- Common Name
- orangutan, orang-utan
- Genus Species
- Pongo (gorilla/orangutan) pygmaeus (small, dwarfish)
- One of the two species of orangutan: Bornean (Pongo pygmaeus) has a round face with dark red coat; Sumatran (Pongo abelii), which has a long narrow face with paler, longer hair.
Male: Adult males of both species have large cheek flaps.
- Male: 0.97 m (3.2 ft.)
Female: 0.78 m (2.6 ft.)
- Male: 90 kg (198 lbs.)
Female: 50 kg (110 lbs.)
- 60% fruit and other plant materials including leaves, bark, flowers, and nuts, occasionally insects and small mammals
- 260 to 270 days
- Sexual Maturity
- 7 to 10 years
- Life Span
- Up to 50 years
- Primary lowland swamp and primary rainforest
- Global: Unknown
- IUCN: Not listed
CITES: Appendix I
- Unlike other great apes, orangutans are solitary by nature; this may be related to their need for large quantities of fruit, which are dispersed throughout the forest.
- Even though they are able to walk upright for short distances, orangutans travel mostly by brachiating (swinging from one branch to another by the arms) through trees, using well-worn corridors in the forest canopy.
- Orangutans shelter themselves from rain and sun by holding leafy branches over their heads, and when constructing a night nest in the trees, will sometimes add a leafy roof.
- Males have a large throat sac that helps them make "long calls." This travels for up to 1 km (.62 mile) through dense vegetation, which helps the males define territories. The "squeak-kiss" noise they make is a sign of annoyance.
- Bornean orangs have the most prolonged development of any mammal therefore they reproduce very slowly.
- Orangs are unable to swim. In rain, they construct a leaf nest to keep dry.The differences between monkeys and apes are easy to see once you know what to look for. Apes do not have a tail and are generally larger than most other primates. They have a more upright body posture as well. Apes rely more on vision than on smell and have a short broad nose rather than a snout, as Old World monkeys do. Apes have a larger brain relative to the body size than other primates do.
Ecology and Conservation
Primarily fruit and plant eaters, orangutans play an essential role as seed dispersers throughout the forests of Indonesia as they digest and eliminate waste. They choose select green leaves and shoots, and in doing so act as pruners that aid in regenerating plant growth. The small food patches in Bornean forests, which cannot support more than one orangutan, force them to remain solitary or semi-solitary, and limits their social interactions.
Uncontrolled increases in human populations in Southeast Asia have reduced the range and numbers of orangutans. Much of their habitat is either clear cut for agriculture or lumber production. Clear-cutting exposes coal, which makes the area susceptible to fires. The capture and sale of baby orangutans is also a worldwide problem. This practice continues despite the many government and non-government organizations created to eliminate the exploitation of endangered wildlife.
The natural habitats of the orangutan, primarily the tropical forests of Borneo and Sumatra, have diminished significantly in recent years. As a result of widespread habitat destruction and hunting, the Bornean orangutan has become an endangered species.
Busch Gardens provides funding for a conservation project focusing on the population status and habitats in multiple-use forests in Malaysia. The study is intended to collect data necessary to plan for long-term conservation of the orangutan. Research is being conducted in a remote region of Lower Kinabatangan of Sabah, Malaysia, where a patchwork of virgin and exploited forests is home to high concentrations of orangutans and other rare species.
Understanding the relationship of orangutans to their environment is a first step in developing sound conservation strategies for this species in an increasingly threatened environment.
Bond, Melanie. 2000. National Zoo Personnel Committee. Apes Conference. Chicago, IL. May, 2000.
Galdikas, Birute M. F. Reflections of Eden. Canada: Little, Brown & Company, 1995.
Goodall, J., Fossey, D., Galdiras, B., and S. Montgomery. 1991. Walking with the Great Apes. Houghton Mifflin. Boston, MS.
Napier, J.R. and P.H. The Natural History of the Primates. Cambridge: MIT Press, 1985.
Nowak, Ronald M. (ed.). Walkers Mammals of the World. Vol. I. Baltimore: Johns Hopkins University Press, 1991.
Parker, S. (ed.). Grizmeks Encyclopedia of Mammals. Vol. II. New York: McGraw-Hill Publishing Co.,1990.
Preston-Mafham, Ken and Rod. Primates of the World. London: Blandford Publishing, 1992.
Rowe, Noel. The Pictorial Guide to the Living Primates. East Hampton, New York: Pogonias Press, 1996.
Tuttle, Russell H. Apes of the World: Their Social Behavior, Communication, Mentality and Ecology. New Jersey: Noyes Publications, 1986.
Orangutan Foundation International. www.ns.net/orangutan/. January 25, 2001.