Orang utan, rainforests on the islands of Borneo and Sumatra, Indonesia

Orangutans are the only exclusively Asian genus of extant great ape. The largest living arboreal animals, they have longer arms than the other, more terrestrial, great apes. They are among the most intelligent primates and use a variety of sophisticated tools, also making sleeping nests each night from branches and foliage. Most of their lives are spent foraging for food in solitude; they are generally not aggressive. Their hair is typically reddish-brown, instead of the brown or black hair typical of other great apes.

Orangutans are currently found only in rainforests on the islands of BorneoSumatra, though fossils have been found in Java, the Thai-Malay Peninsula, Vietnam and Mainland China. There are only two surviving species, both of which are endangered: the Bornean Orangutan (Pongo pygmaeus) and the critically endangered Sumatran Orangutan (Pongo abelii). The subfamily Ponginae also includes the extinct genera Gigantopithecus and Sivapithecus.

A 2007 study by the Government of Indonesia noted in 2004 it was estimated that there was a total wild population of 61,234 orangutans, 54,567 of which were found on the island of Borneo. Conservation centres in Indonesia at Tanjung Puting National Park and Sebangau National Park in Central Kalimantan, Kutai in East Kalimantan, Gunung Palung National Park in West Kalimantan, and Bukit Lawang in the Gunung Leuser National Park on the border of Aceh and North Sumatra.