Amphibians and Reptiles of Guyana, South America: Illustrated Keys, Annotated Species Accounts, and a Biogeographic Synopsis

PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 125(4):317–620. 2013. Amphibians and reptiles of Guyana, South America: illustrated keys, annotated species accounts, and a biogeographic synopsis Charles J. Cole*, Carol R. Townsend, Robert P. Reynolds, Ross D. MacCulloch, and Amy Lathrop (CJC, CRT) Division of Vertebrates (Herpetology), American Museum of Natural History, 200 Central Park West, New York, New York 10024, U.S.A., e-mail: [email protected], [email protected]; (RPR) Biological Survey Unit, United States Geological Survey, Patuxent Wildlife Research Center, National Museum of Natural History, P.O. Box 37012, MRC 111, Washington, D.C. 20013-7012, U.S.A., e-mail: [email protected]; (RDM, AL) Centre for Biodiversity and Conservation Biology, Royal Ontario Museum, 100 Queen’s Park, Toronto, Ontario, M5S 2C6, Canada, e-mail: [email protected], [email protected] Abstract.—Guyana has a very distinctive herpetofauna. In this first ever detailed modern accounting, based on voucher specimens, we document the presence of 324 species of amphibians and reptiles in the country; 148 amphibians, 176 reptiles. Of these, we present species accounts for 317 species and color photographs of about 62% (Plates 1–40). At the rate that new species are being described and distributional records are being found for the first time, we suspect that at least 350 species will be documented in a few decades. The diverse herpetofauna includes 137 species of frogs and toads, 11 caecilians, 4 crocodylians, 4 amphisbaenians, 56 lizards, 97 snakes, and 15 turtles. Endemic species, which occur nowhere else in the world, comprise 15% of the herpetofauna. Most of the endemics are amphibians, comprising 27% of the amphibian fauna. Type localities (where the type specimens or scientific name-bearers of species were found) are located within Guyana for 24% of the herpetofauna, or 36% of the amphibians. This diverse fauna results from the geographic position of Guyana on the Guiana Shield and the isolated highlands or tepuis of the eastern part of the Pantepui Region, which are surrounded by lowland rainforest and savannas. Consequently, there is a mixture of local endemic species and widespread species characteristic of Amazonia and the Guianan Region. Although the size of this volume may mislead some people into thinking that a lot is known about the fauna of Guyana, the work has just begun. Many of the species are known from fewer than five individuals in scientific collections; for many the life history, distribution, ecology, and behavior remain poorly known; few resources in the country are devoted to developing such knowledge; and as far as we are aware, no other group of animals in the fauna of Guyana has been summarized in a volume such as this to document the biological resources. We briefly discuss aspects of biogeography, as reflected in samples collected at seven lowland sites (in rainforest, savanna, and mixed habitats below 500 m elevation) and three isolated highland sites (in montane forest and evergreen high-tepui forest above 1400 m elevation). Comparisons of these sites are preliminary because sampling of the local faunas remains incomplete. * Corresponding author. 318 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON Nevertheless, it is certain that areas of about 2.5 km2 of lowland rainforest can support more than 130 species of amphibians and reptiles (perhaps actually more than 150), while many fewer species (fewer than 30 documented so far) occur in a comparable area of isolated highlands, where low temperatures, frequent cloudiness, and poor soils are relatively unfavorable for amphibians and reptiles. Furthermore, insufficient study has been done in upland sites of intermediate elevations, where lowland and highland faunas overlap significantly, although considerable work is being accomplished in Kaieteur National Park by other investigators. Comparisons of the faunas of the lowland and isolated highland sites showed that very few species occur in common in both the lowlands and isolated highlands; that those few are widespread lowland species that tolerate highland environments; that many endemic species (mostly amphibians) occur in the isolated highlands of the Pakaraima Mountains; and that each of the isolated highlands, lowland savannas, and lowland rainforests at these 10 sites have distinctive faunal elements. No two sites were identical in species composition. Much more work is needed to compare a variety of sites, and especially to incorporate upland sites of intermediate elevations in such comparisons. Five species of sea turtles utilize the limited areas of Atlantic coastal beaches to the northwest of Georgetown. All of these are listed by the International Union for the Conservation of Nature as being of global concern for long-term survival, mostly owing to human predation. The categories of Critically Endangered or Endangered are applied to four of the local sea turtles (80%). It is important to protect the few good nesting beaches for the sea turtles of Guyana. We have documented each of the species now known to comprise the herpetofauna of Guyana by citing specimens that exist in scientific collections, many of which were collected and identified by us and colleagues, including students of the University of Guyana (UG). We also re-identified many old museum specimens collected by others in the past (e.g., collections of William Beebe) and we used documented publications and collection records of colleagues, most of whom have been working more recently. We present dichotomous keys for identifying representatives of the species known to occur in Guyana, and we present brief annotated species accounts. The accounts provide the current scientific name, original name (with citation of the original description, which we personally examined in the literature), some outdated names used in the recent past, type specimens, type localities, general geographic distribution, examples of voucher specimens from Guyana, coloration in life (and often a color photograph), and comments pointing out interesting subjects for future research. Keywords: amphibians, biogeography, Guyana, herpetology, keys, reptiles, South America. VOLUME 125, NUMBER 4 319 Introduction 1–40). A total of 78 of these species were described based on samples collected at Amphibians and reptiles are of interest type localities within Guyana and 39 were to humans for various reasons, ranging described and named in the last 10 years. from their usefulness for biomedical re- The lack of a modern comprehensive search and development of pharmaceuti- volume dedicated to the herpetofauna of cals to fascination with their diverse forms, Guyana has been misunderstood by some colors, life histories and behavior, and as people to mean that these organisms are models for scientific research to better unimportant and perhaps ‘‘nothing’’ was understand the nature of planet Earth. known about the species native to the Amphibians of one kind or another have country. Actually, the majority of the existed for the last 365 million yr, having species have been known to science for evolved from fish. Subsequently, the rep- decades or more (some going back to tiles evolved from an amphibian, and the Linnaeus 1758), as they occur in adjacent mammals (including humans) from a countries or broadly across Amazonia. reptile. These animals are part of our Consequently, this majority of species has own ancestry, as all living things on Earth been known to science, but most of what are part of one family tree that extends we know about them is based on research back for more than 3.5 billion yr. Am- that was done in countries other than phibians were the first terrestrial verte- Guyana. In order to identify specimens brates to appear in Earth history, and they found in Guyana, herpetologists have had and reptiles are important components of to refer to diverse publications scattered our terrestrial and aquatic ecosystems, widely in the technical literature, which especially in the tropics. In contrast, can be a daunting task. Summary publi- humans have existed for considerably less cations (with lists of possibly relevant than the most recent 1 million yr and have species or comprehensive monographs) had significant negative impact on plane- concerning the Guianan Region and South tary ecosystems, particularly in just the last America that have been most broadly 200 yr. In terms of the natural resources of helpful to us include the following: Rivero Guyana, the amphibians and reptiles (1961), Taylor (1968), Peters & Donoso- (herpetofauna) are among the most poorly Barros (1970), Peters & Orejas-Miranda known. (1970), Brazaitis (1973), Hoogmoed (1973, The first checklist of the herpetofauna of 1979), Chippaux (1986), Ernst & Barbour Guyana included a total of 164 species, (1989), Avila-Pires (1995, 2005), Barrio- including 50 frogs and toads, 2 caecilians, Amoro´s (1998), Starace (1998), Gorzula & 1 amphisbaenian, 4 crocodilians, 33 liz- Senãris (1999), Lescure & Marty (2000), ards, 63 snakes, and 11 turtles (Beebe Reynolds et al. (2002), Savage (2002), 1919). Today we are confident that twice Campbell & Lamar (2004), Duellman as many species of amphibians and reptiles (2005), Senãris & MacCulloch (2005), and occur in Guyana. The present volume Frost (2011). Some of these papers provide documents 324 species (plus 20 thought skeleton lists of species of the herpetofau- to occur in Guyana but not yet document- na of Guyana and adjacent areas, but none ed plus an unknown number of new presents the perspective of Guyana on species yet to be discovered), including details for confirmed voucher specimens 137 frogs and toads, 11 caecilians, 4 that were identified or re-identified recent- crocodylians, 4 amphisbaenians, 56 liz- ly, extensive literature citations, identifica- ards, 97 snakes, and 15 turtles (about 62% tion keys, illustrations of specimens, or are shown in color photographs in Plates suggestions for future research. 320 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON The present volume scratches the sur- raphy, faunal comparisons, and conserva- face, as considerable research remains to tion.

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