The effects of cognitive testing on the welfare of zoo-housed Japanese macaques (Macaca fuscata)

Abstract

Cognitive testing programs are being implemented more frequently in zoo settings due to the benefits these programs can provide for the animals, researchers and zoo visitors. However, the impact that cognitive studies have on the welfare of captive animals, particularly for primates in a social group, is debated. Although cognitive testing can be mentally enriching, the provision of monopolisable apparatuses to a primate social group can elicit competition and potentially contribute to negative welfare. We sought to investigate how behaviours changed when a group of 12 Japanese macaques had access to two touchscreen devices. We assessed rates of affiliative behaviours, anxiety-related behaviours, general activity, and aggression over 15 months at matched time periods on days when cognitive testing was available and when it was not. Rates of affiliative behaviours, anxiety-related behaviours, and general activity were not significantly different between conditions. Rates of contact and non-contact aggression were significantly higher during cognitive testing compared to times without cognitive testing (p < 0.05 for both). To further explore this result, we used social network analysis to visualize the aggressive interactions between individual macaques. We found that juveniles were receiving the most aggression. However, because the overall rates of aggression were low and did not deter the macaques from participating in cognitive research, we do not think these results should broadly discourage the implementation of cognitive testing programs. Instead, we intend this study to inform how cognitive testing programs are executed. We also discuss how social interactions and the corresponding welfare implications may differ in closely related macaque species based on species-typical sociality.