Evaluation of an enrichment programme for a colony of long-tailed macaques (Macaca fascicularis) in a rescue centre

Long-tailed macaques are highly social primates that are commonly used in biomedical research as animal models. The aim of this study was to evaluate the effects of different kinds of enrichment on the behaviour and faecal cortisol metabolite (FCM) level in a colony of ex-laboratory long-tailed macaques during a programme of rehabilitation. The research was carried out in three periods, divided into two sessions each. Every period was composed of one control session (SC) and one session characterised by one type of enrichment: feeding enrichment (FE), manipulative enrichment (ME), and the last session during which manipulative and feeding enrichment were provided every day but in a mixed way (MIX). The results showed that manipulative and mixed enrichments caused positive changes to the activity budget of the colony, with a decrease in abnormal behaviour rates and an increase in play compared with control sessions. The rate of affiliative behaviours and low rate of aggression were probably because the group was composed mostly of females and it was stable, with a well-defined hierarchy. The research underlines the importance of a well-studied enrichment programme for the welfare of captive animals, which should exploit species-specific motivations.