Gibbons: Hylobatidae

Physical characteristics: Pileated gibbons have dense, woolly fur. Males are black, with a black face framed in white. Hands and feet are white. Females are silvery beige or ash blond, with a black face and chest. The top of females' head is also black. The body is slender and the small head is rounded. Very long arms have hooklike fingers for brachiation. Thick skin pads line the rears for prolonged sitting. Males weigh 17 to 23 pounds (7.7 to 10.4 kilograms), and females about 14 to 19 pounds (6.3 to 8.6 kilograms). The average head and body length is 17.5 to 25 inches (44 to 63.5 centimeters).

A pileated gibbon family consists of an adult pair and up to four offspring. The family searches for food together. (© Terry Whittaker/Photo Researchers, Inc. Reproduced by permission.)

Geographic range: Pileated gibbons are found in Thailand, Cambodia, and Laos.

Habitat: Pileated gibbons prefer primary forests with well-developed canopies. They live in evergreen and semi-evergreen forests. They also occupy monsoon deciduous forests that have periods of heavy rainfall and dry spells, causing leaves to fall.

Diet: Pileated gibbons eat predominantly ripe fruits, supplemented with flowers, leaves, and insects.

Behavior and reproduction: The family consists of an adult pair and up to four offspring. The gibbons are arboreal and diurnal. Upon waking, the mated pair sings a duet, in which the offspring may join. The family forages soon after. Gibbons are territorial, defending their home against outsiders. They mostly travel by brachiating, but sometimes walk on two feet or leap through wide forest gaps. The family almost never goes down to the forest floor. They sleep before sundown, sitting on tree branches.

Females give birth to an infant every two or three years. The mother is the principal caregiver. The young tend to stay with the parents until they are ready to start their own family at seven or eight years of age. However, the parents may try to expel them when they reach the age of five.

Pileated gibbons and people: Poachers (illegal hunters) kill gibbons for food and capture the young for pets.

Conservation status: The IUCN lists the pileated gibbon as Vulnerable due to habitat loss from logging and human settlement. ∎