Also known as the red ape, or the 'old man of the forest', orang-utans are the largest tree-living mammals. Sumatran orang-utans are even more endangered than their Bornean counterparts.

Life span
About 60 years.

Statistics
Females have a body weight of 37kg, and males weigh 83kg.

Physical description
Sumatran orang-utans have a long red/ginger coat. They have long facial hair, unlike their Bornean counterparts. Orang-utans are the largest arboreal (tree-living) mammals.

Distribution
This species of orang-utan is found in Sumatra, Asia.

Habitat
They live in the tropical rain forests and flood forests of Sumatra. They predominantly live in the underbrush and middle levels of trees.

Diet
Fruit is the most important component of their diet, but they also feed on insects, small vertebrates, leaves and bark.

Behaviour
Adult male and female orang-utans are solitary. Females travel with their young until adolescence. They are diurnal and arboreal.

Reproduction
In captivity, female orang-utans have given birth as young as seven years old. Gestation is 244 days.

Conservation status
Orang-utans are endangered, due to deforestation of their habitat and through land conversion to palm oil plantations. Sumatran orang-utans are disappearing at a rate of 1,000 a year. There are only about 9,000 Sumatran orang-utans left in the world.