Nesting success of birds from Brazilian Atlantic Forest fragments

Abstract

Several aspects of the ecology of tropical birds remain unresolved both descriptively and experimentally, in spite of the high diversity of birds and the high deforestation rates within the Neotropical region. Here, I evaluate apparently for the first time, nesting success and predation levels of open and closed-cupped nesting birds in an avian community from Atlantic Forest fragments in southeastern Brazil. The monitoring of 257 nests of more than 22 species from 1995 to 1999 revealed that overall apparent nest success (42.4%) was in the upper range for tropical species. Average daily probabilities of nest survival for 18 species ranged from 0.900-0.987. Total average survival probability was 55.9 for open cup and 60.1 for closed nests. There was no evidence for an edge effect on the success of either open cup and closed nests. Against predictions, apparent success of closed nests did not differ from open cup nests. However, there were major differences in apparent success within three types of closed nests. Closed nests higher above the ground had greater apparent nest success than lower nests, but this pattern did not occur for open cup nests. This study demonstrates that some patterns and paradigms of nesting success present in the literature for decades should be considered with care or even revaluated when applied to Neotropical species.