DIVERSITY OF AMPHIBIANS AND REPTILES IN FOUR VEGETATION TYPES OF THE RÍA LAGARTOS BIOSPHERE RESERVE, MEXICO

Abstract

We compared the species diversity, community structure, species composition, as well as abundance patterns of amphibians and reptiles among the four most representative vegetation types of the Reserva de la Biosfera Ría Lagartos (RBRL). This study was carried out from September 2004 to July 2005. We conducted bimonthly day and night herpetofaunal samplings by visual encounter surveys in transects in coastal dune (DUN), petenes (PET), tropical floodable forest and medium sub-evergreen forest (SBI and SMS, respectively, by their acronyms in Spanish). We registered 1,401 individuals and 50 species (14 species of amphibians and 36 of reptiles). Amphibians showed notable differences in species diversity among vegetation types, where SBI and SMS were the most important environments in terms of species richness and abundance. In reptiles, species richness was highest in SBI, but other diversity values were similar to vegetation types. Differences among vegetation types were found in the structure and composition of species, indicating high complementarity among environments. We recorded few amphibians at risk according to national and international standards, but a high number of reptile species (24%) are threatened with extinction, including endemic species, as well as two introduced species. Our study offers a deeper understanding of the herpetofaunal patterns of diversity and composition and represents the first research with these vertebrates in the RBRL since its decree as a Protected Area in 1979.