The State of Philippine Herpetology and the Challenges for the Next Decade

Abstract

The herpetological fauna (amphibians and reptiles) of the Philippines is extremely rich in total species numbers, taxonomic diversity, and percent endemism—especially when considered as a function of available land area. The last 10 years of herpetological research in the Philippines have seen a dramatic increase in interest in taxonomy, biogeography, phylogenetic systematics, conservation, and biodiversity of Philippine species, especially amphibians. In the last decade, over 50 previously unrecognized species have been identified. Despite the publication of a recent field guide to the amphibians of the Philippines, available species summaries and diagnostic keys are currently out of date because progress has been so rapid. Revisions of these works are needed but must await the completion of several comprehensive taxonomic investigations currently in progress. In general, amphibians (especially rapid frogs) have received more attention than reptiles.

During the same period. there has been less activity in ecological research and conservation, and little or no activity in disciplines such as behavior, microevolution, reproductive biology, or population biology. In this paper we review a few model studies and point out where others are badly needed. Available biogeographic analyses, combined with new, unpublished data, demonstrate that the distributions of amphibians and reptiles in the Philippines have been strongly influenced by the mid- to late-Pleistocene formation of several aggre-gate island complexes as well as by climatic gradients associated with elevation and anthropogenic disturbances (primarily de-forestation). Each Pleistocene aggregate island complex is a major center of biological diversity, and within these major (and several other minor) land mass amalgamations, there exist numerous sub-centers of endemism and diversity centered on isolated mountains or mountain ranges. Amphibians and reptiles may represent particularly appropriate model organisms for the study of these lesser centers of biological organization due to their tendency towards finer-scale differentiation and isolation on single montane "islands" and mountain ranges. Several recent studies have begun the process of integrating phylogenetic data, species distribution data, and studies of the process of speciation on unique montane habitats, but many more are needed. In particular, the field of molecular systematics stands out as an im-mensely powerful set of tools that has yet to be tapped by conservation biologists in the Philippines. The last decade has seen several attempts to assess the conservation status of many of the Philippines' unique and pre-sumably threatened amphibians and reptiles. These efforts have been hampered by a general lack of knowledge, a paucity of basic baseline survey data, a lack of integration, public disinterest, bureaucratic obstacles to research, and by limitations in resources. The number one cause of amphibian and reptile population declines clearly is catastrophic habitat destruction due to the activities of humans.