Population Viability Analysis to Inform Reintroduction Decisions for a Group‐Living Primate, the Barbary Macaque

Demographic analyses provide valuable insights that can significantly enhance reintroduction planning and decision‐making, helping to improve the likelihood of reintroduction success. We developed a model to evaluate the chances of success for a reintroduction of the endangered Barbary macaque (Macaca sylvanus). The model incorporates age‐specific vital rates estimated from 11 years of demographic data on a wild population, reductions in survival and reproduction due to potential release costs, demographic and environmental stochasticity, reinforcement releases, and catastrophic events. Based on the available individuals considered as best candidates for reintroduction, we compared extinction risks under two release strategies. One strategy entails releasing all individuals as one large social group, while the other entails forming and releasing two smaller, separate groups. Our results suggest that the best strategy for Barbary macaques is to release two separate social groups, for which extinction risks remain low (< 5% in the absence of catastrophic events) as long as survival suffers minimal release costs. Sensitivity testing showed that extinction risks are more sensitive to changes in release costs on survival than on reproduction, and that sensitivity to initial sex ratio depends on initial group size. Extinction risk is dramatically affected by catastrophic events, although it is not highly sensitive to variations in the probability of occurrence of such events. Reinforcement releases help counter the effects of high release costs on survival, thus considerably improving probabilities of population persistence. Our model presents highly promising prospects for the successful reintroduction of a Barbary macaque population, and for the conservation of this species, which is the only extant nonhuman primate in North Africa.