Indonesian named Owa-owa (Hylobates muelleri), also known as the grey gibbon, is a primate in the Hylobatidae or gibbon family.
Grey gibbons are active for 8 to 10 hours per day. These animals are diurnal, rising at dawn and settling for the night before sunset. Males tend to become active earlier and for longer periods than females. Gray gibbons spend most of their day foraging in the main canopy of the forest.