Gibbons are the only true brachiating apes, swinging through forest canopies with extraordinary agility. Their complex pair bonds, elaborate song duets, and need for extensive vertical space make them demanding but rewarding zoo residents.
Gibbon welfare in captivity is defined by two requirements: appropriate social pairing and sufficient arboreal structure for brachiating locomotion. Gibbons housed without a bonded partner show profound psychological distress — self-directed behaviours, stereotypies, and social withdrawal. The pair bond is not merely social preference but a core biological requirement; disrupting established pairs causes lasting welfare harm. Exhibits must provide networks of ropes, bars, and elevated platforms at sufficient height for natural locomotion — gibbons that cannot brachiate are denied their primary mode of movement. Song behaviour is also welfare-relevant: pairs that cannot vocalise freely — because exhibits muffle or penalise loud calls — lose an important pair-reinforcement mechanism. The gibbon rehabilitation crisis in Southeast Asia, where pet trade orphans require years of socialisation before any hope of release, demands attention from both conservation and welfare perspectives. Zoos that hold gibbons should actively contribute to this rehabilitation work.