Low genetic diversity of the reintroduced bearded vulture (Gypaetus barbatus) population in the Alps calls for further releases

Abstract

Reintroductions are a valuable tool to reestablish locally extirpated species. A difficult decision facing all reintroduction projects is when to stop further releases, both from a demographic and genetic view point. Here we address this question in the case of the reintroduction of bearded vultures (Gypaetus barbatus) in the Alps, which were exterminated in the early 20th century mainly due to human hunting. To investigate the genetic diversity present in today’s reintroduced Alpine bearded vulture population, we reconstructed a pedigree, spanning the entire reintroduction program since the beginning of the captive breeding (1973-2010). We found that not every founder bird was equally well represented in the wild population and that founder genome equivalents were low (13). Moreover, wildborn bearded vultures showed a relatively high mean inbreeding coefficient compared to the captive birds and the effective population size was estimated to be only 28. Overall, this suggests that there is not enough genetic diversity in the wild Alpine bearded vulture population to ensure its longterm sustainability. Therefore further releases are recommended.