A Checklist of the Herpetofauna of the Palau Islands (Republic of Belau), Oceania

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 surprises. 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.