In history, orangutans ranged throughout Southeast Asia and into southern China, as well as on the island of Java and in southern Sumatra.
They primarily inhabit peat swamp forest, tropical heath forest, and mixed dipterocarp forest.

Bornean orangutan 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.
The Bornean orangutan has a lifespan of 35–45 years in the wild; in captivity it can live to be about 60.

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.

The Bornean orangutan exhibits nest-building behavior.
Nests are built for use at night or during the day.
Young orangutans learn by observing their mother's nest-building behaviour.
This skill is practiced by juvenile orangutans.
Nests may be elaborate and involve a foundation and mattress made by intertwining leaves and branches and adding broken leafy branches.
Additional features such as shade, waterproof roof, "pillow", and "blanket", all of which are made from branches, twigs and leaves, may also be added.
Nest-building in primates is considered as an example of tool use and not animal architecture.
In history, orangutans ranged throughout Southeast Asia and into southern China, as well as on the island of Java and in southern Sumatra. They primarily inhabit peat swamp forest, tropical heath forest, and mixed dipterocarp forest.
Bornean orangutan 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. The Bornean orangutan has a lifespan of 35–45 years in the wild; in captivity it can live to be about 60.
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.
The Bornean orangutan exhibits nest-building behavior. Nests are built for use at night or during the day. Young orangutans learn by observing their mother's nest-building behaviour. This skill is practiced by juvenile orangutans. Nests may be elaborate and involve a foundation and mattress made by intertwining leaves and branches and adding broken leafy branches. Additional features such as shade, waterproof roof, "pillow", and "blanket", all of which are made from branches, twigs and leaves, may also be added. Nest-building in primates is considered as an example of tool use and not animal architecture.
Bornean orangutan