Leeds, A., Elsner, R., Lukas, K. 2016. The effect of positive reinforcement training on an adult female western lowland gorilla’s (Gorilla gorilla gorilla) rate of abnormal and aggressive behavior. Animal Behavior and Cognition 3(2), 78–87.

Positive reinforcement training (PRT) has become a widely used tool in improving the ease with which husbandry and veterinary procedures are performed for animals under human care. PRT provides positive social interaction, cognitive stimulation, and choice, in addition to desensitization towards potentially stressful situations. As a result, PRT has been used as enrichment to decrease abnormal and aggressive behavior in various primate species, however, this has not been empirically tested in western lowland gorillas (Gorilla gorilla gorilla). This study used an ABA design to test the effect of PRT on the abnormal and aggressive behavior of an adult female gorilla both during and outside of interaction sessions. No change in behavior was observed during the PRT phase of this study. However, a decrease in ear covering and keeper-directed aggression were observed in the post-training period. Here we argue that the combination of both PRT and non-training interactions cumulatively provided social and cognitive stimuli resulting in the observed changes. These results provide further evidence on the importance of interactions between staff and animals in their care. Further systematic evaluation of the usefulness of PRT as enrichment is still needed, specifically in zoos and across different species. However, PRT is helpful in facilitating husbandry and veterinary procedures and thus should be considered an important tool in optimizing the welfare of animals under human care regardless of its effectiveness as enrichment.