Western lowland gorillas are the most commonly kept great ape in zoos, with welfare depending on appropriate social structures that replicate natural harem group dynamics in naturalistic habitat settings.
Gorilla welfare in zoo settings is strongly influenced by social structure quality. Natural gorilla groups have clear hierarchy with a dominant silverback whose stability and temperament affects the entire group welfare. Well-managed zoo gorilla groups with appropriate silverback leadership, compatible female membership, and sufficient space for normal social interaction show good behavioral welfare indicators. Solitary housing — historically common for zoo silverbacks — causes severe welfare compromise. The development of bachelor groups for non-breeding males has provided an appropriate social context for these individuals. Positive reinforcement training that enables voluntary health monitoring is both a welfare tool and welfare indicator — gorillas who participate voluntarily demonstrate positive relationship with keepers and reduced stress during veterinary procedures.