Effects of habitat fragmentation on the genetic variability of the volcano rabbit (Romerolagus diazi)

Fragmentation of ecosystems and habitat loss may produce changes in the structure and distribution of communities. Low values of genetic diversity are generally linked to these processes, as a result of the reduction of the effective locality size. Recent habitat fragmentation has affected the connectivity of volcano rabbit (Romerolagus diazi) populations and has increased the risk of extinction of this species. The goals of this study were to estimate the genetic variability of the volcano rabbit localities in connected and unconnected patches and to estimate their genetic structure.Anon-invasive fecal methodwas used in six collecting sites of the Sierra de Ajusco-Chichinautzin (Coajomulco, Chalchihuites, Pelado I, Pelado II, Tlaloc I, and Tlaloc II), located in the central mountains of the Trans-Mexican Volcanic Belt. Ten nuclear microsatellite loci designed for the species were used, and amplified products were genotyped and analyzed with different statistical programs. All microsatellites were polymorphic with a range of eight to sixteen alleles. Moderate genetic variation was observed as well as levels of expected heterozygosity (H_E = 0.75, H_O = 0.67), with low levels of differentiation (F_ST = 0.05). The greatest genetic variation was found within localities (94%). A fine scale was assessed, and the data suggested that sample patches represented two defined genetic groups (K = 2), although all localities had experienced gene flow. The population size varied between 8386 and 14,572 individuals. Finally, it was estimated that the volcano rabbit localities had reduction in its population sizes in the recent past.