One lauded justification for the keeping of wild animals in captivity is to ensure a secure population that could be used to return a species to the wild, should it ever become extinct. A few celebrated captive breeding and release projects are regularly cited to demonstrate the success of this kind of intervention, such as the Arabian oryx and the black-footed ferret of the plains of North America. However, closer inspection reveals that the effectiveness of these and many other captive breeding programmes is, at best, limited.
Relying on captive populations lulls us into a false sense of security, drawing attention away from threats to wild populations and habitats which, if not protected, could be destroyed leaving no viable location for return. The substantial costs of captive breeding could be used more effectively to protect these wild species and habitats. Many high-profile captive breeding and release projects were only initiated when wild populations were very low – if in situ1 protection had been prioritised they would not have been necessary. Indeed the ‘Rio’ Convention on Biological Diversity states captive breeding should be ‘predominantly for the purpose of complementing in situ measures’.
Captive breeding is only attempted with relatively few individuals, leading to potential issues with inbreeding – the development of hereditary problems due to a limited gene pool. In addition, such breeding removes the challenges animals face in the wild, quickly leading to genetic changes that may make individuals less able to survive in the wild. For example, captive populations of red junglefowl (wild ancestors of chickens) differ significantly in response to predators after just a handful of generations in captivity. Animals that respond badly to captivity may be less likely to breed, even though they may be best adapted for wild conditions.