Effects of habitat structure on the spatial distribution of two species of tinamous (Aves: Tinamidae) in a Amazon terra-firme forest

Abstract

We investigated how the spatial distribution of two species of tinamous (Family Tinamidae) is modulated by the variation in the natural structure of a central Amazonian terra-firme forest. We tested whether five components of forest structure (dead fallen trunks, canopy openness, tree abundance, leaflitter depth and distance to water) influence the spatial distribution of Great (Tinamus major) and Variegated Tinamou (Crypturellus variegatus). We used 30 listening points between October 2012 and April 2013 to estimate the frequency of occurrence of these species within a 25-km2 area. Multiple linear models indicated that the frequency of occurrence of the Great Tinamou was not explained by any tested component of the forest structure. The occurence of the Variegated Tinamou increased significantly in areas beneath more open canopy and those with more fallen dead trunks, but diminished in areas where leaf litter was deeper. We conclude that forest heterogeneity can be an important factor influencing the spatial distribution of terrestrial birds. © 2014 The Neotropical Ornithological Society.