Potential release sites and strategies for a Bearded Vulture Gypaetus barbatus reintroduction in South Africa

Abstract

The southern African population of Bearded Vultures Gypaetus barbatus has declined rapidly and it is threatened with extinction. In response to this decline and the additional threats of wind farm developments in the core of the species’ range, it has been proposed to establish a reintroduced population within their historic South African range as insurance against regional extinction. To facilitate such a reintroduction, we used Maximum Entropy Modelling based on suitable nesting habitat to identify and define five potential reintroduction sites. We then compared the suitability of these sites based on the quantification of various threats and benefits within each site. The two highest-ranking sites were located mostly in the Eastern Cape Province of South Africa. We then compared different release strategies, using a Population Viability Analysis, to determine which approach would be most likely to be successful (defined as >34 individuals after 30 years). These models suggest that establishing a captive breeding programme and releasing captive-bred young would lower failure rates to 25.5–49.8%, compared with the direct releases of wild taken fledglings, without a supporting captive breeding programme (78.3–95.7%). Our models also suggest that even in the presence of high mortality rates at the reintroduction site, such a reintroduction would still be a worthwhile project, because it reduces the probability of extinction of the southern African population by approximately 30% over a 50-year period.