Scientific Name: 
Pongo abelii
Phylum: 
Chordata
Species class: 
Mammalia
Order: 
Primates
Genus: 
Pongo
Species: 
abelii
Population Trend: 
Distribution Map: 
Summary: 

Did you know the Orang-utan is the largest tree-dwelling (arboreal) animal in the world? Like other Great Apes (Chimpanzees and Gorillas), the Orang-utan is highly intelligent and is able to use tools, like sticks, to scratch itself and help it to obtain food. In captivity it has also been taught to communicate using sign language. The Orang-utan is usually solitary, however the female forms close bonds with her offspring.

The name ‘Orang-utan’ comes from a Malay word meaning ‘man of the forest’. The male Orang-utan is almost twice the size of the female and can grow to 170cm tall and 90kg in weight. The male also has a sac in his throat, called a laryngeal sac, which he can inflate to make a loud roaring noise called a ‘long call’. The roar repels other males and also attracts females for courtship.

The Orang-utan is covered in orange to reddish-brown shaggy hair which darkens as the animal becomes older. It has long toes and fingers and a short, opposable thumb. The Orang-utan hooks its fingers over branches and grasps branches with its feet. Powerful arms and legs help the Orang-utan to swing through the forest canopy.

Region: 
Zoo location: 
Conservation information: 

Orang-utans are clinging to survival in lowland and mountainous tropical rainforests of Northern Sumatra and most of lowland Borneo. These forests are rapidly being cut down to plant palm oil plantations due to the rapidly increasing demand for the oil.

Palm Oil is the cheapest vegetable oil in the world and is commonly used for cooking and found in detergents, soap, toothpaste, and chocolate. Plantations will flourish in areas where heat and regular rainfall occur.

The devastating loss of habitat has caused a major decline in Orang-utan numbers as well as other wildlife that depend on these forests for survival. It is estimated that approximately 5000 Orang-utans are killed every year. At this rate, complete extinction of one of our closest relatives would occur within 10 years.

Australasian zoos are working together to help safeguard the species against extinction with internationally-coordinated breeding programs, support for in-situ release projects and by raising public awareness.

Taronga’s Orang-utan’s Jantan and Willow are important ambassadors for their declining species and their Taronga home simulates a rainforest clearing in their natural habitat and endeavours to educate Zoo visitors on how they can assist in protecting it. 

Distribution & Habitat

The Orang-utan is a tropical tree-dwelling creature. It avoids the ground due to risk from predators but sometimes descends to move between patches of trees. When on the ground it walks on all fours. The Orang-utan sleeps in nests up to 30m off the ground made by laying branches across the fork of a tree. The nest keeps the Orang-utan safe from ground dwelling predators as well as providing a good lookout over the forest. A new nest is generally built every one to two nights after which the Orang-utan will move on.

The Orang-utan is a tropical tree-dwelling creature. It avoids the ground due to risk from predators but sometimes descends to move between patches of trees. When on the ground it walks on all fours. The Orang-utan sleeps in nests up to 30m off the ground made by laying branches across the fork of a tree. The nest keeps the Orang-utan safe from ground dwelling predators as well as providing a good lookout over the forest. A new nest is generally built every one to two nights after which the Orang-utan will move on.

The Orang-utan was once found throughout south-east Asia but is now confined to two islands with two separate sub-species. The first lives in Borneo (Pongo pygmaeus pygmaes) and the second in Sumatra (Pongo pygmaeus abelli). The two subspecies can be distinguished by physical characteristics such as cheek size. DNA analysis is also used by zoos to identify the two sub- species.

Breeding

The female Orang-utan becomes sexually mature at about 10 years of age but may not have offspring until she is about 15 years old. The male reaches sexual maturity at about seven years of age but generally does not mate until he is much older due to the presence of larger dominant males. As males mature they develop large cheek pads and will not attract female mates until these develop. A young male will not develop cheek pads when a dominant cheek-padded male is in its range. Males are very territorial and will fight off other males if necessary, forcing adolescent males to look for their own territory.

The female Orang-utan reproduces every four to six years and may only produce four offspring in her whole life. She protects and nurtures her young until they are about six years old. The baby Orang-utan clings to its mother as she swings from tree to tree.

Taronga Zoo’s Orang-utans are part of the regional species management program for these apes, with breeding programs at Perth, Melbourne and Adelaide zoos. One of Taronga’s male Orang-utans is now at Adelaide for breeding.

Diet & Behaviour

About 60 percent of the Orang-utan’s diet consists of fruit. It also eats young leaves, bark, woody lianas, insects and occasionally eggs and small animals. A study conducted in the forests of Tanjung Puting National Park showed Orang-utans feeding on over 400 different kinds of foods. Water is obtained from the food that they eat as well as licking rainwater from plants or from their own fur. The Orang-utan dips its hand into water filled hollow trees and licks the water from its hairy wrists.

Orang-utans are solitary by nature and especially adult males often prefer to live alone. However, sometimes they enjoy a bit of company too. 

Source: 
www.iucnredlist.org