Gibbons are the only non-human apes that sing elaborate territorial duets, and the ability to perform and respond to these vocalizations is central to their social welfare and reproductive success.
Gibbon welfare is intimately tied to intact forest and stable pair bonds. The loss of contiguous canopy forces gibbons to travel on the ground, where they are highly vulnerable to predation and human capture. Fragmented populations cannot maintain the acoustic contact that sustains pair bonds and allows juvenile gibbons to find mates after dispersal. In captivity, welfare is compromised when gibbons lack sufficient height for brachiation, are housed alone, or cannot express natural calling behaviour. Noise-polluted enclosures interfere with the acoustic communication that is fundamental to gibbon social life. Rehabilitation and release programmes must account for the need for juveniles to learn species-appropriate songs before they can successfully pair and hold territory.