Chimpanzees, gorillas, bonobos and orangutans have complex social, cognitive and emotional needs. Meeting these in captivity is one of zoo welfare's greatest challenges.
Great ape welfare in zoos requires institutions to grapple with the deepest questions in animal welfare: what does it mean for a cognitively sophisticated, emotionally complex animal to flourish in captivity? Space is necessary but insufficient - social group composition, management stability, cognitive enrichment quality and keeper relationships all profoundly affect wellbeing. Psychological distress in great apes manifests in behaviours recognisable to any observer: rocking, self-injury, stereotypic pacing. These are not inevitable consequences of captivity but signals of welfare failure that can and must be addressed.