Ecogeographical Distribution of the Herpetofauna of Indio Mountains Research Station, Hudspeth County, Texas

Indio Mountain Research Station (IMRS) in Trans-Pecos, Texas is dominated by Chihuahuan Desert scrub vegetation, but a complexity of plant communities exist relating to elevation, slope, and geologic formations. Surrounding the Indio Mountains are desert grasslands with various desert scrub associations. This mosaic of habitats forms a unique assemblage of amphibians and reptiles. The goal of this study was to determine if the current number of amphibians, turtles, lizards, and snakes (43 species) of IMRS was accurate and identify which biotic and abiotic factors define the distribution of these species. Records from the last approximately 25 years were used to determine species presence at localities throughout IMRS. Surveys were conducted throughout IMRS in 2011. Eight sites across IMRS were sampled with walking searches and pit-fall trapping to compare their herpetofaunal communities and the vegetation community of each site was quantified. No new species were documented. Cophosaurus texanus and Aspidoscelis tesselata were the only species present at all trapping sites. Many other species were recorded throughout IMRS. Double Tank Corral, Oak Arroyo, and Squaw Spring possessed the most distinct vegetation communities. IMRS Headquarters, Prospect Pits, and Squaw Spring shared the most similar herpetofaunal communities, and Lonely Tank had the most dissimilar community. Soils, thermal environment, slope orientation, elevation, vegetation, microhabitat diversity, and water sources are factors likely limiting distribution and influencing habitat occupancy of amphibians and reptiles on IMRS. This thesis represents the current knowledge of amphibian and reptile distribution on IMRS, the major mechanisms influencing species distribution, and identifies the gaps in knowledge necessary to accurately identify population dynamics and interpret community changes on the research station. A species account of all known taxa is also presented