Drill monkeys are critically endangered primates from Central Africa. Their welfare in zoos requires managing complex social hierarchies and providing cognitively stimulating environments.
Drill welfare in zoos is challenging due to their complex hierarchical social structure. In small captive groups, dominant males may monopolise resources and prevent subordinates from accessing food, space, or social contact. Managing these hierarchies requires careful exhibit design with visual barriers, multiple feeding stations, and retreat areas. Cognitive enrichment — foraging puzzles, novel objects, scattered food — is essential for a species with high intelligence and social complexity. Drills in well-managed groups with adequate space and enrichment show diverse natural behaviour including grooming, play, and complex vocal communication that indicates good welfare state.