Home range and habitat selection of captive-bred and rehabilitated cape vultures Gyps coprotheres in southern Africa

Abstract

Following the continual decline of the Cape vulture Gyps coprotheres since the 1960s, captive breeding and rehabilitation programmes have been established to reinforce populations across southern Africa. This study examines the spatial ecology of captive-bred and rehabilitated vultures following release. Our analysis used 253,671 GPS fixes from 20 captive-bred and 13 rehabilitated birds to calculate home range sizes using kernel density estimation. We found that home range size did not differ significantly between captive-bred and rehabilitated birds. The location of home ranges differed: captive-bred birds showed greater site fidelity, remaining close to their release site, whereas rehabilitated birds dispersed more widely across the species' native range. By remaining close to their release site within a protected area, captive-bred birds had a significantly higher per cent of their GPS fixes within protected areas than did rehabilitated birds. Despite fidelity to their release site, captive-bred birds demonstrated innate capabilities for natural foraging behaviours and the same habitat selection strategy as rehabilitated individuals. These findings suggest that captive breeding and reinforcement of populations at declining colonies could provide localized benefits. Future long-term studies should seek to analyse survivorship and identify the breeding behaviour of these captive-bred birds once they reach sexual maturity.