It is included here because little is known about its behavior. The prehensile tail is brown, and the back of the head and neck is reddish. Male hierarchical rank is by age and size. Female rank is matrilineal. Males emigrate as early as age 2.
Group ranges overlap, but intergroup interactions are avoided.
Diurnal and arboreal. During the wet season, small groups spend a high percentage of time traveling and gathering food, with little rest. In the dry season, food gathering time is the same, but they travel much less and rest more. The larger groups have priority access to small food patches, so smaller groups, which are displaced, must conserve energy. Females in large groups have higher fecundity and higher expected lifetime reproductive success than females in small groups.