Spatial variation and the habitat influence in the structure of communities of small mammals in areas of rocky fields in the Federal District

Abstract

In the present study, we investigated the communities of small mammals in rocky fields in the Federal District. We examined the composition, abundance and richness and their relation to the structure of the habitat and if there is significant spatial variation in species composition among sites of rocky fields. Small mammals were sampled by live-trapping techniques in seven sites. The total effort for the seven sites was 5.680 trap-nights; we captured 157 individuals in eight species of rodents. Calomys tener and Cerradomys scotti were the most abundant species in the study sites, with 47.1 and 18.0% of total individuals, respectively. The results showed that the areas of rocky fields of the Federal District have a fauna of small mammals (average of four, range of variation of three to five species), comparable to other Cerrado physiognomies. The complexity of the habitat proved to be a major determinant in the composition of communities of small mammals in rocky fields. There was a distinction between communities of small mammals of the sites of APA Gama e Cabeça do Veado and the sites of the APA de Cafuringa. There was influence of the distance between the places on the composition of species with decreasing similarity with increasing distance among sites. The differences in environmental conditions, the structure of the habitat and the fact that it was possible two biogeographical regions may explain the faunal differences between the two regions.