Several factors, including the site where the colony was established and number of active nests can influence directly or indirectly the breeding success of colonial birds. The red-rumped cacique, Cacicus haemorrhous (Linnaeus, 1766), is a passerine (Icteridae) that breeds in colonies in different environments. The objective of this study was to evaluate the breeding success of red-rumped cacique in relation to three environments (lake edge, forest and swamp) in which colonies were established in an Atlantic Forest reserve in southeast Brazil. Seven colonies from the three environments were monitored during the breeding season of 2001. Overall probability of nest survival was 40.5%. We found that colonies established in the swamp presented higher nest survival than the others and the ones in the lake edge had lower survival. Nest predation was the most important cause of nest failure, representing 46.5% of all nest losses. Other failure causes were abandonment and fall of nests, representing 6.6% and 6.1% of the losses, respectively. Red-rumped cacique had higher success breeding in colonies located in the swamp.
Nest predation; red-rumped cacique; reproduction
