Until recently, scientists classified all orangutans as one species, Pongo pygmaeus. But genetic analysis revealed enough difference between orangutans on the islands of Borneo and Sumatra to merit their being divided into two seperate species. The Bornean orangutan (Pongo pygmaeus) is the more numerous of the two species—there are between 12,000 and 15,000 Bornean orangutans in the wild. Only 3,000 to 5,000 Sumatran orangutans (Pongo abelii) live in the wild. Both species are threatened by habitat loss due to logging and fire.
Bornean orangutans are tree-dwelling primates. Only rarely do they descend to the ground. They sleep in the treetops on mats they build out of woven branches. Females give birth to their young in nests high in the canopy and they young orangutans cling to their mothers as it matures. Despite orangutans being protected by law, young orangutans are sometimes captured and sold illegally as pets.
Bornean orangutans are rather solitary animals that form only loose communities. They sometimes gather in small groups when feeding. Young orangutans remain with their mothers until they are about 8 years old. Adolescent females sometimes travel in groups for a few days.
- Mass: 30 to 90 kg (66 to 198 lbs)
- Body Length: 1.50 m (average) (4.92 ft)
- Diet: herbivores (figs, leaves, flowers, bark), occasionally eat insects
- Breeding Season: Throughout the year
- Age at Sexual Maturity: 7 years
- Number of Offspring: 1-2
- Lifespan: 50 years (wild)
Range and Habitat:
Today, Borneo orangutans are restricted in range to the island of Borneo. Fossil evidence suggests that the species once inhabited a range that extended throughout much of Southeast Asia. Borneo orangutans inhabit forest habitats and spend most of their time in the forest canopy.
- Burnie D, Wilson DE. 2001. Animal. London: Dorling Kindersley. 624 p.
- Ciszek, D. and M. Schommer. 1999. Pongo pygmaeus. Animal Diversity Web. September 14, 2009.