Diversity of large and medium mammals in Juchitan, Isthmus of Tehuantepec, Oaxaca, Mexico

Abstract

The Isthmus of Tehuantepec in Oaxaca, Mexico, is one of the country’s most important regions from a zoogeographical perspective due to the large number of endemic Neotropical species found there. Between September 2007 and August 2008, we sampled medium–sized and large mammals in the Juchitan municipality and compared their diversity in two areas with distinct levels of anthropogenic impact, defined according to estimates of human activities, livestock density and habitat degradation, We obtained 167 records of 18 species, with a 79% representation according to species accumulation models in both areas. The highest species richness and alpha diversity were recorded in the preserved area, whereas the disturbed area exhibited half the diversity found in the preserved area. A high interchange of species was also observed between zones. The two species with the largest number of records were Urocyon cinereoargenteus (n = 52) and Didelphis virginiana (n = 42). In both areas, the highest relative abundance occurred during the rainy season. Habitat degradation and human activities seem to affect the diversity of mammal species in the region.