Community structure of small mammals in an area of riparian savanna in Parque Estadual do Rio Preto, Minas Gerais, Brazil

Abstract

Small mammals comprise an important ecological component of the Cerrado mammalian fauna and its species richness increases among the open fields and forest formations. We captured small mammals (Rodentia and Didelphimorphia) during the dry and wet seasons in an area of savanna riparian forest, in Parque Estadual do Rio Preto, a reserve of Cerrado in southeastern Brazil. We investigated the variation in richness, abundance and use of vertical strata by species. Sampling was carried out from November 2009 to October 2011. In order to catch the animals we used 96 galvanized wire traps (300 mm x 160 mm x 160 mm) arranged on the ground and in the understory with a total effort of 9.216 trap x nights. In total, we obtained 622 captures of 13 species, seven of marsupials and six of rodents. Overall capture success was 7,18 %, being 7,83 % during the dry season and 5,16 % during the rainy season. Total richness (t = 0,296; P = 0,779) and abundance (t = 0,290, P = 0,782) of rodents and marsupials did not vary significantly between seasons. The community showed a relative dominance of marsupials on the rodents, and 76% of the catch has been taken in the understory. There were seasonal responses in the successful capture of species, and the greater complexity and heterogeneity of riparian vegetation seems to support a greater diversity of species regarding the open formations of the Cerrado.

Keywords: Cerrado, Didelphimorphia, diversity, richness, Rodentia.