Population viability analysis of captive and released Bearded Vulture populations Analisis de viabilidad de poblaciones para las poblaciones cautiva y liberada de quebrantahuesos

摘要

With the computer program VORTEX I ran a series of simulation of the Bearded Vulture (Gypaetus barbatus) populations held in captivity in European zoos and of the population released in the Alps. The simulations showed that the risk of extinction of the captive population with the extraction rates currently in use is low. It seems possible to maintain the current release rate of two fledglings per year at each of the four release sites in the Alps, but it does not seem possible to increase the release rate by expanding the project to other European mountains without depleting the captive population. The models showed that the most effective way to increase the release rate without increasing the captive population size is by improving batching success in captivity. The information on the demographic parameters of the Bearded Vulture population released in the Alps was not good enough to predict the ultimate fate of the present population or to allow for recommendations on how long the populations should continue to be supplemented. Although it will be necessary to wait some years to see if Bearded Vultures are able to breed in the wild in the Alps and to estimate fecundity rates, it should be possible to improve the monitoring of the individuals released to obtain more-phase survival estimates. The models of the captive and released population also showed that it should at least be possible to have an artificially supplemented Bearded Vulture population in the Alps, but because this is not the goal of the present reintroduction project, the organizations involved should decide whether this is a politically or economically desirable goal.