These groups are territorial, maintaining their territories partly by conspicuous vocalization, which may involve loud duetting by group members. They are primarily vegetarian, feeding on figs and other fruit, leaves and shoots. They are remarkably active and agile brachiators, capable of exceeding 3m in a swing. Gibbons leap from branch to branch, sometimes travelling more than 9 m in a single leap. They also sometimes walk on large branches or on ground, assuming a bipedal stance with their arms raised for balance.
Gibbons are active during the day.
Fossil hylobatids are known from the Miocene. L. C. Drickamer, S. H. Vessey, and J. F. Merritt. Adaptation, Diversity, and Ecology. WCB McGraw-Hill, Boston. Groves, C. P. 1989.