Drills are one of Africa's most endangered primates and least known to the general public. Zoo breeding programs and rehabilitation centers play critical roles in their conservation.
Drill welfare in captive settings requires large, complex social groups that reflect their wild multi-individual community structure. Small group sizes — common in zoo collections given population constraints — prevent expression of the hierarchical social behavior and coalition formation central to drill society. Large mixed-sex groups with appropriate age-sex composition and space for subordinate individuals to navigate away from dominants provide better welfare outcomes. The Pandrillus Foundation in Nigeria, which houses the world's largest captive drill population and has released rehabilitated individuals to protected forest, provides a model for captive management with direct conservation impact. Foraging enrichment, complex arboreal environments, and keeper relationships built through positive conditioning support welfare. The conservation case for drills is urgent — their obscurity relative to more charismatic primates means they receive a fraction of the conservation funding their status warrants.