Drills are among the world's most endangered primates — their welfare in zoo settings serves a critical conservation function.
Drill welfare in captivity carries exceptional conservation stakes because the wild population is so small that every captive individual is genetically precious and every successful birth in a captive program is a conservation achievement. This conservation importance must motivate rather than justify welfare compromise — drills who are well housed in appropriate social groups, provided cognitive enrichment commensurate with their intelligence, and managed with positive reinforcement-based veterinary care are simultaneously better conservation investments and better welfare outcomes than drills in inadequate conditions. The small number of facilities managing drills globally creates both vulnerability and opportunity for welfare standard leadership.