Name: Orangutan (Pongo)
Conservation Status: Critically Endangered (2021 IUCN Red List)
Wild Population Estimate: 55,000 – 65,000
Range: Malaysian Islands of Borneo and Sumatra
Threats: Development / Mining / Hunting / Agriculture / Transportation / Climate Change
The only great ape that lives on the Asian continent, the orangutan is found on the Malaysian islands of Borneo and Sumatra. Its name means “man of the forest,” and it is one of thousands of species of wildlife that live in tropical Asian forests. The orangutan’s story is similar to that of a large number of Asian animals: its forest habitat is being rapidly destroyed by conversion to agriculture, both by large commercial plantations and smaller subsistence farms.
At the same time, humans are killing the orang’s prey species (birds and small mammals) for food and capturing it for the pet trade.
There are an estimated 55,000 – 65,000 orangutans left in the wild, about 35,000 – 45,000 on Borneo and under 15,000 on Sumatra. Scientists are uncertain whether all orangutans are one species, or whether the Sumatran and Bornean populations have become so isolated from each other that they are two subspecies.
The great apes include gorillas, chimpanzees, and orangutans.
Of these, orangutans are the most arboreal (living in trees). It is rare for an adult orangutan to ever touch the ground. Their strong hands, handlike feet, and long arms (with a span of up to 8 feet) are supremely adapted to life in the trees. They do not even have to come to the ground to drink — they drink the water that collects in tree holes.
Orangutans are omnivorous; they eat both plants and animals. They eat fruit, leaves, nuts, shoots, insects, and, when they can catch them, young birds and small mammals. By about the age of ten, an orang will have learned to identify over 200 different food plants.
The orangutans favorite food is fruit. An orangutan seems to know the location of different fruit trees in the forest, and when each is due to bear fruit. Some trees bear fruit only every two or three years. Young orangutans learn this information from their mothers.
Orangutans spend most of their lives alone. The males are very territorial, and each male’s territory overlaps those of several females. Because orangutans do not tolerate each other very well, they need large areas of forest to survive. Crowding causes them to fight among themselves, possibly over the limited supply of fruit.
Causes of Endangerment
The orangutan’s forest habitat is being cleared for agriculture. Oil palm plantations are taking over more and more of the landscape. One plantation can be 100,000 to 300,000 hectares (1 acre = 2.47 hectares). World development banks provide money to help create many of the oil palm plantations, in an effort to improve the local economy.
Most of the lowland forest on Borneo and Sumatra is gone, and orangutans and other forest species are being forced into higher elevation forests. These forests are not as productive as lowland forests and can not support the same density of animals.
Borneo and Sumatra are rich in oil and gas, so it would seem that the island people and local governments could make money without having to log their forests. However, the national government of Malaysia keeps 95 per cent of the revenue from oil and gas sales, so the local government must raise funds some other way. The local government raises revenue by logging the forests and by farming.
Researchers have found that logging creates major problems for orangutans, other than destroying older forest habitat. In fact, secondary forest grows rapidly after the older forest has been logged, and orangutans are able to adapt to this younger forest habitat.
The bigger problem is that logging companies do not provide food for their workers. Hundreds of loggers are employed to cut down a particular area of forest, and they have to find food for themselves. The loggers, along with settlers who establish communities in the forest, hunt orangs, birds, and small mammals the orangs eat.
Both Borneo and Sumatra have established reserves for orangutans and other imperiled forest species. The reserves are separated from each other by rivers, mountains, and settlements. Scientists do not know whether the reserves can support viable populations, or even how many orangutans live in each reserve.
Atlanta has a Species Survival Plan (SSP) for the orangutan.
Questions for Thought
Can you think of some steps logging companies could take to help orangutans and other threatened and endangered species survive, while continuing to log?
Related Classroom Activities:
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