Breeding biology and diet of the Chaco Eagle (Buteogallus coronatus) in southeast Brazil

Abstract

The Chaco Eagle (Buteogallus coronatus) is a globally "Endangered" raptor with little known about its biology. In this work, we provide data on the reproductive biology of the Chaco Eagle collected between 2007 and 2018 with the discovery of nine nests in five areas of the state of Minas Gerais, Brazil. Clutch size is one egg (n = 6 nests) with incubation occurring between August and November and fledging between January and February. The species showed plasticity in the characteristics of the occupied trees and nesting sites, nesting in both conserved and disturbed areas. Monitoring of some pairs indicated a reproductive reproduction event every 2 to 3 years. Only 33% of the observed breeding attempts generated successful fledglings. Most of the 20 dietary items collected were reptiles and armadillos. Despite presenting environmental plasticity, data from this study suggest low reproductive success for the Chaco Eagle and thus reinforce the importance of long-term monitoring of reproductive sites for planning strategies for its conservation in Brazil.