The Mentawai gibbon weighs about 6 kg (13 lb).
The Mentawai gibbon is found in tropical rain forest.
It occurs in the Sumatran-Nicobar Islands Lowland Forests Global 200 Ecoregion. (Olson & Dinerstein 1998, Olson & Dinerstein 1999)
7 - 8 months.
A single young is usually born. There are 2 - 3 years between births.
Feeding time usually involves 72% on fruit and 25% on animal matter (Macdonald 1984).
All gibbons are arboreal and diurnal.
The Mentawai gibbon is monogamous.
A group of Mentawai gibbons will "stake out" an area in the forest, its home range, which is large enough to provide a reliable food supply. The group will actively defend the core of this area, its territory, against other groups of gibbons. Conflict between groups is minimized because the resident male advertises the group's presence by singing a song to indicate his willingness to defend the group's territory.
20 or more individuals/sq km (50 or more individuals/sq mi). (Nowak & Paradiso 1983)
Territory: About 10 hectares (25 acres). (Nowak & Paradiso 1983)
Home range: 20 - 35 hectares (50 - 85 acres). The territory is about 2/3 of the home range. (Macdonald 1984)