Bornean vs. Sumatran orangutan

Bornean and Sumatran orangutans are the only two species of great apes that can be found outside Africa. Bornean orangutan is native to Borneo, while Sumatran orangutan originates from Sumatra. They inhabit rainforests, swampy forests and mountain forests and spend most of their lives on the trees. Both Sumatran and Bornean orangutan are faced with uncertain future due to accelerated habitat loss (deforestation), uncontrolled hunting and collecting from the wild. Despite 400.000-years-long separate evolution of Bornean and Sumatran orangutans, these two species share many common features. They differ only in few aspects:

Morphology of Face

Sumatran orangutan has narrow face and long beard that can be seen in animals of both sex. Males have orange moustaches and pale (nearly white) hairs on the cheeks. Bornean orangutan has wider face and larger throat pouch than Sumatran orangutan. Males have prominent round face due to wide cheek flaps that are covered with short, bristly hairs.

Color

Sumatran orangutan is covered with long, orange, woolly fur. Bornean orangutan is darker, usually brown, maroon or orange-colored, and it has fur of coarser texture.

Home Range

Males of both species occupy territory of 500 to 4000 hectares, while females live on a territory of 64 to 900 hectares. Since Bornean orangutans inhabit forests on the lower elevation (on the altitude of up to 3280 feet) which provide plenty of food (due to great diversity of plants), they occupy smaller territory than Sumatran orangutans which reside in the forests on the altitude of nearly 5000 feet which provide less food (flora in mountains is less diverse). Bornean orangutans spend more time on the ground than Sumatran orangutans.

Diet

Orangutans like to eat fruit, buds, open flowers, sap, vines, roots, fungi, caterpillars, ants, termites and eggs. Sumatran orangutan is more dependent on the fruit than Bornean orangutan, which likes to eat inner bark of various woody plants. Both types of orangutan play important role in dispersal of seed in the wild.

Predators

Natural enemies of Sumatran orangutan are clouded leopard, tiger, Asian hunting dog and crocodiles. Bornean orangutan is often on a target of various types of wild cats. All these predators prey on immature orangutans and females (male orangutans are often "spared" because of their large size).

Usage of Tools

Orangutans are one of the most intelligent primates. They use various tools, such as leaves to cover themselves from the rain, or sticks to clean their teeth. Sumatran orangutans use tools more frequently.

Conservation Status

Bornean orangutans are more numerous in the wild compared with Sumatran orangutans. There are around 54.000 Bornean orangutans and less than 6.600 Sumatran orangutans in the wild. Bornean orangutan is classified as endangered, while Sumatran orangutan is on the list of critically endangered species.