulata). The stray Morelia amethistina in Basse-Terre was captured by an agent of ONF on 25 March 2010. The snake was 3.5 m long, and died of injuries the following day (Frank Mazeas, pers. comm., March 2010). In August 2010 the DIREN of Martinique and Guadeloupe were asked by the Ministry to produce a project to control Iguana iguana. Unfortunately, the situation is more and more critical and it will be nearly impossible to eliminate I. iguana and hybrids in the last I. delicatissima populations (Breuil et al., 2010b). It is now clear that Basse-Terre lost its natural populations, and the situation is getting worse in St Barts, with more observations of I. iguana and hybrids. In Saint-Martin, Tintamarre which was proposed as a site for translocation of I. delicatissima now has some I. iguana.
338
M. Breuil
References Breuil, M., Guiougou, F., Questel, K., Ibéné, B. (2010a): Modifications du peuplement herpétologique dans les Antilles françaises. Disparitions et espèces allochtones. 1ère partie: HistoriqueAmphibiens. Le Courrier de la Nature 249: 30-37. Breuil, M., Guiougou, F., Questel, K., Ibéné, B. (2010b): Modifications du peuplement herpétologique dans les Antilles françaises. Disparitions et espèces allochtones. 2de partie: Reptiles. Le Courrier de la Nature 251: 36-43.
Conserving the Puerto Rican herpetofauna Rafael L. Joglar1,* , Alberto O. Álvarez2 , T. Mitchell Aide1 , Diane Barber3 , Patricia A. Burrowes1 , Miguel A. García2,4 , Abimael León-Cardona5 , Ana V. Longo1 , Néstor Pérez-Buitrago1,4 , Alberto Puente1,2 , Neftalí Rios-López1 , Peter J. Tolson6 1 Department of Biology, University of Puerto Rico, PO Box 23360, San Juan, Puerto Rico 00931-3360 ∗ Corresponding author; e-mail:
[email protected] 2 Division of Wildlife, Department of Natural and Environmental Resources, P.O. Box 366147, San Juan, Puerto Rico 00906 3 Fort Worth Zoo, 1989 Colonial Parkway, Fort Worth, Texas 76110, USA 4 Center for Applied Tropical Ecology and Conservation (CATEC), University of Puerto Rico–Río Piedras, San Juan, Puerto Rico 00931 5 Aquatic Toxicology Program, University of California-Davis, VetMed:APC, 1321 Haring Hall, Davis, California 95616, USA 6 Conservation Department — Toledo Zoo, Ohio 43614, USA
Abstract. With a total area of 8900 km2 , Puerto Rico is the smallest of the Greater Antilles. It is divided in three physiographic regions or areas of relief: the mountainous interior, the karst region, and the coastal plains and valleys. The island comprises six ecological life zones: subtropical dry forest, subtropical moist forest, subtropical wet forest, subtropical rain forest, lower montane wet forest and lower montane rain forest. The herpetofauna of Puerto Rico consists of 25 species of amphibians (19 native, six introduced) and 56 species of reptiles (52 native, four introduced). The goal of this paper is to describe some of the present studies directed towards the conservation of Puerto Rican herpetofauna. Eleutherodactylus karlschmidti, E. jasperi and E. eneidae have not been seen or heard since 1976, 1981 and 1990, respectively, and are probably extinct. Since 2000, the potential causes of amphibian declines in Puerto Rico have been studied, and a synergistic interaction between climate change (increased dry periods) and disease (chytridiomycosis) have been proposed as an explanation for the patterns observed. Recovery efforts for Peltophryne lemur include a captivebreeding program, reintroductions island-wide educational outreach, protection and restoration of existing habitat, and the creation of new breeding ponds. Among reptiles, the first conservation efforts to protect Epicrates inornatus were limited to trying to halt collection and hunting. However, current strategies to preserve the boa include gathering basic biological information, habitat conservation, and educational outreach. Recent efforts for the conservation of Trachemys s. stejnegeri combine three research approaches to clarify the status of local populations: a mark-recapture-release study, field monitoring of reproductive activity (i.e., nocturnal patrolling to identify nesting activity), and field assessment of the potential impact of introduced species, particularly identification of predatory species and exotic turtles. Recovery initiatives for Cyclura stejnegeri include management of invasive
340
R.L. Joglar et al.
mammals, a headstart program for hatchling iguanas, and the assessment of the etiology of a condition causing blindness in adult iguanas. A reforestation project aimed at recovering a local herpetofaunal assemblage after disturbances in a limestone valley in northern Puerto Rico is discussed. As population sizes of common colonizers such as Eleutherodactylus and Anolis increased, larger forest-interior and predatory species like Epicrates inornatus, Alsophis portoricensis and Anolis cuvieri followed. Finally, the Mona Island marine turtle monitoring program is discussed and compared to other similar programs in Puerto Rico. As these and other similar conservation efforts provide scientifically based management recommendations, we hope to succeed in conserving the diverse herpetofauna that characterizes Puerto Rico. Key words: Amphibian; biodiversity; Caribbean; chytrid; climate change; conservation; Puerto Rico; reptile; West Indies.
Introduction Puerto Rico is the easternmost of the Greater Antilles and it is located between 18◦ 35 −17◦ 55 N and 67◦ 15 −65◦ 35 W. It is the smallest of the Greater Antilles with a total area of 8900 km2 , 12.9, 8.6 and 1.3 times smaller than Cuba, Hispaniola, and Jamaica, respectively. It is 179 km long and 58 km wide, and its highest peak is Cerro Punta in Jayuya (elevation 1338 m). The highest peaks on Cuba, Hispaniola, and Jamaica, respectively, are 1.5, 2.3 and 1.7 times higher than Cerro Punta. The three largest Puerto Rican satellites islands are Vieques (138 km2 ) and Culebra (27 km2 ) in the east, and Mona (57 km2 ) in the west. Physiography and general ecology Puerto Rico is divided in three physiographic regions or areas of relief: (1) the mountainous interior; (2) the karst region; and (3) the coastal plains and valleys (Cruz and Boswell, 1997; Gannon et al., 2005). The mountainous interior is the largest of the three regions, and it is the cradle of the main rivers of the island. This ‘backbone’ or mountainous spine is composed of the Cordillera Central and the Sierra de Luquillo. The Cordillera Central extends in an east-west direction from Sierra de Cayey in the southeast running almost without interruptions to Mayagüez, which lies close to the west coast. Sierra de Luquillo, an isolated upland region in the northeast, and the largest natural protected area of Puerto Rico, shelters montane rainforests at lower elevations and cloud forests and elfin woodland at the highest elevations; one of the largest tracks of elfin woodland in the Caribbean is found in these mountains (Hedges, 1999). The Puerto Rican karst region includes two separate zones: (1) the northern karst, which ranges from Loiza in the northeast to Aguadilla in the northwest; and (2) the southern karst, which extends from Juana Díaz (east of Ponce) to Guayanilla to the west (Cruz and Boswell, 1997; Lugo, 2005). The Puerto Rican northwestern karst topography is similar to that in Cockpit Country of Jamaica, Los Haitises of Hispaniola, and the Viñales region of western Cuba (Hedges, 1999).
Conserving the Puerto Rican herpetofauna
341
According to the Holdridge system of classification, Puerto Rico has been divided into six ecological life zones: (1) subtropical dry forest; (2) subtropical moist forest; (3) subtropical wet forest; (4) subtropical rain forest; (5) lower montane wet forest; and (6) lower montane rain forest (Ewel and Whitmore, 1973). Average annual rainfall is 60-110; 100-220; 200-400 cm in the first three zones, respectively, with a lower rainfall limit of 380 cm in the fourth zone, and with elevations over 1000 m in the lower montane wet forest and lower montane rain forest. An alternative system has been proposed by Lugo (2005), in which geological data were incorporated with temperature, precipitation, and elevation information of the Holdridge system to generate ten geoclimatic zones or forest types for Puerto Rico. Conservation in Puerto Rico Because Puerto Rico is a US Territory governed by a commonwealth, state and federal agencies and their laws are involved in the island’s conservation practices. At the state level, the Planning Board, the Environmental Quality Board, the Department of Agriculture, the Department of Natural and Environmental Resources, and all 78 municipalities through their Territorial Arrangement Plan, deal with corresponding conservation issues (Quevedo, 2008). The main state agency actively engaged in conservation in Puerto Rico is the Department of Natural and Environmental Resources (DNER). Established in 1972, this agency has the difficult responsibility of protecting and managing Puerto Rican natural resources, including biodiversity. Among many other responsibilities, the DNER is in charge of endangered species, forest reserves, wildlife refuges, and corridors. The DNER’s capacity to accomplish these goals and responsibilities are seriously limited by (1) political pressures, (2) budget and (3) excessive responsibilities. At the federal level, the two most important agencies involved in conservation are (1) the U.S. Fish and Wildlife Service (USF&WS) as part of the US Department of Interior (USDI), and (2) the U.S. Forest Service (USFS) as part of the U.S. Department of Agriculture (USDA). Other federal agencies such as the U.S. Environmental Protection Agency (EPA), the USDA Natural Resources Conservation Service (NRCS) and the U.S. Corps of Engineers, are also involved. The USF&WS is responsible for endangered species and their habitats and for managing several federal wildlife refuges, such as Desecheo, Vieques and Cabo Rojo. The USFS is responsible for protecting and managing El Yunque, the largest forest reserve in Puerto Rico. Within the USFS, the International Institute of Tropical Forestry (IITF) is in charge of research and management of forest resources. As in the Continental USA, in Puerto Rico the USF&WS has not been effective at listing endangered species and declaring and protecting critical habitat for listed species. This shows that political pressures and budget limitations for conservation agencies are also a problem at the federal level. Puerto Rico’s history of protecting areas for conservation purposes goes back to 1876, when the Spanish Crown protected areas in El Yunque and Utuado. Laws of the Spanish Crown protected forests, mangroves and water resources. Since then, Puerto Rico has created a system of forest reserves that includes 21 forest reserves
342
R.L. Joglar et al.
(such as Maricao, Toro Negro, Carite, Cambalache and Susua) administrated by the state government (DNER), El Yunque administrated by the federal government (USFS-USDA), and San Patricio, Monte La Choca, Nuevo Milenio and Del Pueblo are co-managed by the state government and local environmental groups that are actively involved in managing and protecting these areas (Sanchez-Martínez, 2007). In addition to these 26 forest reserves, Puerto Rico also has wildlife refuges (federal and state) and natural reserves such as Mona Island and Caja de Muertos. Since all these areas are isolated from each other, a series of corridors have been proposed to connect some of them and increase their conservation value. A very important asset to the conservation of land and biodiversity in the island is the Puerto Rico Conservation Trust, a private corporation. Since 1970 it has managed to acquire and protect 20 natural areas for conservation for a total of 21 364 acres (86.5 km2 ) which is the size of Mona Island and Culebra combined. In addition, they offer excellent interpretative nature programs at Las Cabezas de San Juan Natural Reserve in Fajardo, Hacienda Buena Vista in Ponce and in La Esperanza in Manatí. Taking all protected areas into consideration, including state and federal forest reserves, wildlife reserves and other preserved areas mentioned above, Puerto Rico protects 8.2% of its territory for conservation. To put this number in perspective, the United States protects 25% of its territory, Costa Rica 34%, Cuba 32%, the Dominican Republic 42% and the Virgin Islands, where tourism plays an important role in the economy, 54% (Lloveras, 2008). In 2007 a group of scientists discussing the effect of climate change on Puerto Rican biodiversity and natural resources requested the government to protect 25% of the Puerto Rican territory. We hope that this goal is met in the near future and surpassed thereafter.
The Puerto Rican Herpetofauna and Their Conservation Twenty-five species of amphibians occur in Puerto Rico: 19 are native and six are introduced (Joglar, 2005a; Rios-López and Thomas, 2007; see the appendix for a complete list). The number of native species of amphibians in Puerto Rico (19) is high, especially considering the size of the island. Puerto Rico has the highest number of species of amphibians per area in comparison to the other Greater Antillean islands (table 1) and many other islands of the world (Duellman, 1999a,b; Joglar, 2005a). However, the number of families and genera of native amphibians is low, with only two families (Leptodactylidae and Bufonidae) and three genera (Eleutherodactylus, Leptodactylus and Peltophryne) present. Most of the native species belong to the genus Eleutherodactylus (89.5%) and to the family Leptodactylidae (94.7%). Endemism is high; most native species (15/19 = 78.9%) are endemic to Puerto Rico (Mona Island included); however, four additional species are endemic to the Greater Puerto Rican Bank, as they are also found in the Virgin Islands and on other islands that were connected to Puerto Rico during low sea levels associated with glacial maxima. Six species of amphibians have been
Conserving the Puerto Rican herpetofauna
343
Table 1. Species of amphibians (native, endemic and introduced) and percentage of endemism. Adapted from Hedges (1999) and Duellman (1999a,b). Hispan refers to Hispaniola, PR Bank to Puerto Rican Bank, PR to Puerto Rico and Lesser A. to Lesser Antilles.
Cuba Hispan Jamaica PR Bank PR Lesser A. Bahamas
Native species
Endemic species
Percentage of endemism
Introduced species
Total species
Area (km2 )
Species/ 106 km2
52 63 22 21 19 10 2
50 63 22 21 15 (19) 9 0
96 100 100 100 78.9 (100) 90 0
2 2 4 6 6 4 4
54 65 26 27 25 14 6
110 922 76 470 10 990 9 511 8 990 5 840 11 296
469 824 2002 2103 2002 1712 177
Table 2. Number of reptiles; a according to Uezt (2000; web page); b according to Powell et al. (1996).
Reptiles Turtles Lizards Amphisbaenians Snakes Crocodilians Tuataras
Worlda
West Indies
Puerto Rico
Exotics in PR
Endemic species
Threatened/ endangered
8002 296 4610 160 2911 23 2
500a 13b 321b 12b 107b 4b 0
56 7 34 4 10 1 0
4 1 2 0 ? 1 –
89% (42/47) 0 87% (28/32) 100% 90% 0 –
22-24% 83% (5/6) 12% (4/32) 0 22% (2/9) 0 –
introduced in Puerto Rico since the 1920s (Joglar, 2005a); Puerto Rico has the highest number of introduced species in the Greater Antilles (table 1). Fifty-six species of reptiles occur in Puerto Rico; 52 are native and four are introduced (Joglar, 2005b; see the appendix for a complete list). Included as native species are five marine turtles that have a wide distribution in the West Indies and in the rest of the world. Of the terrestrial native species, 89.4% (42/47) are endemic to Puerto Rico and the Puerto Rican Bank (table 2). The status of Puerto Rican amphibians has been reviewed extensively (Joglar and Burrowes, 1996; Joglar, 1998; Burrowes et al., 2004; Burrowes and Joglar, 2005) — see next section. Eleven reptilian species are currently protected as threatened or endangered (appendix). Some common characteristics among these species are: (1) large body size; (2) specialists in habitat, behavior, or morphology; (3) limited distributions; (4) human consumption or commercial value; and (5) feared and persecuted by humans (Joglar, 2005b). For a summary of factors affecting vulnerability, major threats, conservation activities, and recommendations, see Wilson et al. (2006). The following sections summarize seven important efforts regarding the conservation of Puerto Rican amphibians and reptiles; additional efforts and conservation projects have been implemented but are not included here.
344
R.L. Joglar et al.
Puerto Rican Amphibians, Pathogens and Climate Change Puerto Rico was one of the first countries in the world which noticed what has become an international phenomon known as ‘declining amphibian populations’. We started monitoring amphibian populations in 1988 at El Yunque and, since then, have monitored more than 20 sites with an emphasis on the highlands. We have not found Eleutherodactylus karlschmidti, E. jasperi, or E. eneidae since 1976, 1981 and 1990, respectively, in spite of continuous field expeditions. An interesting population effect is observable at our elfin forest site in the Caribbean National Forest (El Yunque), where E. portoricensis and E. coqui seem to be recovering from population declines observed in the early 1990s. However, populations of three other species (E. wightmanae, E. richmondi and E. locustus) have not recolonized some areas at El Yunque where they were abundant in the past, and are still very scarce in that forest. Fortunately, these species still occur in some parts of the island, and we are monitoring them carefully. Since 2000, we have been studying the potential causes of amphibian declines in Puerto Rico, and have proposed a synergistic interaction between climate change (increased dry periods) and disease (chytridiomycosis) as an explanation for the patterns observed (Burrowes et al., 2004). Our data suggest that, during times of drought, frogs may clump in humid patches of the forest where the fungus is most likely to occur. This could provoke a situation where frogs, stressed from lack of water and clumping, become immunologically deprived in an area where the fungus is potentially abundant. As a consequence, infections by chytrid may increase, generating an epidemic that results in amphibian declines. Recent work led by a graduate student at our lab (Ana Longo) has tested part of this hypothesis. We established a controlled experiment with six terraria in which the number of refugia, food, light and temperature remained constant. Water was applied to the soil on only one half, and later to one fourth of the experimental terraria, while controls received water over the entire surface. The use of retreat sites by high-mountain E. coqui was monitored daily. Frog dispersion within the terraria changed significantly as a result of the water treatments (ANOVA F1,35 = 13.6; P = 0.001). In the experimental terraria, frogs moved from dry to humid sides within three days of drought. Thus, in spite of their territorial behavior, frogs facing limited water supplies clumped in the humid retreat sites, whereas control frogs used refuges on both sides. The next step of this experiment is to inoculate frogs with equal numbers of chytrid zoospores to determine if those forced to clump by a limited water regime are more susceptible to chytridiomycosis. We expect to have results on this work in the near future to better understand patterns of infection and prevalence of this disease among Puerto Rican frogs. Fieldwork involving amphibian monitoring and chytrid detection at various sites on the island (El Yunque, Patillas, Toro Negro and Maricao) suggests that chytrid is abundant throughout the highland forests of Puerto Rico. Efforts to detect chytrid among five amphibian species (157 individuals) at six localities in the lowlands have yielded negative results. Our monitoring program includes four different highland forests in Puerto Rico where we estimate frog densities by species, and sample
Conserving the Puerto Rican herpetofauna
345
for the incidence of chytridiomycosis during dry versus wet seasons, in specific microhabitats, and as a function of gender and ontogenetic stage. An interesting pattern of cyclic decline, survival, and recuperation of the heartiest species is becoming apparent. This has led us to question whether a synergy between climate and disease is playing a role in the prevalence of the fungus in Puerto Rico, as has been described in Australia (Berger et al., 2004; Retallick et al., 2004). To answer this question we have expanded geographical and taxonomic monitoring of amphibian populations and chytrid detection, and have included fine-scale weather data collection at some localities. Finally, we expect to complete historic sampling at other localities to test disease dispersion hypotheses for the chytrid fungus in Puerto Rico. In 2004, with Marcelino Hernandez from the Dominican Republic, we initiated collaborations that included a workshop on monitoring amphibians (by R.L. Joglar), followed by several days of fieldwork in the Cordillera Central. This work resulted in baseline population data for the localities of Ebano Verde (1440 m) and Valle Nuevo (2500 m) and the first records of chytrid for the Dominican Republic in three species of anurans: Eleutherodactylus pituinus, E. patriciae and Hyla vasta. Luis M. Diaz, from Cuba, participated in this training activity, and we hope to develop similar collaborations in the near future.
The Puerto Rican Crested Toad (Peltophryne (Bufo) lemur) This species once occurred on Puerto Rico and Virgin Gorda. Habitat loss and introduced species, such as Bufo marinus, are major causes for the toad’s decline and have led to a listing as Threatened (U.S. Fish and Wildlife Service, 1992) and Critically Endangered by the International Union for Conservation of Nature and Natural Resources (IUCN, 2004). This is the only toad native to Puerto Rico, and is easily distinguished from introduced forms by its unique head crests. It lives in arid to semi-arid climates in karst limestone formations. In Puerto Rico, toad populations once were divided into two distinct populations, one in the north and one in the south. Mitochondrial DNA analyses suggest that these two populations have been separated for up to 1 million years and are genetically distinct (CBSG, 2005). Unfortunately, northern toads have not been seen in the wild since 1988, and biologists consider the population extirpated (Johnson, 1999). Currently, the only known wild population is the southern form, which resides in small ponds located in the Guanica National Forest (CBSG, 2005). In an effort to save this species from extinction, a Species Survival Plan (SSP) was officially created in 1984 through the auspices of the American Zoo and Aquarium Association (AZA). A reintroduction program is a large component of the recovery plan for this species. Each year, captive toads from zoos and aquaria in the United States and Canada are bred, and tadpoles are sent to Puerto Rico for release. Reintroduction efforts began on a small-scale, with the release of northern toadlets in 1982, before the SSP was formed. Between 1982 and 1985, approximately 1300
346
R.L. Joglar et al.
toadlets were released in the Cambalache National Forest, in northern Puerto Rico. Subsequently, more than 90 000 southern tadpoles were released into the Guanica National Forest from 1987 to 2005 (Lentini, 2000; B. Johnson, pers. comm.). The Guanica release site is an isolated man-made pond, geographically separated from the wild population. Although no formal studies have been conducted on the survival of the captive-hatched tadpoles, none are thought to have survived at the Cambalache release site (B. Johnson, pers. comm.). However, in 2003 and 2005, captive-born adult toads returned to the southern release site to breed (M. Canals, pers. comm.), demonstrating the establishment of a second population. Recovery goals for this species also include island-wide education outreach, protection and restoration of existing habitat, creation of new ponds to support six self-sustaining populations (three in the north and three in the south), and research (U.S. Fish and Wildlife Service, 1992). Recovery efforts are primarily directed through the USFWS, Department of Natural and Environmental Resources (DNER) and the AZA. Additional recovery group partners consist of the University of Puerto Rico, Juan Rivero Zoo, Ciudadanos del Karso and Inciativa Herptológica, Inc. Restoration of existing habitat and creation of new ponds has been a continuous process. In 1998, a secondary translocation pond was built in Guanica to serve as an emergency refuge for tadpoles in the event of a large-scale disaster or premature water loss at the last remaining natural breeding pond. Further, in 2000, two ponds (4000 and 9000 sq. ft.) were built adjacent to the release site in Guanica. Unfortunately, infiltration of saltwater has occurred at both ponds and repairs need to be made as soon as a planned hydrology assessment has been completed. In 2005, three small ponds were built in Arecibo (northern Puerto Rico) on private property and northern captive-born toad tadpoles were released there in April 2006. Future research projects will include intensive monitoring of all ponds during and after the breeding season, with a focus on habitat use by tadpoles and newly metamorphosed toadlets, predation and competition, dietary studies of wild and captive tadpoles and toads, hydrological assessments of all pond sites, amphibian monitoring in Quebradillas, and a dietary and health assessment study to characterize health threats prevalent in Bufo marinus that are cohabiting with Peltophryne lemur. During the past twenty years, the Puerto Rican Crested Toad Recovery Program has become a model for amphibian conservation. Much has been learned about this elusive toad, but biologists recognize that many more questions must be answered before this species can fully recover.
Conservation of the Puerto Rican Boa (Epicrates inornatus) The genus Epicrates is represented by nine species in the West Indies (Tolson and Henderson, 1993). In Puerto Rico, the genus is represented by the Virgin Island boa (E. monensis granti), the Mona Island boa (E. m. monensis) and the Puerto Rican boa (E. inornatus). The Puerto Rican boa is the largest snake (maximum known SVL = 2.2 m) inhabiting the Puerto Rico Bank. This species was protected by the
Conserving the Puerto Rican herpetofauna
347
U.S. Endangered Species Act of 1973, and a recovery plan was completed in 1986. In 2004, the Department of Natural and Environmental Resources changed its status to Vulnerable, but it was still considered Endangered by the U.S. Fish and Wildlife Service. The first conservation effort was to protect boas from being collected and hunted (USFW, 1986). More than three decades after its designation as endangered, the ecology and natural history of these snakes still are not well documented. Thus, different conservation strategies are being developed. Recent conservation strategies can be categorized as: (a) gathering of basic biological information; (b) habitat conservation; and (c) outreach. Biological information available consists of studies of distribution, habitat preferences, and life history in the Caribbean Natural Forest (Reagan and Zucca, 1982), diet and foraging behavior (Rodríguez-Durán, 1996; Puente-Rolón and Bird-Picó, 2004; Rodriguez and Reagan, 1984; Wiley, 2003), spatial ecology and habitat use (Puente-Rolón and Bird-Picó, 2004; Wunderle et al., 2004) and captive breeding (Bloxam, 1981). Also, surveys for locations of unknown populations have been conducted (Bird-Picó, 1994). Current research on the species focuses on habitat preferences and requirements, reproductive ecology, survivorship and thermoregulatory behavior. The goal is to contribute scientifically sound management recommendations to the development of a recovery plan for the boa. Habitat loss and landscape fragmentation have become another concern in the conservation of this species. Habitat destruction is increasing, and may disrupt natural population dispersal and gene flow. Due to its protected status, translocation (i.e., movement of wild individuals from one part of their range to another) has become a common practice when boas are found in human settlements. A study on how the translocation influences thermoregulation, movement and survivorship is in progress. Preliminary data show that translocated snakes expand their home ranges when compared to non-relocated individuals (Puente-Rolón, unpubl. data). Other conservation efforts include the development of mechanisms for the identification of potential habitat by local and federal agencies and the acquisition of forested areas in the northern karst region by a non-profit organization known as Ciudadanos del Karso. Preliminary landscape-level analysis of habitat fragmentation and potential habitat available for the boas in the northern karst area has been performed by the U.S. Fish and Wildlife Service to establish land conservation strategies.
Conservation of the Puerto Rican Freshwater Turtle (Trachemys s. stejnegeri) We know almost nothing about the ecology of West Indian freshwater turtles (Schwartz and Henderson, 1991). Turtles of the genus Trachemys might be the least-studied vertebrates in the West Indies. Trachemys s. stejnegeri is the only freshwater turtle native to Puerto Rico. Although its population status is currently undetermined, early studies indicate potential threats to natural populations. For instance, Rivero (1998) suggested that both a limited distribution and possible
348
R.L. Joglar et al.
small population sizes could warrant the protection of these turtles. However, environmental agencies (i.e., Department of Natural and Environmental Resources, and U.S. Fish and Wildlife Service) have been unable to provide legal protection for T. s. stejnegeri due to a lack of data on the status of populations. On the other hand, this species was classified as near-threatened in the Red List of the International Union for the Conservation of Nature and Natural Resources (IUCN) (Hilton-Taylor, 2000). Therefore, comprehensive studies are needed to characterize the nature and extent of the factors threatening the long-term persistence of the Puerto Rican freshwater turtle. Baseline data from such studies are necessary to direct effective management and conservation efforts. Recent efforts for the conservation of the Puerto Rican freshwater turtle (León and Joglar, 2005) combined three main research approaches to clarify the status of local populations: (1) a medium-term mark-recapture-release study, (2) fieldmonitoring of reproductive activity (i.e., nocturnal patrolling to identify nesting activity) and (3) field-assessment of the potential impact of introduced species (i.e., field identification of predatory species and exotic turtles). Research findings provided a comprehensive description of the population ecology and reproductive biology of the Puerto Rican freshwater turtle. Temporal patterns of sightings are proportional to reproductive activity. Specifically, relative abundance peaks during the nesting season from April to June. Presumably, females migrate to limited nesting areas during the reproductive season and are then more frequently sighted. Moreover, identified threats to reproductive success and recruitment of early life stages include, intense egg predation by the exotic Indian mongoose (Herpestes javanicus), habitat alteration and establishment of exotic freshwater turtles in natural ecosystems inhabited by the Puerto Rican freshwater turtle. We recommend two management actions based on current research. First, eradicating Herpestes javanicus from nesting areas is an urgent need. Eradication will have a direct positive effect on the recruitment of early life stages. Second, enforcement of exotic trade laws by local agencies could help in phasing out illegal sales of the red-eared slider (Trachemys scripta elegans). The exotic red-eared slider has been released and is widespread in Puerto Rican wetlands inhabited by native turtles. This observation calls for stopping the introduction of exotic turtles in West Indian ecosystems due to potential detrimental effects of interspecific competition and hybridization in local turtle populations. For instance, recent massive introductions of T. scripta elegans into Europe have had negative impacts on the survival rates of the European pond turtle (Cadi and Joly, 2004).
Recovery Initiatives for the Mona Island Iguana (Cyclura stejnegeri) Iguanas of the genus Cyclura are arguably the most endangered lizard in the world (Alberts, 1999, 2004). Their distribution is limited to the West Indies, with species or subspecies typically restricted to few or single islands or cays. Cyclura stejnegeri is found only on Mona Island, with estimated population densities ranging from
Conserving the Puerto Rican herpetofauna
349
0.33 individuals/ha (Wiewandt, 1977) to 0.96 ± 0.47 individuals/ha (Pérez-Buitrago and Sabat, 2000). These densities are considered very low for this group (Iverson, 1977). Furthermore, a major concern has been the scarcity of immature iguanas (5-10%) in the wild population (Wiewandt, 1977; Pérez-Buitrago and Sabat, 2000). The Mona Island iguana has been listed as threatened and a recovery plan approved (Diaz, 1984). Since then, we have implemented several recovery actions aimed at the management of invasive mammals, a headstart program for hatchling iguanas, and the assessment of the etiology of a condition causing blindness in several adult iguanas. Feral goats and pigs have been controlled for decades on Mona Island using hunters, with a reported total of 314 goats and 49 pigs killed every hunting season from January to April (García et al., 2000). Since estimated population numbers of these animals are unknown, we cannot determine satisfactorily the efficacy of this management strategy. However, hunting success has not changed significantly throughout the years (García et al., 2000); this suggests a stable prey population since feral goat populations increase rapidly in island ecosystems (e.g., Rudge et al., 1970; Baker and Reeser, 1972). On the other hand, the most important iguana nesting sites found on the coastal terrace and in two of the interior forest depressions have been fenced to protect them from trampling and feral pig predation. From 1996 to 2005, intensive hunting and trapping of feral cats have been conducted on Mona Island (García et al., 2001; López and García, unpubl. data). Although we have eliminated a total of 118 cats, we seek to eradicate this predator. The feral cat diet was composed of insects, small mammals, birds and reptiles, including Mona Island iguana hatchlings. The eradication of feral cats in Mona Island is an attainable goal, but more efforts need to be devoted to the hunting activity and the introduction of a feline-specific virus may be necessary. Headstarting is a conservation initiative aimed at increasing the survival of hatchlings and juveniles by keeping them in captivity until they reach a size at which they are protected from early age-class predators. The headstart program for the Mona Island iguana started in 1999 in response to Perez-Buitrago (2000) finding only 13% hatchling survival during the first five months. For the headstart program, hatchlings were collected and kept in captivity under natural conditions until they reach a target size of 25 cm and 950 g. To date, 132 headstarted iguanas have been released into the wild. They are showing adequate survival (40%) and adaptation. Although this is a conservative value because only individuals that are found are considered, it agrees with other headstarted iguana survival values (9–40%; Alberts et al., 2004; Wilson et al., 2004). Therefore, the implementation of the headstart program for the Mona Island iguanas seems to be an appropriate conservation strategy for augmenting the number of juveniles in the wild population. Several blind iguanas had been observed in Mona Island (Haneke, 1995). Therefore, health screening to assess this condition was conducted in 1998 and 1999 by staff from the Toledo Zoo. Nine of 34 iguanas examined in the field (26%) were blind or partially blind in at least one eye, due mainly to cataracts (Hudson and Al-
350
R.L. Joglar et al.
berts, 2004), suggesting that the blindness was an age-related condition (Reichard, Tolson and García, unpubl. data). However, subsequent fieldwork (2000-2005) has determined that 28% of iguanas found (n = 160) were totally or partially blind (Pérez-Buitrago, unpubl. data). Therefore, a comprehensive and conclusive assessment of this condition is urgently needed. In conclusion, we have in a relatively short period been able to address the major threats to this species. In addition, intensive ecological monitoring and research are being conducted (Pérez-Buitrago, unpubl. data). These data will be useful to assess the progress of the Mona Island Iguana Program. Thus, we are confident of the recovery of this species within a decade — if these management strategies are maintained or (preferably) intensified.
Recovery of the Herpetofauna in a Restored Karst Valley in Puerto Rico The main goals of a habitat restoration project are to reestablish the original biota and natural ecological functions (Parker, 1997; Palmer et al., 1997; Zedler, 2001; Block et al., 2001). Studies that have monitored the recovery of animal communities in habitat-restoration projects, however, have focused mainly on birds, mammals, and macro- and microfauna in soils; the herpetofauna is rarely considered, particularly on tropical islands. On Caribbean islands, which lack the large mammals present in the mainland tropics, reptiles and amphibians constitute the top predators (Thomas and Kessler, 1996), and are the most abundant and conspicuous vertebrates (Reagan, 1996; Duellman, 1999b). Given the increased evidence of population declines in amphibians and reptiles worldwide (Pough et al., 2001), largely due to habitat destruction, we need to develop effective habitat restoration projects capable of recovering and maintaining the Caribbean herpetofauna. As an attempt to recover a local Puerto Rican herpetofaunal assemblage, we reforested a limestone valley in Sabana Seca, Toa Baja, Puerto Rico. The study area is in the Subtropical Moist Forest life zone (Ewel and Whitmore, 1973). Average annual rainfall is 1700 mm. Rainfall is mildly seasonal, with most of the rain falling from May to November (Eusse and Aide, 1999). A similar annual pattern exists for temperature, with warmer months between May and November. In January 2000, a deforested valley (160 × 20 m) was reforested with 516 plants of 22 native woody species for a final density of 1666 plants/ha. In April 2002, plant survivorship was 93.6% and mean plant height was 1.78 m. We studied four reference sites, which were within 500 m of each other, and which consisted of a deforested valley that represented the pre-reforested conditions, another valley, which was reforested naturally approximately 30 to 40 years ago, and a karst hillside and hilltop, which have been forested for >65 years. At all sites, we sampled the species richness, monitored changes in community assemblages during a 12-month period, and collected data on vegetation structure and microclimate. Although the main objective for the reforestation of this valley was to create a
Conserving the Puerto Rican herpetofauna
351
forested habitat for the endangered Puerto Rican boa (Epicrates inornatus), we wanted to evaluate the success of this reforestation project in recovering an entire herpetofaunal assemblage. We found a total of 17 species; the karst hillside had the highest number of species (12), whereas the deforested valley had the lowest (2). In the reforested valley, the herpetofaunal species richness increased rapidly from three to eleven species, but the herpetofaunal assemblage composition recovered more slowly when compared to the reference sites. In response to increases in the population sizes of colonizers (e.g., Eleutherodactylus spp. and Anolis spp.), forest interior and predatory species colonized the reforested valley by the end of the study. Among the predatory species were the Puerto Rican boa (E. inornatus), the racer (Alsophis portoricensis) and the arboreal giant anole (Anolis cuvieri). By planting native trees, we increased vegetation cover and heterogeneity. The increase in woody species changed the microclimate, specifically the variation in temperature and humidity, and conditions are converging on the conditions of references sites. These changes, along with the short distance to intact forest (species sources), have contributed to the rapid recovery of herpetofaunal species richness, assemblage composition and trophic structure.
Puerto Rican Marine Turtle Monitoring Programs The first marine turtle studies in Puerto Rico started in 1974 on Mona Island (Pinto-Rodríguez, 1991). Since then several marine turtle monitoring programs have been developed or continued on Mona Island, Vieques, Culebra, Luquillo, Fajardo, Maunabo, Rincón and Piñones. One of these programs stands out because of its long time span, large turtle population and publication record: The hawksbill turtle monitoring program at Mona Island. Marine turtles were studied on Mona Island by Jean Thurston and Thomas Weiwandt in 1974, Molly Olson in 1984 and Anastasia Kontos from 1985 to 1987. These studies concluded that beach erosion and nest predation by pigs were the major threats to Eretmochelys imbricata nesting on the island (Pinto-Rodríguez, 1991). These studies gave origin to management practices on Mona Island from 1989 to 1990 that included fencing the beach from Playa Mujeres to Sardinera to prevent nest predation by pigs. A second phase of marine turtle monitoring was initiated on Mona in 1989 by Carlos E. Diez (DNER) and Robert P. van Dam. Results of their wok have shown that: (1) Mona and Monito Islands are among the few known remaining locations in the Caribbean where hawksbill turtles exist in considerable densities; (2) the large juvenile population of hawksbill turtles around Mona and Monito consist of long-term residents that exhibit strong site fidelity for periods of at least several years; (3) Mona’s hawksbill resident population is composed of individuals from multiple nesting populations in the Wider Caribbean (evidence from genetic data); (4) the conservation of the juvenile population of hawksbill turtles at Mona can contribute to sustaining healthy nesting populations
352
R.L. Joglar et al.
throughout the Caribbean; and (5) Mona Island’s hawksbill population is the largest under U.S. jurisdiction, and the second largest in the Caribbean, after Barbados (Bowen et al., 1996; Possardt et al., 2007; Diez and van Dam, 2002; van Dam and Diez, 1996, 1997a, 1997b, 1998a,b, 1999). Management practices such as beach fencing in Mona and other conservation measures in different areas of the Caribbean seem to be having a positive effect on nest numbers (Robert van Dam, pers. comm.). There has been a significant increase in the number of hawksbill nests in the last decade: 450 to 500 nests between 1997 and 2001; 850 to 925 nests between 2002 and 2004; and over 1000 nests between 2005 and 2006 (Carlos Diez, pers. comm.). There are several additional marine turtle monitoring programs active in Puerto Rico. Unfortunately their results and findings have not been published in peer reviewed journals, making it difficult to review these studies. One of these programs is the leatherback turtle monitoring program in Luquillo and Fajardo which started in 1985. With more than 20 years of continuous monitoring, this is the longest marine turtle monitoring program in Puerto Rico. Hector Horta and other DNER personnel are responsible for this accomplishment. Luis Crespo directs another marine turtle monitoring program in Maunabo.
Concluding Remarks Conservation of the world’s natural resources and biodiversity is one of the greatest challenges humanity faces at present. The obstacles encountered by conservation biologists and environmentalists in Puerto Rico are not very different from those elsewhere. However, among our Caribbean neighbors, we may be distinguished by having the highest population density, level of industrialization, and rate of urban development. Thus, the threats of habitat loss and contamination are of more immediate concern. Unfortunately, an abysmal difference remains between the funds and efforts allocated to ‘economic development’ and those dedicated to the conservation of nature. Finding a balance that will allow for true sustainable yield is the key to preserving our planet. However, this will entail major changes at all levels of our societies (politics, economy, environmental policy, etc.), but most importantly, such changes will require modifications of human conduct. The latter, we can only achieve through education. Teaching the general public the value of our biodiversity is imperative, for people will only strive to conserve that which they consider significant. Author contributions. All authors after the first are listed alphabetically. RLJ conceived and designed the manuscript. Specific topics were written by the following authors: (1) Introduction, Puerto Rican herpetofauna, conservation, Puerto Rican marine turtle monitoring programs and appendices — RLJ; (2) Amphibians, pathogens and climate change — PAB, RLJ and AVL; (3) Puerto Rican crested toad — DB; (4) Puerto Rican Boa — AP; (5) Puerto Rican freshwater turtle —
Conserving the Puerto Rican herpetofauna
353
ALC and RLJ; (6) Mona Island iguana — MAG, NPB, AOA and PJT; and (7) herpetofaunal community — NRL and TMA. RLJ and PAB edited the manuscript.
References Alberts, A.C., Comp. and ed. (1999): West Indian Iguanas: Status Survey and Conservation Action Plan. IUCN/SSC West Indian Iguana Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. Alberts, A.C. (2004): Introduction. In: Iguanas: Biology and Conservation, p. 195-198. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P. (Eds), University of California Press, Berkeley. Alberts, A.C., Lemm, J.L., Grant, T.D., Jackintell, L.A. (2004): Testing the utility of headstarting conservation strategy for West Indian Iguanas. In: Iguanas: Biology and Conservation, p. 210219. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P. (Eds), University of California Press. Berkeley. Baker, J.K., Reeser, D.W. (1972): Goat Management Problems in Hawaii Volcanoes National Park: A History, Analysis and Management Plan. USDI Natural Resources Report 2-22. Berger, L., Speare, R., Hines, H.B., Marantelli, G., Hyatt, A.D., McDonald, K.R., Skerratt, L.F., Olsen, V., Clarke, J.M., Gillespie, G., Mahony, M., Sheppard, N., Williams, C., Tyler, M.J. (2004): Effect of season and temperature on mortality in amphibians due to chytridiomycosis. Austr. Veter. J. 82: 434-439. Bird-Picó, F.J. (1994): Final Report on Epicrates inornatus Survey Throughout Puerto Rico. Unpublished report. Cooperative agreement between U.S. Fish and Wildlife Service and the University of Puerto Rico, Mayagüez Campus # 14-16-0004-92-958. 45 pp. Block, W.M., Franklin, A.B., Ward, Jr. J.P., Ganey, J.L., White, G.C. (2001): Design and implementation of monitoring studies to evaluate the success of ecological restoration on wildlife. Restoration Ecology 9: 293-303. Bloxam, Q. (1981): A comparison of reproduction in three species of Epicrates (Serpentes, Boidae) maintained at the Jersey Wildlife Preservation Trust. Dodo 18: 64-74. Bowen B.W., Bass A.L., García-Rodríguez, A., Diez, C.E., van Dam, R. (1996): Origin of Hawksbill Turtles in a Caribbean Feeding Area as Indicated by Genetic Markers. Ecol. Appl. 6: 566-572. Burrowes, P.A., Joglar, R.L. (2005): El estado de los anfibios de Puerto Rico. In: Biodiversidad de Puerto Rico. Vertebrados Terrestres y Ecosistemas. Serie de Historia Natural, p. 60-65. Joglar R.L. (Ed.), Editorial Instituto de Cultura Puertorriqueña, San Juan, Puerto Rico. Burrowes, P.A., Joglar, R.L., Green, D.E. (2004): Potential causes for amphibian declines in Puerto Rico. Herpetologica 60: 141-154. Cadi, A., Joly, P. (2004): Impact of the introduction of the red-eared slider (Trachemys scripta elegans) on the survival rates of the European pond turtle (Emys orbicularis). Biodivers. Conserv. 13: 25112518. CBSG. (2005): Population and Habitat Viability Analysis for the Puerto Rican Crested Toad. Final Report. IUCN/SSC Conservation Breeding Specialist Group: Apple Valley, MN. Cruz, A.D., Boswell, T.D. (1997): Atlas Puerto Rico. The Cuban American National Council, Inc. Miami, Florida. Díaz, C. (1984): Recovery Plan for the Mona Iguana, Cyclura stejnegeri. Unpublished report. U.S. Fish and Widlife Service. Atlanta, Georgia. Diez, C.E., van Dam, R.P. (2002): Habitat effect on hawksbill turtle growth rates on feeding grounds at Mona and Monito Islands, Puerto Rico. Mar. Ecol. Prog. Ser. 234: 301-309. Duellman, W.E., Ed. (1999a): Patterns of Distributions of Amphibians. A Global Perspective. The Johns Hopkins University Press, Baltimore.
354
R.L. Joglar et al.
Duellman, W.E. (1999b): The West Indies and Middle America: contrasting origins and diversity. In: Caribbean Amphibians and Reptiles, p. 357−369. Crother, B.I. (Ed.), Academic Press, a Division of Hartcourt Brace and Company, San Diego, California. Eusse, A.M., Aide, T.M. (1999): Patterns of litter production across a salinity gradient in a Pterocarpus officinalis tropical wetland. Plant Ecol. 145: 307-315. Ewel, J.J., Whitmore, J.L. (1973): The ecological life zones of Puerto Rico and the U.S. Virgin Islands. Forest Service Research Paper ITF−18. Forest Service, U.S. Department of Agriculture. Institute of Tropical Forestry, Río Piedras, Puerto Rico. García, M.A., Diez, C.E., Alvarez, A.O. (2000): El control de los cabros y cerdos en la Isla de La Mona, Puerto Rico. Acta Científica 14: 83-87. García, M.A., Diez, C.E., Alvarez, A.O. (2001): The impact of feral cats on Mona Island wildlife and recommendations for their control. Carib. J. Sci. 37: 107−108. Gannon, M.R., Kurta, A., Rodríguez, A., Willig, M.R. (2005): Bats of Puerto Rico. An Island Focus and a Caribbean Perspective. The University of the West Indies Press, Jamaica. Haneke, B. (1995): A study of Mona rock iguana (Cyclura cornuta stejnegeri) nesting sites on Mona Island, Puerto Rico. Iguana Times (J. Int. Iguana Soc.) 4: 61-71. Hedges, B. (1999): Distribution patterns of amphibians in the West Indies. In: Patterns of Distributions of Amphibians. A Global Perspective, p. 211-254. Duellman, W.E. (Ed.), The Johns Hopkins University Press, Baltimore. Hilton-Taylor, C., Ed. (2000): 2000 IUCN Red List of Threatened Species. IUCN, Gland, Switzerland and Cambridge, UK. Hudson, R.D., Alberts, A. (2004): The role of zoo in the conservation of West Indian Iguanas. In: Iguanas: Biology and Conservation, p. 274-289. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P. (Eds), University of California Press, Berkeley. IUCN (2004): 2004 IUCN Red List of Threatened Species. www.redlist.org. Downloaded on 12 December 2005. Iverson, J.B. (1977): Behavior and Ecology of the Rock Iguana Cyclura carinata. Unpublished Doctoral Dissertation, University of Florida, Gainesville. Joglar, R.L. (1998): Los Coquíes de Puerto Rico: Su Historia Natural y Conservación. Editorial de la Universidad de Puerto Rico. San Juan, Puerto Rico. Joglar, R.L. (2005a): Anfibios. In: Biodiversidad de Puerto Rico. Vertebrados Terrestres y Ecosistemas. Serie de Historia Natural, p. 39-96. Joglar, R.L. (Ed.), Editorial Instituto de Cultura Puertorriqueña, San Juan, Puerto Rico. Joglar, R.L. (2005b): Reptiles, In: Biodiversidad de Puerto Rico. Vertebrados Terrestres y Ecosistemas. Serie de Historia Natural, p. 99-168. Joglar, R.L. (Ed.), Editorial Instituto de Cultura Puertorriqueña, San Juan, Puerto Rico. Joglar, R.L., Burrowes, P. (1996): Declining amphibian populations in Puerto Rico. In: Contributions to West Indian Herpetology: A Tribute to Albert Schwartz, p. 371-380. Powell, R., Henderson, R.W. (Eds), Society for the Study of Amphibians and Reptiles, Contributions to Herpetology, Volume 12. Ithaca, New York. Johnson, B. (1999): Endangered Species Bulletin. May/June. 24 (3): 8-9. Lentini, A. (2000): Puerto Rican Crested Toad (Peltophryne lemur) SSP Husbandry Manual. Keeper and Curator Edition. Toronto Zoo, Scarborough, Ontario. León, A., Joglar, R.L. (2005): La jicotea puertorriqueña. In: Biodiversidad de Puerto Rico: Vertebrados Terrestres y Ecosistemas. Serie de Historia Natural, p. 181-190. Joglar, R.L. (Ed.), Editorial Instituto de Cultura Puertorriqueña, San Juan, Puerto Rico. Lugo, A.E. (2005): Bosques, In: Biodiversidad de Puerto Rico. Vertebrados Terrestres y Ecosistemas. Serie de Historia Natural, p. 397-545. Joglar, R.L. (Ed.), Editorial Instituto de Cultura Puertorriqueña. San Juan, Puerto Rico.
Conserving the Puerto Rican herpetofauna
355
Lloveras San Miguel, F. (2008): En ruta al colapso: Busquemos otro camino. In: Biodiversidad de Puerto Rico. Agustín Stahl, Flora y Hongos. Serie de Historia Natural, p. 19-20. Joglar, R.L. (Ed.), Editorial de la Universidad de Puerto Rico. San Juan, Puerto Rico. Palmer, M.A., Ambrose, R.F., Poff, N.L. (1997): Ecological theory and community restoration ecology. Restor. Ecol. 5: 291-300. Parker, V.T. (1997): The scale of successional models and restoration objectives. Restor. Ecol. 5: 301306. Pérez-Buitrago, N. (2000): Survival and Dispersal of Rock Iguana Hatchlings (Cyclura cornuta stejnegeri) on Mona Island, Puerto Rico. Unpublished Masters Thesis. University of Puerto Rico. Rio Piedras Campus. Pérez, N., Sabat, A. (2000): Population status of the rock ground iguana (Cyclura cornuta stejnegeri) in Mona Island, Puerto Rico. Acta Científica. 14: 67-76. Pinto-Rodríguez, B. (1991): Biología y conservación de tortugas marinas en Isla de Mona. Naturaleza Edición Mona Febrero 1991: 39. Possardt, E., Schroeder, B., MacPherson, S. (2007): Convención Internamericana para la Protección y Conservación de las Tortugas Marinas Estados Unidos de America. Informe Anual 2007: 1-19. Pough, F.H., Andrews, R.M., Cadle, J.E., Crump, M.L., Savitzky, A.H., Wells, K.D. (2001): Herpetology, 2nd edn. Prentice Hall, Inc. Upper Saddle River, New Jersey. Puente-Rolón, A.R., Bird-Picó, F.J. (2004): Foraging behavior, home range, movements and activity patterns of Epicrates inornatus (Boidae) at Mata de Plátano Reserve in Arecibo, Puerto Rico. Carib. J. Sci. 40: 343-352. Quevedo, V. (2008): Herramientas legales para la conservación de la flora de Puerto Rico. In: Biodiversidad de Puerto Rico. Agustín Stahl, Flora y Hongos. Serie de Historia Natural, p. 159163. Joglar, R.L. (Ed.), Editorial de la Universidad de Puerto Rico. San Juan. Puerto Rico. Reagan, D.P. (1996): The role of amphibians and reptiles in a West Indian rain forest food web. In: Contributions to West Indian Herpetology: A Tribute to Albert Schwartz, p. 217-227. Powell, R., Henderson, R.W. (Eds), Society for the Study of Amphibians and Reptiles, Ithaca (New York). Contributions to Herpetology, volume 12. Reagan D.P., Zucca, C.P. (1982): Inventory of the Puerto Rican Boa (Epicrates inornatus) in the Caribbean National Forest. CEER T-136. Retallik, R.W.R., McCallum, H., Speare, R. (2004): Endemic infection of the amphibian chytrid fungus in a frog community post-decline. PLOS Biol. 2 (11): 1-7. Rios-López, N., Thomas, R. (2007): A new species of palustrine Eleutherodactylus (Anura: Leptodatylidae) from Puerto Rico. Zootaxa 1512: 51-64. Rivero, J.A. (1998): Amphibians and Reptiles of Puerto Rico (2nd edn). Editorial de la Universidad de Puerto Rico. San Juan, Puerto Rico. Rodríguez-Durán, A. (1996): Foraging ecology of the Puerto Rican boa (Epicrates inornatus): bat predation, carrion feeding and piracy. J. Herpetol. 30: 533-536. Rodríguez, G., Reagan, D.A. (1984): Bat predation by the Puerto Rican boa, Epicrates inornatus. Copeia 1984: 219−220. Rudge, M.R., Hutt, L., Smith, T.J. (1970): Expected rate of increase of hunted population of feral goats (Capra hircus) in New Zealand. New Zeal. J. Sci. 13: 256-259. Sanchez-Martínez, H. (2007): Puerto Rico ¡Qué Grande! Publicaciones Puertorriqueñas. San Juan, Puerto Rico. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. University of Florida Press, Gainesville. Thomas, R., Kessler, A.G. (1996): Non-anoline reptiles. In: The Food Web of a Tropical Rain Forest, p. 347-362. Reagan, D.P., Waide R.W. (Eds), University of Chicago Press, Chicago, Illinois. Tolson, P.J., Henderson, R.W. (1993): The Natural History of West Indian Boas. R&A Publishing Limited, Somerset, England.
356
R.L. Joglar et al.
U.S. Fish and Wildlife Service. (1986): Puerto Rican Boa Recovery Plan. Unpublished report. U.S. Fish and Wildlife Service, Atlanta, Georgia. U.S. Fish and Wildlife Service. (1992): Recovery Plan for the Puerto Rican Crested Toad (Peltophryne lemur). Unpublished report. Atlanta, Georgia. van Dam, R.P., Diez, C.E. (1996): Diving behavior of immature hawksbills (Eretmochelys imbricata) in a Caribbean cliff wall habitat. Mar. Biol. 127: 171-178. van Dam, R.P., Diez, C.E. (1997a): Diving behavior of immature hawksbill turtles (Eretmochelys imbricata) on the reefs of Mona Island, Puerto Rico. Coral Reefs 16: 133-138. van Dam, R.P., Diez, C.E. (1997b): Surfacing behavior of the marine turtle (Eretmochelys imbricata). J. Herpetol. 31: 313-316. van Dam, R.P., Diez, C.E. (1998a): Home range of immature hawksbillturtles (Eretmochelys imbricata) at two Caribbean islands. J. Exp. Mar. Biol. Ecol. 220: 15-24. van Dam, R.P., Diez, C.E. (1998b): Caribbean hawksbill turtle morphometrics. Bull. Mar. Sci. 62: 145-155. van Dam, R.P., Diez, C.E. (1999): Differential tag retention in Caribbean hawksbill turtles. Chelonian Conserv. Biol. 3: 225-229. Wiewandt, T. (1977): Ecology, Behavior, and Management of the Mona Island Ground Iguana, Cyclura stejnegeri. Unpublished Doctoral Dissertation. Cornell University. Ithaca, New York. Wiley, J.W. (2003): Habitat association, size, stomach contents and reproductive condition of the Puerto Rican boa (Epicrates inornatus). Carib. J. Sci. 39: 189-194. Wilson B.S., Alberts, A.C., Graham, K.S., Hudson, R.D., Bjorkland, R.K., Lewis, D.S., Lung, N.P., Nelson, R., Thompson, N., Kunna, J.L., Vogel, P. (2004): Survival and reproduction of repatriated Jamaican Iguanas. In: Iguanas: Biology and Conservation, p. 220-231. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P. (Eds), University of California Press, Berkeley. Wilson, B.S., Horrocks, J.A., Hailey, A. (2006): Conservation of insular herpetofaunas in the West Indies. Appl. Herpetol. 3: 181-195. Wunderle J.M., Mercado Parresol, J.E., Terranova, E. (2004): Spatial ecology of Puerto Rican boa (Epicrates inornatus) in a hurricane impacted forest. Biotropica 36: 555–571. Zedler, J. B. (2001): Declining biodiversity: why species matter and how their functions might be restored in Californian tidal marshes. BioScience Dec. 2001.
Accepted: August 29, 2007 (BSW). Reprinted from Applied Herpetology 4: 327-345 (2007).
Appendix. Amphibians and reptiles in Puerto Rico (#: introduced species in Puerto Rico). Bufonidae Peltophryne lemur Leptodactylidae Eleutherodactylus antillensis E. cooki E. gryllus E. karlschmidti E. portoricensis E. wightmanae Ranidae Rana catesbeiana # Hylidae Hyla cinerea #
Bufo marinus # E. brittoni E. coqui E. hedricki E. locustus E. richmondi E. juanariveroi
E. cochranae E. eneidae E. jasperi E. monensis E. unicolor Leptodactylus albilabris
Rana grylio # Osteopilus septentrionalis #
Scinax ruber #
Conserving the Puerto Rican herpetofauna Testudines Caretta caretta Eretmochelys imbricata Trachemys s. stejnegeri Gekkonidae Hemidactylus brooki Sphaerodactylus gaigeae S. macrolepis S. nicholsi Teiidae Ameiva alboguttata A. wetmorei Scincidae Mabuya mabouya Anguidae Diploglossus pleei Polychrotidae Anolis cooki A. desechensis A. krugi A. poncensis A. stratulus Iguanidae Cyclura nubila # Amphisbaenia Amphisbaena bakeri A. xera Typhlopidae Typhlops granti T. platycephalus Boidae Epicrates inornatus Colubridae Alsophis portoricensis Crocodylia Caiman crocodilus # Extinct reptiles Anolis roosevelti Cyclura pinguis Leiocephalus etheridgei Leiocephalus partitus Monachelys monensis
357
Chelonia mydas Lepidochelys olivacea
Dermochelys coriacea Trachemys scripta #
Hemidactylus mabouia S. klauberi S. micropithecus S. roosevelti
Phyllodactylus wirshingi S. levinsi S. monensis S. townsendi
A. desechensis
A. exsul
A. cristatellus A. evermanni A. monensis A. pulchellus
A. cuvieri A. gundlachi A. occultus A. roosevelti
C. stejnegeri
Iguana iguana #
A. caeca
A. schmidti
T. hypomethes T. richardii
T. monensis T. rostellatus
E. monensis Arrhyton exiguum
extinction circa 1930 old extinction (>500 years) in Puerto Rico; extant populations in the BVI old extinction (>500 years) old extinction (>500 years) old extinction (>500 years)
The St. Vincent (Lesser Antilles) herpetofauna: Conservation concerns Robert Powell1 , Robert W. Henderson2 1 Department of Biology, Avila University, Kansas City, Missouri 64145, USA; e-mail:
[email protected] 2 Section of Vertebrate Zoology, Milwaukee Public Museum, 800 W. Wells St., Milwaukee, Wisconsin 53233-1478, USA; e-mail:
[email protected]
Abstract. The Lesser Antillean island of St. Vincent harbors 18 species of terrestrial amphibians and reptiles: four frogs (including the endemic Pristimantis shrevei), one turtle, ten lizards (including endemic Anolis griseus and A. trinitatis), and three snakes (including endemic Corallus cookii and Chironius vincenti). In addition, four species of marine turtles are known from the region. Ecological relationships of an introduced frog (E. johnstonei) and an introduced lizard (A. sagrei) should be monitored in order to evaluate any potentially negative impact on endemic congeners. Two endangered endemic species (P. shrevei and C. vincenti) may benefit from sympatry with the endemic parrot, Amazona guildingii, the national bird of St. Vincent, with which they share high-quality upland forest habitat. Like other West Indian herpetofaunas, that on St. Vincent faces threats that include dramatic habitat alterations, introduced predators (mongooses, domestic cats) and competitors (e.g., A. sagrei), changes in the prey base, and the potential introduction of the chytrid fungus. These threats can best be addressed by development and implementation of effective management programs based on ecological studies by local and foreign biologists. Key words: Amphibians; conservation; reptiles; St. Vincent.
Introduction St. Vincent, with an area of 345 km2 , is one of the Windward Islands in the southern Lesser Antilles. Humans likely entered the Lesser Antilles from South America about 2000 B.C. (Wilson, 2001), so some degree of habitat alteration has probably been ongoing for about 4000 years, with the vast majority of it post-Columbus. On St. Vincent, pottery remains are available from as early as 160 ± 100 A.D. (Bullen and Bullen, 1972; Callaghan, 2007). Caribs entered the Windward Islands after 1000 A.D. (Rouse, 1989), and they lived on St. Vincent, believed to have been the center of island Carib culture, “. . . more or less undisturbed for nearly
360
R. Powell, R.W. Henderson
200 years. . . ” post-Columbus (Bullen and Bullen, 1972). The first permanent nonnative residents were African slaves that had been shipwrecked in 1635. The British, French, and Caribs subsequently vied for possession of the island during the 1700s, with the Caribs finally surrendering to the British in 1796. A plantation economy flourished during the 1800s, with principal crops of sugar, coffee, cotton, and cacao, but the sugar economy dwindled toward the end of the 19th century — only to be replaced with the intensely cultivated banana industry. Even more than sugar, bananas exploited forested hillsides and introduced subsidized use of chemical fertilizers and extensive applications of pesticides and herbicides. The latter may or may not have affected the herpetofauna directly, but undoubtedly had a negative impact on the arthropodan prey base of many species. Agriculture and the plantation system, dating largely to the sugar economy and prevalent on many Caribbean islands, has been primarily responsible for creating a patchwork landscape that, to this day, affects the distribution of frogs and reptiles. Like the other Windward Islands that comprise the Inner Arc of the Lesser Antilles (sometime called the “Volcanic Caribees”), St. Vincent is of volcanic origin. La Soufrière (1180 m), its principal peak, is the northernmost and youngest volcano on the island. Historical eruptions of La Soufrière occurred in 1718, 1812, 1902, and 1979 (Venzke et al., 2002-2007). The 1902 eruption dramatically affected the northern third of St. Vincent (Hovey, 1902). Effects of the 1979 eruption were less extensive (Fiske and Sigurdsson, 1982), and frogs (Pristimantis shrevei) were collected near the summit about 10 years later (Kaiser et al., 1994). The topography of the island consists largely of steep slopes dissected by lush valleys, with relatively narrow coastal plains (fig. 1). Because of the harsh topography, many of the uplands were spared the extensive deforestation during the colonial era that occurred on Lesser Antillean islands with less relief (Callaghan, 2007). In 1993, about 38% of the land area was covered by forest, about 5% of which was mature, mostly undisturbed primary forest. At that time, land above 305 m was reserved to conserve remaining forests (SVG Forestry Department, 1993). Conservation programs fall under the Ministry of Agriculture, Forestry and Fisheries, with terrestrial systems under the Department of Forestry. Because of the consequent emphasis on conserving forests, legislation and enforcement appropriately emphasize entire ecosystems instead of the species-by-species approach evident in many nations. The St. Vincent Parrot Reserve, established for the protection of the endangered St. Vincent Parrot (Amazona guildingii), extends protection to habitat, thereby benefiting other species that rely on intact mature forest. As of 1993 (SVG Forestry Department, 1993), no formal system of national parks and protected areas existed, although designation of Soufrière Volcano as a national park had been proposed. Eight areas on St. Vincent were declared wildlife reserves under the 1987 Wildlife Protection Act. The largest of these is the St. Vincent Parrot Reserve (3075 ha in 1993, 4399 ha in 2007; Gardner, 2007). Unfortunately, the system of wildlife reserves existed largely on paper, boundaries were not clearly demarcated, and the ability of forestry officers to function as wildlife protection
The St Vincent herpetofauna
361
Figure 1. Map of St. Vincent with sites mentioned in the text. Contour shading is at 610 m and 915 m.
officers was doubtful. By 2004, in addition to recommendations regarding the categorization and delineation of protected areas and heritage sites, Strategy 42 of the Environmental Management Strategy and Action Plan (2004-2006) stated: “Take necessary precautionary measures to avoid or minimize the intentional or accidental introduction or escape, into or from the environment, and the control of alien or living modified organisms that are likely to impact adversely on other organisms, the environment or on human health” (Homer and Shim, 2004). Building
362
R. Powell, R.W. Henderson
on the 2004 report, the Review of the Policy, Legal and Institutional Frameworks for Protected Areas Management in St. Vincent and the Grenadines (Gardner, 2007) listed sites recommended for inclusion in the system of protected areas; these include on St. Vincent proper: one national park (Soufrière), eight forest reserves, and three national landmarks. To date, however, protected areas still exist primarily on paper. Enforcement is sporadic and limited largely to efforts by Department of Forestry personnel, complicated considerably by the illegal cultivation of marijuana in some upland areas.
The Herpetofauna and Associated Conservation Concerns Eighteen species of terrestrial amphibians and reptiles and four species of marine turtles comprise the known herpetofauna of St. Vincent (Table 1). Of these, two, Eleutherodactylus johnstonei and Anolis sagrei, are known to be introduced, and three others, Bufo marinus, Geochelone sp., Hemidactylus mabouia, may have been introduced by human agency or might have reached the islands by natural means. Five species, Pristimantis shrevei (formerly Eleutherodactylus shrevei; Heinicke et al., 2007), A. griseus, A. trinitatis, Chironius vincenti, Corallus cookii, and one subspecies, Sphaerodactylus vincenti vincenti, are island endemics. Three, Leptodactylus validus, Ameiva ameiva, Mastigodryas bruesi, have West Indian distributions limited to the St. Vincent and Grenada banks. Anolis trinitatis and M. bruesi have been introduced elsewhere, M. bruesi to Barbados within the West Indies and A. trinitatis to Trinidad. The marine turtles and all other terrestrial species known to occur on the island are widely distributed in the Lesser Antilles or throughout the Caribbean region. Frogs All four species of anurans found on St. Vincent are potentially of conservation concern, the two introduced species because of their real or possible impact on native taxa and the two species that occur naturally because of their vulnerability to habitat destruction and to the potential threat of the chytridiomycosis (= chytrid) fungus that has decimated many high-elevation populations of amphibians throughout the Neotropics (e.g., Lips, 1999). Bufo marinus. Populations of these large toads were presumably introduced on St. Vincent to control insects in agricultural fields (e.g., Lever, 2003), but may have reached the island by natural over-water dispersal. In many parts of the world, introduced populations have become pests and major threats to native frogs, with which they compete and on which they may feed. Bufo marinus is found throughout the lowlands of St. Vincent in a wide variety of habitats that include urban situations and various moist to dry low-elevation forests (Mallery et al., 2007). This species is a generalist predator, well known for its gluttony (Zug and Zug, 1979), feeding
The St Vincent herpetofauna
363
Table 1. The herpetofauna of St. Vincent. Species names followed by (I) are introduced or presumed to be so. Conservation Status refers to either the IUCN Red Book designation (CR = Critically Endangered, EN = Endangered, VU = Vulnerable) or to a CITES Appendix (I or II). Species Anurans Bufo marinus (I?) Eleutherodactylus johnstonei (I) Leptodactylus validus Pristimantis shrevei Marine turtles Caretta caretta Chelonia mydas Dermochelys coriacea Eretmochelys imbricata Land turtles Geochelone sp. (I?) Lizards Ameiva ameiva Anolis sagrei (I) Anolis griseus Anolis trinitatis Gymnophthalmus underwoodi Hemidactylus mabouia (I?) Iguana iguana Mabuya sp. Sphaerodactylus vincenti Thecadactylus rapicauda Snakes Chironius vincenti Corallus cookii Mastigodryas bruesi
West Indian distribution
Conservation status
widespread widespread St. Vincent, Grenada Bank St. Vincent endemic
EN
widespread widespread widespread widespread
EN, CITES I EN, CITES I CR, CITES I CR, CITES I
widespread
VU, CITES II*
St. Vincent, Grenada Bank widespread St. Vincent endemic St. Vincent endemic widespread (Lesser Antilles) widespread widespread widespread St. Vincent, Dominica, St. Lucia, Martinique island banks widespread St. Vincent endemic St. Vincent endemic St. Vincent, Grenada Bank, Barbados (I)
CITES II
CR CITES II
* IUCN Red List status applies only to G. denticulata; both G. carbonaria and G. denticulata are listed
in CITES Appendix II (see text for remarks regarding the identity of tortoises on St. Vincent).
on nearly anything it can fit in its mouth (Murphy, 1997). The only other anurans with which these toads presumably come into regular contact are Eleutherodactylus johnstonei, also an introduced species on St. Vincent, and Leptodactylus validus, the status of which is unknown. Conservation concerns deal with the unknown effects of these voracious predators on native invertebrates and the possibility that they may have played a role in displacing endemic Pristimantis shrevei, if that species ever occurred at lower elevations. Eleutherodactylus johnstonei. This species is essentially ubiquitous at lower elevations on St. Vincent (Mallery et al., 2007) and is commonly encountered at all but the highest elevations near the peak of La Soufrière, where its presence is
364
R. Powell, R.W. Henderson
sporadic (Díaz-Lameiro et al., 2007). Although the introduction of E. johnstonei to St. Vincent may have impacted Pristimantis shrevei, the impact is difficult to assess, as is the impact of introduced E. johnstonei on P. euphronides (formerly Eleutherodactylus euphronides; Heinicke et al., 2007) in Grenada (Henderson and Berg, 2006). Data regarding distributions and population densities of the endemic Pristimantis prior to the introductions of E. johnstonei on St. Vincent and Grenada are lacking, and E. johnstonei has been on Grenada (and possibly on St. Vincent) for more than a century (Barbour, 1914). Numbers of E. johnstonei on both islands generally dwindle with increasing elevation and, conversely, numbers of P. shrevei and P. euphronides increase at higher elevations. Whether biotic and/or abiotic factors limit E. johnstonei numbers at higher elevations, or if they have not yet had enough time to invade the upper elevations on St. Vincent and Grenada remains to be seen (assuming that their introduction points were at or close to sea level). Certainly, E. johnstonei has now entered forested situations on Grenada, where it had not been a decade earlier (Kaiser and Henderson, 1994; Germano et al., 2003), but whether that species is actually displacing P. euphronides is unknown. Monitoring the situation on St. Vincent is critical in order to determine the ecological relationships between the introduced and native species. Leptodactylus validus. These frogs are associated with ditches and small streams throughout the lowlands of St. Vincent, but the species’ islandwide distribution is not well known (Treglia, 2006). Although locally common at, for example, the Botanic Garden in Kingstown (Mallery et al., 2007), the potential vulnerability of populations to habitat alterations, effects on water quality, and possible predation by B. marinus suggests that surveys and monitoring of extant populations are needed. Pristimantis shrevei. The only anuran endemic to St. Vincent, P. shrevei is known to occur only in forested habitat at elevations in excess of 300 m (Díaz-Lameiro et al., 2007). In June 2006, the species was found to be abundant in forested areas in the Vermont Nature Reserve (400 m) and along the trail to Soufrière Volcano (∼980 m). In addition to the possible impact of E. johnstonei and despite their current abundance in forested areas at higher elevations, these frogs are potentially vulnerable to introductions of the chytrid fungus to St. Vincent. The presence of the fungus has been documented on other West Indian islands (Burrowes et al., 2004; Díaz et al., 2007), and means of reducing the likelihood of its arrival on St. Vincent have not been implemented. This species is listed as “endangered” on the IUCN Red List (Hedges and Powell, 2004), primarily because of its limited distribution and the threat of deforestation. However, concerns regarding its status have been disseminated via educational posters published by the SVG Department of Forestry. The habitat of P. shrevei also is that favored by the endemic endangered St. Vincent Parrot (Amazona guildingii), thus providing this endemic anuran some degree of protection by way of sympatry.
The St Vincent herpetofauna
365
Marine turtles Four species of marine turtles occur in the region around St. Vincent and the associated Grenadines (e.g., Debrot et al., 2005; Bräutigam and Eckert, 2006; Henderson and Berg, 2006). The IUCN Red List designates Caretta caretta (Marine Turtle Specialist Group, 1996) and Chelonia mydas (Seminoff, 2004) as “endangered” and Dermochelys coriacea (Sarti Martinez, 2000) and Eretmochelys imbricata (Red List Standards & Petitions Subcommittee, 1996) as “critically endangered.” All four species are listed in CITES Appendix I. Incomplete data indicate that 24 sites on St. Vincent, one on Bequia, five on Mustique, eight on Canouan, one on Mayreau, eight on Union Island, one on Frigate, one on Palm, and one on Petit Tobac in the Tobago Cays, are turtle nesting sites (N. Scott and J.A. Horrocks, in Bräutigam and Eckert, 2006). The Fisheries Division of the Ministry of Agriculture, Forestry and Fisheries is responsible for marine turtle management, but “There appears to be little active management of marine turtles. . . ” and “Restrictions on exploitation are few and biologically inappropriate. . . ” (Bräutigam and Eckert, 2006). Little information exists regarding the historical and current status of nesting and foraging populations of marine turtles, as well as for levels and trends in marine turtle landings and other means of exploitation. Although St. Vincent and the Grenadines acceded to CITES in 1989, they did so with a reservation entered with respect to the Hawksbill Turtle (Eretmochelys imbricata, the most common nesting species, both on St. Vincent and throughout the Grenadines), which exempts the country from CITES requirements for this species (Bräutigam and Eckert, 2006). Furthermore, current restrictions target exploitation of the most important age classes (i.e., large juveniles and adults), which are necessary to maintain populations and promote population recovery, and the “published literature is consistent in concluding that marine turtle stocks have ‘declined dramatically’ based on what data exist,” and “there is no basis to conclude that marine turtles in the country have recovered in number” (Bräutigam and Eckert, 2006). Furthermore, poaching of nesting females continues to be a problem (de Silva and Wilson, 2006). On a positive note, in 1998, five uninhabited islands were designated the Tobago Cays National Marine Park, the country’s only marine protected area (Bräutigam and Eckert, 2006). Land turtles Both Geochelone carbonaria and G. denticulata are known to occur in the Lesser Antilles (e.g., Breuil, 2002). All species in the genus are listed in CITES Appendix II; G. denticulata also is listed in the IUCN Red List as “vulnerable” (Tortoise & Freshwater Turtle Specialist Group, 1996). The only tortoises we encountered on St. Vincent were captive G. carbonaria of unknown origins. We cannot say with any certainty whether all tortoises on the island are of that species. Tortoises are very hardy, tolerant of prolonged exposure to salt water, and float well. At least some Lesser Antillean populations likely were established
366
R. Powell, R.W. Henderson
by natural over-water dispersal from South America (Censky, 1988). However, tortoises presumably were transported from island to island by Amerindians and early European settlers, probably to establish populations that later could be harvested for food. More recently, these turtles have become very popular in the pet trade, and released animals are known to occur on many Lesser Antillean islands (e.g., Powell et al., 2005). Consequently, many populations probably represent composites of naturally occurring individuals and others that are descendants of tortoises introduced by human activities. Regardless, tortoises appear to be rare on St. Vincent (they are notoriously difficult to locate, even in areas where they are abundant) and still may be exploited for food or as pets. They should be afforded protection, at least until detailed genetic studies can determine their identities and probable origins. Lizards Several species of lizards are abundant and are not of immediate conservation concern. Anolis trinitatis, an island endemic, is essentially ubiquitous on the island, occasionally at very high densities (to 27,923/ha; Hite et al., 2008). It can generally be found wherever any form of vertical structure is present. It also occurs on the St. Vincent satellites of Young Island and Chateaubelair Islet (Corke, 1992). They are most commonly encountered in open, at least partially insolated situations and along habitat edges. These lizards are ecological generalists that have adapted well to human alterations of habitats and appear to thrive even in dramatically modified situations (e.g., Henderson and Powell, 1999, 2001). Litter-dwelling Sphaerodactylus vincenti and Gymnophthalmus underwoodi also are abundant (Treglia, 2006; Mallery et al., 2007), with the former found in mesic areas (Steinberg et al., 2007) and the latter common at drier sites (it also occurs on the satellite Chateaubelair Islet; Corke, 1992). Even when found in close association, litter depth and moisture effectively segregate the microhabitats used by these two species. Thecadactylus rapicauda appears to be widely distributed across the island (Mallery et al., 2007). Because they are primarily active at night, exhibit an apparent preference for forests rather than human structures (e.g., Vitt and Zani, 1997; Howard et al., 2001), and are extremely cryptic and consequently difficult to see (fig. 2), they are encountered only rarely. Nevertheless, the species likely remains quite common. Hemidactylus mabouia is a known human commensal (Vitt and Zani, 1997; Powell et al., 1998, 2005; Henderson and Powell, 2001; Howard et al., 2001; Hodge et al., 2003), and is seen frequently on buildings and other human structures, often concentrated around lights that attract insect prey at night (Mallery et al., 2007). Because of their close association with humans, these “house geckos” may have been introduced with goods and materials transported from island to island. However, like T. rapicauda, both adults and eggs are tolerant of exposure, and
The St Vincent herpetofauna
367
Figure 2. Assessments of abundance may be complicated by difficulties of finding individuals in certain microhabitats or by the effective crypsis of many species, such as this Thecadactylus rapicauda (photograph by R. Powell). (Color original — see www.ahailey.f9.co.uk/appliedherpetology/ cariherp.htm)
populations of both geckos may well have become established as a consequence of natural over-water dispersal on flotsam originating in South America. The five other species of lizards known to occur on St. Vincent, however, are of conservation concern. Ameiva ameiva. Although this species may have been more widely distributed at one time, A. ameiva now is limited to small enclaves, Barrouallie on the leeward coast and Georgetown on the windward side of the island (Treglia, 2006). Daudin
368
R. Powell, R.W. Henderson
and de Silva (2007) also reported it from the Ratho Mill/Villa area. That unusual distribution may be the consequence of extirpations from other suitable lowland habitats or might have resulted from separate introductions, possibly from the Grenadines (Treglia, 2006). The species’ disappearance from much of its natural range in the West Indies (the St. Vincent and Grenada banks) has been attributed to the introduction of mongooses (Herpestes javanicus), cats, and dogs (e.g., Powell and Henderson, 2005; Simmons et al., 2005), all of which are known to prey on Ameiva. Islands on the Grenada Bank that remain mongoose-free still support healthy populations of A. ameiva, although cats are impacting populations around human habitations on some of the Grenadines (Daudin and de Silva, 2007). Unless the isolated St. Vincent populations clearly are shown to be introduced, efforts to preserve the known enclaves are appropriate. Anolis griseus. These large endemic anoles remain widely distributed across the island, but are rare or absent where vegetation is sparse and in areas dramatically altered by human activities (Treglia, 2006; Mallery et al., 2007; Hite et al., 2008). Although they may reach high population densities in some areas (to 5,208/ha; Hite et al., 2008), their apparent dependence on forested areas renders them vulnerable to deforestation by expansions of agriculture or development. Anolis sagrei. Introduced populations of Anolis sagrei are of concern because of the impact they may have on native anoles. Although populations of this species on St. Vincent have only recently become established (Henderson and Powell, 2005; Treglia et al., 2008), and evaluating any impact on native species may be premature, Treglia et al. (2008) described a habitat shift in A. trinitatis at one locality where the two species are sympatric and which might be attributable to the presence of A. sagrei. Unlike the situation on Grenada (Greene et al., 2002), where both native species are larger than A. sagrei and where introduced populations appear to be restricted to marginal habitats, A. trinitatis is comparable in size, exploits similar microhabitats, and may be vulnerable to displacement by A. sagrei in a fashion similar to that species’ effects on A. carolinensis in the southeastern United States (e.g., Campbell, 2000). The situation should be monitored carefully, although implementation of remedial action (e.g., exclusion of A. sagrei) may already be moot. Iguana iguana. Like Lesser Antillean populations of tortoises (see above), those of Green Iguanas (Iguana iguana) may be a result of natural (non-human-mediated) overwater dispersal, introduction by Amerindians or early European settlers (probably for food), recent establishment as a consequence of escaped pets, or combinations thereof (Powell, 2004). The population on St. Vincent presumably is native (Powell, 2004). These lizards also are known to occur on the satellite islands of Milligan Cay (Corke, 1992), Young Island (RP, pers. obs.) and, at least at one time, on Chateaubelair Islet (M. de Silva, pers. comm., 2006).
The St Vincent herpetofauna
369
Because of this species’ broad continental range, which extends from México through Central America and much of northern South America, and a general lack of recognition of genetic variability among populations, protective measures are minimal. Iguana iguana is listed in CITES Appendix II, but export quotas exist for many countries, primarily for live animals (pet trade) or products (leather goods and meat). No distinction is made for native versus introduced or for continental versus insular populations. On St. Vincent, hunting is regulated, with a hunting season and efforts to educate hunters not to overharvest or to take small animals or females with eggs, but the fact that iguanas may be harvested legally creates opportunities for an illegal market. Iguanas remain locally abundant (e.g., at the Botanic Garden in Kingstown), but, since we have no current data on distribution, basic natural history, or population densities, surveys are necessary. Also, even if taxonomic recognition is not warranted, isolated insular populations with minimal or no gene flow with other island or mainland populations represent unique gene pools. Consideration should be given to implementing surveys and possibly restricting hunting until more data are available. Mabuya sp. Skinks in the genus Mabuya occupy similar niches on many islands (Breuil, 2002; Schwartz and Henderson, 1991). Although widespread, they are nowhere abundant, and populations on St.-Martin/St. Maarten, Basse-Terre (Guadeloupe), Marie-Galante, and Martinique have apparently been extirpated (Breuil, 2002). Predation by mongooses, cats and other exotic predators combined with deforestation and the resultant loss of surface litter on which these animals depend appear to be primarily responsible for extirpations, rarity, and possible population declines. Although records of skinks from St. Vincent exist, the status of these lizards on the island is unknown. No individuals were encountered during fieldwork in 2006. Much of the lack of concern by conservation biologists may be attributable to the assumption that these are relatively recent introductions of one or two species that are widely distributed on the American mainland and other Antillean islands. However, no detailed systematic studies exist and, since potentially threatened endemic taxa could be hidden among populations currently assigned to M. mabouya or M. sloanii (see comments in Mayer and Lazell, 2000; Miralles, 2005; Powell and Henderson, 2003, 2005), establishing the identity and relationships of Antillean populations should be high priorities. Skinks have been recorded from Young Island (Corke, 1992). Snakes Throughout most of the world where they occur, snakes are persecuted for no reason other than for being snakes. That fact, unfortunately, holds true for the West Indies, where only two species (on Martinique and St. Lucia) of about 140 are dangerous to humans (Henderson, 2004; Tolson and Henderson, 2006). Aside from wanton killing by humans, declines in snake populations can be attributable to habitat alterations, the introduction of alien predators (e.g., mongooses, domestic cats),
370
R. Powell, R.W. Henderson
commercial exploitation, and changes in the prey base (Tolson and Henderson, 2006). St. Vincent harbors three snake species, two of which are island endemics (Corallus cookii and Chironius vincenti). The third species, Mastigodryas bruesi, also occurs on the Grenada Bank and has been introduced on Barbados. It is a frog and lizard predator that may be found on the ground or in low vegetation during the day. It is not uncommon in disturbed situations (gardens, vacant lots) and is frequently encountered in proximity to human residences. We do not feel it requires special attention at his time. Chironius vincenti. Certainly the rarest of the island’s three snake species, C. vincenti is seldom encountered. Unlike Corallus cookii and Mastigodryas bruesi, the species likely has never been “common” (i.e., routinely encountered when in appropriate habitat). Although we have heard reports that, when the water catchment was being constructed at Hermitage (360-400 m elevation), C. vincenti was observed on a daily basis (I.E. Kirby, pers. comm., 1992). More recent testimony suggests that the species is now rare at Hermitage and seen very infrequently (D. Porter, pers. comm., 2006). The latest records for the species of which we are aware, are for an adult inadvertently killed on 17 March 1992 in the Vermont Nature Reserve and an adult photographed by Amos Glasgow, SVG Forestry Department, at Hermitage in 1999 (Treglia, 2006). Like Pristimantis shrevei, these snakes are more habitat-specific than other members of the herpetofauna. They occur in primary and secondary rainforest at elevations between 275 and 600 m (Henderson and Haas, 1993). A distributional survey for C. vincenti in 1992 indicated that most people living on the windward side of St. Vincent were not aware of the presence of the “blacksnake” (= C. vincenti), but did have knowledge of Corallus cookii and Mastigodryas bruesi. In contrast, people on the leeward side were aware of all three species (Henderson and Haas, 1993). Like P. shrevei, the distribution of C. vincenti largely overlaps that of the endangered St. Vincent Parrot, thus providing protection for a substantial piece of its rainforest habitat. Also like P. shrevei, the conservation status of this species has been disseminated via an educational poster published by the SVG Department of Forestry. Chironius vincenti is listed as “critically endangered” on the IUCN Red List (Henderson, 1996). Corallus cookii. In 1937, Barbour suggested that this endemic boid had been eliminated from St. Vincent, and Albert Schwartz (pers. comm., 1987) considered it rare. In 1987, it was found to be common in a heavily disturbed area of mixed agriculture (Henderson, 2002), but subsequent visits (1988, 1990, 1992) to the island were less successful in finding these snakes. Based on recent (2006) fieldwork, however, this endemic boid appears to be remarkably abundant, occurring in habitats ranging from basically intact (Vermont Nature Reserve) to dramatically altered (residential areas in Kingstown; Kingstown Botanic Garden; Powell et al., 2007). During the 2006 surveys, C. cookii was encountered in every habitat at
The St Vincent herpetofauna
371
elevations less than 500 m where tree crown vegetation was contiguous (with the notable exception of a Musa monoculture), including residential areas with streetlights and steady vehicular and pedestrian traffic. Adult C. cookii is a rodent predator (Mus and Rattus; Henderson, 2002). Treeboas are common in fruit orchards (often in close proximity to residences), helping to minimize rodent-inflicted damage to produce, and are not dangerous to humans (i.e., they are not venomous), therefore unwarranted killing of the snakes is counterproductive. Nevertheless, many locals fear and persecute them when encountered. Their present abundance in even heavily trafficked areas is attributable to nocturnal activity and secretive nature by day. Like all boids, C. cookii is listed in CITES Appendix II, but these snakes’ obvious dependence on contiguous canopies renders them vulnerable to uncontrolled deforestation or changes in agricultural practices that would affect the extent of orchards.
Discussion With designation of the King’s Hill Forest Reserve in 1791, St. Vincent and the Grenadines is credited with having enacted what is believed to be the “first piece of legislation providing for protected areas in the Americas” (UNEP, 1996). Despite that acumen by 18th century legislators, the St. Vincent herpetofauna today faces many of the same threats and challenges as others throughout the world, and elsewhere in the West Indies in particular: e.g., habitat destruction via development for the local population and for tourism, introduction of alien predators and competitors, the possible introduction of the chytrid fungus and its impact on frog populations, climate change, “misunderstanding” and consequent persecution of snakes, and lack of detailed survey work documenting faunal composition, distributions, and ecology. Some of these challenges can be met successfully, others are less likely to be addressed effectively. West Indian islands have a long history as tourist destinations, and the economies of many islands rely heavily on income generated by tourism. We believe that, at some point, a trade-off is inevitable. That point occurs when so much of an island’s area has been developed that it is no longer attractive to tourists. The main attractions of the Antilles are climate, beaches, and beautiful scenery. Might not too many hotels, golf courses, restaurants and gift shops compromise the islands’ natural appeal? St. Vincent seems to be a perfect candidate for developing a highly profitable eco-tourism industry. The leeward coast and interior uplands provide one beautiful vista after another, and the Vermont Nature Reserve and Soufrière Volcano offer opportunities for adventurous but safe hikes through intact rainforest habitats. The more of that landscape that can be maintained in a “natural” state, the more appealing it will be to visitors — and to wildlife. Lizards (Anolis, Hemidactylus, Iguana) and frogs (Eleutherodactylus) are perhaps the most conspicuous vertebrates that tourists experience (especially in and around hotels). By generating an appreciation for the native herpetofauna, such encounters
372
R. Powell, R.W. Henderson
can be among the highlights of any eco-tourism program. Although snakes are rarely seen by tourists, discussing them in a positive context (harmless to humans, control rodent populations, graceful, etc.) is important. Critical to such efforts are effective and visible educational programs, such as those offered by the National Trust, which easily could be incorporated into programs aimed at tourists and residents alike. Furthermore, if citizens observe the interest and respect visitors have for native reptiles and amphibians, perhaps they will re-evaluate their attitudes. On St. Vincent, during the course of surveys for Corallus grenadensis (Powell et al., 2007), we encountered residents who knew that the species was harmless and they maintained a live-and-let-live attitude toward these snakes. Unfortunately, we also met many people who were frightened of snakes and even lizards and had no qualms about killing them. Stopping the spread of the chytrid fungus may be difficult or impossible. In the West Indies, it has been documented on Puerto Rico (Burrowes et al., 2004) and Cuba (Díaz et al., 2007), and unconfirmed reports place it on other Antillean islands. That it will be discovered in additional West Indian frog faunas probably is inevitable. Questioning visitors arriving in St. Vincent from the Neotropical mainland or from another island regarding potential contact with the chytrid fungus is unrealistic. Most would not know what chytrid is, and few would have any idea whether or not they had the potential to be carriers. Nevertheless, all efforts should be made to monitor the health of Pristimantis shrevei and Leptodactylus validus populations on St. Vincent. With education by cruise lines or tour companies, tourists undoubtedly would be eager to do their part in conserving native species. With development comes an increasingly critical need to understand if and how native species respond to the accompanying changes in their habitats. Some adapt readily to even dramatic alterations (e.g., Anolis trinitatis), others cannot — and knowing which fall into each category becomes progressively more important if viable management plans are to be developed and implemented. We know remarkably little about the natural history of all but a few reptiles and amphibians on St. Vincent (and the Grenadines) — and St. Vincent is not unique in this respect. Henderson and Powell (1999) estimated that only about 12% of the West Indian herpetofauna (comprised of over 700 species) has been the subject of detailed ecological investigations. Although we have cited a number of papers that address some aspects of natural history for the herpetofauna of St. Vincent, only seven of 18 terrestrial species (Pristimantis shrevei and Eleutherodactylus johnstonei, Sphaerodactylus vincenti, three species of Anolis, Corallus cookii) have been the subjects of ecological studies, and most of the projects that generated ecological data were conducted during a three-week period in 2006. Consequently, we encourage wildlife officials on St. Vincent (and elsewhere in the West Indies) to promote studies by qualified biologists, both local and foreign. For example, data about diets, reproduction, geographic variation, and possible new species can be generated by responsible sampling and proper preservation of specimens (e.g., Hedges, 2006;
The St Vincent herpetofauna
373
Hedges and Thomas, 1991), and those data, coupled with field-based ecological studies, can provide much of the critical information needed for the development and implementation of effective conservation efforts. Acknowledgements. Fieldwork in St. Vincent by RWH has been funded by the Milwaukee Public Museum, the late Albert Schwartz, and the Chicago Zoological Society; the National Science Foundation (Grant DBI-0242589 to RP) funded fieldwork conducted by both of us. Our companions in the field enhanced the enjoyment and contributed to our successes; they include Craig Berg, Gary Haas, Rose Henderson, Samantha Larimer, John Parmerlee, Richard Sajdak, and students in the 2006 Research Experience for Undergraduates program at Avila University. Mark de Silva made helpful comments on an earlier draft, and John S. Parmerlee, Jr. prepared the map (fig. 1). Karen Eckert provided germane information regarding marine turtles. Permits to conduct research on St. Vincent were issued by the Department of Forestry, St. Vincent and the Grenadines. Brian Johnson, Director, Cornelius Richards, Amos Glasgow, and especially FitzGerald Providence facilitated our efforts on St. Vincent; Brian Johnson and FitzGerald Providence also commented on a draft of this article. Nigel Weeks, Director of National Parks, granted permission to conduct research on the grounds of the Botanic Garden. Notes added in proof. Yanek et al. [2006: Genetic resolution of the enigmatic Lesser Antillean distribution of the frog Leptodactylus validus (Anura, Leptodactylidae). S. Amer. J. Herpetol. 1: 192-201] indicated that L. validus, as redefined, is present in Trinidad and Tobago and northern South America, and suggested that the Lesser Antillean populations on the Grenada and St. Vincent banks were introduced via human agency. Malhotra et al. (2007: A report on the status of the herpetofauna of the Commonwealth of Dominica, West Indies. Appl. Herpetol. 4: 177-194) documented the presence of the chytrid fungus on Dominica.
References Barbour, T. (1914): A contribution to the zoögeography of the West Indies, with especial reference to amphibians and reptiles. Mem. Mus. Comp. Zoöl. 44: 209-359. Barbour, T. (1937): Third list of Antillean reptiles and amphibians. Bull. Mus. Comp. Zool. 82: 77166. Bräutigam, A., Eckert, K.L. (2006): Turning the Tide: Exploitation, Trade and Management of Marine Turtles in the Lesser Antilles, Central America, Colombia and Venezuela. Cambridge, UK: TRAFFIC International. Breuil, M. (2002): Histoire naturelle des amphibiens et reptiles terrestres de l’archipel Guadeloupéen. Guadeloupe, Saint-Martin, Saint-Barthélemy. Patrimoines Naturels, Paris 54: 1-339. Bullen, R.P., Bullen, A.K. (1972): Archeological investigations on St. Vincent and the Grenadines, West Indies. William L. Bryant Found., American Stud. 8: vi, 1-170. Burrowes, P.A., Joglar, R.L., Green, D.E. (2004): Potential causes for amphibian declines in Puerto Rico. Herpetologica 60: 141-154.
374
R. Powell, R.W. Henderson
Callaghan, R.T. (2007): Prehistoric settlement patterns on St. Vincent, West Indies. Carib. J. Sci. 43: in press. Campbell, T.S. (2000): The Cuban Brown Anole invasion in Florida: It’s not easy being green. Aliens Newsl. 10: 4-5. Censky, E.J. (1988): Geochelone carbonaria (Reptilia: Testudines) in the West Indies. Florida Sci. 51: 108-114. Corke, D. (1992): The status and conservation needs of the terrestrial herpetofauna of the Windward Islands (West Indies). Biol. Conserv. 62: 47-58. Daudin, J., de Silva, M. (2007): An annotated checklist of the amphibians and terrestrial reptiles of the Grenadines with notes on their local natural history and conservation. Appl. Herpetol. 4: 163-175. Debrot, A.O., Esteban, N., le Scao, R., Caballero, A., Hoetjes, P.C. (2005): New sea turtle nesting records for the Netherlands Antilles provide impetus to conservation action. Carib. J. Sci. 41: 334339. de Silva, M., Wilson, D. (2006): A Natural History of Mustique. Mustique Island, St. Vincent and the Grenadines: The Mustique Co., Ltd. Díaz, L.M., Cadiz, A., Chong, A., Silva, A. (2007): First report of chytridiomycosis in a dying toad (Anura: Bufonidae) from Cuba: A new conservation challenge for the island. EcoHealth 2007; DOI: 10.1007/s 10393-007-0094-4 (www.jcu.edu.au/school/phtm/PHTM/frogs/papers/diaz2007.pdf). Díaz-Lameiro, A.M., Powell, R., Berg, C.S. (2007): Colour pattern polymorphism in Pristimantis shrevei and Eleutherodactylus johnstonei (Leptodactylidae) on St. Vincent, West Indies. Herpetol. Bull. 101: 18-25. Fiske, R.S., Sigurdsson, H. (1982): Soufriere Volcano, St. Vincent: Observations of its 1979 eruption from the ground, aircraft, and satellites. Science 216: 1105-1126. Gardner, L. (2007): Review of the Policy, Legal and Institutional Frameworks for Protected Areas Management in St. Vincent and the Grenadines. (http://www.stat.oecs.org/ESDU/documents/ opaal/OPAALPA_PolicyReview-StVincent_FinalReport.pdf) Germano, J.M, Sander, J.M., Henderson, R.W., Powell, R. (2003): Herpetofaunal communities in Grenada: A comparison of altered sites, with an annotated checklist of Grenadian amphibians and reptiles. Carib. J. Sci. 39: 68-76. Greene, B.T., Yorks, D.T., Parmerlee, J.S., Jr, Powell, R., Henderson, R.W. (2002): Discovery of Anolis sagrei in Grenada with comments on its potential impact on native anoles. Carib. J. Sci. 38: 270-272. Hedges, S.B. (2006): An overview of the evolution and conservation of West Indian amphibians and reptiles. Appl. Herpetol. 3: 281-292. Hedges, S.B., Powell, R. (2004): Eleutherodactylus shrevei. In: IUCN 2006. 2006 IUCN Red List of Threatened Species (www.iucnredlist.org). Hedges, S.B., Thomas, R. (1991): The importance of systematic research in the conservation of amphibian and reptile populations. In: Status y Distribución de los Reptiles y Anfibios de la Region de Puerto Rico, p. 56-61. Moreno, J.A., Ed. Publ. Cientif. Misc. 1, Depto. Recursos Nat. Puerto Rico, San Juan. Heinicke, M.P., Duellman, W.E., Hedges, S.B. (2007): Major Caribbean and Central American frog faunas originated by ancient oceanic dispersal. Proc. Natl. Acad. Sci. (USA) 104: 10092-10097. Henderson, R. (1996): Chironius vincenti. In: IUCN 2006. 2006 IUCN Red List of Threatened Species (www.iucnredlist.org). Henderson, R.W. (2002): Neotropical Treeboas: Natural History of the Corallus hortulanus Complex. Malabar, Florida: Krieger Publ. Co. Henderson, R.W. (2004): Lesser Antillean snake faunas: distribution, ecology, and conservation concerns. Oryx 38: 311-320. Henderson, R.W., Berg, C.S. (2006): The herpetofauna of Grenada and the Grenada Grenadines: conservation concerns. Appl. Herpetol. 3: 197-213.
The St Vincent herpetofauna
375
Henderson, R.W., Haas, G.T. (1993): Status of the West Indian snake Chironius vincenti. Oryx 27: 181-184. Henderson, R.W., Powell, R. (1999): West Indian herpetoecology. In: Caribbean Amphibians and Reptiles, p. 223-268. Crother, B.I., Ed. San Diego, California: Academic Press. Henderson, R.W., Powell, R. (2001): Responses by the West Indian herpetofauna to human-influenced resources. Carib. J. Sci. 37: 41-54. Henderson, R.W., Powell, R. (2005): Geographic distribution: Anolis sagrei. Herpetol. Rev. 36: 467. Hite, J.L., Rodríguez Gómez, C.A., Larimer, S.C., Díaz-Lameiro, A.M., Powell, R. (2008): Anoles of St. Vincent (squamata: Polychrotidae): Population densities and structural habitat use. Carib. J. Sci. 44: 102-115. Hodge, K.V.D., Censky, E.J., Powell, R. (2003): The Reptiles and Amphibians of Anguilla, British West Indies. The Valley, Anguilla, British West Indies, Anguilla National Trust. Homer, F., Shim, D. (2004): St. Vincent & the Grenadines Environmental Management and Action Plan. (http://www.oecs.org/ESDU/documents/Nems/SVGNEMSFinal19Apr04.pdf) Hovey, E.O. 1902. Martinique and St. Vincent; a preliminary report upon the eruptions of 1902. Bull. Amer. Mus. Nat. Hist. 16: 333-372 + 51 pl. Howard, K.G., Parmerlee, J.S., Jr, Powell, R. (2001): Natural history of the edificarian geckos Hemidactylus mabouia, Thecadactylus rapicauda, and Sphaerodactylus sputator on Anguilla. Carib. J. Sci. 37: 285-288. Kaiser, H., Hardy, J.D., Jr, Green, D.M. (1994): Taxonomic status of Caribbean and South American frogs currently ascribed to Eleutherodactylus urichi (Anura: Leptodactylidae). Copeia 1994: 780796. Kaiser, H., Henderson, R.W. (1994): The conservation status of Lesser Antillean frogs. Herpetol Nat. Hist. 2: 41-56. Lever, C. (2003): Naturalized Reptiles and Amphibians of the World. Oxford, Oxford Univ. Press. Lips, K.R. (1999): Mass mortality and population declines of anurans at an upland site in western Panama. Conserv. Biol. 13: 117-125. Mallery, C.S., Jr, Marcum, M.A., Powell, R., Parmerlee, J.S., Jr, Henderson, R.W. (2007): Herpetofaunal communities on St. Vincent: A comparison of sites variously altered by human activity. Appl. Herpetol. 4: 313-325. Marine Turtle Specialist Group. (1996): Caretta caretta. In: IUCN 2006. 2006 IUCN Red List of Threatened Species (www.iucnredlist.org). Mayer, G.C., Lazell, J. (2000): A new species of Mabuya (Sauria: Scincidae) from the British Virgin Islands. Proc. Biol. Soc. Washington 113: 871-886. Miralles, A. (2005): The identity of Lacertus mabouya Lacepède, 1788, with description of a neotype: An approach toward the taxonomy of New World Mabuya. Herpetologica 61: 46-53. Murphy, J.C. (1997): Amphibians and Reptiles of Trinidad and Tobago. Malabar, Florida: Krieger Publ. Co. Powell, R. (2004): Conservation of iguanas (Iguana delicatissima and I. iguana) in the Lesser Antilles. Iguana 11: 239-246. Powell, R., Crombie, R.I., Boos, H.E.A. (1998): Hemidactylus mabouia. Cat. Amer. Amphib. Rept. 674: 1-11. Powell, R., Henderson, R.W. (2003): A second set of addenda to the checklist of West Indian amphibians and reptiles. Herpetol. Rev. 34: 341-345. Powell, R., Henderson, R.W. (2005): Conservation status of Lesser Antillean reptiles. Iguana 12: 6277. Powell, R., Henderson, R.W., Parmerlee, J.S., Jr. (2005): Reptiles and Amphibians of the Dutch Caribbean: St. Eustatius, Saba, and St. Maarten. Gallows Bay, St. Eustatius, Netherlands Antilles, St. Eustatius National Parks Foundation. Powell, S.B., Treglia, M.L., Henderson, R.W., Powell, R. (2007): Treeboas in the West Indies: Responses of Corallus cookii and Corallus grenadensis to disturbed habitats. In: Biology of the
376
R. Powell, R.W. Henderson
Boas and Pythons, p. 375-386. Henderson, R.W., Powell, R., Eds. Eagle Mountain Publ. LC, Eagle Mountain, Utah. Red List Standards & Petitions Subcommittee. (1996): Eretmochelys imbricata. In: IUCN 2006. 2006 IUCN Red List of Threatened Species (www.iucnredlist.org). Rouse, I. (1989): Peopling and repeopling of the West Indies. In: Biogeography of the West Indies: Past, Present, and Future, p. 119-136. Woods, C.A., Ed. Gainesville, Florida, Sandhill Crane Press. Sarti Martinez, A.L. (2000): Dermochelys coriacea. In: IUCN 2006. 2006 IUCN Red List of Threatened Species (www.iucnredlist.org). Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. Gainesville, Univ. Florida Press. Seminoff, J.A. (2004): Chelonia mydas. In: IUCN 2006. 2006 IUCN Red List of Threatened Species (www.iucnredlist.org). Simmons, P.M., Greene, B.T., Williamson, K.E., Powell, R., Parmerlee, J.S., Jr. (2005): Ecological interactions within a lizard community on Grenada. Herpetologica 61: 124-134. Steinberg, D.S., Powell, S.D., Powell, R., Parmerlee, J.S., Jr, Henderson, R.W. (2007): Population densities, water loss rates, and diets of Sphaerodactylus vincenti on St. Vincent, West Indies. J. Herpetol. 41: 330-336. SVG Forestry Department. (1993): National Forestry Action Plan — St. Vincent & the Grenadines: Executive Summary (www.fao.org/docrep/X5655E/x5655e00.HTM). Tolson, P.J., Henderson, R.W. (2006): An overview of snake conservation in the West Indies. Appl. Herpetol. 3: 345-356. Tortoise & Freshwater Turtle Specialist Group. (1996): Geochelone denticulata. In: IUCN 2006. 2006 IUCN Red List of Threatened Species (www.iucnredlist.org). Treglia, M.L. (2006): An annotated checklist of the amphibians and reptiles of St. Vincent, West Indies. Iguana 13: 252-263. Treglia, M.L., Muensch, A.J., Powell, R., Parmerlee, J.S., Jr. (2008): Invasive Anolis sagrei on St. Vincent and its potential impact on perch heights of Anolis trinitatis. Carib. J. Sci. 44: 251-256. UNEP. (1996): Status of Protected Area Systems in the Wider Caribbean Region. Technical Report No. 36. U.N. Environment Programme, Caribbean Environment Programme, Kingston, Jamaica (www.cep.unep.org/pubs/techreports/tr36en). Venzke, E., Wunderman, R.W., McClelland, L., Simkin, T., Luhr, J.F., Siebert, L., Mayberry, G. (eds). (2002-2007): Global Volcanism, 1968 to the Present. Smithsonian Institution, Global Volcanism Program Digital Information Series, GVP-4 (www.volcano.si.edu/reports/). Vitt, L.J., Zani, P.A. (1997): Ecology of the nocturnal lizard Thecadactylus rapicauda (Sauria: Gekkonidae) in the Amazon Region. Herpetologica 53: 165-179. Wilson, S.M. (2001): The prehistory and early history of the Caribbean. In: Biogeography of the West Indies: Patterns and Perspectives, p. 519-527. Woods, C.A., Sergile, F.E., Eds. Boca Raton, Florida, CRC Press. Zug, G.R., Zug, P.A. (1979): The Marine Toad, Bufo marinus: A natural history resumé of native populations. Smithsonian Contrib. Zool. 284: i-iv + 1-58.
Accepted: June 7, 2007 (AH). Reprinted from Applied Herpetology 4: 295-312 (2007).
Status, conservation, and introduction of amphibians and reptiles in the Turks and Caicos Islands, British West Indies R. Graham Reynolds Department of Ecology and Evolutionary Biology, University of Tennessee, 569 Dabney Hall, Knoxville, TN 37996-1610, USA E-mail:
[email protected] Abstract. The Turks and Caicos Islands, located at the southern terminus of the Bahamian Archipelago, contain a unique native reptile assemblage consisting of 13 species, nine of which are endemic species or subspecies. At least four species are listed as endangered by the International Union for Conservation of Nature, though most species in the region have not been evaluated. In addition to the native reptiles, at least 10 herpetofaunal species are introduced in the islands, including two amphibians. The native fauna of the region face a plenitude of threats, including feral predators such as cats, loss of habitat due to development, unsustainable exploitation (sea turtles), habitat degradation by semi-feral herbivores, and malicious killing. Sea turtles continue to be legally exploited for meat and their shells, and nesting activity is declining. The endemic iguana, Cyclura carinata, has been extirpated from most major islands in the archipelago and survives on isolated islands that lack introduced vertebrate predators. The endemic boid Epicrates c. chrysogaster has been extirpated from several islands and faces additional extirpations on highly developed islands such as Providenciales. Though iguanas have received a great deal of attention from conservationists, local government, and citizens, little is known about the biology or conservation concerns of other unique species. Additional research must be implemented to inform conservation agendas, and I provide recommendations to improve the long-term survival of this unique herpetofaunal assemblage. Key words: Amphibians; conservation; Cyclura carinata; Epicrates chrysogaster; introduced species; reptiles; sea turtles.
Introduction The Turks and Caicos Islands (TCI; fig. 1), located at the southern terminus of the Bahamian Archipelago, contain a unique endemic reptile fauna (Reynolds and Niemiller, 2010a) that is threatened by rapidly increasing development and population growth. These islands are in the midst of a huge development push to accommodate an exponentially increasing tourist market. Tourism increased nearly
378
R.G. Reynolds
Figure 1. Map of the Turks and Caicos Islands showing the approximate extent of the banks in light gray, representing approximately the 10 m depth line. Both banks were emergent during the last glacial maximum, and islands on each bank were part of a single emergent land mass. The banks are separated by the deep (>1 km) Turks Island Passage and have never been joined.
90% between 1995 and 2005, and in the rush to accommodate these visitors more than 20 resorts opened during the same period on the island of Providenciales alone (Tsui, 2005). Providenciales has become so crowded in the last 20 years that large new developments are moving to neighboring islands in the archipelago, including the formerly undeveloped island of West Caicos where a new resort has recently been completed. In addition, small islands such as Big Ambergris Cay are being bought by foreign development companies and turned into exclusive vacation areas. It has been demonstrated that human influences are causing drastic declines among populations of several species of the native reptiles in this region (Iverson, 1978). In addition, the number of introduced herpetofaunal species has recently become nearly equal to the number of native reptile species (Reynolds and Niemiller, 2010a). Here I provide a comprehensive review of the herpetofauna of the TCI, which includes 13 native and 10 introduced species, as well as a discussion of conservation concerns faced by individual species and the fauna as a whole. The TCI (20◦ 59 -21◦ 58 N and 70◦ 55 -72◦ 30 W) consist of more than 200 islands ranging in size from <1 ha to >12,000 ha; plus many small rock islets distributed on two shallow banks, the Turks bank to the east and the Caicos bank to the west (figs 1
Amphibians and reptiles in the Turks and Caicos Islands
379
Figure 2. Names of major islands in the Turks and Caicos Archipelago.
and 2). These banks consist of platforms of marine sediments overlaid with oolitic limestone dating back at least 150 my (Sealey, 2006), and for much of this period the banks likely remained near the surface due to reef building (Hedges, 2006). Islands on the banks have likely been ephemeral throughout the Pleistocene as the banks were variously inundated and emergent (Sealey, 2006). The Turks and Caicos banks existed as emergent islands at the height of the last (Wisconsin) glaciations 17,000 years before present, though the two banks are separated by the narrow and deep Turks Island Passage and have never been joined (Lighty et al., 1982; Fairbanks, 1989; Welch et al., 2004). Since this last glacial maximum, rising sea levels have fragmented the banks into the present islands and islets (Morgan, 1989). The current islands are elevated ridges formed from wind-blown oolitic deposits of the larger glacially-emergent islands (Sealey, 2006; Ricklefs and Bermingham, 2007), and the highest elevation is about 50 m above sea level. Total land area of the islands is approximately 500 km2 . Vegetation consists of low coastal scrub on most islands, interspersed with coppice on larger islands and remnant tropical dry forest on North Caicos, where most moisture occurs (Iverson, 1979; Correll and Correll, 1982; Manco, 2008a). Extensive sea grass beds occur on the bank side of the major islands of the Caicos bank, dominated by turtle grass (Thalassia testudinum) and manatee grass (Syringodium filiforme), and provide refuge and forage for young green turtles (Manco, 2008a). Annual rainfall averages 750 mm on the Caicos bank,
380
R.G. Reynolds
with most rain occurring September to December. Considerable local variation in rainfall occurs, however, with the northwestern end of the TCI receiving more rainfall than the drier southwestern end (Sealey, 2006). Human history A valuable reference exists on the history of the TCI (Mills, 2008a), but I will provide a brief account in the context of conservation issues. Humans have occupied the archipelago for at least 1300 years, beginning with the Taíno arriving from Hispaniola around 705 C.E. (Newsom and Wing, 2004; Carlson and Keegan, 2006; Marvel, 2008). These peoples evolved culturally into the Lucayans, who may have numbered as many as 10,000 in the TCI prior to European contact (Marvel, 2008). Amerindians likely had a significant impact on the native wildlife of the TCI (Newsom and Wing, 2004; Franz and Franz, 2009). They practiced “swidden agriculture”, which involved removing native vegetation to grow food plants, and also made extensive use of the local terrestrial fauna, including reptiles (table 1). A large species of tortoise (Chelonoidis sp.) has been found in middens on Grand Turk (“Coralie” site) (Carlson, 1999; Newsom and Wing, 2004) and Middle Caicos (Franz and Franz, 2009); which was likely driven extinct by hunting and egg gathering. The boids Epicrates chrysogaster and Tropidophis greenwayi have been found in archeological sites on Grand Turk and Middle Caicos, respectively (Newsom and Wing, 2004). Anolis scriptus has been found at Middle Caicos sites and Leiocephalus psammodromus has been found at the Grand Turk site (Newsom and Wing, 2004). Iguanas (Cyclura) and turtles (Chelonia, Caretta, and Trachemys) were also used as major food sources and are represented at sites on Grand Turk and Table 1. Terrestrial and marine reptiles represented in archeological sites on Middle Caicos (MC-6, MC-12, and MC-32; Wing and Scudder, 1983) and Grand Turk (Coralie; Carlson, 1999). Counts are given as the Minimum Number of Individuals (MNI), which indicates the approximate number of individuals encountered at each site. Question marks indicate that individuals have been found though MNI for each site is unknown. After Newsom and Wing (2004). Taxon Anolis sp. Cyclura sp. Cyclura carinata Iguanidae Leiocephalus psammodromus Epicrates chrysogaster Tropidophis sp. Trachemys sp. Chelonoidis sp. Caretta caretta Chelonia mydas Cheloniidae
MC-6
MC-12
MC-32
Coralie
1 11 0 0 0 0 0 0 ? 0 0 4
0 2 0 1 0 0 0 0 ? 0 0 1
0 1 0 2 0 0 1 1 ? 1 0 0
0 1 386 0 12 2 0 0 18 1 50 0
Amphibians and reptiles in the Turks and Caicos Islands
381
Middle Caicos (Seidel, 1996; Lee and Ross, 2001; IUCN Iguana Specialist Group, 2003; Newsom and Wing, 2004; Campbell, 2006). After European contact, human population density dropped in the archipelago, and Ponce de Leon allegedly noted in 1513 that he did not see evidence of people during a passage through the islands (Marvel, 2008). European settlement did not begin in earnest until the early 17th century, when salt-raking became a profitable colonial enterprise. Most of this activity was centered on the Turks bank, where the population was probably only a few dozen to a few hundred per island, with Grand Turk and Salt Cay having the most inhabitants. In 1781, 921 inhabitants were recorded on the Turks bank, though most of these were seasonal migrants (Sadler, 2008a). At this time land on the Caicos bank was being granted to Loyalists after the American War of Independence and cleared for cotton plantations. Valuable hardwoods were removed during this period, greatly altering hydrological cycles and microclimates on the islands. By 1843 the population of the TCI was estimated to be 2495 (Sadler, 2008b). A second wave of agriculture came in 1890, when thousands of hectares were cleared on both banks for sisal (Agave sisalana) production. Population size probably remained below 6000 until the 1960s, when tourism sparked a wave of immigration from Jamaica and Hispaniola that continues today. By 1996 the population reached 15,000, doubling to 30,600 by 2005 and increasing at roughly 3.5% per year (Jones, 2008). However, the population is likely higher than the current (2008) estimated census of 36,605, as waves of undocumented immigrants have arrived from Haiti in recent years, including several hundred after the catastrophic Haitian earthquake of 2010 (TCI Department of Planning and Statistics, 2010). Well over half of the population lives on the island of Providenciales, which has seen a huge increase in development since the completion of the new international airport and several resorts in the early 1980s. Tourism and banking are the two major industries, and over 265,000 tourists arrive annually (TCI Department of Planning and Statistics, 2010). Many foreigners are buying homes and property in the islands, and development is occurring at a rapid pace. As waves of tourists come to enjoy the wildlife of the islands, there is some desire among locals to mitigate consequences of development on wildlife; however, this is not often accomplished in practice. Conservation legislation and infrastructure A National Parks committee was established in the TCI in 1969 and prepared a list of areas to be protected as Historical Sites, Sanctuaries, and Recreational Areas. These areas were surveyed and augmented by Ray and Sprunt (1971), and a National Parks Ordinance was first enacted in 1975 to provide the framework for legal protection of areas (Homer, 2000). Protection in practice was not established until the creation of the National Parks Order in 1992, which supported four classifications for protected areas in the TCI, from most to least restricted: Sanctuaries, Nature Reserves, National Parks, and Areas of Historical Interest (table 2). The Department of Environment and Coastal Resources (DECR) was established in 1995 to oversee
2411 3848 1
NP NP NR NR NP H
Chalk Sound Northwest Point Marine Northwest Point Pond
Pigeon Pond and Frenchman’s Creek Princess Alexandria Land and Sea Cheshire Hall
1461 1687 57
660
NR
Little Ambergris Cay (Proposed)
155
S
Caicos Bank French, Bush, and Seal Cays
Providenciales Providenciales
Providenciales
Providenciales Providenciales Providenciales
Little Ambergris Cay
Southern Caicos Bank
Populations of Cyclura and Leiocephalus (?). Marine turtle foraging and nesting Populations of Cyclura, Epicrates (?), Leiocephalus, Anolis, Aristelliger, and Sphaerodactylus species. Marine turtle foraging and nesting Populations of Cyclura and Anolis Hawksbill turtle foraging Populations of Leiocephalus, Anolis, and Sphaerodactylus species Populations of Epicrates, Leiocephalus, Anolis, and Sphaerodactylus Marine turtle foraging and nesting Populations of Epicrates (?), Leiocephalus, Anolis, Mabuya, and Sphaerodactylus
Table 2. Marine and terrestrial protected areas in the TCI, excluding shipwrecks. Four separate management units (MU) were established by the TCI National Park Ordinance of 1989 (further defined in 1992) with primary and secondary goals for protection. Benefit to native reptiles as identified by the Department of Environment and Coastal Resources, TCI Government. The designation “Not Identified” indicates that the area has not been assessed for importance to native reptiles, and a question mark indicates that this species is suspected to be present. After Carleton et al. (2006). Protected Area MU* Size (ha) Location Benefit to Native Reptiles Turks Bank Columbus Landfall Marine Park NP 1127 Grand Turk Marine turtle foraging and nesting South Creek NP 98 Grand Turk Not identified Grand Turk Cays Land and Sea NP 198 Turks Cays Populations of Epicrates, Leiocephalus, Anolis, and Sphaerodactylus species. Marine turtle foraging and nesting Long Cay Sanctuary S 80 Long Cay Populations of Cyclura, Leiocephalus, Anolis, and Sphaerodactylus species Big Sand Cay Sanctuary S 179 Big Sand Cay Populations of Cyclura, Leiocephalus, and Anolis species. Marine turtle foraging and nesting Salt Cay Area of Historic Interest H 176 Salt Cay Not identified, terrestrial habitat severely degraded
382 R.G. Reynolds
NP NR NR NR S NP NR
NP NR
NP NR NP NR
Fort George Land and Sea Dick Hill Creek
Cottage Pond
Pumpkin Bluff Pond
Three Mary Cays East Bay Islands North, Middle and East Ramsar Site
Conch Bar Caves
Admiral Cockburn
Admiral Cockburn Land and Sea Bell Sound West Caicos Marine Lake Catherine
*Management Units Sanctuary (S) Nature Reserve (NR) National Park (NP) Area of Historical Interest (H)
MU* NR
Table 2. (Continued). Protected Area Princess Alexandria
849 1157 467 397
321
94
15 3377 58,654
166
8
738 402
South Caicos South Caicos West Caicos West Caicos
South Caicos
Middle Caicos
North Caicos North Caicos North, Middle, and East Caicos
North Caicos
North Caicos
Caicos Cays North Caicos
Location Caicos Cays
Primary Goal Protection of natural ecology Ecosystem and biological conservation Ecosystem and biological conservation Protection of an area or object
Size (ha) 117
Secondary Goal Avoidance of disturbance Recreation (low priority) Recreation None
Benefit to Native Reptiles Populations of Cyclura, Leiocephalus, Anolis, Mabuya, and Sphaerodactylus Populations of Leiocephalus and Anolis Populations of Epicrates, Leiocephalus, Anolis, Mabuya, Tropidophis (?), and Sphaerodactylus Populations of Epicrates, Leiocephalus, Anolis, Mabuya, Tropidophis (?), and Sphaerodactylus Populations of Epicrates, Leiocephalus, Anolis, Mabuya, Tropidophis (?), and Sphaerodactylus Populations of Cyclura and Anolis Populations of Cyclura, Anolis, and Leiocephalus Populations of Epicrates, Typhlops, Anolis, Mabuya, Tropidophis, and Leiocephalus. Green turtle foraging Populations of Epicrates, Anolis, Mabuya, Tropidophis, and Leiocephalus Populations of Epicrates, Cyclura, Anolis, Aristelliger, Tropidophis, and Leiocephalus. Marine turtle foraging and nesting Marine turtle foraging and nesting Marine turtle foraging and nesting Marine turtle foraging and nesting Populations of Anolis
Amphibians and reptiles in the Turks and Caicos Islands 383
384
R.G. Reynolds
protection of these areas, and today serves as the authority for reserves and biological resources, employing ∼180 individuals. Enforcement of environmental regulations is carried out by ∼38 patrolling conservation officers, largely active around Providenciales, Grand Turk, and South Caicos and operating with a limited budget of around $50,000 US/year for gas, vehicles, and supplies (DECR, 2008). The DECR also works with the TCI National Trust, a small non-governmental organization founded in 1992 and tasked with preservation and promotion of the natural, cultural and historical heritage of the TCI (TCI National Trust, 2010). The Trust preserves a number of heritage sites independent of the national park system, some of which are significant for local reptile populations. Wades Green Plantation on North Caicos protects remnants of tropical dry forest which supports large populations of Anolis, Epicrates, Tropidophis, and Aristelliger species, as well as populations of most of the other native terrestrial reptile species (Reynolds and Manco, unpubl.). The DECR has issued a series of ordinances and policies for protection of wildlife (birds, flora) and fisheries (including marine turtles), and in 2001 the TCI Environment Charter was issued jointly by the UK and the TCI to establish guidelines and goals for environmental conservation and resource use. Priorities to date have included protection of marine fisheries, native vegetation, and protected areas; though an endangered species bill including provisions for CITES is currently under review.
The Native Herpetofauna The terrestrial herpetofauna of the TCI is largely derived from Hispaniola, which lies approximately 130 km to the south of the Caicos bank, a distributional pattern that follows ocean currents and hurricane tracks which might facilitate ocean dispersal (Schwartz, 1967, 1968; Schwartz and Crombie, 1975; Buden, 1981; Tolson, 1987; Pregill, 1992; Franz et al., 1996; Hower and Hedges, 2003; Hedges, 2006). At least six endemic reptile species occur on the islands, though no endemic reptile genera are present. Two species, Cyclura carinata and Anolis scriptus, share conspecifics on Mayaguana (Anolis) or its satellite Booby Cay (Anolis, Cyclura). Epicrates c. chrysogaster is a subspecies of the southern Bahamas boa, with other subspecies occurring on the Inaguas and the Crooked-Acklins islands. Most of the native reptilian fauna is widespread throughout the TCI, though recent extirpations have narrowed the range of some (table 3). The lizards Leiocephalus psammodromus and Sphaerodactylus show a genetic split between banks, with subspecies of the former occurring on each bank and widely divergent species of the later isolated on each bank (Reynolds et al., unpubl.). A few single-island endemic subspecies have been described for both Leiocephalus (Schwartz, 1967) and Tropidophis (Schwartz, 1963), though it remains to be seen whether these subspecific epithets are confirmed by molecular analysis. A single widespread species, Mabuya cf. sloanii, ranges well beyond the TCI throughout the Greater and northern Lesser Antilles (Hedges, 2010).
• •
•
• •
• • • • • • • • • •
NE NE NE NE NE NE NE NE
EN EN CR • •
•
•
•
•
NE
•
•
•
•
•
†
•
•
CR
MC
Turks Bank
Caicos Bank
IUCN Status
is endemic to the TCI but introduced elsewhere. might persist though population is functionally extinct.
§ Individuals
‡ Species
Species Reptilia, Squamata Iguanidae Cyclura carinata*‡ Leiocephalidae L. psammodromus* Polychrotidae Anolis scriptus Scinidae Mabuya cf. sloanii Sphaerodactylidae Aristelliger hechti* S. caicosensis* S. underwoodi* Boidae Epicrates chrysogaster Tropidophidae Tropidophis greenwayi* Typhlopidae Typhlops cf. platycephalus Reptilia, Testudines Chelonidae Caretta caretta Chelonia mydas Eretmochelys imbricata •
•
•
•
• •
•
•
•
§
NC
• † †
•
•
•
•
•
•
•
•
PR
• •
?
•
•
• •
•
•
•
†
EC
?
?
?
•
•
•
•
†
WC
† †
?
•
†
• •
•
•
†
†
SC
•
• •
?
•
•
•
LA
•
•
•
•
• •
•
•
•
•
BA
† †
†
•
•
•
†
†
GT
† †
•
•
•
†
†
SLT
?
?
•
•
•
•
•
•
CCS
• •
•
•
•
•
•
•
TKS
Table 3. Distribution of native reptiles of the Turks and Caicos with their IUCN status designations. Distributions are shown for the two banks, as well as larger islands (>4 km2 ) and groups of smaller islands (Caicos Cays and Turks Cays). Species endemic to the TCI are identified with an asterisk. Extirpated populations are denoted with a dagger (†), while unknown occurrences are denoted with a question mark. Sea turtle distribution shows confirmed (•), potential (?), and extirpated (†) nesting beaches only. Abbreviations are as follows: MC = Middle Caicos; NC = North Caicos; PR = Providenciales; EC = East Caicos; WC = West Caicos; SC = South Caicos; LA = Little Ambergris Cay; BA = Big Ambergris Cay; GT = Grand Turk; SLT = Salt Cay; CCS = Caicos Cays (cays between Providenciales and North Caicos); TKS = Turks Cays (small cays on the Turks Bank). IUCN status abbreviations are CR = Critical; EN = Endangered; NE = Not Evaluated (Gerber, 2004; Marine Turtle Specialist Group, 1996; Mortimer and Donnelly, 2008; Seminoff, 2004).
Amphibians and reptiles in the Turks and Caicos Islands 385
386
R.G. Reynolds
Information contained in the species accounts is compiled from a variety of sources, especially Schwartz and Henderson (1991) and Henderson and Powell (2009), and relies heavily on my own and others’ work in this region. In order to provide taxonomic consistency, I have chosen to use scientific nomenclature consistent with other recent published works in the field of Caribbean herpetology (e.g., Henderson and Powell, 2009), with standard names largely consistent with Hedges (2010). There are two islands named “Long Cay”; one on the Caicos bank 0.75 km southwest of South Caicos and one on the Turks bank 2.85 km southeast of Grand Turk (fig.1); I therefore specify in parenthesis the appropriate bank. Major islands in this region are East Caicos, Grand Turk, North Caicos, Middle Caicos, Providenciales, South Caicos, and West Caicos. Natural history information pertinent to status and conservation of each species follows, and each account includes an assessment of the conservation status and main threats to the species. Data deficient indicates that little information on natural history, distribution, and/or conservation status is available for the species in the TCI. Testudines Cheloniidae. Caretta caretta (loggerhead turtle). Adults and juveniles are infrequent locally, and at least one confirmed nesting event was recorded on Long Bay, Providenciales in May 2005 (Pardee, 2005; Richardson et al., 2009). This species is data deficient in the TCI. Chelonia mydas (green turtle). Adults and juveniles are common in local waters. Small numbers of this species are nesting or potentially nesting on Big Sand Cay, Bush Cay, East Caicos, and Gibbs Cay (table 3; Godley et al., 2004; Richardson et al., 2009). Several nesting populations appear to have been recently extirpated (table 3; Godley et al., 2004; Richardson et al., 2009). Eretmochelys imbricata (hawksbill turtle). Adults and juveniles are common in local waters, with greater nesting frequency than green or loggerhead turtles (Richardson et al., 2009). Small numbers of this species are nesting or potentially nesting on Big Ambergris Cay, Big Sand Cay, Bush Cay, East Caicos, Fish Cay, Middle Caicos, and North Caicos (table 3; Godley et al., 2004; Richardson et al., 2009). Several nesting populations appear to have been recently extirpated (table 3; Godley et al., 2004; Richardson et al., 2009). Sauria Sphaerodactylidae. Aristelliger hechti (Caicos or Hecht’s barking gecko). This species is restricted to the Caicos bank (table 3; Bauer and Russell, 1993). They are common in xeric scrub on Big Ambergris Cay and in tropical dry forest on North Caicos. Populations possibly occur on Middle Caicos, though this species has not been recorded during many herpetological surveys of that island. Individuals are frequently found underneath rock piles during the day or on vegetation, rock walls, and rocks at night; and are also associated with artificial cover (Schwartz and Crombie, 1975; Bauer and Russell, 1993). The biology of this species is poorly understood, though the fragile skin of A. hechti has been discussed by
Amphibians and reptiles in the Turks and Caicos Islands
387
several authors (Greene, 1988; Bauer and Russell, 1992, 1993; Bauer et al., 1992). The range appears to be locally restricted within islands. This species is likely a conservation concern due to its restricted range, the presence of feral mammals on some islands within its range, low density, and widespread introduction of the gecko Hemidactylus mabouia, which is a possible competitor (Reynolds and Niemiller, 2009, 2010a). Sphaerodactylus caicosensis (Caicos banded dwarf gecko). This species is restricted to the Caicos bank on all major islands and some small cays and rock islands with some vegetation (table 3). They are common in xeric habitat behind beaches as well as in more mesic tropical dry forest on North Caicos. Individuals are frequently found under rocks and litter along beaches and roads and commonly encountered on rock walls, low vegetation, and on stones on the ground at night. Many populations are edificarian and common near human habitation and in areas with high densities of feral mammals. This species does not appear to be a conservation concern. Sphaerodactylus underwoodi (Turks island dwarf gecko). This species is restricted to the Turks bank (table 3). Individuals are edificarian and xerophillic, common underneath rocks and litter in areas behind beaches, and common in urban lots with some vegetation on Grand Turk. This species does not appear to be a conservation concern. Iguanidae. Cyclura carinata (Turks and Caicos rock iguana). This species is distributed on many small cays and rock islands with some vegetation on both the Turks and Caicos Banks (table 3; Welch et al., 2004). Extirpated on most of the large islands in the TCI, this species survives on small cays that lack introduced vertebrate predators. The largest remaining populations occur on Big and Little Ambergris Cays on the southeastern edge of the Caicos bank. Individuals of this species have been translocated to several outlying cays to ensure their long-term survival in the event of the introduction of cats and dogs to the Ambergris Cays (Gerber, 1996, 2004, 2007). Leiocephalidae. Leiocephalus psammodromus (Turks and Caicos curly-tailed lizard). This species occurs on most major islands larger than 0.42 km2 on the Turks and Caicos Banks (table 3; Reynolds and Fitzpatrick, unpubl.). They are likely extirpated from some islands with a long history of European habitation and feral populations of vertebrate predators and herbivores, as evidenced by their presence in middens on Grand Turk (Newsom and Wing, 2004). Some smaller cays (<1.0 km2 ) on the Caicos bank do not have populations of this species (e.g., Mangrove Cay, Middleton Cay). Six subspecies are currently recognized (Schwartz, 1967), though perhaps none are warranted given current molecular data (Reynolds and Fitzpatrick, unpubl.). Conspicuous where they occur, individuals occupy a variety of xeric habitats with access to both full sun and shade (Smith, 1994, 1995), as well as edificarian irrigated situations. Curly-tailed lizards are extremely susceptible to predation by feral mammals (Iverson, 1978; Smith and Iverson, 1993), and have low clutch sizes (Smith and Iverson, 1993). More information is needed to assess
388
R.G. Reynolds
the conservation status of this species, but it is apparently extirpated from some islands while still common on many others. Polychrotidae. Anolis scriptus scriptus (Turks and Caicos anole). This species occurs on all major islands and most small cays and rocks with some vegetation (table 3). Populations in the TCI are considered a subspecies of the southern Bahamas anole complex (Rand, 1962). Individuals are common in most habitat types, including edificarian and xeric to relatively mesic zones, as well as irrigated areas. This species does not appear to be a conservation concern. Scincidae. Mabuya cf. sloanii (Antillean slipperyback or skink). The specific epithet sloanii is likely to change for populations in the Turks and Caicos to more accurately reflect actual evolutionary relationships (Conn and Hedges, pers. comm.). Populations are present on all major islands and some smaller islands and cays (table 3), though this species is data deficient in the TCI. This species is encountered infrequently, though it might be locally common. Individuals are often encountered in leaf litter or underneath flat rocks. This species does not appear to be a conservation concern. Serpentes Boidae. Epicrates chrysogaster chrysogaster (Turks island boa). This species occurs on some islands on the Caicos bank, and was recently rediscovered on Gibbs Cay in the Turks Cays (Reynolds and Niemiller, 2008, 2010b, unpubl.; Reynolds et al., in review). Populations of this species could possibly occur on Long Cay (Turks bank), East Cay (Buden, 1975), and West Caicos (Reynolds and Gerber, unpubl.). The original holotype is from Grand Turk, though until recently no individuals were reported from the Turks bank since the collection of the type specimen (ANSP 10322; Cope, 1871) (Tolson and Henderson, 1993). Populations have apparently been extirpated from Grand Turk, and possibly from Salt Cay and some of the Caicos Cays (small islands between Providenciales and North Caicos). Individuals are uncommon to rare on Providenciales and infrequent on other islands except for Big Ambergris Cay, where this species is abundant (Reynolds et al., unpubl.). Diurnal refugia include large limestone rocks, logs, subterranean interstices, human debris, and palm litter (Sheplan and Schwartz, 1974; Buden, 1975; Reynolds and Gerber, unpubl.). This species is CITES Appendix II (2009) listed and is a major conservation concern due to loss of habitat, removal for the pet trade, direct persecution, and introduced mammalian predators. Tropidophiidae. Tropidophis greenwayi (Caicos dwarf boa). This species is restricted to major islands on the Caicos bank, as well as Long Cay (Caicos bank) and Middleton Cay (Iverson, 1986). There are currently two recognized subspecies: T. g. greenwayi distributed on Big Ambergris Cay and T. g. lanthanus distributed elsewhere on the Caicos bank (Iverson, 1986; Schwartz and Henderson, 1991; Hedges, 2002; Henderson and Powell, 2009). It is possible that the subspecific epithets will
Amphibians and reptiles in the Turks and Caicos Islands
389
collapse following further analysis (J. Iverson, in litt.). The Big Ambergris Cay population was thought to be extirpated, as the only known specimens (n = 2) were collected as types by Barbour and Shreve in 1936. Reynolds et al. (2010) found an additional individual on 20 March 2009, indicating that this subspecies might persist, though it is possible that this specimen represents an individual introduced during movement of construction equipment from Providenciales. T. g. greenwayi is likely xerophilic, while T. g. lanthanus is mesophilic, frequently occurring near sources of standing water or ground water such as old wells, ephemeral ponds, and thick forest. Individuals are occasionally found in xeric situations as well, such as rocky well-drained hillsides on Middle Caicos (Reynolds and Deal, unpubl.), and open cactus shrubland on South Caicos (Iverson, 1986). This species is a serious conservation concern, as it has been collected extensively for the pet trade and is likely susceptible to introduced mammalian predators (Iverson, 1986). Additionally, the subspecies T. g. greenwayi faces an uncertain future, as it was likely never abundant and its range is apparently restricted to Big Ambergris Cay, which is currently being heavily developed. Typhlopidae. Typhlops cf. platycephalus (Caicos blindsnake, sensu B. Hedges, in litt.). This species is restricted to the Caicos bank, though it is data deficient. Individuals from the Caicos Islands, considered to be T. richardii in Schwartz and Henderson (1991), were reassigned to T. platycephalus by Hedges and Thomas (1991) and are currently being assigned to a unique species based on DNA sequence data to more accurately reflect evolutionary relationships (B. Hedges, in litt.). These individuals were not recognized as T. platycephalus in Henderson and Powell (2009), though this species does appear to be derived from the Puerto Rican bank (B. Hedges, in litt.). Individuals are xerophilic, found underneath rocks in sandy soil in low scrub (Big Ambergris Cay: Reynolds, 2010) and tropical dry forest (North Caicos), and are occasionally found on the surface at night. Conservation status of this species is unknown; however, it may become a conservation concern if found to be an endemic species and if competition exists with the introduced Brahminy blind snake (Rhamphotyphlops braminus) (Reynolds and Niemiller, 2010a).
Introduced Amphibians and Reptiles The following is a complete list of all historical and current records of introduced amphibians and reptiles in the TCI. The majority of this information comes from Manco (2008b) and Reynolds and Niemiller (2010a), with some additional observations added. Populations are considered established if juveniles and/or evidence of reproduction (i.e., hatched eggs) have been observed. Amphibia Eleutherodactylidae. Eleutherodactylus planirostris (greenhouse frog). Populations are established on some islands on the Caicos bank (table 4), though indi-
Table 4. Introduced reptile and amphibian species in the TCI. Refer to table 3 for abbreviations. Status designations are as follows: Reproducing — hatched nests and/or juveniles observed; Not Reproducing — no juveniles or nests observed; Extirpated — populations of introduced species likely no longer occurring in the TCI. Species Islands Status Source Eleutherodactylidae Eleutherodactylus planirostris GT, PR, MC, NC Reproducing Manco, 2008b; Reynolds and Niemiller, 2010a Hylidae Osteopilus septentrionalis PR, MC, NC Reproducing Manco, 2008b; Reynolds and Niemiller, 2010a Emydidae Trachemys scripta elegans PR Not Reproducing Reynolds and Niemiller, 2010a Trachemys stejnegeri malonei Pine Cay Not Reproducing Seidel, 1988, 1986; Lee and Ross, 2001; Reynolds and Niemiller, 2010a Gekkonidae Hemidactylus mabouia GT, PR, MC, NC, SLT, SC Reproducing Reynolds and Niemiller, 2009, 2010a Sphaerodactlyidae Sphaerodactylus mariguanae GT Extirpated? Schwartz, 1968; Reynolds and Niemiller, 2010a Iguanidae Iguana iguana GT, PR Not Reproducing Reynolds and Niemiller, 2010a Polychrotidae Anolis equestris PR Not Reproducing Reynolds and Niemiller, 2010a Colubridae Pantherophis guttatus GT Not Reproducing Reynolds and Niemiller, 2010a Typlopidae Rhamphotyphlops braminus GT, PR Reproducing Reynolds and Niemiller, 2010a
390 R.G. Reynolds
Amphibians and reptiles in the Turks and Caicos Islands
391
viduals are likely to be found on additional islands. This species can be common, especially during the wet season. Individuals frequent both landscaped areas as well as rocky areas within tropical dry forest on North Caicos; their terrestrial mode of reproduction undoubtedly facilitates their colonization and range expansion. Hylidae. Osteopilus septentrionalis (Cuban treefrog). Populations are established on some islands on the Caicos bank (table 4), though individuals are likely to be found on additional islands. This species is abundant during rainy autumn nights on North Caicos, where individuals frequent roadways. Individuals are very common in uncovered wells and water tanks. This species is a documented prey item for Tropidophis greenwayi on Providenciales (Manco, 2006). Adult T. greenwayi have been observed to be especially common inside the walls of old stone wells where metamorphic O. septentrionalis emerge from the water below (Tolson and Henderson, 1993; Reynolds and Niemiller, 2010a). Testudines Emydidae. Trachemys scripta elegans (red-eared slider). This species is infrequent and not established in the TCI. Individuals have been released by residents into artificial freshwater ponds at the golf course on the east end of Providenciales. Three have been removed by conservation officials and several others have been sighted. No hatchlings or juveniles have been observed. Trachemys stejnegeri malonei (Antillean slider). One individual was collected from Pine Cay in 1975 (W. Auffenberg; UF 49,423), though others were seen in a freshwater pond on Pine Cay in December 1997 (Seidel, 1988, 1996; Lee and Ross, 2001). The current status of this population is unknown, though to my knowledge individuals have not been reported from Pine Cay since Lee and Ross’s last observation in 1997. This population is believed to represent a human-mediated introduction (Seidel, 1988, 1996) from Great Inagua. However, archeological remains (shell fragments) over 700 years old have been reported from Middle Caicos and Grand Turk purportedly from the genus Trachemys (Carlson, 1994; Seidel, 1996; Lee and Ross, 2001; Newsom and Wing, 2004), though Keegan and Carlson (2008) did not consider these to represent this genus. As slider turtles were commonly used throughout the Antilles as a food source by the Taíno (Keegan and Carlson, 2008), it is possible that repeated historic introductions to the TCI occurred. Sauria Gekkonidae. Hemidactylus mabouia (wood slave). Populations are established on several islands in the TCI (table 4), though individuals are likely to be found on additional islands (Minton and Minton, 1975; Reynolds and Niemiller, 2010a). Nests are reported from Salt Cay and hatchlings have been reported from all six islands (Reynolds and Niemiller, 2009, 2010a). The influence of this species on the endemic gecko Aristelliger hechti is unknown.
392
R.G. Reynolds
Sphaerodactylidae. Sphaerodactylus mariguanae (Mayaguana dwarf gecko or sphaero). This species was originally reported from Grand Turk (Schwartz, 1968; Schwartz and Henderson, 1991), though apparently has not been collected recently. Schwartz (1968) collected a series of 40 individuals from Cockburn Town, Grand Turk and found them to be distinct from S. underwoodi in size, color pattern, and scalation. It has been suggested that these records might have been a misidentification; however, this seems unlikely given the large numbers examined and Schwartz’s comparison with other populations of S. mariguanae from Booby Cay (Mayaguana) and Mayaguana (∼185 km NW of Grand Turk). Schwartz speculated that Grand Turk was within the natural range of this species, as several other reptiles are found on both the Turks bank and Booby Cay (Cyclura carinata, Anolis scriptus, Mabuya sloanii) and postulated that S. mariguanae would be found on the Caicos bank (it hasn’t). If Grand Turk S. mariguanae are within the natural range of this species, it is curious that they have not been seen in recent years and that they were never recorded from other islands on the Turks bank. Schwartz (1968) also speculated that Grand Turk individuals may be an introduced population, and the most likely scenario seems to be an introduction followed by what appears to be an extirpation of S. mariguanae on Grand Turk (Reynolds and Niemiller, 2010a). Iguanidae. Iguana iguana (green iguana). This species has been recorded from both the Turks and Caicos banks, though it is not established on either. Individuals likely represent escaped or released pets, and no hatchlings or juveniles have been reported. At least one individual was captured and removed from Providenciales, though others are occasionally seen on both Providenciales and Grand Turk. Polychrotidae. Anolis equestris (knight anole). Adults of this species have only been documented from Providenciales and it is not currently established. At least six individuals have been recorded from the landscaped grounds of a resort in the Grace Bay area of Providenciales and likely represent escaped or released pets. Four individuals were removed and placed in captivity. No hatchlings or juveniles have been found. Serpentes Colubridae. Pantherophis [Elaphe] guttatus (corn snake). Three individuals of this species have been removed from Grand Turk, one of which was a road-killed specimen. One individual laid a clutch of inviable eggs after capture (Reynolds and Niemiller 2010a). This species is likely represented by either escaped pets or individuals (possibly eggs) in live trees brought from Florida (Reynolds and Niemiller, 2010a). Two of the three specimens were found near the new cruise ship terminal, while the location of the third is unclear. Typhlopidae. Rhamphotyphlops braminus (brahminy blind snake). This species is established and common on Grand Turk and Providenciales, likely having arrived
Amphibians and reptiles in the Turks and Caicos Islands
393
as a stowaway in the soil of potted plants. The influence of this species on the native Typhlops is unknown. Other non-native species Occasional pets are released or escape and survive for a period of time in the wild. A savanna monitor lizard (Varanus exanthematicus) was occasionally spotted on Providenciales until 2004 and was a known release of a pet by a resident of that island (B. Riggs and B.N. Manco, in litt.). Cuban brown anoles (Anolis sagrei) are not yet reported from the TCI, though the eventual arrival of this species seems a distinct possibility.
Species of Special Concern Sea turtles Four species of sea turtles occur in TCI waters; however, only three are known to actively nest on the islands. The fourth, Dermochelys coriacea (leatherback turtle), is occasionally seen offshore but not known to nest within the archipelago. Loggerhead turtles formerly nested in the archipelago, though nesting is now extremely rare and sporadic (Pardee, 2005; Richardson et al., 2009). Hawksbill and green turtles continue to nest in low density on the more remote cays in the archipelago, with hawksbill nesting occurring from at least July to January and Green turtle nesting in September (Richardson et al., 2009). Though the TCI appear to support low nesting activity, the sea grass beds and fringing reefs likely provide regionally significant foraging areas for young green and hawksbill turtles (Richardson et al., 2009). Harvest of green turtles remains legal in TCI waters (Richardson et al., 2006; Broderick et al., 2006), though annual take is largely unknown due to logistical challenges for monitoring or enforcement. Godley et al. (2004) estimated that 2401130 individuals were harvested annually in local waters in directed fishery, plus an additional 100 individuals that were captured annually as incidental catch. Rudd (2003) estimated that the harvest was several hundred annually, whereas Richardson et al. (2009) estimated that annual harvest of green turtles may be around 210. Juveniles are common in the extensive sea grass beds and tidal creeks on the bank sides of the major Caicos Islands. Richardson et al. (2009) document fibropapilloma symptoms in a juvenile green turtle from the Caicos bank, indicating that this population might be affected by this disease. This species is listed as endangered by the IUCN (Seminoff, 2004), and current and historical take have likely significantly decreased nesting populations in the Turks and Caicos archipelago (Richardson et al., 2009). Harvest of hawksbill turtles also remains legal in TCI waters (Richardson et al., 2006; Broderick et al., 2006), though annual take is largely unknown du due to logistical challenges for monitoring or enforcement. Godley et al. (2004)
394
R.G. Reynolds
estimated that between 180 and 900 individuals are harvested annually in local waters in directed fishery, plus an additional 100 individuals captured annually as incidental catch. Rudd (2003) estimated that the harvest was several hundred annually. Juveniles are common on patch reefs on the Turks and Caicos banks, and exhibit a higher growth rate than other Caribbean populations (Richardson et al., 2009). Current and historical take of this species have likely significantly decreased nesting populations in the Turks and Caicos archipelago (Richardson et al., 2009). Though turtle soup has recently been removed from menus on the main tourist islands, turtles continue to be harvested for local consumption. Current fishing regulations (Fisheries Protection Ordinance, 1998) allow harvesting of one turtle per person per week, weighing >20 pounds or measuring >50.8 cm carapace length to be legally taken in TCI waters (Broderick et al., 2006; Richardson, 2006). Under these regulations, the harvesting of eggs, nesting females, and juveniles is prohibited, though previous legislation (TCI Fisheries Protection Regulations, 1976) failed to prevent the estimated harvest of 8000-10,000 eggs per year (Fletemeyer, 1984) due to lack of enforcement (Richardson et al., 2009). Eggs are still harvested and either consumed or sold, though probably in much lower numbers than in the 1970s and 1980s (Richardson et al., 2009). Penalties for illegal take of turtles have increased recently, with an individual receiving a maximum fine of US$7000 in 2008 (P. Dickerson, pers. comm.). Combined with the development of coastal areas, fibropapilloma, and legal harvest, sea turtles in the TCI face an uncertain future. To ensure that nesting activity is not completely eliminated from the islands, increased surveillance of nesting beaches is encouraged. Additional research on sea turtles is ongoing in the archipelago (Marine Turtle Research Group, University of Exeter, TCI Department of Environment and Coastal Resources, and Turtles in the UK Overseas Territories), which should help to inform oversight of the turtle fishery and contribute to regulations that ensure that the ongoing take does not impact local or regional populations. Cyclura carinata The genus Cyclura is notable for both its high level of endemism, with most of the 16 species restricted to one or a few islands in the Caribbean (Etheridge, 1982; Alberts, 2000; Welch et al., 2004), as well as the rapid decline of most species in the genus due to human activities (Iverson, 1978; Alberts et al., 2004). The species Cyclura carinata, first described by Harlan (1824), is restricted to the Turks and Caicos banks, as well as Booby Cay, a satellite of Mayaguana located approximately 63 km northwest of the Caicos bank. This Booby Cay population was formerly referred to as the subspecies C. c. bartschi, though subsequent molecular analysis has revealed that this population is not unique enough to warrant subspecific status (Bryan et al., 2007) and was probably introduced from the Turks bank. Welch et al. (2004) found evidence for recent colonization of the Turks bank from populations of C. carinata on the eastern Caicos bank. Iguanas will not willingly enter the
Amphibians and reptiles in the Turks and Caicos Islands
395
water, though occasionally individuals may be swept out to sea, and at least one individual has been found alive drifting on the Caicos bank several kilometers from the nearest population (Gerber, pers. comm.). Though not mentioned by Welch et al. (2004), one possible means of conveyance to the Turks bank is human-assisted dispersal. It is known that indigenous, and possibly European, people used iguanas for food, and hence may have facilitated transport of individuals to other islands in the archipelago (IUCN Iguana Specialist Group, 2003). Iguanas formerly occupied most islands in the TCI, though recently they have been extirpated from most of the large islands and are now restricted to small cays and rock islands, a total area of only 13 km2 (Gerber and Iverson, 2000; Gerber, 2004) and less than 5% of their former range (Hudson and Alberts, 2004). The major threats faced by iguanas include feral dogs and cats, which prey on young iguanas and destroy burrows (Iverson, 1978). Iverson (1978) documented the systematic near extirpation of iguanas from Pine Cay on the Caicos bank in a matter of years. Iguanas have since returned to Pine Cay (Smith, 1992a) and now occur in extremely low density on that island, though the population has never recovered and likely will not recover until feral mammals are removed. Iguanas were also extirpated from Long Cay on the Caicos bank due to predation by feral cats (Mitchell et al., 2002). A cat-eradication campaign was begun in 1999 using targeted poison-baits, and 800 iguanas were translocated from Big Ambergris Cay following removal of the invasive predator (Mitchell et al., 2002). The population of iguanas on Long Cay has successfully established since re-introduction, and juvenile recruitment is occurring (Reynolds, pers. obs., 2008). Currently, the largest remaining population of iguanas occurs on Big and Little Ambergris Cays, where an estimated 15,000-20,000 individuals occurred prior to the start of development of Big Ambergris Cay (Gerber, 2004). Though Little Ambergris Cay remains protected at the moment by the TCI National Trust, Big Ambergris Cay is currently being heavily developed, and iguanas there are threatened by habitat loss due to blasting and building as well as vehicle strikes. This population has already declined, and current ongoing studies are determining whether individuals can be moved from areas of the island slated to be developed in the immediate future to areas that will remain undeveloped in the near future (Gerber, 1998, 2010). Iguanas have also been successfully translocated from this source population on Big Ambergris Cay to outlying islands that are predator and development free (Alberts, 2001; Alberts and Gerber, 2004; Gerber, 2007). These populations are being monitored annually for juvenile recruitment and survival and are intended to serve as buffers against catastrophic loss of other populations such as the one on Big Ambergris Cay. Little Ambergris Cay also remains under threat of being bought and developed by foreign companies, though it is hoped that these entreaties will be resisted. Iguanas in the TCI are subject to intensive monitoring and research, initiated in the mid-1970s (Iverson) and continuing today (Glenn Gerber, San Diego Zoo Institute for Conservation Research). A small population of iguanas on Little Water
396
R.G. Reynolds
Cay (within Princess Alexandria National Park) serves as an extremely popular tourist destination, and the TCI National Trust employs guides and guards to introduce visitors to the plight of the endangered iguanas. Little Water Cay is now connected to Water and Pine Cays by a strip of sand, which allows feral mammals from these islands to invade and potentially impact the population of iguanas on Little Water Cay. Iguana awareness campaigns have shown great success, and an atmosphere of stewardship for this species exists in the Turks and Caicos, though developers and pet owners often overlook the impacts of their respective activities. It is hoped that intensive management and mitigation may allow the persistence of rock iguanas, though additional predator removal campaigns would greatly benefit this species. Epicrates chrysogaster chrysogaster This endemic subspecies was first described by Cope (1871) based on an individual from “Turk’s Island”, which has been taken to refer to what is now Grand Turk. Since this description E. c. chrysogaster has not been recorded on Grand Turk, and was thought to have been extirpated from the Turks bank. However, Reynolds and Niemiller (2010b) and Reynolds et al. (unpubl.) report four individuals discovered on Gibbs Cay, which is a very small island about 1.5 km SE of Grand Turk, representing the first report of this species on the Turks bank since the original description in 1871, and the only report from an island on this bank other than Grand Turk. In addition, these individuals are fixed at a unique mitochondrial haplotype that is ∼1% divergent from Caicos bank haplotypes (Reynolds et al., unpubl.). It has been suggested that given the inconsistency of map labeling of the region until the 1970s (Buden, 1975), the holotype locality was in fact a different island than Grand Turk. However, it now seems more likely that this species was in fact extirpated from Grand Turk and remnants of the Turks bank lineage remain on at least one of the Turks cays. Genetic analysis for this species (Reynolds et al., unpubl.) has shown surprisingly shallow overall genetic divergence among island populations of E. chrysogaster. The largest divergence (1%) in a mitochondrial gene is between haplotypes on Gibbs Cay and Big Ambergris Cay, while two nuclear genes show almost no divergence. This is in sharp contrast to other squamates in the region, which have been described as unique subspecies (Leiocephalus, Tropidophis) or species (Sphaerodactylus) and show large genetic divergence (Reynolds and Koneczny, unpubl.; Reynolds et al., unpubl.). This shallow genetic divergence is hypothesized to be due to lack of historical population structure when the Turks and Caicos Banks were each emergent during the last glaciation (Reynolds et al., unpubl.). Turks Island boas are susceptible to predation by feral mammals (Reynolds, pers. observ.), as well as habitat loss, direct persecution, and vehicle strikes. It is likely that this species has already been extirpated from Grand Turk and South Caicos, which both have a long history of European occupation (Mills, 2008a; Sadler, 2008c). As development continues at an astounding rate in the region, it is likely
Amphibians and reptiles in the Turks and Caicos Islands
397
that more populations will be extirpated. Boas are becoming difficult to find on Providenciales, and the future survival of that population seems bleak. The densest population of boas in the TCI, and one of the densest population of Epicrates anywhere, currently occurs on Big Ambergris Cay, where a long-term monitoring effort has recently been started (Reynolds and Gerber, unpubl.). This private island is being heavily developed into vacation homes, and conservation officials and researchers are working closely with developers and owners to implement effective mitigation measures. Epicrates chrysogaster had been a long-neglected species in terms of research and conservation assessment (likely due to a perceived low abundance), though thankfully this has changed in the last five years. Now focused research programs including natural history, ecology, and genetic analysis have been begun (G. Reynolds and B. Fitzpatrick, University of Tennessee; G. Gerber, San Diego Zoo Institute for Conservation Research) and are leading to more informed conservation decisions. The public is also becoming aware of these snakes through the use of media outlets such as local magazines, brochures, interpretive exhibits, and television appearances. It is hoped that this new wave of enthusiasm will serve to ensure that sensitive populations, such as those on Providenciales and Big Ambergris Cay can be protected in situ.
Discussion The herpetofauna of the TCI consists of 23 species; 13 native (57%) and 10 introduced (43%). Of the native species, two are critically endangered, two are endangered, and the rest have not been evaluated (IUCN, 2010). Reptiles in the region are threatened by loss of habitat, feral predators, unsustainable exploitation (sea turtles), habitat degradation by semi-feral herbivores, and direct persecution (i.e., killing of snakes) (Iverson, 1978; Smith and Iverson, 1993; Gerber, 2004; Richardson et al., 2009; Reynolds et al., unpubl.). Invasive or introduced species also threaten the native herpetofauna, though the impact of introduced amphibians and reptiles is not yet known (Reynolds and Niemiller, 2010a). Many islands in the Turks and Caicos remain uninhabitable by iguanas due to feral cats and dogs, while boas (Epicrates) appear to be extirpated from some islands such as Grand Turk and are likely declining on Providenciales (Reynolds et al., unpubl.). Curlytailed lizards are apparently extirpated from South Caicos, Grand Turk, Salt Cay, and Cotton Cay, likely due to predation by cats (Iverson, 1978; Smith and Iverson, 1993) and loss of habitat due to hundreds of years of human activities and the persistence of semi-feral populations of donkeys, cows, goats, and horses. These herbivores have greatly altered the vegetation of many of the islands in the TCI. Indeed, the interiors of Salt Cay and South Caicos are dusty and sandy due to a loss of undergrowth. Sea turtle nesting is declining in the region (Richardson et al., 2009) due to harvesting of adults and loss of suitable beach nesting habitat to development. Some snake populations face a tenuous future, as some locals perceive them to be
398
R.G. Reynolds
venomous or malevolent spirits and many are either killed on sight, suffer mortality from car strikes, or succumb to habitat loss or introduced predators (Reynolds et al., in review). Amazingly, a former government official granted a permit to reptile dealers to remove thousands of Tropidophis greenwayi from North Caicos for the pet trade, allegedly implying that it would be preferred if they removed all of the snakes (Manco, pers. comm.)! Collection of iguanas and boas for the pet trade was common in the 1980s, and though it likely still occurs, it has probably slowed in recent years due to increased port-of-entry surveillance in response to perceived increases in threats of terrorism and illegal immigration. Collection has the ability to devastate local populations of reptiles (Webb et al., 2002), and hence enforcement must remain strict. One of the major obstacles to conservation of the herpetofauna of the region has been a lack of knowledge about the biology, ecology, and distribution of species in the archipelago. Thankfully, this has begun to change with increased field work and the addition of individual species conservation programs. Turks and Caicos rock iguanas have likely been saved from extinction by the efforts of local authorities, NGOs, and conservation biologists from the U.S. and elsewhere (IUCN Iguana Specialist Group, 2003; Gerber, 2004), initiated by a detailed study of their biology and behavior (Iverson, 1979) and the witnessing of their near extirpation from Pine Cay (Iverson, 1978). Cyclura carinata is now the focus of a major awareness and conservation campaign, and has become one of the natural symbols of the TCI. Worldwide declines in snake populations have recently been noted and represent an increasing concern for conservationists (Mullin and Seigel, 2009; Reading et al., 2010). In 2007, a snake conservation program was initiated to increase knowledge of the biology, ecology, and distribution of Epicrates chrysogaster, and to increase awareness of the threats that this species faces (Reynolds, 2007; Reynolds and Deal, 2010). An annual monitoring campaign, now in its third year, is taking place on Big Ambergris Cay (Reynolds and Gerber, unpubl.). The future of some species of herpetofauna in the Turks and Caicos remains uncertain, and important steps must be taken to ensure not only survival of the species, but also preservation of evolutionary significant units (ESUs — Ryder, 1986; Waples, 1991; Dizon et al., 1992; Mortiz, 1994; Crandall et al., 2000) in the form of genetic diversity. The following strategies might contribute to alleviating impacts on the native herpetofauna of the region: 1. One of the greatest current threats to native herpetofauna in the Turks and Caicos is the introduction of feral predators such as cats and dogs to ecologically naïve island communities (Iverson, 1978). It is recommended that a great deal more effort be exerted to prevent future introductions of cats and dogs, to spay and neuter pets or semi-feral animals, and to increase eradication campaigns on sensitive islands. Cats can survive on islands without a permanent source of freshwater, and hence have been able to colonize many islands in the archipelago, which can have serious consequences for local wildlife (Iverson, 1978). It is imperative that cats be prevented from establishing on islands such as Big and Little Ambergris
Amphibians and reptiles in the Turks and Caicos Islands
399
Cays, which currently harbor critical populations of Cyclura carinata and Epicrates chrysogaster, as well as the endemic subspecies Tropidophis g. greenwayi and Leiocephalus psammodromus apocrinus. A cat recently colonized Big Ambergris Cay from a construction barge and survived for at least three months before being captured and removed. Removal campaigns have been shown to restore islands for reintroduction of iguanas (Mitchell et al., 2002) and are becoming increasingly effective (Veitch and Clout, 2002). 2. Development continues at a rapid pace in the region, and mitigation of the consequences of habitat loss must be a priority for conservation. Though Big Ambergris Cay is one of the most important refuges for herpetofauna in the archipelago, it is currently under heavy development, with future plans indicating that nearly two thirds of the island will be developed. Developers engaged in this project have thus far attempted to cooperate with conservation biologists, and property owners and managers seem to genuinely appreciate the need to minimize the impact on the native wildlife. An environmental center was recently completed on the island, complete with naturalist staff, to allow residents and guests to learn about the local flora and fauna. However, populations of Cyclura and Epicrates are likely decreasing there due to blasting, clearing, and vehicle strikes. It is hoped that as development slows and heavy construction trucks are replaced with golf carts, vehicle strikes will lessen, and owners will take an active role in stewardship of their island’s natural resources. Other developments should be required to take an active role in mitigation, such as reducing nighttime illumination along beaches (which disorient hatchling marine turtles: Lohmann et al., 1997) and not developing ecologically imperiled habitats such as the tropical dry forest on North Caicos, a large patch of which was recently clear-cut for a municipal development. 3. Several reserves, both terrestrial and marine, exist in the TCI (table 4; www.environment.tc; Carleton et al., 2006), some of which protect sensitive habitat and important reptile populations. These protected areas consist of four management units, established by the TCI National Park Ordinance (1989): National Parks, Nature Reserves, Sanctuaries, and Areas of Historic Interest (table 4). In addition, the Turks and Caicos National Trust, a local non-governmental organization, protects a number of sites of historical interest on the Caicos bank. It is recommended that these areas be maintained in perpetuity, and that enforcement of regulations that protect these areas be increased. In addition, areas designated as Sanctuaries, which exist for “the avoidance of disturbance of the area by people” (Department of Environment and Coastal Resources, TCI, 2010), should be expanded to include additional important areas such as sea grass beds and fringing reefs which serve as juvenile sea turtle rookeries. Additional recently proposed protected areas should increase protection of native reptile populations (Carleton et al., 2006). 4. Introduction of non-native herpetofauna is an increasing issue in the Turks and Caicos (Reynolds and Niemiller, 2010a). Though it is not known whether current introductions have negatively impacted the native herpetofauna (Reynolds and Niemiller, 2010a), the number of recent introductions is alarming, and the
400
R.G. Reynolds
potential exists for the introduction of extremely harmful species. It has recently been shown that the introduced Bufo (Rhinella) marinus (cane toad) in Jamaica is causing mortality to the endangered Epicrates subflavus (Jamaican boa) due to ingestion of bufogenin toxin (Wilson et al., 2010). Importantly, Wilson et al. (2010) suggest that other island populations of Epicrates, which evolved in isolation from the genus Bufo and their associated bufadienolide glycosides, may be especially susceptible to these toxins. 5. Awareness campaigns targeted at increasing public appreciation for endemic herpetofauna have shown some success, especially for species such as the rock iguana (Cyclura carinata). Indeed, the motto for the TCI is “Beautiful by Nature”, and a sense of stewardship must be encouraged among citizens, visitors, and government. Many visitors to the island of Providenciales pay for ecotourism trips, which usually involve a stop at Little Water Cay to see the iguanas there. It is hoped that this type of interaction and the associated monetary benefits will encourage protection of endemic species (Knapp, 2004). Recent campaigns to raise awareness of snakes in the islands face greater difficulties, including a general fear of snakes that contributes to malicious killing. Introductions to the threats faced by the endemic snakes have been highlighted in magazine and newspaper articles, brochures, interpretive exhibits at the National Environmental Centre on Providenciales, television appearances, and use of captive animals in children’s nature programs (Manco, 2006; Reynolds and Deal, 2010). 6. A great impediment to species conservation has been a lack of knowledge of the biology, ecology, population size, and conservation concerns for most species of native reptiles in the Turks and Caicos. This has recently begun to change, with long-term intensive monitoring of Cyclura carinata (Gerber, 2004, 2010) and sea turtles (i.e., Richardson et al., 2009), and the start of a long-term research program focused on Epicrates chrysogaster (Reynolds and Gerber, unpubl.). Additional studies have been conducted on Leiocephalus psammodromus and Anolis s. scriptus (Smith, 1992b, 1994, 1995; Smith and Iverson, 1993; Reynolds et al., unpubl.), and more recently for Sphaerodactylus caicosensis and S. underwoodi (Reynolds and Koneczny, unpubl.) and Tropidophis greenwayi (Reynolds et al., 2010; unpubl.). Additional work is needed on other endemics such as Aristelliger hechti and Typhlops cf. platycephalus (Hedges, unpubl.). The TCI are unique for their natural beauty and endemic species, both of which are responsible for drawing a large number of economically vital tourists. However, this natural beauty is under assault from a plenitude of damaging processes which threaten to permanently damage or destroy the environmental uniqueness of the archipelago. Recently publicized environmental disasters, such as a large amount of raw sewage in Turtle Cove Marina, Providenciales (Godley et al., 2004) could potentially have important economic impacts. It is hoped that the above recommendations will contribute to the long term preservation of the native reptiles of the TCI.
Amphibians and reptiles in the Turks and Caicos Islands
401
Acknowledgements. This work would not have been possible without the many years of research conducted by my fellow scientists in the TCI. I would like to acknowledge the significant contributions of other individuals working with the herpetofauna of the TCI, especially my collaborator and mentor G. Gerber. A special thanks to the many field assistants who have helped with herpetological surveys and field work over the years. I am also grateful to the Department of Environment and Coastal Resources, TCI for scientific research permits and support, and to the Turks and Caicos National Trust for logistical support. My research in the TCI is supported by the following: Department of Ecology and Evolutionary Biology, The University of Tennessee Summer Research Grant Program, The Sigma Xi Grantin-Aid of Research, The Mohamed bin Zayed Species Conservation Fund, the San Diego Zoo Institute for Conservation Research and the Offield Family Foundation, The American Philosophical Society Lewis and Clark Fund for Exploration and Research, The American Museum of Natural History Theodore Roosevelt Memorial Fund Grant in Support of Research, and The University of Tennessee W.K. McClure Scholarship for the Study of World Affairs. This manuscript was greatly improved by discussions with G. Gerber and M. Welch and comments from A. Hailey and two anonymous reviewers.
References Alberts, A.C., Ed. (2000): West Indian Iguanas: Status survey and conservation action plan. IUCN — the World Conservation Union, Gland, Switzerland. Alberts, A.C. (2001): Turks and Caicos iguana rescue and translocation program, Caribbean. Reintroduction News 20: 22. Alberts, A.C., Gerber, G.P. (2004): Turks and Caicos iguana translocation program update. Reintroduction News 23: 7. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds. (2004): Iguanas: Biology and Conservation. Los Angeles, University of California Press. Barbour, T., Shreve, B. (1936): New races of Tropidophis and of Ameiva from the Bahamas. Proc. New Eng. Zoo. Club 16: 1-3. Bauer, A.M., Russell, A.P. (1992): The evolutionary significance of regional integumentary loss in island geckoes: A compliment to caudal autotomy. Ecol. Ethol. Evol. 4: 343-358. Bauer, A.M., Russell, A.P. (1993): Aristelliger hechti. Cat. Am. Amph. Rept. 569: 1-2. Bauer, A.M., Russell, A.P., Shadwick, R.E. (1992): Skin mechanics and morphology in Sphaerodactylus roosevelti (Reptilia: Gekkonidae). Herpetologica 48: 124-133. Broderick, A.C., Fraustein, R., George, T., Glenn, F., Hayes, G.C., Jackson, A.D., Ruxton, G.R., Godley, B.J. (2006): Are green turtles globally endangered? Glob. Ecol. Biogeo. 15: 21-26. Bryan, J.J., Gerber, G.P., Welch, M.E., Stephen, C.L. (2007): Re-evaluating the taxonomic status of the Booby Cay Iguana, Cyclura carinata bartschi. Copeia 2007: 734-739. Buden, D.W. (1975): Notes on Epicrates chrysogaster (Serpentes: Boidae) of the Southern Bahamas, with description of a new species. Herpetologica 31: 166-177. Buden, D.W. (1981): Endemism and patterns of distribution among terrestrial vertebrates in the Bahamas. Bahamas Nat. 5: 2-18.
402
R.G. Reynolds
Campbell, D.G. (2006): The animals Columbus saw: The controversial first zoology of the Bahama Islands. Bahamas Nat. J. Sci. 1: 4-15. Carleton, C., Hambrey, J., Pardee, M., Wood, K. (2006): Review and re-assesment of the TCI protected areas system. Nautilus Consultants Ltd., 61 pp. (http://www.environment.tc/content/root/files/ ReviewRe-AssessmentofTCIProtectedAreasStudy.pdf). Carlson, L.A. (1994): Analysis of the vertebrate fauna from MC-32 on the north coast of Middle Caicos, Turks and Caicos Islands, B.W.I. Florida Mus. Nat. Hist. Carlson, L.A. (1999): Aftermath of a feast: Human colonization of the southern Bahama Archipelago and its effects on the indigenous fauna. Ph.D. Dissertation, Department of Anthropology, University of Florida. Carlson, L.A., Keegan, B. (2006): Talking Taino: Boat trips. Times of the Islands, Summer 2006. CITES (2009): Appendices I, II, and III to the Convention on International Trade in Endangered Species of Wild Fauna and Flora. United Nations Environment Programme, 41 pp. (http://www.cites.org/eng/app/e-appendices.pdf). Cope, E.D. (1871): Eighth contribution to the herpetology of tropical America. Proc. Acad. Nat. Sci. Phila. 1894: 429-442. Correll, D.S., Correll, H.B. (1982): Flora of the Bahamian Archipelago. Vaduz, Liechtenstein, A.R.G. Ganter Verlag K.-G. Crandall, K.A., Bininda-Edmonds, O.R.P., Mace, G.M., Wayne, R.K. (2000): Considering evolutionary processes in conservation biology: an alternative to ‘evolutionary significant units’. Trends Ecol. Evol. 15: 290-295. Department of Environment and Coastal Resources, Turks and Caicos Islands (2010): Protected Areas Division (http://www.environment.tc/Protected-Areas- Division.html). Dizon, A.E., Lockyer, C., Perrin, W.F., Demaster, D., Sisson, J. (1992): Rethinking the stock concepta phylogeographic approach. Conserv. Biol. 6: 24-36. Etheridge, R.E. (1982): Checklist of the iguanine and Malagasy iguanid lizards. In: Iguanas of the World: Their Behavior, Ecology, and Conservation, p. 7-37. Burghardt, G.M., Rand, A.S., Eds, Park Ridge, New Jersey, Noyes. Fairbanks, R.G. (1989): A 17,000 year glacio-eustatic sea level record: Influence of glacial melting rates on the Younger Dryas event and deep-ocean circulation. Nature 342: 637-642. Fletemeyer, J.R. (1984): The national report for the country of Turks and Caicos Islands. In: Proceedings of the Western Atlantic Turtle Symposium, p. 409-422. Bacon, P., Berry, F., Bjorndal, K., Hirth, H., Ogren, L., Weber, M., Eds, Miami, FL, University of Miami Press. Franz, R., Franz, S. (2009): A new fossil tortoise in the genus Chelonoidis (Testudies: Testudinidae) from the northern Bahamas, with an osteological assessment of other Neotropical tortoises. Bull. Fla. Mus. Nat. Hist. 49: 1-44. Franz, R., Dodd, C.K., Buckner, S.D. (1996): A review of herpetology of the Bahamian Archipelago. Bahamas J. Sci. 6: 22-30. Gerber, G.P. (1996): Cyclura carinata ssp. carinata. In: IUCN 2010. 2010 IUCN Red List of Threatened Species. Version 2010.1 (www.iucnredlist.org) (23 March 2010). Gerber, G.P. (1998): Management plan for the protection of the iguana. In: Strategic Environmental Assessment for Big Ambergris Cay, Turks and Caicos Islands, British West Indies, p. C1-C37. Coastal Systems International, Coral Gables, FL. Gerber, G.P. (2004): Cyclura carinata. In: IUCN 2010. 2010 IUCN Red List of Threatened Species. Version 2010.1 (www.iucnredlist.org) (23 March 2010). Gerber, G.P. (2007): Turks and Caicos iguana translocation program, Bahama Archipelago. Reintroduction News 26: 53-55. Gerber, G.P. (2010): Development and conservation in the Turks and Caicos Islands. San Diego Zoo Newsletter, Zoological Society of San Diego.
Amphibians and reptiles in the Turks and Caicos Islands
403
Gerber, G.P., Iverson, J.B. (2000): Turks and Caicos Iguana, Cyclura carinata carinata. In: West Indian Iguanas: Status Survey and Conservation Action Plan, Alberts, A.C., Ed., Gland, Switzerland, IUCN the World Conservation Union. Godley, B.J., Broderick, A.C., Campbell, L.M., Ranger, S., Richardson, P.B. (2004): An assessment of the status and exploitation of marine turtles in the Turks and Caicos Islands. In: An Assessment of the Status and Exploitation of Marine Turtles in the UK Overseas Territories in the Wider Caribbean, p. 180-222. Final Project Report for the Department of Environment, Food and Rural Affairs and the Foreign and Commonwealth Office. Greene, H.W. (1988): Antipredator mechanisms in reptiles. In: Biology of the Reptilia, vol. 16, Ecology B. Gans, C., Huey, R.B., Eds, New York, Alan R. Liss, Inc., 1-152. Harlan, R. (1824): Description of two new species of Linnean Lacerta not before described, and construction of the new genus Cyclura. J. Acad. Nat. Sci. Philadelphia 4: 242-251. Hedges, S.B. (2002): Morphological variation and the definition of species in the snake genus Tropidophis (Serpentes, Tropidophiidae). Bull. Nat. Hist. Mus. 68: 83-90. Hedges, S.B. (2006): Paleogeography of the Antilles and origin of West Indian terrestrial vertebrates. Ann. Missouri Bot. Gard. 93: 231-244. Hedges, S.B. (2010): Caribherp: West Indian amphibians and reptiles. Pennsylvania State University, University Park, Pennsylvania (www.caribherp.org). Hedges, S.B., Thomas, R. (1991): Cryptic species of snakes (Typhlopidae: Typhlops) from the Puerto Rico bank detected by protein electrophoresis. Herpetologica 47: 448-459. Henderson, R.W., Powell, R. (2009): Natural History of West Indian Reptiles and Amphibians. Gainesville, University Press of Florida. Homer, F. (2000): Management plan for the Princess Alexandria Land and Sea National Park Providenciales, Turks and Caicos Islands, 2000-2004 (http://sustrust.org/documents/ PALSNP%20Mgt%20Plan.pdf). Hower, L.M., Hedges, S.B. (2003): Molecular phylogeny and biogeography of West Indian teiid lizards of the genus Ameiva. Carib. J. Sci. 39: 298-306. Hudson, R.D., Alberts, A.C. (2004): The role of zoos in the conservation of West Indian iguanas. In: Iguanas: Biology and Conservation, p. 274-289. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Los Angeles, University of California Press. IUCN Iguana Specialist Group (2003): Turks and Caicos Iguana, Cyclura carinata carinata conservation and management plan, 2005-2009. Workshop Proceedings from the IUCN/SSC Iguana Specialist Group, Providenciales, Turks and Caicos Islands. IUCN (2010): 2010 IUCN Red List of Threatened Species — A Global Species Assessment. Gland, Switzerland, World Conservation Union (http:///www.iucnredlist.org). Iverson, J.B. (1978): The impact of feral cats and dogs on populations of the West Indian rock iguana, Cyclura carinata. Biol. Conserv. 14: 63-73. Iverson, J.B. (1979): Behavior and ecology of the rock iguana Cyclura carinata. Bull. Florida State Mus. Biol. Sci. 24: 175-358. Iverson, J.B. (1986): Notes on the natural history of the Caicos Islands dwarf boa, Tropidophis greenwayi. Carib. J. Sci. 22: 191-198. Jones, D. (2008): Turks and Caicos Islands’ economic structure, challenges and prospects. In: A History of the Turks and Caicos Islands, p. 222-232. Mills, C., Ed., Oxford, Macmillan. Keegan, B., Carlson, B. (2008): Mother sea turtle. Times of the Islands, Spring 2008. Knapp, C.R. (2004): Ecotourism and it’s potential impact on iguana conservation in the Caribbean. In: Iguanas: Biology and Conservation, p. 290-301. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Los Angeles, University of California Press. Lee, D.S., Ross, J.P. (2001): The Cat Island turtle, a reptile of problematic origin, including a bibliographic review of the genus Trachemys in the West Indian region. In: Proceedings of the 8th Symposium on the Natural History of the Bahamas, p. 36-47. Clark-Simpson, C., Smith, G.W., Eds, San Salvador, Bahamas, Gerace Research Center.
404
R.G. Reynolds
Lighty, R.G., Macintyre, J.G., Stuckenrath, R. (1982): Acropora palmate reef framework: A reliable indicator of sea level in the western Atlantic for the past 10,000 years. Coral Reefs 1: 25-30. Lohmann, K.J., Witherington, B.E., Lohmann, C.M.F., Salmon, M. (1997): Orientation, navigation, and natal beach homing in sea turtles. In: The Biology of Sea Turtles, p. 107-135. Lutz, P.L., Musick, J.A., Eds, Boca Raton, FL, CRC Press. Manco, B.N. (2006): Our boa belongers. Times of the Islands, Fall 2006. Manco, B.N. (2008a): Native flora of the Turks and Caicos islands. In: A History of the Turks and Caicos Islands, p. 32-40. Mills, C., Ed., Oxford, Macmillan. Manco, B.N. (2008b): Native fauna of the Turks and Caicos islands. In: A History of the Turks and Caicos Islands, p. 41-58. Mills, C., Ed., Oxford, Macmillan. Marine Turtle Specialist Group (1996): Caretta caretta. In: IUCN 2010. 2010 IUCN Red List of Threatened Species. Version 2010.1 (www.iucnredlist.org) (23 March 2010). Marvel, J. (2008): Our first colonists: The pre-Columbian people of the Turks and Caicos Islands. In: A History of the Turks and Caicos Islands, p. 79-86. Mills, C., Ed., Oxford, Macmillan. Mills, C., Ed. (2008a): A history of the Turks and Caicos Islands. Macmillan, Oxford. Mills, C. (2008b): The Turks and Caicos Islands: Overview. In: A History of the Turks and Caicos Islands, p. 1-14. Mills, C., Ed., Oxford, Macmillan. Minton, M.R., Minton, S.A. (1975): Geographic Distribution. Hemidactylus mabouia. Herpetol. Rev. 6: 116. Mitchell, N.C. (2000): Geographic Distribution. Epicrates chrysogaster chrysogaster. Herpetol. Rev. 31: 255. Mitchell, N., Haeffner, R., Veer, V., Fulford-Gardner, M., Clerveaux, W., Veitch, C.R., Mitchell, G. (2002): Cat eradication and the restoration of endangered iguanas (Cyclura carinata) on Long Cay, Caicos bank, Turks and Caicos Islands, British West Indies. In: Turning the Tide: The Eradication of Invasive Species (proceedings of the international conference on eradication of island invasives), p. 206-212. Veitch, C.R., Clout, M.N., Eds, Gland, Switzerland and Cambridge, UK, IUCN. Morgan, G.S. (1989): Fossil Chiroptera and Rodentia from the Bahamas, and the historical biogeography of the Bahamian mammal fauna. In: Biogeography of the West Indies: Past, Present, and Future, p. 685-740. Woods, C.A., Ed., Boca Raton, FL, CRC Press. Mortiz, C. (1994): Defining ‘evolutionary significant units’ for conservation. Trends Ecol. Evol. 9: 373-375. Mortimer, J.A., Donnelly, M. (2008): Eretmochelys imbricata. In: IUCN 2010. 2010 IUCN Red List of Threatened Species. Version 2010.1 (www.iucnredlist.org) (23 March 2010). Mullin, S.J., Seigel, R.A. (2009): Snakes: Ecology and Conservation. Ithaca, New York, Cornell University Press. Newsom, L.A., Wing, E.S. (2004): On land and sea: Native American uses of biological resources in the West Indies. Tuscaloosa, The University of Alabama Press. Pardee, M. (2005): DECR announces the birth of 101 baby loggerhead turtles. Times of the Islands, Fall 2007. Pregill, G.K. (1992): Systematics of the West Indian lizard genus Leiocephalus (Squamata: Iguania: Tropiduridae). Univ. Kansas Mus. Nat. Hist., Misc. Publ. 84: 1-69. Rand, A.S. (1962): Anolis scriptus Garman 1887, an earlier name for Anolis leucophaeus Garman 1888. Brevoria, Mus. Comp. Zoo. 153: 1-5. Ray, C., Sprunt IV, A. (1971): Parks and conservation in the Turks and Caicos Islands: A report on the ecology of the TC with particular emphasis upon the impact of development upon the natural environment. Unpublished report to the Turks and Caicos Islands Government, Grand Turk. Reading, C.J., Luiselli, L.M., Akani, G.C., Bonnet, X., Amori, G., Ballouard, J.M., Filippi, E., Naulleau, G., Pearson, D., Rugiero, L. (2010): Are snake populations in widespread decline? Biol. Lett. 6: 777-780. Reynolds, R.G. (2007): The snakes of the Turks and Caicos Islands. Brochure for the National Environmental Centre, Providenciales (http://web.utk.edu/∼rreyno16/tcisnakes.pdf).
Amphibians and reptiles in the Turks and Caicos Islands
405
Reynolds, R.G. (2010): Typhlops platycephalus (Caicos Blinsnake), distribution. Caribb. Herpetol. 1: 16. Reynolds, R.G., Deal, C. (2010): Where do all the babies go? Understanding the biology of juvenile Rainbow Boas. Times of the Islands, Winter 2010. Reynolds, R.G., Gerber, G.P., Burgess, J. (2010): Tropidophis greenwayi greenwayi (Caicos dwarf boa). Distribution. Herpetol. Rev. 41: 520. Reynolds, R.G., Niemiller, M.L. (2008): Expedition Report and Recommendations for the Department of Environment and Costal Resources. Unpublished Technical Report. Ministry of Natural Resources, Turks and Caicos Islands. Reynolds, R.G., Niemiller, M.L. (2009): Hemidactylus mabouia (Wood Slave). Distribution. Herpetol. Rev. 40: 452. Reynolds, R.G., Niemiller, M.L. (2010a): Island invaders: Introduced reptiles and amphibians of the Turks and Caicos Islands. Rept. Amph. 17: 117-121. Reynolds, R.G., Niemiller, M.L. (2010b): Epicrates chrysogaster (Turks Island Boa), distribution. Caribb. Herpetol. 1: 14. Reynolds, R.G., Niemiller, M.L., Manco, B.N. (In press): Epicrates chrysogaster chrysogaster (Turks Island Boa). Maximum Size. Herpetol. Rev. Richardson, P.B., Broderick, A.C., Campbell, L.M., Godley, B.J., Ranger, S. (2006): Marine turtle fisheries in the UK Overseas Territories of the Caribbean: Domestic legislation and the requirement of multilateral agreements. J. Int. Wild. Law Pol. 9: 223-246. Richardson, P.B., Bruford, M.W., Calosso, M.C., Campbell, L.M., Clerveaux, W., Formia, A., Godley, B.J., Henderson, A.C., McClellan, K., Newman, S., Parsons, K., Pepper, M., Ranger, S., Silver, J.J., Slade, L., Broderick, A.C. (2009): Marine turtles in the Turks and Caicos Islands: remnant rookeries, regionally significant foraging stocks, and a major turtle fishery. Chelonian Conserv. Biol. 8: 192-207. Ricklefs, R., Bermingham, E. (2007): The West Indies as a laboratory of biogeography and evolution. Phil. Trans. R. Soc. B 363: 2393-2413. Rudd, M.A. (2003): Fisheries landings and trade in the Turks and Caicos Islands. Fisheries Centre Research Reports 11: 149-161. Ryder, O.A. (1986): Species conservation and systematics: The dilemma of subspecies. Trends Ecol. Evol. 1: 9-10. Sadler, N. (2008a): The Bahamas years (1764-1848; 1962-1973). In: A History of the Turks and Caicos Islands, p. 102-110. Mills, C., Ed., Oxford, Macmillan. Sadler, N. (2008b): Turks and Caicos shipwrecks. In: A History of the Turks and Caicos Islands, p. 126-131. Mills, C., Ed., Oxford, Macmillan. Sadler, N. (2008c): The anti-Columbus landfall argument. In: A History of the Turks and Caicos Islands, p. 92-101. Mills, C., Ed., Oxford, Macmillan. Schwartz, A. (1963): A new subspecies of Tropidophis greenwayi from the Caicos bank. Brevoria, Mus. Comp. Zool. 194: 1-6. Schwartz, A. (1967): The Leiocephalus (Lacertilia, Iguanidae) of the southern Bahama islands. Ann. Carnegie Mus. 39: 153-185. Schwartz, A. (1968): The geckoes (Sphaerodactylus) of the southern Bahama islands. Ann. Carnegie Mus. 39: 227-271. Schwartz, A., Crombie, R.I. (1975): A new species of the genus Aristelliger (Sauria: Gekkonidae) from the Caicos Islands. Proc. Biol. Soc. Wash. 88: 305-313. Schwartz, A., Henderson, R.W. (1992): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. Gainesville, University of Florida Press. Sealey, N.E. (2006): Bahamian landscapes, 3rd edition. Oxford, Macmillan-Caribbean. Seidel, M.E. (1988): Revision of the West Indian emydid turtles (Testudines). Amer. Mus. Novit. 2918: 1-41.
406
R.G. Reynolds
Seidel, M.E. (1996): Current status of biogeography of the West Indian turtles in the genus Trachemys (Emydidae). In: Contributions to West Indian Herpetology: A Tribute to Albert Schwartz, p. 169174. Powell, R., Henderson, R.W., Eds, Ithaca New York, Society for the Study of Amphibians and Reptiles. Seminoff, J.A. (2004): Chelonia mydas. In: IUCN 2010. 2010 IUCN Red List of Threatened Species. Version 2010.3 (www.iucnredlist.org) (23 March 2010). Sheplan, B.R., Schwartz, A. (1974): Hispaniolan Boas of the genus Epicrates (Serpentes: Boidae) and their Antillean relationships. Ann. Carnegie Mus. 45: 57-141. Smith, G.R. (1992a): Return of Cyclura carinata to Pine Cay, Turks and Caicos Islands, BWI. Herpetol. Rev. 23: 21-23. Smith, G.R. (1992b): Sexual dimorphism in the curly-tailed lizard, Leiocephalus psammodromus. Caribb. J. Sci. 28: 99-101. Smith, G.R. (1994): Observations on activity in two lizards (Anolis scriptus and Leiocephalus psammodromus). Bull. Maryland Herpetol. Soc. 30: 120-125. Smith, G.R. (1995): Observations on perch use in two lizards (Anolis scriptus and Leiocephalus psammodromus). Herpetol. J. 5: 285-286. Smith, G.R., Iverson, J.B. (1993): Reproduction in the curly-tailed lizard Leiocephalus psammodromus from the Caicos Islands. Can. J. Zool. 71: 2147-2151. Tolson, P.J. (1987): Phylogenetics of the boid snake genus Epicrates and Caribbean vicariance theory. Occ. Papers Mus. Zool. Univ. Michigan 715: 1-66. Tolson, P.J., Henderson, R.W. (1993): The Natural History of West Indian Boas. Taunton, Somerset, England, R & A Publishing. Tolson, P. J., Henderson, R.W. (2006): An overview of snake conservation in the West Indies. Appl. Herpetol. 3: 345-356. Tsui, B. (2005): In Turks and Caicos, luxury now joins natural beauty. International Herald Tribune. Travel Section. 2/4/2005. Turks and Caicos Islands Department of Planning and Statistics. (2010): Population and vital statistics (http://www.depstc.org/quickstats/qstat1.html). Veitch, C.R., Clout, M.N., Eds. (2002): Turning the Tide: The Eradication of Invasive Species (proceedings of the international conference on eradication of island invasives). Occasional Paper of the IUCN Species Survival Commission No. 27. Gland, Switzerland and Cambridge, UK, IUCN. Waples, R.S. (1991): Pacific Salmon, Oncorhynchus spp., and the definition of “species” under the Endangered Species Act. Mar. Fish. Rev. 53: 11-22. Webb, J.K., Brook, B.W., Shine, R. (2002): Collectors endanger Australia’s most threatened snake, the broad-headed snake Hoplocephalus bungaroides. Oryx 36: 170-181. Welch, M.E., Gerber, G.P., Davis, S.K. (2004): Genetic structure of the Turks and Caicos rock iguana and its implications for species conservation. In: Iguanas: Biology and Conservation, p. 58-70. Alberts, A.C., Carter, R.L., Hayes, W.K., Martins, E.P., Eds, Los Angeles, University of California Press. Wilson, B.S., Koenig, S.E., Van Veen, R., Miersma, E., Rudolph, D.C. (2010): Cane toads a threat to West Indian wildlife: mortality of Jamaican boas attributable to toad ingestion. Biol. Invasions 13: 55-60. Wing, E.S., Scutter, S.J. (1983): Animal exploitation by people living on a tropical marine edge. In: Animals and Archeology. Grigson, C., Clutton-Brock, J., Eds, BAR International Series 183. Oxford, British Archaeological Reports.
Accepted: October 4, 2010 (AH).
Conservation status of reptiles and amphibians in the U.S. Virgin Islands Renata J. Platenberg1,2 , Ralf H. Boulon, Jr.3 1 Division
of Fish and Wildlife, Department of Planning and Natural Resources, 6291 Estate Nazareth, St. Thomas, US Virgin Islands, 00802, USA 2 Corresponding author; e-mail:
[email protected] 3 Virgin Islands National Park/Coral Reef National Monument, 1300 Cruz Bay Creek, St. John, USVI, 00830, USA Abstract. The United States Virgin Islands (USVI) are situated along the Puerto Rico Bank near the eastern terminus of the Greater Antilles in the northern Caribbean, and comprise four major inhabited islands and more than 50 satellite cays. The small sizes of the islands, their relative isolation, and unpredictable weather events such as hurricanes make natural populations vulnerable to humaninduced impacts of habitat loss and the introduction of invasive exotic species. There are currently 30 extant species of reptiles and amphibians in the USVI, 24 of which are native. Four species have been extirpated from all or part of their former distribution, four species are endangered, one is threatened, and eight are considered data deficient. Five reptiles and amphibians are fairly recent (within the last 150 years) introductions. Species of particular conservation concern are the St. Croix ground lizard (Ameiva polops), Virgin Islands tree boa (Epicrates monensis granti), and sea turtles, and recovery efforts are underway for these species. Habitat protection and reduction of exotic predators are important conservation actions required to protect herpetofauna, combined with ecological studies and population monitoring. Key words: Amphibians; conservation; reptiles; sea turtles; US Virgin Islands.
Introduction Located near the eastern terminus of the Greater Antillean chain of islands in the northern Caribbean Sea, the United States Virgin Islands (USVI) comprise four major inhabited islands and more than 50 smaller offshore cays with a total land area of about 353 km2 (fig. 1). St. Thomas (74 km2 ) and St. John (50 km2 ) are the two major islands to the north, situated on the Puerto Rico Bank to the east of Puerto Rico and its eastern offshore islands (Culebra and Vieques), and west of the British Virgin Islands (BVI). Separated by a distance of roughly 3 km, both islands are
408
R.J. Platenberg, R.H. Boulon, Jr.
Figure 1. Location of U.S. Virgin Islands.
mountainous (up to 477 m high on St. Thomas, 387 m on St. John), thus attracting a moderate amount of precipitation, ca. 110 cm/yr at Trunk Bay, St. John (R.H. Boulon, unpubl. data) and 97 cm/year in Red Hook, St. Thomas (Division of Fish and Wildlife data 2001-2005). Their coastlines are irregular with numerous small bays and offshore cays. Water Island comprises a land mass of 2 km2 located at the mouth of St. Thomas harbor. The more isolated St. Croix (217 km2 ), ca. 64 km to the south, is generally flatter (up to 355 m high in the hilly northwest) and drier, with fewer bays and offshore cays. Combined, all offshore cays comprise about 3% of the territory’s area (12 km2 ).
Conservation status of reptiles and amphibians in the U.S. Virgin Islands
409
During the Pleistocene, St. Thomas, St. John, their satellite cays, the BVI, and Puerto Rico (but not St. Croix) were connected via a single land mass approximately twice the area of Puerto Rico today (Heatwole and MacKenzie, 1967). Rising water levels had separated the islands into the archipelago of the Puerto Rico Bank by ca. 8000 years before present, with each island retaining a high degree of faunal similarity. The species assemblage on St. Croix reflects its isolation, with a higher proportion of endemic species. Historically, the islands have been important for human colonization and settlement within the Caribbean. The first inhabitants are dated to ca. 1500 BC and limited agriculture was in practice by Pre-Taino Indians by ca. 600 AD, with a heavy reliance on marine resources for food. By the time Columbus “discovered” the islands in 1492, the Island Caribs had already become established on St. Croix (Brewer, 2005). St. Thomas, St. John and St. Croix were under Danish rule from 1672, during which time there was extensive deforestation to make way for sugar cane plantations. Control of the Danish West Indies passed to the U.S. in 1917, which established a naval base active through World War II. Tourism accelerated in the 1950s, and the USVI has subsequently become a major tourist destination noted for taxfree shopping and marine recreation. Currently, the territory receives two million visitors annually (http://www.cia.gov/cia/publications/factbook/geos/vq.html), with up to 18,000 arriving daily on cruise ships alone. The demands for space by a rapidly growing human population of over 100,000 have resulted in extensive loss and degradation of natural ecosystems in the USVI, especially on densely populated St. Thomas. Sprawling residential communities and commercial centers have replaced or fragmented much of the native forest. Resorts, condominiums, and marinas have been constructed on coastal wetlands and marine recreational activities have damaged fragile mangrove swamps, coral reefs, and seagrass beds. Human development has led to increased pollution, particularly nonpoint source pollution that ultimately contaminates wetlands and marine environments. The introduction of exotic and feral animals such as mongooses, cats, dogs, donkeys, chickens, pigs, and goats and the spread of exotic landscape plants has had a major impact on wildlife and habitats. Moreover, the natural ecosystems are subject to the effects of short- and long-term wet and dry climatic cycles, and to periodic disturbances from hurricanes, including Hugo in 1989 and Marilyn in 1995. Most of the land within the USVI is divided into small privately-owned parcels that make the implementation of habitat conservation measures difficult. As a U.S. territory, the USVI is subject to U.S. federal regulations. Two that are of particular relevance to the herpetofauna within the territory are the Endangered Species Act of 1973 (ESA) and the Coastal Zone Management Act of 1972 (CZM). The ESA provides protection to listed species, while the CZM restricts activities that are detrimental to habitats and species in coastal areas. The Virgin Islands Indigenous and Endangered Species Act of 1990 further protects all native wildlife in the territory. Enforcement of these regulations, however, is inconsistent, and violations often go unreported, uninvestigated, or not penalized.
410
R.J. Platenberg, R.H. Boulon, Jr.
Despite the burgeoning human population, the USVI contains several protected areas of high regional importance. Owned by the U.S. National Park Service (NPS), approximately 56% of St. John is contained within the Virgin Islands National Park (2,816 ha of land and 2,287 ha of water), comprising forests and watersheds extending into the marine environment. Buck Island Reef National Monument (69 ha of land and 7,424 ha of water), off northeastern St. Croix, also protects valuable marine and terrestrial resources, including important hawksbill turtle nesting and foraging areas. The Virgin Islands Coral Reef National Monument (5,008 ha of submerged lands) south and east of St. John protects marine habitats from mangrove shorelines and seagrass beds to deep coral reefs and algal plains. The Sandy Point National Wildlife Refuge (146 ha) on St. Croix, owned by the U.S. Fish and Wildlife Service (USFWS), provides nesting sites for the largest breeding population of leatherback turtles in the U.S. (Boulon et al., 1996), and The Nature Conservancy (TNC)-owned Jack’s and Isaac’s Bays and East End Marine Park protects nesting areas for green and hawksbill turtles. On St. Thomas, the ca. 130 ha Magen’s Bay Preserve, jointly owned by the USVI government and TNC, protects an entire forested watershed important for migratory birds and herpetofauna (TNC, 2005). In total, 41 cays, owned by the USVI government, NPS, or USFWS, are protected as wildlife reserves (a complete list of protected areas can be found in Platenberg et al., 2005). Ecotourism activities within terrestrial environments in the USVI are limited because the majority of the tourism interest is focused on the marine environment. The most important public participation opportunity occurs at Sandy Point refuge on St. Croix, where Earthwatch volunteers monitor the beach for leatherback nesting, the USFWS offers educational programs for local schoolchildren, and West Indies Marine Animal Research and Conservation Service, a local nongovernmental organization, provides training for sea turtle conservation within the local community. On St. John, the NPS offers guided tours along forested trails, enabling ample reptile and amphibian viewing opportunities. Out of a total of 21 extant native terrestrial reptile and amphibian species, four have been extirpated from all or part of their former distribution in the USVI (Virgin Islands bo-peep, St. Croix ground lizard, slipperyback skink, and Puerto Rican racer; scientific names provided under species accounts), one is in serious decline (Virgin Islands tree boa), and eight are deficient in information regarding distribution, abundance, and ecological parameters (whistling frog, mute frog, redfooted tortoise, St. Croix dwarf gecko, slipperyback skink, garden snake, blind snake, and amphisbaena). A full 25% of the terrestrial herpetofauna currently recorded in the USVI is non-native. In spite of loss of nesting and foraging habitat, two of the four species of sea turtles (hawksbill and green) are exhibiting apparently stable population numbers although not anywhere near historic numbers. The leatherback, however, is making a recovery towards historic nesting levels. The loggerhead may be considered as a rare transient and not a resident species.
Conservation status of reptiles and amphibians in the U.S. Virgin Islands
411
Species Accounts Table 1 summarizes the species currently recorded in the USVI and management recommendations. The following accounts are based on information from MacLean (1982), Schwartz and Henderson (1991), Rice et al. (2005), and personal field observations by the authors. This work represents the first review of herpetofauna conservation status in the USVI since MacLean (1982). Amphibia Leptodactilidae. The Antillean frog (Eleutherodactylus antillensis) inhabits woodlands and forests up to the highest elevations in the USVI. The whistling frog (E. cochranae) inhabits more xeric woodlands, sheltering in bromeliads and coconut leaf sheaths, and occurs higher in trees and the canopy than the Antillean frog. Both species are sympatric in the USVI, although the whistling frog is absent from St. Croix, and its distribution and abundance is poorly documented. The endemic mute frog (E. lentus) has a limited distributional range that is restricted to the USVI. It is larger than the previous two species, and inhabits open semi-xeric habitats, sheltering under surface debris (fig. 2). This species is often encountered in agricultural areas on St. Thomas. Due to its small geographic range and current levels of habitat modification within its range, such as habitat loss from development or conversion, the mute frog has been listed as Endangered on the Red List of Threatened Species (IUCN et al., 2004), and there is insufficient information on its abundance and distribution. The Virgin Islands bo-peep (E. schwartzi) is endemic to St. John and BVI and is also listed as Endangered on the Red List (IUCN et al., 2004). It is apparently extirpated from the USVI (Philibosian and Yntema, 1977). The white-lipped frog (Leptodactylus albilabris) is a medium-sized frog native to Puerto Rico, USVI, and BVI. Although abundant and widespread in the USVI, there are indications this frog is in decline in the BVI (Perry and Gerber, 2006). This semi-aquatic species occupies habitats near streams, ditches, marshes, and other freshwater sources. Bufonidae. The Puerto Rican crested toad Bufo (Peltophryne) lemur is a medium sized toad (to 120 mm) inhabiting semi-arid rocky areas in lowlands within Puerto Rico and BVI. This species is listed on the Red List as Critically Endangered throughout its range (IUCN et al., 2004). One account of this toad occurring on St. John has been published (Norton, 1997; 1998), but this sighting has not been confirmed by any other observations and the species is believed to be extirpated throughout the USVI. Testudines (excluding sea turtles — see Species of Concern) Testudinidae. The terrestrial red-footed tortoise (Geochelone carbonaria) is widespread in tropical South America, and was likely introduced to the West Indies by the Pre-Columbian Indians centuries ago, and potentially augmented by introductions by early European settlers and more recently as discarded or escaped pets. The
T, J, C, W T, J, W T, J, C T, J, C J T, J, C T, J, C J T, C, J T, J, C T, J, C, cays T, J, C, cays T, J, C, cays C (Buck Is.) T, J, C, W T, C, J T, J, W, cays C (cays only)
Amphibia: Leptodactylidae Eleutherodactylus antillensis E. cochranae E. coqui (I) E. lentus E. schwartzi Leptodactylus albilabris
Amphibia: Hylidae Osteopilus septentrionalis (I)
Amphibia: Bufonidae Bufo lemur Bufo marinus (I)
Amphisbaenia: Amphisbaenidae Amphisbaena fenestrata
Testudines: Dermochelyidae Dermochelys coriacea
Testudines: Cheloniidae Eretmochelys imbricata Chelonia mydas Caretta caretta
Testundines: Testudinidae Geochelone carbonaria
Testudines: Emydidae Trachemys scripta (I)
Sauria: Teiidae Ameiva exsul A. polops FE
FE FT FT
FE
FT
High concern
Mild concern
Data deficient
High concern High concern
High concern
Data deficient
Extirpated High concern
High concern
Data deficient Mild concern Data deficient Extirpated
Monitor Population enhancement, recovery, control predators
Control
Survey
Monitor Monitor Monitor
Monitor
Ecological study, monitor
Monitor, control
Monitor, control
Monitor Monitor Ecological study Ecological study Survey Monitor
Table 1. Amphibian and reptile species present within the U.S. Virgin Islands. Island abbreviations: T = St. Thomas, J = St. John, C = St. Croix, W = Water Island. Statutory Status: FE = Federally Endangered, FT = Federally Threatened, LE = Locally Endangered. (I) = Introduced. Species Island Statutory status Management concern Conservation action 412 R.J. Platenberg, R.H. Boulon, Jr.
C T, J, W, cays T, J, W, cays T, J, W, cays Cays only T, J, C, W C T, J, C, W, cays T, J, C, W, cays T W, cays C T, J T T, J, C, cays
Sauria: Scincidae Mabuya sloanii complex
Sauria: Iguanidae Iguana iguana
Sauria: Gekkonidae Sphaerodactylus beattyi S. macrolepis Hemidactylus mabouia (I)
Serpentes: Colubridae Elaphe guttata (I) Alsophis portoricensis A. sanctaecrucis Arrhyton exiguum
Serpentes: Boidae Epicrates monensis granti
Serpentes: Typhlopidae Typhlops richardii
Table 1. (Continued). Island
Sauria: Polychrotidae Anolis acutus A. cristatellus A. pulchellus A. stratulus
Species
FE
LE
Statutory status
Data deficient
High concern
Mild concern High concern Extinct Data deficient
Data deficient
High concern
Management concern
Systematic study, monitor
Systematic study, ecological study, recovery, monitor
Monitor
Survey, monitor, control Control predators
Survey
Systematic study
Systematic study, survey, monitor
Monitor
Conservation action
Conservation status of reptiles and amphibians in the U.S. Virgin Islands 413
414
R.J. Platenberg, R.H. Boulon, Jr.
Figure 2. The endemic Eleutherodactylus lentus (mute frog) is common within many habitat types in the USVI. Photo by R.J.P. (Colour original — see www.ahailey.f9.co.uk/appliedherpetology/ cariherp.htm.)
status of this species is unknown in the USVI, where it is infrequently encountered. A reported sighting of the yellow-footed tortoise (G. denticulata) on St. John has yet to be verified. Amphisbaenia Amphisbaenidae. The Virgin Islands amphisbaena (Amphisbaena fenestrata) is also known locally as the blind snake or worm lizard. It is usually found under stones and rocks on heavily wooded hillsides, and under debris associated with Danish plantation ruins. Almost nothing is known about its ecological requirements, and its abundance and distribution within the USVI is unknown. It is known to aggressively bite when captured and may prey on virtually any organism it encounters smaller than itself. Observations of this species are limited to mesic habitats at higher elevations, although it likely exists elsewhere. Sauria Gekkonidae. Two species of dwarf geckos occur in the USVI. The extremely abundant but often unnoticed common dwarf gecko (Sphaerodactylus macrolepis) occurs on the four major islands, including Water Island, and on some of the
Conservation status of reptiles and amphibians in the U.S. Virgin Islands
415
cays, and is distributed across Puerto Rico, BVI, and southward into the Lesser Antilles. It primarily inhabits mesic forested habitats in leaf litter and under logs and other surface debris. Population densities on Guana Island, BVI, may reach 67,000 individuals per hectare, one of the highest densities known for any lizard (Rodda et al., 2001). The St. Croix dwarf gecko (S. beattyi) is restricted to certain areas in St. Croix and its satellite cays, and whose non-overlapping range with S. macrolepis includes more xeric habitats. Its status is unknown. The tropical house gecko (Hemidactylus mabouia) is widely distributed across the West Indies and eastern South America, most likely introduced from Africa via slave ships. This nocturnal species primarily occurs around human structures where it forages for insects under artificial lighting. Another introduced lizard, the fattailed gecko (Thecadactylus rapicauda) is only present on St. Croix, although its distribution and abundance is undocumented. The possible impact of these species on native reptile and amphibian populations is unknown. Iguanidae. The green iguana (Iguana iguana) is not likely to have originated in the USVI. The iguana is native to Central and South America, and its present distribution extends across Puerto Rico, USVI, BVI and the Lesser Antilles. It is thought that this species was introduced to the islands by Pre-Colombian Indians, possibly to replace the native rock iguana (see below) as a food source, although it may also have floated here. The iguana is a popular pet that is occasionally intentionally or unintentionally released, and there have likely been several introductions of this species from different locations over time. Under the Virgin Islands Code, it is illegal to kill iguanas (and agoutis, Dasyprocta spp.); this measure was probably initiated to prevent the poaching of these animals for food. The green iguana is widespread and abundant in the USVI on all main islands, but absent from most of the cays. The Anegada rock iguana (Cyclura pinguis) is native to Anegada, BVI, although its historical range may have included the entire Puerto Rican Bank. It is known from one fossil remain in a midden at Magen’s Bay, St. Thomas (Pregill, 1981), although there is some controversy as to whether this species ever inhabited the USVI (J.D. Lazell and G. Gerber, pers. comm.). Successful translocations from Anegada to Guana Island and other islands in the BVI have occurred (Goodyear and Lazell, 1994; Perry and Gerber, 2006). There are currently no plans to establish the rock iguana in the USVI. Polychrotidae. Four species of Anolis, one of the most diverse and abundant lizard genera in the Caribbean, occupy the USVI. Three species occupy St. Thomas and St. John: the crested (Anolis cristatellus), barred (A. stratulus), and grass anoles (A. pulchellus), all common species across the Puerto Rico Bank, while St. Croix has only the endemic St. Croix anole (A. acutus). The crested anole is one of the best-studied lizards on the Puerto Rico Bank (e.g., Philibosian, 1975; Chandler and Tolson, 1990; Leal and Rodríguez-Robles, 1997;
416
R.J. Platenberg, R.H. Boulon, Jr.
Perry et al., 2000; Genet, 2002; Jensen, 2002; Perry et al., 2004). It is widespread and abundant on St. Thomas, St. John, Water Island, and most of the adjacent cays. This is primarily a forest dweller, although it also inhabits coastal areas and is common around human habitation. The barred anole occupies the higher limbs and trunks of trees, and as such is more difficult to locate. This lizard occurs in xeric to mesic forests and is fairly common on St. Thomas, St. John, Water Island, but only some of the cays. The grass anole inhabits open, exposed grassy areas with some scrub layer, and is present and locally abundant on St. Thomas, St. John, and Water Island, although rare on the adjacent cays. The abundant St. Croix anole inhabits a wide range of habitat types and structures. Adults are sedentary, showing little vagility once territories are established. Scincidae. The slipperyback skink (Mabuya sloanii) is listed as territorially endangered due to its apparent absence from the main islands, although it does occur on some cays (fig. 3). The absence of this species from the major islands is likely due to predation by the small Indian mongoose (Herpestes javanicus). This lizard is found in low, dense vegetation on the beaches and lower slopes of cays, sheltering in grass and brush litter, under rocks and other surface debris, in rocky fissures, and on branches of low shrubs. The distributional range of this species includes the Turks and Caicos Islands, Jamaica, Hispaniola, Puerto Rico, USVI and BVI, although it is poorly documented in the USVI. The systematics of this species
Figure 3. Mabuya sloanii (slipperyback skink) is now only found on the offshore islands, most likely due to negative influences of the introduced mongoose. Photo by R.J.P. (colour original — see www.ahailey.f9.co.uk/appliedherpetology/cariherp.htm).
Conservation status of reptiles and amphibians in the U.S. Virgin Islands
417
requires additional study, as there may be more than one genetically distinct form in the Virgin Islands (Mayer and Lazell, 2000). Teiidae. Two species of ground lizards occur in the USVI, the common ground lizard (Ameiva exsul), found on St. Thomas and St. John, and the endemic St. Croix ground lizard (A. polops; see Species of Concern, below). The distribution of the common ground lizard is limited to the Puerto Rico Bank. It is abundant on St. Thomas, St. John, Water Island, and many of the cays, found primarily in the lower elevations in xeric open areas with sandy soils, leaf litter and scrubby vegetation. This lizard adapts well to human presence, and is often observed foraging on beaches and around houses and basking on roads. Habitat modification may actually increase available habitat for this species, by opening up areas previously too densely vegetated for occupation. The common ground lizard has recently been introduced to St. Croix (W.C. Coles, pers. comm.). In its current range it poses no threat to the St. Croix ground lizard, which has been extirpated from the main island and is restricted to the cays, however, any range expansion on St. Croix could pose serious implications and should be closely monitored and controlled. Serpentes (excluding tree boa — see Species of Concern) Colubridae. The Puerto Rican racer (Alsophis portoricensis) is apparently extirpated from St. Thomas and St. John, although these snakes are regularly observed on Water Island and several of the cays. The likely reason for its absence from the two main islands is the presence of the mongoose, a cause of decline of Alsophis elsewhere in the West Indies (Powell and Henderson, 2005). The snake is not present on St. Croix. Its distribution encompasses Puerto Rico, USVI, and BVI. This snake is an active diurnal forager, preying primarily on anoline lizards, as well as geckos, ground lizards, small iguanas and frogs. It is both ground dwelling and arboreal, and is frequently encountered basking during the hotter parts of the day in xeric habitats. The St. Croix racer (Alsophis sanctaecrucis), endemic to St. Croix, is believed to be extinct (Philibosian and Yntema, 1977). The small garden snake (Arrhyton exiguum) is widespread across the Puerto Rico Bank, and absent from St. Croix. This mesophilic species occurs in coastal woodlands and moist upland forest under logs, rocks, and surface debris. It is occasionally encountered as it travels along the forest floor or along roads, most frequently during rainy periods. Its diet consists of small vertebrates: frogs, dwarf geckos, and juvenile anoline lizards, but little else is known about this snake. Its distribution and abundance is poorly documented in the USVI. Typhlopidae. The blind snake (Typhlops richardii), also known locally as the worm snake, is small, highly secretive, and primarily fossorial. This species is present on all three major islands of the USVI and across the Puerto Rico Bank in both xeric and mesic wooded areas, although it probably prefers xeric woodland
418
R.J. Platenberg, R.H. Boulon, Jr.
habitats with sandy soils. It burrows in loose dirt, and shelters under rocks, boards, and other surface refugia, feeding on termite and ant pupae, larvae, eggs, and adults. Although not previously recorded on the cays, two individuals were observed on an island off of St. John in 2005, and they are likely to have a wider distribution in the USVI than previously thought. There may be more than one genetically distinct species of Typhlops in the USVI (S.B. Hedges, pers. comm.), and a systematic study is needed.
Species of Concern Sea turtles The USVI is known to have four species of sea turtles present for various portions of each species’ life history. Hawksbill (Eretmochelys imbricata) and green (Chelonia mydas) sea turtles are found in USVI waters year-round, both foraging in nearshore habitats and nesting on sandy beaches. The leatherback turtle (Dermochelys coriacea) nests in the USVI, predominantly on St. Croix at Sandy Point, the site of the largest U.S. nesting population of the species. During the period between seasonal nestings, this species ranges throughout the North Atlantic Basin. Loggerhead sea turtles (Caretta caretta) are known only from rare sightings and just a few documented nestings on Buck Island, St. Croix (Z. Hillis-Starr, pers. comm.). Sea turtles historically have played an important role in the culture and economy of the USVI. They are reported to have been so abundant at one time that they would dig up previously laid nests while nesting and fishermen would regularly run into them in small hand-propelled fishing boats. Although the islands are still characterized by many small and often undeveloped beaches, with very few exceptions, sea turtle nesting densities are low throughout the territory. As well, there are many areas where one may consistently observe green turtles and/or hawksbills foraging, but nowhere does the density approach historically reported levels. The reasons for this decline are many. It started with subsistence harvest and evolved into commercial harvest for eggs and meat. A major decline of hawksbills occurred with the advent of the “tortoiseshell” trade when turtles were taken solely for the financial rewards of selling the scutes for jewelry and other articles of ornamentation. At this time the waste was truly wanton, with carcasses abandoned on the shoreline after scute removal. After World War II the demand for tortoiseshell decreased due to increased use of plastics. However, the growing human population on the islands placed an increasing impact on the remaining sea turtle populations through subsistence harvest. The increase in tourism also affected sea turtle populations through restaurant demand and loss of coastal nesting habitat to hotels and resorts. Nest predation by introduced mongooses and dogs has also been a major contributor to the decline in turtle populations (Nellis and Small, 1983). In 1972 the USVI outlawed the take of hawksbill and leatherback turtles. This was superceded by the 1973 U.S. Endangered Species Act, which added the green turtle
Conservation status of reptiles and amphibians in the U.S. Virgin Islands
419
as a threatened species in 1978. While this protection for sea turtles in the USVI has had a positive effect on their juvenile foraging populations, the nesting populations of hawksbill and green turtles have been slow to respond, compared to leatherback populations at Sandy Point, St. Croix. This may be due to slower growth rates to maturity and greater sensitivity to development impacts on their nesting beaches. Hawksbill and green turtle nests also suffer greater predation from mongooses and dogs than the much deeper laid eggs of the leatherback. Conservation efforts for sea turtles in the USVI have increased substantially over the past two decades. Sandy Point National Wildlife Refuge was established to protect the primary nesting population of leatherback turtles in the U.S., which has grown from less than 30 individual nesters per year in the early 1980s to nearly 200 individual nesters per year presently (Eckert and Eckert, 1983; Garner et al., 2005). A tagging program to track nesting individuals has been in place at this rookery since 1977, resulting in long-term trend assessment, showing that leatherbacks are on the increase (Dutton et al., 2005). Other beaches on St. Croix have been acquired by TNC to protect nesting populations of hawksbill and green turtles. NPS units (Buck Island Reef National Monument and VI National Park) provide protection for turtles within their jurisdictions. Greater territorial enforcement presence around the islands has reduced poaching of eggs and turtles to relatively low levels (S.A. Garner, pers. comm.). Education programs and conservation groups have begun to develop a sense of stewardship for these species in the local human population that was not present two decades ago. As more turtles reach maturity in USVI waters, we anticipate an increase in nesting populations and a recovery to sustainable population levels. St. Croix ground lizard The endemic St. Croix ground lizard was once widespread along the coast of St. Croix and nearby islands. Last recorded on the main island in 1968 (Philibosian and Ruibal, 1971), it has since been extirpated from St. Croix and Buck Island by the lizard’s primary predator, the introduced mongoose (Baskin and Williams, 1966; Philibosian and Ruibal, 1971; Henderson, 1992). Natural populations have persisted on Protestant Cay (1.2 ha) and Green Cay (5.2 ha), which are free of mammalian predators. The impacts of the mongoose and housing and resort development in the lizard’s habitat, coupled with the vulnerability of the small isolated cay populations to introduced predators and stochastic events, caused the St. Croix ground lizard to be listed as endangered in 1977, with Protestant and Green cays designated as critical habitat (Dodd, 1978). The natural habitat on Protestant Cay, however, has almost completely been displaced by a hotel, associated infrastructure, and exotic landscaping vegetation, and only 20% of the cay is now occupied by 30-36 lizards (McNair, 2003; McNair and Coles, 2003). Green Cay (owned by USFWS) is undeveloped and harbors the largest population of the lizards, estimated at between 180-400 animals, although numbers may have declined from indirect effects of
420
R.J. Platenberg, R.H. Boulon, Jr.
hurricanes since Hugo in 1989 that have altered habitat structure (McNair, 2003; McNair and Lombard, 2004). Individuals taken from Protestant Cay were released on Buck Island (69 ha), a National Monument under the jurisdiction of the NPS, in the late 1960s (Philibosian and Ruibal, 1971) and on Ruth Island (7.5 ha), a dredgespoil cay off the south coast, in the early 1990s (Knowles, 1990, 1997). The Buck Island population did not persist, likely due to unsuccessful attempts at mongoose eradication (Knowles, 1990; Meier et al., 1993), but the population on Ruth Island has increased (McNair and Mackay, 2005). The St. Croix ground lizard thrives in dry, rocky coastal areas with sandy soils, and tolerates a considerable amount of disturbance in beach and dry forest habitats. Key habitat components comprise bare ground (including sandy, exposed areas), high densities of leaf and tidal litter, woody debris, scrub and forest with intermediate to high woody stem densities, and burrows including those made by crabs (Philibosian and Ruibal, 1971; Meier et al., 1993; McNair, 2003; McNair and Coles, 2003; McNair and Lombard, 2004). Efforts are underway to eliminate the rats (Witmer et al., 2002) and exotic plant species (D. Clark, NPS, pers. comm.) on Buck Island and to eliminate the rats that have recently recolonized Green Cay (C. Lombard, pers. comm.). Future conservation plans for the St. Croix ground lizard include restoration of the quality and amount of habitat on Protestant Cay, removal of exotic vegetation from Green Cay and Buck Island, and translocation of animals from Green Cay and/or Ruth Island to Buck Island following confirmation of eradication of the mongoose and rats. On-going studies on abundances, habitat associations, and behavior are being conducted on Green and Ruth cays (McNair and Lombard, 2004; McNair and Mackay, 2005). Virgin Islands tree boa The Virgin Islands tree boa (Epicrates monensis granti), listed by the USFWS as an endangered species in 1979 (USFWS, 1980), is a semi-arboreal nocturnal snake with an extremely disjunct distribution indicative of a long history of extirpation and decline (fig. 4). In the USVI it is restricted to eastern St. Thomas (Nellis et al., 1983), although it is present in some locations in Puerto Rico and its satellite islands and BVI (Mayer and Lazell, 1988; Tolson, 1992a; P.J. Tolson, pers. comm.). It has been reported from nearby cays and St. John, but formal surveys have failed to locate any animals (P.J. Tolson, unpubl. data). Its optimal habitat is subtropical dry forest with an interlocking canopy, where it forages at night on lizards sleeping in trees and seeks refuge during the day in termite nests, tarantula holes, or under rocks and debris. The boa’s long-term survival in the highly developed and densely populated eastern end of St. Thomas, where it is uncommon and presumably declining, is unlikely. Relatively unrestricted development has severely altered its habitat, and there are few locations remaining with intact forest. The increasing volume of vehicular traffic increases the risk of road fatalities and increased encounters
Conservation status of reptiles and amphibians in the U.S. Virgin Islands
421
Figure 4. The U.S. Federally Endangered Epicrates monensis granti (Virgin Islands tree boa) is only found on the eastern end of St. Thomas, where habitat loss to development is occurring at unprecedented levels. Photo by R.J.P. (Colour original — see www.ahailey.f9.co.uk/appliedherpetology/ cariherp.htm.)
with humans often result in wanton killing. Furthermore, the boa is susceptible to predation by domestic cats and rats, which thrive in developed areas. The boa’s reproductive strategy of high female longevity, biennial reproduction, and small litter size render its population highly vulnerable to such threats. To address these threats, a recovery plan mandated evaluation of potential sites for release and reintroduction of the boa within its historical range (USFWS, 1986). The plan also mandated a captive breeding program, which was initiated in 1986 by the Toledo Zoological Society in cooperation with the USFWS, the Puerto Rico Department of Natural and Environmental Resources and the USVI Division of Fish and Wildlife (Tolson, 1989, 1990). In 1993-1994, captive bred boas were released onto a satellite cay off Puerto Rico (P.J. Tolson, pers. comm.), and in 2002 captive bred boas were released on an undisclosed cay in the USVI. Additional boas captured in eastern St. Thomas have since been translocated to this cay. This population is stable, with reproduction occurring, although the location has likely reached its carrying capacity for boas (Tolson, 2005). Although the release of boas to this cay has led to the establishment of a single small population, this situation is not ideal for the long-term survival of the species in the USVI. This isolated population is extremely vulnerable to stochastic
422
R.J. Platenberg, R.H. Boulon, Jr.
events. Other suitable release sites must be located and enhanced where necessary, by removing mammalian predators such as rats, in order to establish new boa populations. Additionally, threats to the natural population on St. Thomas need to be minimized by protecting available habitat. Studies on population dynamics, habitat use, and distribution need to be conducted on St. Thomas, and critical habitat identified and designated by USFWS. In situ conservation measures are critical for the preservation of this species. Additionally, genetic studies are required to elucidate the systematics of the genus. Studies on the boa include status and biogeography (Nellis et al., 1983; Mayer and Lazell, 1988; Tolson, 1992a), ecology and behavior (Tolson, 1988, 1992b; Chandler and Tolson, 1990), and captive breeding (Tolson, 1989, 1990, 1992b). A study is currently underway to identify and characterize tree boa habitat on St. Thomas, although no other ecological studies have been conducted on the extant population on this island. Introduced species of concern Leptodactylidae. The Puerto Rican coquí (E. coqui) was introduced to the USVI, most likely as a stowaway in ornamental and agricultural plant containers. This frog inhabits the canopy of mesic forests at all elevations in the USVI. Although listed as threatened within its native range (IUCN et al., 2004), it has been able to successfully colonize new locations. This species poses a serious threat to native ecosystems in Hawaii (e.g., Kraus et al., 1999), and may have significant effects on invertebrate populations, thereby altering ecosystem processes (Beard et al., 2003). Although it is unknown what likely impacts this species might have in the USVI, it probably competes with native frogs for food and nesting resources. This species is particularly common around an agricultural area on St. Thomas and several resort facilities on St. Thomas and St. John where high numbers of ornamental plants have been imported. Hylidae. The Cuban treefrog (Osteopilus septentrionalis), native to Cuba and the Bahamas, is introduced and highly invasive in the USVI. It occurs on all three main islands and the BVI (Owen et al., 2005; Waddle et al., 2005), and has been reported from Water Island although these reports are unverified. Unfumigated ornamental plants and construction materials transported from Florida and Puerto Rico are the likely forms of introduction. It is widespread in both mesic and more xeric areas. This species requires water in which to breed, and tadpoles are frequently found in cisterns, ponds, ditches, and pools in ravines. Adults congregate around water sources, frequently in large numbers. Diet studies of this species in BVI indicate that it can ingest a wide variety of vertebrate prey items (Owen, 2005). The Cuban treefrog appears to be increasing in abundance across the USVI, and anecdotal evidence suggests that in locations where it is well-established the native frogs are in decline.
Conservation status of reptiles and amphibians in the U.S. Virgin Islands
423
Bufonidae. The cane toad (Bufo marinus) is a giant toad, up to 225 mm in length. Native to Central and South America, this species has been successfully introduced throughout the West Indies (IUCN et al., 2004). It was first introduced to Puerto Rico in the early 1920s to control agricultural invertebrate pests (Van Volkenberg, 1935), and was probably introduced to the USVI for similar purposes. This highly adaptable species occurs in a variety of habitat types including lowland and upland forests, grasslands, coastal scrub, beaches, agricultural pastures, and urban areas, sheltering under surface debris. It breeds in still or slow-moving water of ponds, ditches, temporary pools, reservoirs, and streams. Tadpoles can survive in brackish water and have a high heat tolerance and are competitive with and highly toxic to other tadpoles (Crossland, 2000; Smith, 2005). Their impact on native wildlife, particularly in Australia, has been devastating (e.g., Phillips et al., 2003). The impact of the cane toad to native wildlife in USVI is unknown. Its distribution in the USVI appears to be restricted to agricultural areas with livestock ponds. It is widespread on St. Croix, and fairly rare on St. Thomas. Although reported from St. John, it is unknown if populations are established on that island. Emydidae. The red-eared slider (Trachemys scripta) is a highly invasive freshwater turtle from the south-central U.S. It was most likely introduced to USVI via the pet trade, and is restricted to aquatic habitats, primarily freshwater ponds, including the agricultural wetlands and ornamental ponds associated with resorts. There may be additional species of feral freshwater turtles present in the USVI that have not yet been documented. Colubridae. The corn snake (Elaphe guttata) has been repeatedly reported and verified from locations around the container port on St. Thomas (Perry et al., 2003). It has also been observed at several large construction sites on St. Thomas where it is assumed to have been introduced from containerized construction materials. It is likely restricted to small areas by urban infrastructure and dense vehicular traffic. This species is expected to have a severe detrimental impact should its distribution become more widespread, through predation on native wildlife and competition with the tree boa.
Recommendations The two major threats to herpetofauna, and indeed all wildlife, in the USVI are habitat loss from uncontrolled development and impacts of introduced species. The mongoose is blamed for extirpating the ground lizard from St. Croix, and likely attributed to the extinction of the St. Croix racer (Baskin and Williams, 1966; Philibosian and Ruibal, 1971). The absence of the Puerto Rican racer from St. Thomas and St. John is also likely due to the mongoose, as this species is abundant on mongoose-free islands, including Water Island, which has similar
424
R.J. Platenberg, R.H. Boulon, Jr.
pressures as those on the main islands (i.e., mammalian predators, habitat loss from development, and vehicular traffic). The presence of rats on cays may be one reason for the lack of tree boas despite suitable habitat (Tolson, 1988). Despite near uncontrolled levels of habitat loss for development, there are still large tracts of land within the USVI, including on over-crowded and over-developed St. Thomas, that provide valuable habitat for reptiles and amphibians, and a mechanism needs to be identified that will allow for the long-term protection of these areas. A territorial land and water use plan is called for to address habitat loss and pollution issues, primarily through the establishment of a single-tier system whereby current CZM regulations for development in the coastal zone would apply throughout the islands. Other mechanisms, such as Habitat Conservation Plans, habitat easements, and stewardship programs through private landowners, have not yet been applied locally and may be future possibilities. The territorial government has recently established a herpetofauna conservation program with the aim of rectifying gaps in knowledge and initiating conservation actions to reverse negative trends, but the funding is limited and not guaranteed long-term. There are currently no means for providing public outreach and education for terrestrial herpetofauna. Additionally, the lack of enforcement allows the continued disregard for environmental regulations. However, the considerable proportion of protected areas in the USVI is a positive element. The reptiles occupying cays that harbor important seabird colonies benefit from conservation measures such as rat and goat eradication (Pierce, 2003; Witmer et al., 2002). The NPS continues to monitor and control mammalian predators (NPS, 2002) and habitat-altering herbivores (NPS, 2004). Increased sea turtle nesting success has resulted from beach monitoring and nest protection efforts, and on-going research is revealing effective management requirements for the St. Croix ground lizard.
Acknowledgements. This review and associated field work was supported in part under State Wildlife Grants T-2 and T-5 from USFWS, and part of the text also appears in Platenberg et al. (2005). Gad Perry and two anonymous reviewers provided valuable comments on the manuscript.
References Baskin, J.N., Williams, E.E. (1966): The Lesser Antillean Ameiva: re-evaluation, zoogeography and the effects of predation. Studies on the Fauna of Curaçao and other Caribbean Islands 23: 144-178. Beard, K.H., Eschtruth, A.K., Vogt, K.A., Vogt, D.J., Scatena, F.N. (2003): The effects of the frog Eleutherodactylus coqui on invertebrates and ecosystem processes at two scales in the Luquillo Experimental Forest, Puerto Rico. J. Trop. Ecol. 19: 607-617. Boulon, R.H., Dutton, P.H., McDonald, D.L. (1996): Leatherback turtles (Dermochelys coriacea) on St. Croix, U.S. Virgin Islands: fifteen years of conservation. Chelonian Conserv. Biol. 2: 141-147.
Conservation status of reptiles and amphibians in the U.S. Virgin Islands
425
Brewer, D.M. (2005): Cultural history of the Virgin Islands: a short primer. In: Island Peak to Coral Reef: a Field Guide to the Plant and Marine Communities of the Virgin Islands, p. 19-23. Maddox, E.M., Coombie, V., Devine D., Eds, University of the Virgin Islands Press. Chandler, C.R., Tolson, P.J. (1990): Habitat use by a boid snake, Epicrates monensis, and its anoline prey, Anolis cristatellus. J. Herpetol. 24: 151-157. Crossland, M.R. (2000): Direct and indirect effects of the introduced toad Bufo marinus (Anura: Bufonidae) on populations of native anuran larvae in Australia. Ecography 23: 283-290. Dodd, C.K., Jr. (1978): Island lizard in danger. Natl. Parks and Conserv. Mag. 52: 10-11. Dutton, D.L., Dutton, P.H., Chaloupka, M., Boulon, R.H. (2005): Increase of a Caribbean leatherback turtle Dermochelys coriacea nesting population linked to long-term nest protection. Biol. Conserv. 126: 186-194. Eckert, K.L., Eckert, S.A. (1983): Tagging and Nesting Research of Leatherback Sea Turtles (Dermochelys coriacea) on Sandy Point, St. Croix, U.S. Virgin Islands, 1983. Final Report. U.S. Fish and Wildlife Service. Garner, J.A., Garner, S., Coles, W. (2005): Tagging and Nesting Research of Leatherback Sea Turtles (Dermochelys coriacea) on Sandy Point, St. Croix, U.S. Virgin Islands, 2005. Annual Report. U.S. Fish and Wildlife Service. Genet, K.S. (2002): Structural habitat and ecological overlap of the Puerto Rican lizards Anolis cristatellus and A. cooki, with comments on the long-term survival and conservation of A. cooki. Caribbean J. Sci. 38: 272-278. Goodyear, N.C., Lazell, J. (1994): Status of a relocated population of endangered Iguana pinguis on Guana Island, British Virgin Islands. Restoration Ecol. 2: 43-50. Heatwole, H., MacKenzie, F. (1967): Herpetogeography of Puerto Rico. IV. Paleogeography, faunal similarity and endemism. Evolution 21: 429-438. Henderson, R.W. (1992): Consequences of predator introductions and habitat destruction on amphibians and reptiles in the post-Columbus West Indies. Caribbean J. Sci. 28: 1-10. IUCN, Conservation International, NatureServe (2004): Global Amphibian Assessment. International Union for the Conservation of Nature (http://www.globalamphibians.org.). Jensen, T.A. (2002): Spatial awareness by the lizard Anolis cristatellus: why should a non-ranging species demonstrate homing behavior? Herpetologica 58: 364-371. Knowles, W.C. (1990): Conservation of the St. Croix Ground Lizard, Ameiva polops. Study 2-B. Final report. Division of Fish and Wildlife, St. Croix. Knowles, W.C. (1997): Conservation of the St. Croix Ground Lizard, Ameiva polops. Study 2-B. Final report. Division of Fish and Wildlife, St. Croix. Kraus, F., Campbell, E.W., Allison, A., Pratt, T. (1999): Eleutherodactylus frog introductions to Hawaii. Herpetol. Rev. 30: 21-25. Leal, M., Rodríguez-Robles, J.A. (1997): Signalling displays during predator-prey interactions in a Puerto Rican anole Anolis cristatellus. Anim. Behav. 54: 1147-1154. MacLean, W.P. (1982): Reptiles and Amphibians of the Virgin Islands. London, Macmillan Education Ltd. Mayer, G.C., Lazell, J. (2000): A new species of Mabuya (Sauria: Scincidae) from the British Virgin Islands. Proc. Biol. Soc. Washington 113: 871-886. Mayer, G.C., Lazell, J.D., Jr. (1988): Distributional records for reptiles and amphibians from the Puerto Rican Bank. Herpetol. Rev. 19: 23-24. McNair, D.B. (2003): Population estimate, habitat associations, and conservation of the St. Croix ground lizard Ameiva polops at Protestant Cay, United States Virgin Islands. Caribbean J. Sci. 39: 94-99. McNair, D.B., Coles, W. (2003): Response of the St. Croix ground lizard Ameiva polops to severe local disturbance of critical habitat at Protestant Cay: before-and-after comparison. Caribbean J. Sci. 39: 392-398.
426
R.J. Platenberg, R.H. Boulon, Jr.
McNair, D.B., Lombard, C.D. (2004): Population estimates, habitat associations, and management of Ameiva polops (Cope) at Green Cay, United States Virgin Islands. Caribbean J. Sci. 40: 353-361. McNair, D.B., Mackay, A. (2005): Population estimates and management of Ameiva polops (Cope) at Ruth Island, United States Virgin Islands. Caribbean J. Sci. 41: 352-357. Meier, A.J., Noble, R.E., Rathbun, S.L. (1993): Population status and notes on the biology and behavior of the St. Croix ground lizard on Green Cay (St. Croix, U.S. Virgin Islands). Caribbean J. Sci. 29: 147-152. Nellis, D.W., Norton, R.L., MacLean, W.P. (1983): On the biogeography of the Virgin Islands boa, Epicrates monensis granti. J. Herpetol. 17: 413-417. Nellis, D.W., Small, V. (1983): Mongoose predation on sea turtle eggs and nests. Biotropica 15: 159160. Norton, R.L. (1997): First report of Peltophryne [sic] lemur from St. John, U.S. Virgin Islands. Bull. Chicago Herpetol. Soc. 32: 106-107. Norton, R.L. (1998): Comments on habitat and threats to populations of the Puerto Rican crested toad (Peltophryne [sic] lemur) in the Virgin Islands. Brit. Herpetol. Soc. Bull. 62: 20-21. NPS (2002): Sustained Reduction of Non-native Rats, Cats, and Mongooses from Virgin Islands National Park. Final Environmental Assessment Report. Department of Interior National Park Service Southeast Region. NPS (2004): Sustained Reduction Plan for Non-native Goats and Sheep within Virgin Islands National Park. Final Environmental Assessment Report. Department of Interior National Park Service Southeast Region. Owen, J. (2005): The Cuban Treefrog (Osteopilus septentrionalis): Diet, Reproduction, and Distribution of an Invasive Species in the British Virgin Islands. MS thesis, Texas Tech. University. Owen, J., Perry, G., Lazell, J., Petrovic, C., Engelhoff, J. (2005): Osteopilus septentrionalis (Cuban tree frog). Distribution. Herpetol. Rev. 36: 76. Perry, G., Gerber, G.P. (2006): Conservation of amphibians and reptiles in the British Virgin Islands: status and patterns. Appl. Herpetol. [in press]. Perry, G., Levering, K. Gerard, I., Garland, T., Jr. (2004): Locomotor performance and social dominance in male Anolis cristatellus. Anim. Behav. 67: 37-47. Perry, G., Pierce, J., Griffin, D., Van Buurt, G., Lazell, J. (2003): Elaphe guttata guttata. Herpetol. Rev. 34: 264-265. Perry, G., Razi, D., Lazell, J. (2000): Evaporative water loss in insular populations of Anolis cristatellus (Reptilia: Sauria) in the British Virgin Islands. III. Response to the end of drought and a common garden experiment. Biotropica 32: 722-728. Philibosian, R. (1975): Territorial behavior and population regulation in the lizards, Anolis acutus and A. cristatellus. Copeia 1975: 428-444. Philibosian, R.A., Ruibal, R. (1971): Conservation of the lizard Ameiva polops in the Virgin Islands. Herpetologica 27: 450-454. Philibosian R., Yntema, J.A. (1977): Annotated Checklist of the Birds, Mammals, Reptiles, and Amphibians of the Virgin Islands and Puerto Rico. St. Croix, Information Services. Phillips, B.L., Brown, G.P., Shine, R. (2003): Assessing the potential impact of cane toads on Australian snakes. Conserv. Biol. 17: 1738-1747. Pierce, J.J. (2003). Eradication of Non-native Rats from Virgin Islands Offshore Cays. Environmental Assessment Report, Wildlife Restoration Project W-11. St. Thomas, Division of Fish and Wildlife. Platenberg, R.J., Hayes, F.E., McNair, D.B., Pierce, J.J. (2005): A Comprehensive Wildlife Conservation Strategy for the U.S. Virgin Islands. St. Thomas, Division of Fish and Wildlife. Powell, R., Henderson, R.W. (2005): Conservation status of Lesser Antillean reptiles. Iguana 12: 2-17. Pregill, G. (1981): Late Pleistocene Herpetofaunas from Puerto Rico. Misc. Publ. No. 71. University of Kansas Publication. Lawrence, Museum of Natural History.
Conservation status of reptiles and amphibians in the U.S. Virgin Islands
427
Rice, K.G., Waddle, J.H., Crockett, M.E., Carthy, R.R., Percival, H.F. (2005): Herpetofaunal Inventories of the National Parks of South Florida and the Caribbean: Volume II. Virgin Islands National Park. Open-File Report 2005-1301. Fort Lauderdale, U.S. Geological Survey. Rodda, G.H., Perry, G., Rondeau, R.J., Lazell, J. (2001): The densest terrestrial vertebrate. J. Trop. Ecol. 17: 331-338. Schwartz, A., Henderson, R.W. (1991): Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. Gainesville, University of Florida Press. Smith, K.G. (2005): Effects of nonindigenous tadpoles on native tadpoles in Florida: evidence of competition. Biol. Conserv. 123: 433-441. TNC (2005): A Survey of the Plants, Birds, Reptiles, and Amphibians at the Magen’s Bay Preserve, St. Thomas, U.S. Virgin Islands. The Nature Conservancy. U.S.V.I., Department of Planning and Natural Resources. Tolson, P.J. (1988): Critical Habitat, Predator Pressures, and Management of Epicrates monensis on the Puerto Rico Bank: a multivariate analysis. U.S. Department of Agriculture, Forest Service General Technical Report RM-166: 228-238. Tolson, P.J. (1989): Breeding the Virgin Islands Boa, Epicrates monensis granti, at the Toledo Zoological Gardens. Int. Zoo Yearbook 28: 163-167. Tolson, P.J. (1990): Captive breeding and reintroduction: recovery efforts for the Virgin Islands Boa, Epicrates monensis granti. Endangered Species Update 8: 52-53. Tolson, P.J. (1992a): The conservation status of Epicrates monensis (Serpentes: Boidae) on the Puerto Rico Bank. In: Status y Distribución de los Reptiles y Anfibios de la Región de Puerto Rico, Publicación Cientifica Miscelania Número 1, p. 11-19. Moreno, J.A., Ed., Departamento de Recursos Naturales de Puerto Rico. Tolson, P.J. (1992b): The reproductive biology of the Neotropical boid genus Epicrates (Serpentes: Boidae). In: Reproductive Biology of South American Vertebrates, p. 165-178. Hamlett, W.C., Ed., New York, Springer-Verlag. Tolson, P.J. (2005): Reintroduction Evaluation and Habitat Assessments of the Virgin Islands Tree Boa, Epicrates monesis granti, to the U.S. Virgin Islands. Grant T-1, Final Report. St. Thomas, Division of Fish and Wildlife. USFWS (1980): Status of Virgin Islands boa clarified. U.S. Fish and Wildlife Service. Endangered Species Tech. Bull. 5: 12. USFWS (1986): Virgin Islands Tree Boa (Epicrates monensis granti) Recovery Plan. Atlanta, U.S. Fish and Wildlife Service. Van Volkenberg, H.L. (1935): Biological control of an insect pest by a toad. Science 82: 278-279. Waddle, J.H., Crockett, M.E., Rice, K.G. (2005): Osteopilus septentrionalis. Geographic Distribution. Herpetol. Rev. 36: 333. Witmer, G.W., Boyd, F., Campbell, E.W., III, Wakefield, J., Hillis-Starr, Z. (2002): The Eradication of Introduced Rats at Buck Island Reef National Monument, St. Croix, U.S. Virgin Islands. Final report. Fort Collins, U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services USDA National Wildlife Research Center and St. Croix, U.S. Department of Interior, National Park Service, Buck Island Reef National Monument. Accepted: May 14, 2006 (AH). Reprinted from Applied Herpetology 3: 215-235 (2006).
Addendum The status of two native species within the US Virgin Islands has changed since this article was originally published. The Puerto Rican racer (Alsophis portoricensis)
428
R.J. Platenberg, R.H. Boulon, Jr.
has recolonized the extreme eastern end of St. Thomas and appears to be expanding westwards. Reported sightings of this snake began in 2008, with two of these verified. Ten more sightings were verified in 2009, and several more in 2010 indicating westerly dispersal. There are two possible explanations for the presence of this snake: (1) the snakes swam from nearby colonized islands and the decline in mongoose density in this area allowed for their survival and subsequent dispersal; or (2) the snakes arrived as stowaways in cargo shipments from Puerto Rico. The second explanation is less favored, since landscaping and building materials from Puerto Rico have been transported to other areas of St. Thomas yet no racers have been observed elsewhere. Where possible, the snake is captured and the tail tip taken for genetic analysis to determine the source of the individuals. The racers have been documented predating on the introduced Cuban treefrog (Osteopilus septentrionalis). Fifty-seven individuals of the endangered St. Croix ground lizard (Ameiva polops) from Green Cay were introduced to Buck Island (St. Croix) in 2008 (L. Fitzgerald, pers. comm.). Monitoring conducted in 2009 indicated that the individuals have shown a high survival rate and have been reproducing and dispersing from the initial release location (pers. obs.). Prior to the release of the lizards, it was confirmed that Buck Island is free of mammalian predators; signs of their potential presence are being closely monitored by the National Park Service. Several species of non-native herpetofauna have expanded their range. The common ground lizard (Ameiva exsul) has become established in several locations on St. Croix (Platenberg, 2007), having been introduced via cargo shipments from Puerto Rico and/or St. Thomas. Cuban treefrogs have dispersed to the inhabited offshore cays of Little St. James and Inner Brass (Perry and Platenberg, 2007; Platenberg, pers. obs.), in both cases observed breeding in hydrologically altered and man-made freshwater coastal ponds, respectively. Other potentially invasive species have been reported but as yet have not become established, namely Boa constrictor and Python regius. Although corn snakes (Elaphe guttata) have been established for many years on St. Thomas, individuals incidentally sighted on St. Croix, Little St. James, and other areas on St. Thomas (Perry and Platenberg, 2007) have not resulted in established populations.
References Platenberg, R.J. (2007): Impact of introduced species on an island ecosystem: non-native reptiles and amphibians in the US Virgin Islands. In: Managing Vertebrate Invasive Species: Proceedings of an International Symposium, p. 168-174. Witmer, G.W., Pitt, W.C., Fagerstone, K.A., Eds, Fort Collins, Colorado, USDA/APHIS/WS, National Wildlife Research Center. Perry, G., Platenberg, R. (2007): Recent additions to the herpetofauna of Little St. James, US Virgin Islands. Appl. Herpetol. 4: 387-389.
Index of genera and species
Acacia, 151, 240, 249 Acanthophis praelongus, 137 Achatina fulica, 93 Agave sisalana, 381 Aiphanes, 319 Alligator mississippiensis, 67 Allobates, 329 Allobates chalcopis, 210, 213, 215, 219, 311, 313, 329 Alsophis, 9, 113, 180, 189, 195, 196, 218, 250, 303, 417 Alsophis alsophis, 51 anomalus, 175, 176, 187 antiguae, 17, 25, 26, 28, 29, 31, 33, 35, 41, 42, 50, 51, 220 antiguae sajdaki, 50 antillensis, 28, 156, 210, 215, 317 ater, 218 cantherigerus caymanus, 131 cantherigerus fuscicauda, 131
cantherigerus ruttyi, 131 melanichnus, 171, 175, 176, 187 portoricensis, 113, 340, 351, 357, 413, 417, 427 rijgersmaei, 3, 7, 8, 11, 192, 194, 195, 199, 210, 215 rufiventris, 191, 192, 194, 195, 197 sajdaki, 51 sanctaecrucis, 218, 413, 417 sanctonum, 208, 210, 215 sanctonum sanctonum, 312, 317 Amanoa caribaea, 151 Amazona, 303 Amazona guildingii, 359, 360, 364 Ameiva, 9, 57, 61, 97, 112, 177, 189, 195, 196, 216, 218, 248, 252, 329, 330, 368 Ameiva alboguttata, 357 ameiva, 89, 92, 97, 239, 243, 245,
248, 252, 258, 261, 362, 363, 367, 368 ameiva tobagana, 262, 265 atrata, 17, 25, 27, 30, 42, 51 auberi, 59 cineracea, 209, 212 corax, 3, 6, 7, 9, 10, 11 corvina, 3, 6, 7, 9, 10, 11 desechensis, 357 dorsalis, 277, 302 erythrocephala, 192, 194, 195 exsul, 112, 357, 412, 417, 428 fuscata, 154, 158 griswoldi, 17, 25, 27, 29–31, 33, 34, 40, 42 lineolata, 177 major, 208, 209, 212, 313, 329, 330 maynardi, 59 plei, 3, 7–9, 192, 194, 195, 210, 218 pluvionotata, 27 polops, 407, 412, 417, 428 taeniura, 177
430
taeniura meyerabichi, 177 vanzoi, 218 wetmorei, 357 Amphisbaena bakeri, 357 caeca, 357 fenestrata, 112, 412, 414 schmidti, 357 xera, 357 Anolis, 61, 208, 216, 221, 239, 243, 258, 275, 282, 284, 301, 319, 321, 340, 351, 371, 372, 380, 382–384, 415 Anolis acutus, 413, 415 aeneus, 244, 245, 262, 264 altavelensis, 176 angusticeps, 59 bahorucoensis, 176 baleatus, 176 barahonae, 176 barbouri, 176 bimaculatus, 191, 192, 207 brunneus, 59 carolinensis, 3, 6–8, 135, 137, 368 conspersus, 133, 137, 138 conspersus lewisi, 133 cooki, 357 cristatellus, 31, 107, 110, 149, 150, 154, 159, 160, 164, 171, 357, 413, 415
Index of genera and species
cuvieri, 340, 351, 357 cybotes, 160 desechensis, 357 distichus, 59, 171 equestris, 66, 134, 135, 138, 390, 392 ernestwilliamsi, 107, 110 evermanni, 357 extremus, 92, 97, 98, 100 fairchildi, 59, 60, 62 ferreus, 210 forresti, 17, 27, 44 fuscata, 154 garmani, 135, 277 gingivinus, 3, 6–9, 192, 210 grahami, 277 griseus, 359, 362, 363, 368 gundlachi, 357 krugi, 357 leachi, 24, 27, 40 lineatopus, 277 luteosignifer, 131, 133 marmoratus, 210 marmoratus chrysops, 222, 223, 236 marmoratus kahouannensis, 235 maynardi, 133–135, 137 monensis, 357 nubilus, 17, 24, 27, 42, 51 occultus, 357
oculatus, 32, 149, 150, 152, 154, 160, 163, 164 opalinus, 277 pogus, 6, 7, 192, 208, 210, 215 poncensis, 357 porcatus, 171 pulchellus, 110, 357, 413, 415 reconditus, 277, 301 richardii, 244, 245, 262, 264 ricordii, 176 roosevelti, 111, 357 roquet, 210, 218, 313, 318, 330 roquet caracoli, 332 roquet salinei, 332 sabanus, 192, 197 sagrei, 59, 60, 62, 89, 97, 98, 100, 133–135, 137, 138, 203, 221, 244, 245, 277, 280, 301, 359, 362, 363, 368, 393 sagrei luteosignifer, 131 sagrei scriptus, 400 schwartzi, 192 scriptus, 59, 380, 384, 385, 392 scriptus scriptus, 388 sheplani, 176 smaragdinus, 59 strahmi, 176 stratulus, 110, 111, 357, 413, 415 terraealtae, 208, 210 trinitatis, 359, 362, 363, 366, 368, 372 valencienni, 277
Index of genera and species
wattsi, 17, 27, 29, 40, 44 wattsi forresti, 24 whitemani, 176 Antigonon, 199 Antillophis parvifrons, 187 Aristelliger, 186, 187, 282, 382–384 Aristelliger barbouri, 59 expectatus, 187 hechti, 385, 386, 391, 400 lar, 187 praesignis, 277, 282, 301, 302 praesignis praesignis, 133 Arrhyton, 303 Arrhyton exiguum, 113, 357, 413, 417 Astrochelys sulcata, 337 Avicularia versicolor, 332 Azadirachta indica, 32 Bachia heteropa, 245, 258, 261, 264 heteropa alleni, 262, 266, 267 Bambusa vulgaris, 279 Basiliscus, 66 Batrachochytrium dendrobatidis, 32, 255, 256, 273, 280, 282, 283, 288–291 Battowia, 261
431
Boa, 311, 313, 315 Boa constrictor, 17, 25, 28, 29, 156, 192, 199, 209, 212, 216, 218, 328, 428 constrictor nebulosa, 156 constrictor orophias, 156 lanceolatus, 332 nebulosa, 316 orophias, 315, 316 Bothrops, 315, 317, 318 Bothrops asper, 317 atrox, 317 caribbaeus, 218, 317 lanceolatus, 210, 215, 217–219, 312, 313, 317, 318 Brachylophus, 218 Brachylophus vitiensis, 226 Bubulcus ibis, 97, 264 Bufo, 109, 400, 411 Bufo fluviaticus, 172, 175, 180, 187 fractus, 172, 175, 180, 187 guentheri, 172, 175, 187 lemur, 345, 412 marinus, 21, 23, 31, 93, 118, 171, 186, 187, 214, 245, 262, 275, 280, 283, 324, 345, 346, 356, 362–364, 400, 412, 423
Bursera simaruba, 151, 242 Butorides virescens, 97 Caiman crocodilus, 261, 357 Callophylum calaba, 151 Canis lupus familiaris, 31 Cannabis sativa, 285 Capra hircus, 31 Caretta, 380 Caretta caretta, 6, 7, 10, 11, 22, 23, 60, 68, 70, 95, 110, 133, 140, 153, 173, 175, 192–194, 207, 209, 245, 247, 291, 357, 363, 365, 380, 385, 386, 412, 418 Celestus, 167, 181, 273, 282, 296 Celestus anelpistus, 173, 176, 179, 180 barbouri, 276, 296 crusculus, 276, 296, 298 crusculus molesworthi, 296 duquesneyi, 276, 279, 296, 297 fowleri, 276, 298 hewardii, 276, 298 maculates, 133 marcanoi, 176 microblepharis, 276, 298
432
molesworthi, 276, 298 occiduus, 276, 298, 299 warreni, 173, 176, 179, 180 Cephaelis schwartzii, 151 Cercopithecus mona, 247 Chaunus marinus, 93, 187, 211, 214, 311, 313, 324, 326 Chelonia, 57, 380 Chelonia mydas, 6, 7, 10, 11, 17, 22, 23, 57, 60, 68, 70, 89, 93, 109, 133, 140, 153, 173, 175, 192–194, 209, 222, 245, 247, 291, 357, 363, 365, 380, 385, 386, 412, 418 Chelonoidis, 57, 58, 380 Chelonoidis carbonaria, 6–8, 211, 214, 219, 313, 326, 327, 337 denticulata, 207, 326, 337 nigra, 226 Chironius vincenti, 359, 362, 363, 370 Chlorocebus sabaeus, 91 Clelia, 156, 207, 250, 252, 258 Clelia
Index of genera and species
clelia, 17, 25, 28, 29, 156, 239, 245, 250, 252, 258 errabunda, 156, 250 Clusia, 151, 152 Clusia mangle, 152 Cnemidophorus vanzoi, 218 Coccoloba uvifera, 151 Coenobita clipeatus, 226 Colostethus chalcopis, 213, 329 Columba squamosa, 247 Conolophus pallidus, 226 subcristatus, 226 Corallus, 252, 257 Corallus cookii, 241, 359, 362, 363, 370–372 grenadensis, 239, 241, 244, 245, 248–250, 252, 256, 257, 262, 264, 267, 372 Crocodylus acutus, 132–134, 167, 171, 172, 175, 180, 181, 275, 277, 295 porosus, 132 rhombifer, 58, 132 Ctenosaura similis, 65, 66 Cubophis, 70 Cubophis caymanus, 131, 133 cychlura figginsi, 70
cychlura inornata, 70 fuscicauda, 131, 133 rileyi nuchalis, 70 ruttyi, 131, 133 vudii, 58, 60 Cyclura, 53, 57, 58, 64, 65, 68, 71, 76, 114, 142, 143, 167, 173, 193, 226, 331, 348, 380, 382–384, 394, 399 Cyclura carinata, 59, 220, 377, 380, 384, 385, 387, 392, 394, 398–400 carinata bartschi, 60, 394 carinata carinata, 218, 226 collei, 276, 297, 299, 300 cornuta, 173, 175, 179 cychlura, 59, 75 cychlura cychlura, 69 cychlura figginsi, 60, 61 cychlura inornata, 60–64, 71 duquesneyi, 301 lewisi, 129, 131, 133, 136, 137, 139, 140 nubila, 92, 135, 357 nubila caymanensis, 133–135, 137 nubila lewisi, 131 pinguis, 105, 111, 113–115, 119, 125, 217, 357, 415
Index of genera and species
ricordii, 173, 175, 179 rileyi, 59, 75 rileyi cristata, 60, 61, 64, 220 rileyi rileyi, 71, 72, 78 stejnegeri, 339, 348, 357 Cymbopogon citratus, 32 Dacryodes excelsea, 151 Dama dama, 31 Darlingtonia haetianus, 176, 187 Dasyprocta, 415 Dasyprocta leporina, 217 Dasypus novemcinctus, 247 Dermochelys coriacea, 6, 7, 10, 11, 22, 23, 60, 89, 95, 109, 140, 153, 173, 175, 192, 194, 209, 222, 245, 247, 291, 357, 363, 365, 393, 412, 418 Diadophis punctatus punctatus, 135 Didelphis, 249 Didelphis marsupialis, 217, 247, 249, 311, 314 marsupialis insularis, 267 Diploglossus montiserrati, 28 pleei, 357
433
Dipsochelys dussumieri, 226 Elaphe chrysogaster, 396 chrysogaster chrysogaster, 396 guttata, 25, 28, 44, 126, 192, 199, 207, 392, 413, 423, 428 Eleutherodactylus, 21, 152, 153, 161, 164, 171, 181, 186, 187, 207, 208, 216, 219, 246, 279, 280, 284, 290, 322, 327, 329, 340, 342, 351, 371 Eleutherodactylus alcoae, 172 alticola, 276, 290 amplinympha, 152, 153, 162 andrewsi, 276 antillensis, 109, 124, 356, 411, 412 armstrongi, 172 audanti, 172 auriculatoides, 172 barlagnei, 210, 215 brittoni, 356 cavernicola, 276, 291 cochranae, 109, 356, 411, 412 cooki, 356 coqui, 118, 344, 356, 412, 422 cundalli, 276 eneidae, 339, 344, 356 euphronides, 239, 244–246, 252, 256, 364
flavescens, 172 fowleri, 172 furcyensis, 172 fuscus, 276, 291 glaucoreius, 276 gossei, 276 grabhami, 276 griphus, 276, 291 gryllus, 356 haitianus, 172 hedricki, 356 heminota, 172 hypostenor, 172 inornatus, 351 jamaicensiss, 276 jasperi, 339, 344, 356 johnstonei, 3, 6–8, 12, 21, 23, 32, 35, 92, 93, 124, 153, 159, 160, 189, 191, 192, 211–214, 216, 219, 221, 243–245, 252, 255–257, 262, 276, 279, 280, 311, 313, 322, 327, 330, 359, 362–364, 372 juanariveroi, 356 jugans, 172 junori, 276, 291 karlschmidti, 339, 344, 356 lentus, 124, 411, 412, 414 leoncei, 172 locustus, 344, 356 luteolus, 276 martinicensis, 21, 23, 35, 44, 153, 162, 210, 212–214,
434
216, 219, 313, 322, 327, 330, 332 minutus, 172 monensis, 356 montanus, 172 nortoni, 172 nubicola, 276 orcutti, 273, 276, 283, 288, 290, 291 oxyrhynchus, 172 pantoni, 276 parabates, 172 patriciae, 172, 345 pentasyringos, 276 pictissimus, 172 pinchoni, 210, 215, 216 pituinus, 172, 345 planirostris, 59, 133, 137, 207, 261, 276, 279, 389, 390 portoricensis, 344, 356 probolaeus, 172 richmondi, 344, 356 rogersi, 59, 60 rufifemoralis, 172 ruthae, 172 schmidti, 172 schwartzi, 109, 411, 412 shrevei, 362 sisyphodemus, 276, 291 unicolor, 356 wetmorei, 172 wightmanae, 344, 356 Epicrates, 70, 167, 346, 382–384, 397, 399, 400 Epicrates cenchria, 328
Index of genera and species
chrysogaster, 60, 68, 377, 380, 385, 397–400 chrysogaster chrysogaster, 377, 384, 388, 396 exsul, 60, 68 fordii, 173, 175 gracilis, 173, 175 inornatus, 339, 340, 346, 351, 357 monensis, 113, 126, 357 monensis granti, 346, 407, 413, 420, 421 monensis monensis, 346 striatus, 60, 68, 73, 171, 173, 175 striatus fosteri, 62 striatus fowleri, 62 subflavus, 137, 277, 280, 303, 400 Epictia columbi, 58, 60, 78 Equus asinus, 31 Eretmochelys, 57 Eretmochelys imbricata, 6, 7, 10, 11, 17, 22, 23, 29, 57, 60, 68, 70, 89, 94, 110, 133, 140, 153, 173, 175, 180, 192, 194, 209, 220, 222, 236, 245, 247, 291, 351, 357, 363, 365, 385, 386, 412, 418 Felis catus, 31 Ficus
citrifolia, 151 laevigata, 242 lentiginosa, 242 Funambulus, 217 Gastrophryne carolinensis, 66, 135 Gayacum, 319 Gecarcinus ruricola, 221 Gekko gecko, 211, 214, 236, 311, 313, 326, 332 Geochelone, 57, 58, 90, 362, 363 Geochelone carbonaria, 22, 23, 35, 92, 95, 110, 126, 154, 189, 191, 192, 194, 199, 244–246, 261–263, 363, 365, 411, 412 denticulata, 363, 365, 414 sulcata, 328 Glomeropitcairnia penduliflora, 321 Gonatodes, 186, 243, 264 Gonatodes albogularis, 135, 207, 277, 280 daudini, 259, 261, 262, 264, 266, 269 vittatus, 164 Graptemys pseudogeographica, 328 Guaiacum officinale, 221, 227 Gymnophthalmus, 44, 155, 157, 208, 323, 328
Index of genera and species
Gymnophthalmus pleii, 24, 42, 155, 157, 210, 313, 323, 328, 330, 332, 337 underwoodi, 24, 27, 31, 92, 96, 186, 203, 211–213, 219, 236, 243, 245, 262, 267, 311, 313, 322, 323, 328, 332, 363, 366 Haematoxylon campechianum, 151 Haitiophis anomalus, 187 Hemidactylus, 186, 196, 213, 282, 327, 371 Hemidactylus angulatus, 171, 328 brooki, 328, 357 frenatus, 186, 221 garnotii, 66 haitianus, 171, 328 mabouia, 6–8, 22, 23, 66, 92, 96, 111, 126, 134, 135, 155, 171, 189, 191, 192, 211–213, 219, 245, 261, 262, 264, 276, 280, 302, 311–313, 327, 328, 332, 357, 362, 363, 366, 387, 390, 391, 413, 415 Herpestes, 250, 252 Herpestes auropunctatus, 206, 217, 220, 279
435
javanicus, 17, 91, 112, 113, 171, 175, 189, 239, 248, 252, 348, 368, 416 javanicus auropunctatus, 29 Hibiscus tulipiflorus, 152 Hippomane mancinella, 151, 242 Hyla barbudensis, 21 cinerea, 356 squirella, 66 vasta, 345 Hypsiboas heilprini, 172 Hypsirhynchus, 303 Hypsirhynchus ater, 277, 303 callilaemum, 277, 303, 304 funereum, 277, 303, 304 melanichnus, 187 parvifrons, 58, 60, 70, 187 polylepis, 277, 304 Ialtris, 175, 180 Ialtris agyrtes, 176 dorsalis, 176 haetianus, 187 Iguana, 27, 35, 216, 218, 219, 237, 371 Iguana delicatissima, 3, 7–9, 13, 17, 24, 26, 29, 35, 37, 41, 42, 149, 154, 155, 158, 159, 162, 163, 189,
192–195, 199, 205, 210, 215, 216, 218, 219, 221–223, 225–228, 236, 237, 311, 313, 314, 323–326, 330–332, 337 iguana, 3, 6–9, 12, 24, 26, 31, 35, 50, 65, 66, 111, 125, 126, 135, 137, 142, 143, 154, 159, 189, 191–195, 197, 199, 211, 215, 216, 219, 227, 236, 237, 245, 247, 261, 262, 265, 311, 313, 323, 326, 330–332, 337, 357, 363, 368, 369, 390, 392, 413, 415 Kentropyx, 98 Kentropyx borckiana, 92, 97, 98 Kinixys erosa, 207 homeana, 207 Lama glama, 31 Lantana, 151 Laudakia stellio, 328 Leiocephalus, 57, 61, 177, 218, 382–384, 396 Leiocephalus altavelensis, 176
436
carinatus, 59, 73, 221 carinatus granti, 133 carinatus varius, 133, 138 cuneus, 17, 24, 27, 29, 209, 212 etheridgei, 357 greenwayi, 59, 60, 62 herminieri, 209, 212, 311, 313, 315 inaguae, 59, 60, 62 loxogrammus, 59 partitus, 357 psammodromus, 380, 384, 385, 387, 400 psammodromus apocrinus, 399 punctatus, 59 Lepidochelys kempi, 22, 95, 207 olivacea, 22, 60, 95, 207, 209, 222, 357 Leptodactylus, 162, 171, 329, 342 Leptodactylus albilabris, 109, 171–173, 356, 411, 412 dominicensis, 173 fallax, 21, 149, 152, 158, 162–164, 209, 212, 216, 218, 311, 313–315, 326 validus, 244, 245, 255, 259, 261–263, 362–364, 372, 373 Leptotyphlops, 176 Leptotyphlops asbolepis, 176, 187 bilineata, 98
Index of genera and species
bilineatus, 92, 98, 210, 313, 323, 330, 332 breuili, 98 calypso, 176, 187 carlae, 89, 92 pyrites, 176, 187 tenella, 25, 28 Leucida leucocephala, 151 Licania ternatensis, 151 Liophis, 99, 100, 218, 250 Liophis cursor, 209, 212, 218, 311, 313, 316, 330, 331, 337 juliae, 152, 156, 210, 215 ornatus, 218 perfuscus, 89, 90, 92, 99, 100 Lithobates, 186 Lithobates catesbeianus, 187 clamitans, 66 grylio, 66 sphenocephala, 66 Lonchocarpus benthamianus, 242 latifolius, 151 Mabuya, 3, 7–9, 167, 189, 192, 194–196, 199, 208, 218, 239, 245, 248, 252, 262, 265, 316, 363, 369, 382, 383 Mabuya bistriata, 22, 265 lineolata, 176 mabouya, 22, 90, 97, 155, 210, 215,
219, 222, 265, 311, 313, 316, 330, 357, 369 macleani, 112 nigropunctata, 265 sloanii, 22, 24, 112, 171, 210, 212, 215, 265, 276, 301, 369, 384, 385, 392, 413, 416 sloanii sloanii, 388 Mastigodryas, 100 Mastigodryas bruesi, 89, 92, 100, 244, 245, 251, 262, 264, 268, 362, 363, 370 Megalobulimus oblongus, 93 Mimus gilvus, 221 Mitophis asbolepis, 187 calypso, 187 pyrites, 187 Molossus molossus, 326 Monachelys monensis, 357 Morelia amethistina, 236, 337 Morinda citrifolia, 151 Musa, 371 Mus, 371 Mus musculus, 217, 248, 252, 279 Nactus, 221 Nactus coindemirensis, 221 durrelli, 221
Index of genera and species
serpensinsula, 221 Natrix natrix, 328, 329 Nephroolepis, 279 Norops conspersus conspersus, 133 conspersus lewisi, 133 luteosignifer, 133 sagrei, 133–135 Ocyophis anomalus, 187 melanichnus, 187 Oligosoma smithi, 220 suteri, 220 Opheodrys aestivus, 66 Ophionyssus natricis, 32 Ophisaurus ventralis, 135 Opuntia dillenii, 265 Oreochromis, 280 Oryzomys, 248 Osteopilus, 275, 288, 290 Osteopilus brunneus, 275, 290 crucialis, 275 marianae, 275 pulchrilineata, 172 septentrionalis, 6–8, 11, 22, 23, 59, 60, 109, 124, 133, 137, 164, 192, 203, 211, 214, 356, 390, 391, 412, 422, 428 vastus, 172, 175 wilderi, 275, 290
437
Ovis aries, 31 Pantherophis alleghaniensis, 66 guttatus, 3, 6–8, 66, 135, 137, 328, 390, 392 Peltophryne, 186, 342 Peltophryne fluviatica, 187 fracta, 187 guentheri, 187 lemur, 109, 339, 345, 346, 356, 411 Pelusios castaneus, 211, 214, 219, 236 Phrynops geoffroanus, 6, 7 Phyllodactylus, 186, 187 Phyllodactylus hispaniolae, 176, 187 pulcher, 89, 90, 92, 96 sommeri, 187 wirshingi, 357 Pimenta racemosa, 151 Pinus caribaea bahamensis, 56 Pisonia fragrans, 242 Podocarpus coriaceus, 152 Prestoea acuminata, 152 Pristimantis, 258, 364 Pristimantis euphronides, 256, 257, 364
shrevei, 359, 360, 362–364, 370, 372 Procyon lotor, 91, 217, 220 Pseudemys nelsoni, 110 Python regius, 328, 428 Quiscalus lugubris, 97, 264 Ramphotyphlops braminus, 6–8, 89, 99, 134, 135, 192, 199, 203, 207, 211, 214, 236, 332 Rana catesbeiana, 171, 186, 187, 276, 280, 356 grylio, 356 Rattus, 64, 206, 279, 293, 371 Rattus exulans, 220 norvegicus, 31, 91, 217, 279 rattus, 17, 21, 31, 39, 41, 91, 217, 220, 227, 236, 248, 252, 279 Rhamphotyphlops braminus, 389, 390, 392 Rhinella, 186 Rhinella marina, 3, 6–8, 89, 91, 93, 134, 135, 137, 187 Rhizophora, 249 Scinax, 337 Scinax
438
ruber, 211, 214, 311, 313, 327, 332, 356 x-signatus, 211, 214, 236, 332, 337 Scolopendra subspinipes, 97 Sloanea, 151 Solenopsis, 279 Speotyla cunicularia amaura, 31 Sphaerodactylus, 3, 6, 7, 9, 17, 22, 24, 51, 111, 176, 186, 187, 196, 300, 302, 321, 322, 382–384, 396 Sphaerodactylus argivus argivus, 133 argivus bartschi, 133 argivus lewisi, 133 argus, 59, 277, 302 beattyi, 413, 415 caicosensis, 385, 387, 400 cochranae, 176 copei, 66 corticola, 59 dacnicolor, 277 darlingtoni noblei, 177 elegans, 171 elegantulus, 17, 22, 24, 26 epiurus, 186 fantasticus, 155, 210, 236 fantasticus fuga, 155 fantasticus karukera, 222 gaigeae, 357 gilvitorques, 277, 302
Index of genera and species
goniorhynchus, 277, 302 inaguae, 59, 60 kirbyi, 261–264, 266 klauberi, 357 ladae, 176 levinsi, 357 macrolepis, 107, 111, 357, 413–415 mariguanae, 59, 390, 392 microlepis, 157, 207 micropithecus, 220, 357 monensis, 357 nicholsi, 357 nigropunctatus, 59 notatus, 59 ocoae, 176 oxyrhinus, 277 parkeri, 277 parthenopion, 111, 126 parvus, 7, 8, 192, 208, 210 perissodactylius, 176, 186 richardsoni, 277 roosevelti, 357 sabanus, 192 samanensis, 176 savagei, 177 schuberti, 187 semasiops, 277 sputator, 7, 8, 192, 210 townsendi, 357 underwoodi, 385, 387, 392, 400 vincenti, 152, 155, 162, 210, 264, 313, 319, 321, 330, 363, 366, 372
vincenti ronaldi, 332 vincenti vincenti, 362 Stenostoma bilineatum, 98 Sterculia caribaea, 151, 152 Sterna antillarum, 221 Storeria dekayi, 66 Swietenia mahogani, 242 Syagrus amara, 151 Syringodium filiforme, 379 Tabebuia, 319 Tabebuia heterophylla, 151 pallida, 242 Tadarida brasiliensis, 326 Tantilla melanocephala, 258, 261 Tapura antillana, 151 Tarentola albertschwartzi, 276, 300 americana, 59 Terminalia catappa, 151 Terrapene carolina, 67, 328 Tetracheilostoma carlae, 89, 92, 98–100 Thalassia testudinum, 93, 379 Thamnophis sauritus, 66 sirtalis, 66
Index of genera and species
Thecadactylus, 196, 323 Thecadactylus rapicauda, 7, 8, 22, 24, 111, 155, 189, 191, 192, 210, 212, 213, 245, 262, 264, 312, 313, 323, 328, 330, 332, 363, 366, 367, 415 solimoensis, 323 Thespesia pallida, 151 populnea, 151 Tillandsia utriculata, 263, 267 Trachemys, 53, 57, 67, 68, 78, 167, 347, 380, 391 Trachemys decorata, 67, 171, 173, 175, 180 decussata, 134, 137, 138 decussata angusta, 135 felis, 67 scripta, 67, 135, 137, 171, 180, 192, 199, 207, 211, 214, 357, 412, 423 scripta elegans, 68, 92, 110, 125, 171, 236, 295, 328, 337, 348, 390, 391 scripta stejnegeri, 357 stejnegeri, 60, 171, 173, 180, 211, 214, 219, 337
439
stejnegeri malonei, 67, 68, 390, 391 stejnegeri stejnegeri, 339, 347, 348 stejnegeri vicina, 175 terrapen, 60, 67, 68, 277, 278, 294, 295 Tretanorhinus variabilis lewisi, 133 Tropidophis, 70, 143, 277, 278, 304, 380, 383, 384, 396 Tropidophis canus, 60, 68 caymanensis, 131, 133, 137, 138 caymanensis caymanensis, 131 caymanensis parkeri, 131 caymanensis schwartzi, 131 curtus, 60, 68, 73 greenwayi, 380, 385, 388, 391, 398, 400 greenwayi greenwayi, 388, 389, 399 greenwayi lanthanus, 388, 389 haetianus, 167, 173, 175, 304 jamaicensis, 277, 304 parkeri, 131, 133, 137 schwartzi, 131, 133, 137 stejnegeri, 277, 304 stullae, 277, 304 Typhlops, 383, 393, 418
Typhlops annae, 210, 215, 219 biminiensis, 60 catapontus, 112 caymanensis, 133, 136, 137 dominicana, 156 epactius, 133, 136, 137 granti, 357 guadeloupensis, 156, 208, 210 hypomethes, 357 jamaicensis, 277, 304 lumbricalis, 60 monastus geotomus, 25, 28 monensis, 357 paradoxus, 60 platycephalus, 357, 385, 389, 400 richardii, 112, 357, 389, 413, 417 rostellatus, 357 sulcatus, 171 tasymicris, 239, 244, 245, 251 Tyrannus dominicensis, 97 Varanus exanthematicus, 393 Zanthoxylum caribaeum, 151 spinosum, 151
