The siamang is the largest of the gibbons. © Getty Images

The siamang is the largest of the gibbons. © Getty Images

 

Gibbons are small apes. There are about twelve species (kinds) of gibbon, making them the largest group in the ape family (some scientists say there are 15 or 16 species of gibbon).  The ape family is part of the larger family of primates, and consists of gorillas, bonobos, chimpanzees, orangutans and gibbons.

There are four groups of gibbons: one species of siamang; four species of crested gibbons; one species of hoolock and six species of lar or dwarf gibbons. 

Habitat and distribution (where they are found)

Gibbons are found in the evergreen tropical rainforests of Southeast Asia. The various species of gibbon are found in areas ranging from northeastern India to southern China to Borneo.  

A female white-cheeked gibbon grooming her black male young. ©Getty Images

A female white-cheeked gibbon grooming her black male young. ©Getty Images

Appearance

All gibbons are tailless, and their long fur varies from cream to brown to black. Many have white markings on their faces, hands, and feet. The largest species are the siamangs, which can grow to about 13 kilograms. Smaller species reach only about four kilograms.

A baby female pileated gibbon. Males have black fur. ©Getty Images

A baby female pileated gibbon. Males have black fur. ©Getty Images

Gibbons have extremely long arms with strong, hook-shaped hands.  In relation to their body size, their arms are the longest of any ape. They have long, powerful legs.  In some species of gibbon,  the male and female have different coloured fur. The white-cheeked gibbon is one of those - males are all black and females are mostly a cream colour, with a black head and belly. Similarly, pileated gibbons and red-cheeked gibbons are different colours according to whether they are male or female.

Gibbons spend most of the time in trees. ©Getty Images

Gibbons spend most of the time in trees. ©Getty Images

 

Movement

Gibbons are arboreal, which means they spend most of their time in the tree tops, rarely coming down to the ground. They move swiftly through the trees in a motion called brachiation, meaning they swing from branch to branch. One strong hand grasps a branch, and the other long arm stretches out to a reach faraway branch.

They cross gaps as wide as 15 metres in a single swinging move. Their long, powerful legs help propel them as they swing. Their shoulder joints are specially adapted to allow a greater range of motion when swinging. They can travel this way as fast as 56 kilometres an hour, looking as though they are flying.

Gibbons walk on two legs © Getty Images

Gibbons walk on two legs © Getty Images

When gibbons do walk, either along branches or the very rare times they come to the ground, they walk on two legs, throwing their long arms above their head for balance.

Walking on two legs is called bipedalism. Gibbons do not walk on all four legs.

Behaviours

Gibbons live in family groups of 2-6,  consisting of an adult pair and their young. They are territorial, and a family’s territory is about 20-40 hectares in size. They defend territory aggressively. Unlike other apes, gibbons do not make nests to sleep in, but sleep upright on tree branches. They have specially tough pads on their bottoms so they can sit comfortably.

Large throat pouches make their calls echo through the forest. © Getty Images

Large throat pouches make their calls echo through the forest. © Getty Images

Gibbons make loud calls that echo for miles through the forest. Some species have large throat pouches so that their calls are echoed further. In the early morning, the rainforest echoes with gibbon songs. Mated pairs sing duets but sometimes the family sings together.

Gibbon songs last for between 10 and 30 minutes, and identify each animal. The songs probably also help to mark boundaries and to find partners. Singing is very rare in mammals, and gibbons’ songs are the most complicated of all land mammals.

Gibbons pair for life, which is rare among primates. The adult female is the dominant one in the group, the next most powerful are her daughters, then her sons, and then her male mate.

Diet

As fruit trees are plentiful in their habitat, fruit forms the main part of a gibbon diet, but they are especially fond of figs. They also occasionally eat leaves and insects. Their brachiating ability gives gibbons the advantage of being able to swing out and grab fruits growing at the end of branches, an advantage over other animals with a similar diet.

Life cycle

About 7 months after mating with a male, a female gibbon gives birth to a single young. Females give birth every 2-3 years, and the young stay with their parents for 6-8 years before moving away. Unusually for primates, the male helps look after the young.  A baby pileated gibbon - being female, she is mostly a cream colour (males are black)

A rare white-handed gibbon in Thailand. © Getty Images

A rare white-handed gibbon in Thailand. © Getty Images

Conservation Status and Threats

Gibbons are among the most threatened of all primates. Their habitat is disappearing rapidly, and they are often captured and sold as pets or killed for use in traditional medicines.

All but one species of gibbon is listed as Endangered or Critically Endangered.

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