Influence of environmental factors on the breeding success of Cinereous Vultures Aegypius monachus

Breeding success determines the fate of bird populations and, therefore, understanding its determinants is an important issue for the application of conservation measures for endangered species. Breeding success depends on diverse, not mutually exclusive, effects such as the life strategies developed by species, environmental, ecological and anthropogenic factors. The influence of nest and nest tree characteristics, landscape composition and human disturbance on the breeding success of the vulnerable Cinereous Vulture Aegypius monachus in breeding colony in central Spain was analysed. A number of variables characterising the vegetation around the nest-tree, the nest-tree, and the nest itself were selected and analysed. We found that bigger and less deteriorated nests, taller nesting trees and a higher shrub coverage in a radius of 100 m around the nest resulted in an increased breeding success. Although nesting sites characteristics and nest quality can be related to birds' age and breeding experience, our findings show that geographical orientation of the slope where the nest is located as well as nest accessibility and habitat selection have an influence on Cinereous Vulture breeding success. We recommend that mature forests, steeper slopes should be carefully conserved and protected from anthropogenic disturbances in order to strengthen the conservation of breeding areas of this forest-dwelling endangered raptor species.This work was carried out within the framework of the LIFE project 03/NAT/E/0050, by CBD Habitat Foundation with the collaboration of Castilla-La Mancha, Extremadura and Madrid regional governments, and the Spanish Ministry of Environment. It was co-funded by the European Commission. A.M. was supported by a “Ramón y Cajal” research contract from the Ministry of Economy and Competitiveness (RYC-2012-11867).Peer reviewe