Richardson, S. (2024). Primate enrichment categories: A literature review of current trends. Animal Behavior and Cognition, 11(1), 87-100.  https://doi.org/10.26451/abc.11.01.06.2024

Environmental enrichment aims to enhance primate wellbeing by providing physical and mental stimuli to address the biological and psychological needs of individuals. However, lack of knowledge regarding the development of enrichment research hampers implementors and future inquiries. Therefore, a collection of data from 227 peer-reviewed and freely available articles on primate enrichment (published from 1978 to 2019) was performed to present enrichment trends and outcomes through descriptive statistics. Behavior was the most recorded parameter (n=203), whereas physiological data were reported less frequently (n=20). Feeding enrichment (n=87) and tactile enrichment (n=62) were the most investigated enrichment categories, while other categories, such as olfactory enrichment (n=5) gained less attention. A total of 71 primate species were recorded across zoological (n=57), laboratory (n=22), and unspecified (not stated) research settings (n=5), with laboratory environments being predominant (n=135) over zoological environments (n=87). Notably, a substantial majority of published articles (>99%) achieved their initial research rationale, which represents a potential publication bias. To advance our understanding of enrichment welfare benefits and the specific relevance of individual enrichment methods to different primate species and taxa, a comprehensive meta-analysis incorporating all peer-reviewed primate enrichment research is crucial. Subsequent primate enrichment studies should prioritize the investigation of underrepresented enrichment categories, species, and environmental conditions, thus fostering a more comprehensive understanding of how environmental enrichment impacts primate welfare.

Environment enrichment, Descriptive statistics, Primate welfare, Laboratory, Zoo