The Success of Post-Release Vervet Monkeys (Chlorocebus pygerythrus hilgerti) in Kenya: An Analysis of Pre-Release Threat-Awareness Tests, Training, and Post-Release Success

We are in the midst of a primate conservation crisis as 75% of the world’s primates are in population decline. However, translocation attempts are a promising option to reinforce and reestablish struggling primate populations. While factors that often result in translocation failures have been identified in previous research, there is still a poor understanding of what aspects of rehabilitation creates or predicts repeatable success post-release. This thesis is an analysis of Andrea Donaldson’s original case study on the rehabilitation release of vervet monkeys, Chlorocebus pygerythrus hilgerti, in Diani, Kenya. I aimed to evaluate the efficacy of pre-release threat-awareness tests and electrical wire training by investigating the behavioural responses of the vervet monkeys, how their individual traits may influence their response, the influence of social learning, and the predictive nature of their response to these tests and training on their post-release survival and success. Before release, the vervets underwent awareness tests for the predicted threats found in their anticipated habitat, which included baboons, dogs, humans, and snakes, and they were trained to avoid electrical wires. The responses of each vervet were recorded and statistically analysed. Results indicated that vervets showed inconsistent threat response improvement during rehabilitation; however, electrical wire training was effective. While no statistical correlation was found between a vervet's background and their response score, their survival rates upon release into the wild were comparable to those of a wild control group. Additionally, observing another individual receiving a shock during pre-release training had no subsequent effect on the number of shocks administered to the observer during electrical exposures. These findings affirmed the efficacy of these methods of rehabilitation pre-release and indicated that future research can further perfect the process of threat training and testing to promote post-release success.