Drills are critically endangered African primates whose complex social hierarchies require sophisticated management in zoo settings. Their zoo populations are essential for species survival.
Zoo drill welfare centers on replicating key elements of their complex wild social structure. Large, stable social groups with an appropriate age and sex composition support natural dominance hierarchies and social behavior. Males may be intensely competitive, requiring space design that allows subordinate individuals to avoid dominant males. Foraging enrichment distributed across complex exhibits reduces food competition and promotes activity spread across exhibit space. Their facial color signaling provides welfare assessment opportunities — stress may dampen facial coloration in lower-ranking males. Drill sanctuaries in Nigeria provide welfare conditions approaching wild life for hundreds of rescued individuals, demonstrating that effective large-scale drill management is achievable.