Territory: Unlike gorillas, common chimpanzees and bonobos, which live in large social groups, orangutans lead a mainly solitary life. The males constantly move from one area of forest to another. The dominant male ranges over a particular area for several months mating with any receptive females he comes across. When all the females have been mated, he moves on to another area. The adult male advertises his presence to females and other males by making a long, booming call. Adult females spend very little time with other orangutans, but may occasionally travel together or feed in the same tree - although they don't usually take much notice of each other! Young orangutans which have left their mother may move around in groups of two or three.
Daily life: The orangutan is diurnal - that is, active during daylight hours. It lives high above the ground in the forest canopy, moving slowly and carefully through the trees, using all four limbs. The hands and feet are hook-shaped, designed for grasping branches and its powerful arms allow it to swing and climb easily. Because of its tree-top lifestyle, the orangutan has developed arms longer and stronger than any other ape. Bornean orangutans may go down to the ground for brief periods each day, but in Sumatra the orangutans hardly ever venture onto the forest floor, as the Sumatran tiger, a predator, still roams there. When walking on the ground, the feet and hands are clenched and bent inwards.
Every night, orangutans make simple nests to sleep in. They bend branches together to form a platform - it only takes about 5 minutes to build. Sometimes they make a roof over the nest to protect them from the rain. They all sleep lying on their side, cushioning their head on their arms.
Read More: Orangutans and Humans