Microgeographic Variation in Species Composition of the Herpetofaunal Communities of Tambopata Region, Peru1

Abstract

Neotropid herpetofaunas have been studied at selected Central and South American sites, but intra-regional analyses in the Neotropics have not been possible due to lack of long-term data. A particular problem in interpreting herpetofaunal communities is the large geographic distances between the known localities. Such sampling does not take into account the patchiness of the habitat and this prevents analysis of regional diversity. In this study, five Neotropid herpetofaunal communities within a small geographic area (1600 !an2) were examined to determine if species composition varies microgeographically. We sampled sites within the Tambopata Province, southeastern Peru. The five sites were surveyed intensively during a two-year period. The herpetofauna of the Tambopata region indudes 210 species and, because of extensive sampling, has the highest overall herpetofaunal richness of any known region. Sites were compared using the coefficient of biogeographic resemblance (CBR). The CBRs were similar among all sites but the differences were determined primarily by their positions with respect to the two main rivers of the region and not directly correlated to distance among sites. Sites were also examined by partitioning their species into six microhabitat classes. Sites were found to differ in their proportions of reptiles and amphibians in each microhabitat class. The results of our study were compared to former investigations of various sites within the Tambopata region and elsewhere. This study identified more species than past investigations in all cases. Species composition was shown to vary at a microgeographic level. Based on our findings, we recommend that hture studies examine multiple sites within each region to fully comprehend the herpetofaunal communities that exist in complex rain forest habitats.