Mandrills are the world's largest monkeys and among the most socially complex primates in zoological collections, requiring large mixed-sex groups and substantial space to express natural dominance hierarchies without chronic aggression.
Managing mandrill social dynamics in zoo settings is genuinely difficult. Wild mandrills resolve dominance conflict through spatial separation — subordinate males can move to the periphery of a large horde. In confined zoo groups, subordinate males cannot escape persistent harassment, causing chronic psychological stress evidenced by reduced colouration, elevated cortisol, and submissive stereotypies. The minimum viable group size for mandrill welfare is debated, but small bachelor groups or single-male harems with multiple females are preferable to forcing multiple adult males into confined spaces without escape options. High-welfare facilities provide complex, large enclosures with visual barriers that allow subordinate animals to avoid dominant individuals.