The Bornean Orangutan is originary from this island. It lives in tropical and subtropical moist broadleaf forests in the Bornean lowlands, as well as mountainous areas up to 1.500 metres above sea level.

The Bornean Orangutan is the third-heaviest living primate after the two species of gorilla, and the largest truly arboreal animal alive today. In wild, males weigh an average of 75 kg (ranging from 50 to 100 Kg.), and 1,2 to 1,4 meters long. Females average 38,5 Kg., ranging from 30 to 50 Kg,. And 1-1,2 meters long. While in captivity they use to grow considerably overweight.

The Bornean Orangutan has a distinctive body, with so long arms, which can be up to 1,5 meters. Its fur is reddish and both its hands and feet are prehensiles.

Their diet is composed of over 400 types of food, including figs, seeds, bird eggs, flowers, honey and insects, among others. They get the necessary quantities of water from both fruit and from tree holes.

Females, which reach maturity between 6 to 11 years do not give birth for the first time till they are 14-15 years old. The youngs stay some years with the mother who teach them all they need to survive, then they go their own.

Bornean Orangutans are in danger according to the IUCN red list and are included within the appendix 1 from CITES. It is estimated that only 54.500 live in the wild.

Their main threats are the fires (habitat destruction), hunting and illegal traffic of youngs as pets at the black market.