Recently extirpated in Lancang county, China. May visit 16 or more widely spaced food trees in a day's foraging. Rest of diet consists of leaves, young plant shoots, flowers, birds' eggs, birds, insects, and spiders. Zoo diet is primate chow, fruits, vegetables and browse. They drink by licking their own fur after a storm, or dipping an arm into a tree hole or rubbing it on wet foliage.
Gibbons live in small family groups consisting of the mated pair and their immature offspring.
There is almost no sexual dimorphism and males are not socially or physically dominant over females. The function of calling seems to be both territorial and to reinforce the pair bond. The calling bout is usually initiated by the female. The male usually takes the lead in attacking other gibbons encountered, although actual fighting is uncommon. There is no particular breeding season.