Mandrills are the world's largest monkey species and form complex multi-male, multi-female groups in the wild — welfare in captivity depends critically on appropriate group composition and social management.
Mandrill welfare in zoos depends heavily on group composition and management. Small groups fail to provide the social complexity that mandrills are evolved for — subordinate males may be chronically harassed without the social buffer of a larger group structure. Large, appropriately structured groups with sufficient space show richer behavioral repertoires and lower stress indicators. The environmental complexity of mandrill enclosures is critical: providing ground-level foraging substrate, varied terrain, and foraging enrichment allows expression of their natural food-finding behaviors. The relationship between dominance status and hormonal expression means that chronic social stress has measurable physiological consequences that are visible in behavioral and physical indicators.