Orang Utans (from the Malay phrase Orang Hutan, 'man of the forest') live in Southeast Asia, on the islands of Borneo and Sumatra. 10,000 years ago, Orang Utans ranged as far north as China, and as far south as Java in Indonesia. Now they are only present on the islands of Borneo (estimated population: 22,000) and Sumatra (estimated population: 5,000).

The Orang Utan is the largest tree-climbing animal in the world. It has evolved for life in the trees, with both hands and feet adapted for gripping branches. Although arboreal, male Orang Utans have been known to spend between 4 and 5 hours on the forest floor.

Why are they endangered?

The greatest threats to Orang Utans is habitat loss due to mechanised logging. Agriculture is the most obvious threat presently facing Orang Utan populations. Under ideal conditions, these solitary animals roam the forest in search of widely distributed food sources. The reduction of suitable habitat is forcing Orang Utan populations into smaller areas, which cannot support them. In addition, Orang Utans have a slow reproductive rate: female Orang Utans have only one baby every 7 to 8 years.

Young Orang Utans are also threatened by poachers who capture them to be sold as pets. The mother is often shot in order to gain access to the baby Orang Utan.

Orang Utans are totally protected in Malaysia. 10,000 years ago Orang Utans ranged as far north as China and as far south as Java in Indonesia. Now they are only present on the islands of Borneo and Sumatra. Best estimates suggest that only around 22,000 and 5,000 remain on these islands, respectively.

How do they live in the wild?

Unlike their close relatives, the chimpanzees and gorillas, Orang Utans do not live in large social or family groups. Orang Utans are semi-solitary animals. Adult males are usually found alone and adult females are generally accompanied by one or two offspring. Adolescent Orang Utans are the most sociable, spending up to half of their time in small groups (between 2 and 5 individuals).

Adult male Orang Utans are much larger than adult females. They are able to grow to 5 feet in height and average 120 kilos in weight. Adult females, on the other hand, only grow to about 4 feet in height and 45 kilos in weight. Unlike females, adult males also have large cheek pads and a large pouch of skin under their chin.

Orang Utans eat leaves, barks, buds, stems, fruit and will occasionally eat insects, although they are mainly frugivorous (fruit eaters). Pregnancies lasts for about eight and a half months. Usually only one infant is born on average of one every seven to eight years. Only very rarely are Orang Utan twins born.

Orang Utan infants stay with their mothers until they are about 7 or 8 years old, as they have a lot to learn before they can survive in the forest without their mother. Female Orang Utans achieve sexual maturity between the ages of 9 and 12 years. Male Orang Utans reach sexual maturity between 8 and 15 years. However, development of the adult male secondary sexual characteristics (cheek pads and throat pouch) may sometimes be delayed until they are twenty years old.

What can be done to help?

Rehabilitation Centres, such as those in Sepilok, have been set up to accommodate confiscated pet Orang Utans. The aim of the rehabilitation centre is to guide the young Orang Utans through their development and ultimately return them to the forest. Many such Orang Utans have already been successfully returned.

For more information about Orang Utans and their conservation, please visit the following links:

Australian Orang Utan Project

Orang Utan Foundation International