These elusive, tree-dwelling primates are the only great ape in all of Asia and exist only on the islands of Borneo and Sumatra, in neighboring Indonesia. They spend much of their time searching for fruit, using their long arms and legs to move from tree to tree.
Each night, orangutans build a nest of leaves and sticks high above the ground, often with "roofs" to provide shelter from the rain. The orangutan's dependence on trees for food and shelter, along with a slow breeding rate, makes the orangutan vulnerable to human intrusions such as deforestation. The orangutans of Borneo were declared a completely separate species from the Sumatran orangutans in 2000.
Macaques (Macaca spp.)
Macaques spend most of their time in trees, foraging for fruits and small animals to eat. These creatures can be a nuisance to farmers, causing damage to cropland that was once rainforest. Primates are a critical component of the ecosystems within the Heart of Borneo.