Gibbons: Hylobatidae

Physical characteristics: Lar gibbons have thick, shaggy fur that is dark brown, beige, or a combination of both. The hands and feet are white. The black naked face is surrounded by a ring of white hair. Extremely long arms end in slender fingers that hook over branches when brachiating. The buttocks have thickened pads, adapted for prolonged sitting while asleep. Males weigh 11 to 16.8 pounds (5 to 7.6 kilograms), and females about 9.7 to 15 pounds (4.4 to 6.8 kilograms). The average head and body length is 16.5 to 23 inches (42 to 58 centimeters).

Geographic range: Lar gibbons are found in China, Indonesia, Malaysia, Myanmar, and Thailand.

Lar gibbon mother with young. The parents might send their young away by age five, but some females stay with the family until age eight. (Gail Shumway/Bruce Coleman Inc. Reproduced by permission.)

Habitat: Lar gibbons prefer the high forest canopy where plentiful fruits are found. They occupy evergreen and semi-evergreen forests. They also inhabit monsoon deciduous forests, characterized by heavy rainfall and dry periods during which leaves fall.

Diet: Lar gibbons feed mainly on fruits, supplemented with flowers, leaves, and insects.

Behavior and reproduction: Lars gibbons are arboreal and diurnal. Brachiation is their chief means of moving through the forest. On the ground and on wider branches, they walk on two feet, holding their long arms over their heads for balance and to avoid tripping over the arms. They are territorial, chasing neighbors off their home boundaries and advertising ownership by loud singing.

The family consists of the mated pair and their young. However, there have been reports of the adult male or female moving in with the neighbors. Some stay permanently; others eventually return home. Females give birth to one infant every two or three years. When a juvenile reaches the age of five, the parent of the same sex may force it to leave. The young may continue to stay in the vicinity of the family, but keeps a distance when feeding and sleeping. Young females typically leave home by age eight.

Lar gibbons and people: The young are captured for the pet trade, and the mothers are usually killed.

Conservation status: The IUCN lists the lar gibbon as Near Threatened, not threatened, but could become so, due to habitat loss and degradation from agriculture, logging, and capture for the pet trade. ∎