Estimation of the Bearded vulture's (Gypaetus barbatus ) trophic resources in Catalonia (NE Spain) and implications about its conservation

The trophic resources of the population of bearded vulture (Gypaetus barbatus) in Catalonia is estimated using a methodology which distinguishes the food supplies available during the pre-laying/breeding periods and the summer ones. The different variables used to calculate it are: distribution and seasonal availability of the trophic resources, death rate of lame and wild ungulates, usable biomass per carrion and energetic requirements; per pailr and year. The results allow us to theorize on the implications that the trophic estimation may have for the conservation of this species: 1.- The food provided by the genera Ovis, Capra and Rupicapra is enough to supply the energetic requiremente of the present breeding pairs. The abundant availability of food may permit the acceptance of a larger number of breeding pairs. 2.- The reproductive success of the studied pairs is not limited by food availability, although both the differents between the adult and young birds' diels and the incidence of an adverse climate may condition it. 3.- The natural food availability would appear to decrease the importanee of sorne supplementary feeding points. However, their predictability may help some breeding pairs and juvenile populations, and as such, it is necessary to maintain and boost them.Peer reviewe