A estrutura da vegetação determina a composição de aves no Cerrado?

Abstract

The vegetation is an important characteristic of habitat to understand how bird species are distributed. The landscape of the brazilian Cerrado is formed by a vegetation mosaic of different types of phytophysionomies, where forest and fields fragments coexists, providing high variety of habitats. We investigated the hypothesis that the structure of the cerrado vegetationcomposed of a gradient ranging from fields to forests is determinant the species composition of bird assemblages. For this, 36 sites, distributed among three regions were sampled in the Chapada dos Guimarães National Park, in the molds of the Research Program on Biodiversity (PPBio). The vegetation structure was measured in two ways: by the proportion of physiognomic categories and vegetation index (EVI) of each site. Data collection methods for the birds were through captures with mist nets and censuses by fixed listener. Were recorded 3041 specimens of 120 species birds belonging to 21 families of the Order passerine.The structure of the vegetation was not a determinant to explain the composition of bird assemblages considered when all portions of three modules simultaneously. But when each module was analyzed separately, the structure of the Rio Claro region of vegetation had a significant effect on the composition of the assembly of birds. This effect was determined by the occurrence of birds preferentially found in high abundance in areas with higher cerrado extensions. Bird species with a preference for forest or fields habitats, were present in areas with a lower proportion of cerrado, but in low abundance.