The Bornean Orangutan is a species of orangutan native to the island of Borneo. Together with the Sumatran orangutan, it belongs to the only genus of great apes native to Asia. Like the other great apes, orangutans are highly intelligent, displaying advanced tool use and distinct cultural patterns in the wild. Orangutans share approximately 97% of their DNA with humans. The Bornean orangutan is an endangered species, with deforestation, palm oil plantations and hunting posing a serious threat to its continued existence.
The Bornean orangutan is the third-heaviest living primate after the two species of gorilla, and the largest truly arboreal (or tree-dwelling) animal alive today. Body weights broadly overlap with the considerably taller Homo sapiens, but that species, of course, is more variable in size. The Sumatran orangutan is similar in size, but is on average marginally lighter in weight. A survey of wild orangutans found that males weigh on average 75 kg (165 lb), ranging from 50–100 kg (110–220 lb), and 1.2–1.4 m (3.9–4.6 ft) long; females average 38.5 kg (85 lb), ranging from 30–50 kg (66–110 lb), and 1–1.2 m (3.3–3.9 ft) long. While in captivity, orangutans can grow considerably overweight, up to more than 165 kg (364 lb). The heaviest known male orangutan in captivity was an obese male named "Andy", who weighed 204 kg (450 lb) in 1959 when he was 13 years old. The Bornean orangutan has a distinctive body shape with very long arms that may reach up to 1.5 meters in length. It has a coarse, shaggy, reddish coat and prehensile, grasping hands and feet.
Bornean orangutans lives in tropical and subtropical moist broad-leaf forests in the Bornean lowlands, as well as mountainous areas up to 1,500 meters (4,900 ft) above sea level. This species lives throughout the canopy of primary and secondary forests, and moves large distances to find trees bearing fruit.
Bornean orangutans are more solitary than their Sumatran relatives. Two or three orangutans with overlapping territories may interact, but only for short periods of time. Although orangutans are not territorial, adult males will display threatening behaviors upon meeting other males, and only socialize with females to mate. Males are considered the most solitary of the orangutans.
Despite being arboreal, the Bornean orangutan travels on the ground more than its Sumatran counterpart. This may be in part because no large terrestrial predators could threaten an orangutan in Borneo. In Sumatra, orangutans must face predation by the fierce Sumatran tiger.
Bornean orangutans diet is composed of over 400 types of food, including wild figs, durians, leaves, seeds, bird eggs, flowers, honey, insects, and, to a lesser extent than the Sumatran orangutan, bark. They have also been known to consume the inner shoots of plants and vines. They get the necessary quantities of water from both fruit and from tree holes. On rare occasions, orangutans will prey upon other, smaller primates, such as slow lorises.