Great apes are among the most cognitively complex animals in captivity. Their welfare needs are correspondingly high and often challenged by zoo environments however well-intentioned.
Great ape welfare in captivity is one of the most scrutinised areas of zoo practice and one of the most consistently challenging. The cognitive sophistication that makes apes compelling to zoo visitors is the same quality that makes inadequate captive environments so damaging to their psychological health. Apes in under-stimulating environments develop abnormal behaviour — rocking, self-hitting, regurgitation and reingestion — that reflects genuine psychological distress. The best zoo great ape facilities invest heavily in enrichment, keeper relationships, social group management, and choice architecture that gives apes agency over their environment. Even so, the question of whether captivity can ever be adequate for animals requiring vast ranging areas and complex social lives remains genuinely contested among welfare scientists.