Drills are critically endangered African primates whose complex social structures require large mixed-sex groups in captivity and urgent habitat protection in the wild.
Drills are among the most socially complex of the Old World monkeys, and their welfare in captivity depends critically on social group size and composition. Solitary or pair-housed drills show severe behavioral abnormalities. Best practice involves maintaining multi-male, multi-female groups with adequate space for sub-group formation and separation during conflict. The DRILL Ranch in Nigeria represents a pioneering model for drill conservation — combining sanctuary care for bushmeat orphans with community engagement to reduce hunting. In zoos, foraging enrichment that requires skill and persistence (puzzle feeders, buried food, scatter feeding) significantly improves behavioral diversity. In situ conservation requires addressing both bushmeat trade and forest loss in Nigeria and Cameroon.