Fenología y parámetros reproductores del Buitre Leonado (Gyps fulvus) en una colonia de Guipúzcoa (N España) (1984-1993)

Abstract

Phenology and breeding parameters of a Griffon Vulture (Gyps fulvus) colony in Guipuzcoa (N Spain) (1984-1993)
The breeding season of a Griffon Vulture (Gyps fulvus) colony in Guipuzcoa (N Spain) was studied over ten consecutive years (1984-1993). Annual changes in phenology were found, and the total number of breeding pairs decreased. Mean productivity of the colony was 0.76 ± 0.22 chicks/pair. Most of the chicks in nests (95.3%) left the colony. Most Griffon Vultures (82.2%, n = 62) made their nests in rocky cover sites. Nest-site placement affected the breeding success. Bad weather conditions and low nest-site availability could explain why the breeding colonies located in Guipuzcoa are formed by a low number of pairs.