Orang-utan (say oh-RANG-oo-tan)

Orang-utans are apes.

They live in trees in rainforest.

They swing from tree to tree.

They hardly ever come down to the ground.

They eat mostly fruit, leaves and flowers.

Asian Apes
Orang-utans are apes, and are the largest tree-living mammals. The orang-utan is the only great ape that lives in Asia, the only ape living outside Africa. They are the only apes that live almost completely in trees, and the only apes with red fur. They are very closely related to humans.

There are two kinds of orang-utan, Sumatran and Bornean, named for the islands on which they live. Sumatran orang-utans have lighter-coloured fur and a longer beard. Bornean orang-utans have narrower cheek pads.

Habitat and Distribution (where they are found)
Orang-utans live in the oldest rainforests in the world, on the islands of Borneo and Sumatra. The word 'orang-utan' means 'person of the forest'. However, orang-utans once were found over much of China and Southeast Asia.

Body and Appearance
Orang-utans are covered with long reddish hair. Their long, strong arms are ideally adapted for swinging from branch to branch and tree to tree. Their feet are like hands, which helps this movement through the high treetops.

They are the largest arboreal (almost completely tree-living) animals. They rarely come down from treetops, and when they do, they move quite slowly and awkwardly on the ground. Adult males weigh about 144 kilograms, often about twice the size of the females, who weigh about 65 kilograms.

Adult male orang-utans have large cheek flaps on their faces. They have a sac under their chins which they inflate with air to make a long call which can be heard about a kilometre away.

 Behaviour
Male orang-utans are generally solitary animals, spending almost all their time on their own. Females are accompanied by their young. In Sumatra, when the wild fig trees are full of fruit, orang-utans will share feeding time at the same trees, but at other times they are alone. Males and females only meet in order to mate.

Orang-utans rarely come to the forest floor, spending their time mostly in the upper canopy (the treetops) of the rainforest. They build a fresh nest each night, high up in a tree. Sometimes they make an umbrella of leaves over the nest if it is raining.

Much of their time is spent eating. This is because they are mainly fruit eaters, and this diet doesn't give a lot of energy to such large animals, so they need to eat a lot. Wild figs and durians are their preferred food. However, about 400 separate items have been identified as part of their diet, including roots, nuts and berries, insects, reptiles, eggs, bark and leaves.

Orang-utans are gentle and highly intelligent animals. They use tools in the wild to help them get food, for example, using a stick to reach into a beehive to get honey. They have excellent memories, and remember where to go in the forest at different seasons to find trees bearing fruit.

Life Cycle
Male orang-utans are about 15-20 before they are large enough to compete for females successfully. Females only breed every 7-8 years.

Females give birth to one young, rarely twins, about 8-9 months after mating. For its first year, the young orang-utan clings to its mother and suckles milk from her. Young orang-utans are dependent on their mothers for about 8 years, and are fully grown at about 10 - 12 years. Only human young are dependent for a longer period of time.

A two day old orang-utan

In the wild, orang-utans live for about 35 years, longer in captivity.

Conservation status and action
In the 2007 Red List of Threatened Species:
Sumatran Orang-utans are classified as Critically Endangered.
Bornean Orang-utans are classified as Endangered.
This means they are seriously in danger of becoming extinct in the wild within a very few years.

Their habitat is fast being destroyed. About 80% of the rainforest has gone. Logging for timber is one reason for this. Rainforest is not quick to regrow: some trees take 60 years to reach maturity and 200 years to reach full height.

Palm plantations are being planted in many places where the rainforest has been cut down: palm oil is in great demand by the western world. It is a major ingredient in soaps, shampoos and in processed foods. When a habitat is destroyed, many different species of animal and plant is affected.

Baby orang-utans are very cute, and in demand for the pet trade. Their mothers are killed and the young taken and sold as pets. When the orang-utan gets too big and strong to be a suitable pet, many are dumped. There are rescue centres which save orang-utans from disease and the damage done to them by illegal poachers and pet owners. There are programs to reintroduce these orang-utans to the wild in protected areas. This is a slow process and orang-utan numbers continue to decline.

If you use any part of this in your work, acknowledge this source in your bibliography like this:
Orangutan (2000). [Online], Available: www.kidcyber.com.au

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Updated September 2007