Population ecology of Ameivula ocellifera (Spix, 1825) (Reptilia, Squamata), in an area of caatinga in Pernambuco, Brazil

The Caatinga is an exclusively Brazilian biome, which has many endemic life forms and species adapted to semi-arid conditions. Spix’s whiptail Ameivula ocellifera is amply distributed in the semi-arid polygon of South America, and is common in anthropogenic environments. The present study investigated the ecology and genetic variability of A. ocellifera in an area of Caatinga in the Brazilian state of Pernambuco. A total of 12 field trips were conducted between November 2015 and October 2016, with three environments being surveyed: pasture, a prickly pear plantation, and secondary Caatinga vegetation. All the specimens collected were measured and samples were obtained for the analysis of the ISSR molecular marker. A total of 32 A. ocellifera specimens, which presented a sex ratio typical of the species, with a continuous reproductive period, which reflects the adaptive success of this species to the Caatinga environment. Based on similarity indices, it was possible to confirm that all the specimens collected were closely related. However, the larger number of individuals and the greater genetic variability found in the specimens collected from the farmland indicate that this environment constitutes a refuge for the lizards, providing shelter and feeding resources. However, this anthropogenic microenvironment also represents a risk to the species due to increasing intra- and interspecific competition, and a reduction of genetic variability through endogamy.