Assessing the release success of rehabilitated vervet monkeys in South Africa

Eight post-rehabilitation vervet monkey troop releases were assessed with regard to their outcomes, environmental aspects of release sites and consistency with IUCN guidelines for non-human primate re-introductions. Based on our criteria, none could be considered successful as survival rates were too low. Troops with the best outcomes were close to the mean wild troop size. Despite release sites falling into two major groups in terms of climate, land cover and anthropogenic landscape alteration, we found no clear association between site characteristics and projected long-Term survival. A number of IUCN guidelines were not followed. Recommended improvements include implementation of quarantine, disease screening and environmental enrichment, better assessment of release sites, and fitting all individuals with tracking devices to monitor for >1 year.