Evaluating social housing strategies in zoo-housed aye-ayes (Daubentonia madagascariensis): behavioural considerations for welfare and management

Introduction Sociality in primates is associated with survival and welfare benefits, yet many nocturnal species remain understudied. The aye-aye ( Daubentonia madagascariensis ) is generally classified as solitary, although field and captive observations suggest variable social tolerance. This study investigated whether (1) captive aye-ayes exhibit social behaviour under social housing and whether social behaviour differs among social configurations, (2) housing condition alters non-social behavioural time budgets, and (3) extended social housing influences non-social behaviour over time. Methods Behavioural data were collected from three captive-born aye-ayes (adult female, adult male, juvenile male) housed under solitary, dyadic, and group conditions over nine weeks. Instantaneous scan sampling was conducted during 60-minute sessions, five days per week. Behavioural proportions were analysed using binomial generalised linear mixed models with logit links and individual- and observation-level random intercepts. Results All individuals expressed social behaviour during social housing (juvenile male 16.25%, adult female 14.02%, adult male 12.37%), with affiliative interactions predominating and agonistic behaviour remaining rare (<0.35%). Social behaviour was higher in all social housing conditions than in solitary housing but did not differ among social configurations. Locomotion increased in group housing (p = 0.048) and the sire–juvenile dyad (p = 0.034) relative to solitary housing, while exploration increased in the sire–juvenile condition (p = 0.002) but decreased in group housing (p = 0.041). Maintenance and abnormal behaviour decreased in group housing (p < 0.001 and p = 0.003, respectively). Feeding and foraging were unaffected. Over three weeks of group housing, exploration, feeding and foraging, and abnormal behaviour increased over time, with individual variation in trajectories. Discussion Hypotheses were partially supported; social housing promoted affiliative social behaviour without reducing feeding and foraging or increasing abnormal behaviour relative to solitary housing, suggesting behavioural tolerance. However, increased abnormal behaviour during extended group housing warrants further investigation to determine if responses plateau or reflect sustained stress. Although constrained by a small sample size warranting cautious interpretation, these findings provide preliminary evidence that managed short-term social housing, particularly group housing, may be behaviourally beneficial in captive aye-ayes and highlight the need for larger, multi-institutional studies integrating behavioural and physiological welfare measures.