Diet and food preferences of the endangered Bearded Vulture Gypaetus barbatus: a basis for their conservation

The Bearded Vulture Gypaetus barbatus population in the Pyrenees is managed using feeding stations to increase breeding success and reduce mortality in the pre-adult population. Nevertheless, very little quantitative and qualitative information has been published on such basic aspects of the species' ecology as feeding habits and dietary preferences. This study investigated both aspects through direct and unbiased observation of breeding Bearded Vultures during the chick-rearing period. Bearded Vulture diet comprises mammals (93%), birds (6%) and reptiles (1%), with medium-sized ungulates (mainly sheep/goats) the most important species in the diet (61%, n  = 677). Prey items were not selected in proportion to their availability, with the remains of larger species (cows and horses) being avoided, probably due to the variable cost/benefit ratios in handling efficiency, ingestion process and transport. There is no relationship between the proportion of sheep limbs in the diet and the proximity of feeding stations, suggesting that these sites are probably less important for breeding adults than for the pre-adult population. On the other hand, diet specificity seems related to productivity, with territories with greater trophic breadth being those with higher fecundity. Bearded Vultures prefer to eat limbs, although meat remains (provided principally by small mammals) can play an important role in guaranteeing breeding success during the first few weeks after hatching. The management of carrion provided by animals that die naturally in extensive livestock practices and the remains of wild ungulates which have died naturally or by human hunting, are important conservation tools for the Bearded Vulture and other carrion-eating species.