Orang Hutan - Ecology and Behaviour

Ecology and Behaviour

Orangutans live in primary and old secondary forests, particularly dipterocarp forests and peat swamp forests. Both species can be found in mountainous and lowland swampy areas. Sumatran orangutans live at elevations as high as 1500 m (4921 ft), while Bornean orangutans live no higher than 1000 m (3281 ft). Other habitats used by orangutans include grasslands, cultivated fields, gardens, young secondary forest, and shallow lakes. Orangutans are the most arboreal of the great apes, spending nearly all their time in the trees. Most of the day is spent feeding, resting, and travelling. They start the day feeding for 2–3 hours in the morning. They rest during midday then travel in the late afternoon. When evening arrives, they begin to prepare their nests for the night. Orangutans do not swim, although they have been recorded wading in water.

The main predators of orangutans are tigers. Other predators include clouded leopards, wild dogs and crocodiles. The absence of tigers on Borneo may explain why Bornean orangutans can be found on the ground more often than their Sumatran relatives. Orangutans communicate with various sounds. Male will make long calls, both to attract females and advertise themselves to other males. Both sexes will try to intimidate conspecifics with a series of low guttural noises known collectively as the "rolling call". When annoyed, an orangutan will suck in air through pursed lips, making a kissing sound that is hence known as the "kiss squeak". Infants make soft hoots when distressed. Orangutans are also known to blow a raspberry.