Riqueza e densidade de aves que nidificam em cavidades em plantações abandonadas de eucalipto

Abstract

Eucalypt planted forests are replacing natural forests in many areas of the world, impacting wildlife by diminishing availability of habitats and resources. Several species of birds require hollows in trees for nesting, and the lack of this resource may decrease richness and density of cavity-nesting birds in planted forests. The aim of this study was to compare species richness and density of cavity-nesting birds in abandoned eucalypt planted forests and natural forests in two conservation units at Minas Gerais State, southeastern Brazil. Bird surveys were conducted using 25 point counts in both areas during 2013. Species richness was estimated using Jackknife, and density was estimated using the maximum likelyhood; candidate models that could influence abundance of birds were evaluated using Akaike Information Criterion (AIC). Results showed that species richness was higher in native forests and density was significantly higher in native forests than in abandoned eucalypt planted forests, and that vegetation type and hour of day influences the abundance and detection of the birds. These results indicate that abandoned eucalypt planted forests negatively influence the cavity-nesting bird's community, probably due to the lack of cavities or the lack of a recovered understory. Eucalypt planted forests normally do not substitute native forests and their use should be controlled in conservation areas.