Herpetologists' League A Checklist of the Herpetofauna of the Palau Islands (Republic of Belau), Oceania Author(s): Ronald I. Crombie and Gregory K. Pregill Source: Herpetological Monographs, Vol. 13 (1999), pp. 29-80 Published by: Herpetologists' League Stable URL: http://www.jstor.org/stable/1467060 Accessed: 05/10/2008 09:49 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=herpetologists. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with the scholarly community to preserve their work and the materials they rely upon, and to build a common research platform that promotes the discovery and use of these resources. For more information about JSTOR, please contact [email protected]. Herpetologists' League is collaborating with JSTOR to digitize, preserve and extend access to Herpetological Monographs. http://www.jstor.org Herpetological Monographs, 13, 1999, 29-80 ? 1999 by The Herpetologists' League, Inc. A CHECKLIST OF THE HERPETOFAUNA OF THE PALAU ISLANDS (REPUBLIC OF BELAU), OCEANIA RONALD I. CROMBIE1 AND GREGORY K. PREGILL2 'Division of Amphibians and Reptiles, United States National Museum, Smithsonian Institution, Washington D.C. 20560 2Department of Biology, University of San Diego, San Diego, CA 92110-2492 ABSTRACT: The Palau islands of western Micronesia comprise one of the most physiographically varied archipelagos in the Pacific. There are some 350 islands of volcanic and coralline origin that range from Babeldaob at 333 km2 (about 80% of Palau's total land area) to others, unnamed, that are less than one hectare. A barrier reef encircles most of the archipelago creating a lagoon up to 20 km wide. The majority of the islands are uninhabited, accessible with difficulty only by boat at high tide, and are densely vegetated over steep, rocky terrain. Because of their proximity to the Philippines, New Guinea, the Moluccas, and Borneo, the Palau islands host a significantly richer herpetofauna with more unique taxa than is found on other Pacific islands to the east. As with most other Pacific island groups, however, the herpetofauna has been poorly documented. Since the earliest investigations that began in the nineteen century, Palau's herpetofauna has been uncovered piecemeal. No sustained field effort had been conducted until we began a systematic survey of the islands in 1992. Since then we have collected in Palau every month of the year at least once. This checklist of 46 species of reptiles and amphibians includes almost twice as many taxa as were known from Palau (Owen, 1977) at the beginning of our study. Among these are new species or Palauan records of Gehyra, Hemiphyllodactylus, Lepidodactylus, Nactus, Perochirus, Emoia and Sphenomorphus. Because of the difficulties in surveying so many islands we believe that additional taxa and distributional records await discovery; even the smallest island in Palau can turn up sur- prises. Nonetheless, it is appropriate to consolidate what is now known about this intriguing fauna and environment. We provide an historical summary of previous collecting efforts, an overview of the islands' geology and habitats, and for each species account we include distributional information, taxonomic and systematic discussion, natural history observations, and a comprehensive bibliography. Key words: Micronesia, Palau Islands, Amphibians, Reptiles PERHAPS THE MOST zoogeographically island group with a more diverse extant significant yet poorly known archipelago in fauna that is closer to potential source ar- the Oceanic realm is the Palau Island eas. Therefore, in 1992 we began extensive group (now the independent Republic of surveys of the extant and extinct verte- Belau) in western Micronesia. The earliest brates of Palau. Although we have accu- herpetological investigations of this area by mulated significant collections and data in the Germans in the mid-1800's revealed our field work to date, each additionaltrip new taxa in genera (Hypsilurus, Spheno- yields important (and often surprising) morphus, and others) otherwise unknown new specimens and distributional infor- from the oceanic islands of the Pacific mation. Nevertheless, given the consider- Plate, and the few subsequent field studies able recent increase of interest in Micro- continued to yield additional novelties. Al- nesian biology and conservation (e.g., though these early collections suggested a Rodda et al., 1991), we feel it is appropri- diverse fauna with unexpectedly high lev- ate to present our working list. els of endemism, they were insufficient for Modern summaries of the Palauan her- addressing the numerous systematic and petofauna (e.g., Cassell et al., 1992; Oto- zoogeographic problems of this region. bed and Maiava, 1994) have had to rely on Because many other islands in the Pa- the incomplete and taxonomically outdat- cific have relatively depauperate extant ed list of Owen (1977). Despite the ad- vertebrate faunas but much larger lists of mitted shortcomings of the data, our list recently extinct taxa (e.g., Steadman, reflects current herpetological taxonomy 1995), Palau provides an ideal opportunity (to August 1998) and it contains nearly to see if this pattern also obtains on an twice as many species as listed by Owen 29 30 HERPETOLOGICAL MONOGRAPHS [No. 13 (1977), with many systematic problems think that the following list adequately duly noted. It is our intention to resolve documents that the discovery phase is far some of these problems with future field from over. work and collections. The strong zoogeo- graphic affinities between Palau and the GEOGRAPHY AND ECOLOGY Papuan region, and additional influences Spelling of Place Names from the Philippines, Borneo, and Ocean- The inconsistent spelling of Palauan ia, further complicate systematic studies. place names is attributable to idiosyncratic This is especially so with respect to the useage by four separate foreign adminis- logistics of obtaining pertinent compara- trations over the past one hundred years. tive material from such a broad area that These administrators made a limited at- includes several political entities not tempt at using native names, and often known for expansive cooperation with sci- misinterpreted their meaning when they entific endeavours. We hope that our ac- did. Moreover, none of these languages cumulated specimens and data-base for (Spanish, German, Japanese, English) is Palau are such that future studies involving adequate to fully capture the phonics of this area will be facilitated. the Palauan tongue, such as the clipped The taxonomic of our list is com- aspect nasal-quality ng. Even within Palau it is prehensive, but we particularly want to common to see the same name spelled two stress the incomplete nature of the distri- or three different ways. There are, for ex- butional data we present. Although we list ample, some 15 spellings for Palau itself, all island records currently available for with the most common alternate being each species, the results of earlier surveys "Belau". The population center, both the plus our own field work have sampled only island and the town, called "Koror" by a small fraction of the multitude of islands practically everybody who lives there is in Palau, with varying degrees of rigor. The spelled "Oreor" on many maps. For all logistics of even briefly sampling islands place names we follow the spelling found spread across nearly six degrees of latitude on the USGS Topographic Maps of the Pa- are daunting and expensive; the survey lau Islands (1983-1984), which are the work itself is grueling and often danger- most detailed available and are used by ous. The Rock Islands in particular are of- most governmental agencies. We note, ten very difficult to land on, much less to however, that some of the spellings on survey adequately for cryptic and elusive these topographic sheets are at odds with amphibians and reptiles. Even the smallest local or casual useage, or are not followed and islands should seemingly insignificant in older (e.g., Anon., 1957; Brigham, 1900; not be ignored, as demonstrated by the re- Bryan, 1971) or recent (Karolle, 1993; cent discoveries of Lepidodactylus pauro- Motteler, 1986) literature. Finally, most of lepis (Ota et al., 1995), Emoia impar, Lep- Palau's smaller islands are unnamed. idodactylus sp. nov., and Nactus sp. (this The following is a list of our island local- paper). Our distributional data are intend- ities and their common alternate spellings. ed to convey only the most general pat- Coordinates are for the center of the island/ terns, many of which will undoubtedly be group (Lat. 0.000 N, Long. 000.000 E) modified with additional field work. We but hope that the data presented Babeldaob (Babelthuap, 7.5 134.5 here are not used to generate or justify Babeldaop) "conservation" efforts Bablomekang 7.14 134.316 counterproductive Beliliou (Peleliu) 7.0 134.25 that will hinder or prevent the much-need- Chemoi Island Group 7.19 134.38 ed continuing data collection that is nec- Euidelchol (Ashakasengu) 7.19 134.36 essary to make sense of the Palauan her- loulomekang 7.134 134.304 Kmekumer Islands 7.19 134.24 petofauna. In short, we emphasize that (island these data are for 46 from Wiles and presented general use, Conry, 1990) with the major caveat that they are not the Malakal (Ngemelachel) 7.33 134.45 "last word" in Palauan herpetology.