Alejandro, J., Huffman, M. A., Bercovitch, F. B. 2022. Costs and benefits of living in a vegetated, compared with non‐vegetated, enclosure in male Japanese macaques (Macaca fuscata). Zoo Biology 41(2), 97-107.

Improving captive environments for primates has been an important tool to enhance animal welfare. One method has been to provide primates with naturalistic vegetated enclosures to promote species-specific behaviors, enhancing interactions with their social and natural environment, such as an increase in feeding, foraging, and positive social behaviors such as play. To investigate the benefits in which living in naturalistic environments promote general animal well-being, we observed immature and adult males living in two outdoor housed groups of Japanese macaques (Macaca fuscata) in the Kyoto University Primate Research Institute (KUPRI), Inuyama, Japan, from June of 2015 until June 2016. One enclosure was naturally vegetated and the other was not. We recorded male activity budgets, affiliative (groom, play) behaviors, and rates of agonistic interactions. To examine health status, we recorded and compared coat conditions for both groups. We found that males in the vegetated enclosure spent more time in social play than males in the non-vegetated enclosure, while males in the non-vegetated enclosure displayed more stereotypic behaviors and agonistic interactions. We recorded better coat conditions in the vegetated enclosure males while rates of social grooming or self-grooming were no different between males in the two enclosures. The males in the vegetated enclosure did not have activity budgets more similar to their wild counterparts; but they spent more time in feeding-related activities and less time resting, which was more similar to their wild counterparts than males in the non-vegetated enclosure. Our findings suggest that individuals housed in naturalistic environments have significantly greater behavioral and physical markers of wellbeing than those housed in unnatural, large outdoor enclosures. Although we found that males in both types of enclosures overall had similar time budgets to males in the wild, the detailed behavioral and health results suggest that the welfare benefits to males were greater in the vegetated enclosure, compared with non-vegetated enclosures. Efforts to mimic more natural environments should promote the well-being of primates.