Ex situ gibbon conservation: status, management and birth sex ratios



Many zoos take part in captive-management programmes for gibbon species, which contribute to the conservation of this highly threatened taxon. Eight gibbon species are represented in captive-management programmes globally, although the numbers held are highly biased towards only two species, which fill most of the space available in zoos. The other gibbon species are held in small populations that are difficult to manage and, thus, are unlikely in their current form to be self-sustaining. Effort and, more importantly, space are required to grow these small gibbon populations. In addition, the space that is available needs to be used wisely. This may require that only animals that can actively contribute, whether genetically or socially, to the goal of achieving a self-sustaining captive population are maintained. There is also a need to investigate the impact of environmental factors in captivity as they relate to birth and death rates, which would enable evidence-based captive management of gibbons with the aim of stimulating breeding and mitigating the potential deleterious impacts associated with managing small populations.