Orangutans live in Indonesia and Malaysia on the islands of Sumatra and Borneo. These are the only places where they live in the wild. Orangutans are born with an ability to reason and think. This large, gentle red ape is one of humankind’s closest relatives, sharing 97% of the same DNA. Indigenous peoples of Indonesia and Malaysia call this ape “orang hutan” literally translating into English as “person of the forest.”
Globally classified as endangered due to their habitat being destroyed, fragmented and poaching, orang-utans in Malaysia (Sabah and Sarawak) are probably best classed as ‘vulnerable’. Much of their prime habitat has been converted to plantations and the rate of habitat loss has hit a very low level in recent years. There is almost no hunting of this species in Malaysia, and most of the remaining populations are found in forests that are protected or under natural forest management.
Orangutans are unique in the ape world. There are four kinds of great apes: gorillas, chimpanzees, bonobos and orangutans. Only the orangutan comes from Asia; the others all come from Africa.
Borneo is unique in that it has three distinct populations or subspecies of orang-utans:
- Pongo pygmaeus pygmaeus (northwest populations)
- Pongo pygmaeus morio (northeast and east populations)
- Pongo pygmaeus wurmbii (southwest populations)
Orang-utans in the Malaysian states of Sabah and Sarawak occur mainly in the lowlands. In Sarawak, there are about 1,300 orang-utans, almost all in the Lanjak-Entimau Wildlife Sanctuary and Batang Ai National Park in the south next to West Kalimantan, Indonesia. In Sabah, there were five main areas of special importance with a total of 20,000 orang-utans in the mid 1980s (by WWF-Malaysia working with the Sabah Forestry Department, 1986). By 2004, the orang-utan population in Sabah had dropped to about 11,000 individuals (by Kinabatangan Orang-utan Conservation Project working with Sabah Wildlife Department, 2003). This decline in their numbers in the last twenty years was caused by planned conversion of forests to plantations in the eastern lowlands.
What do orangutans look like?
Orang-utans generally have brown and rust-coloured shaggy fur. Male and female orangutans look quite different - they both have long red hair, but males are much bigger than females.Weighing in at an average of 50 kg, female orang-utans grow to about 1.1 m in height and weigh 30 - 50 kg. Males weigh 50-90 kg and stand 1.2 - 1.5 m tall. Male orangutans grow a beard and moustache when they become adults, some male orangutans also grow cheek pads and throat pouches.
In the wild, orangutans may live up to 45 years or more. The oldest captive orangutan was a male called "Guas" at the Philadelphia Zoo who lived until he was 58 years old.
Orangutans eat mostly fruit - their favourites are huge spiky fruits called Durian, these fruits smell very bad, and taste a bit like custard and garlic, but orangutans love them! Orangutans also eat some flowers, honey, bark, leaves and insects.
Orangutans eat mostly fruit - their favourites are huge spiky fruits called Durian, these fruits smell very bad, and taste a bit like custard and garlic, but orangutans love them! Orangutans also eat some flowers, honey, bark, leaves and insects.
The arboreal orang-utan lives up in trees where they bend twigs and small branches together to make a large nest-platform for sleeping. They are the largest tree dwelling mammal in the world. Adult orang-utans are solitary, except during mating. Orangutans are arboreal, which means that they spend nearly all their time in the trees and hardly ever come to the ground. This makes them different from other apes like chimpanzees, gorillas and humans who all spend a lot of time on the ground. Orang-utans are not territorial, maintaining a loose relationship in a given area although adult males are hostile to one another. Crowding may cause them to fight over the limited supply of fruits. An adult female gives birth about once every six years.
Do orangutans live in groups?
No, unlike the other great apes (chimpanzees, bonobos, gorillas and humans) orangutans do not like to live in groups. Female orangutans usually have 1 or 2 babies with them, but males are usually alone.
How many babies do orangutans have?
The orangutan has the longest childhood dependence on the mother of any animal in the world, because there is so much for a young orangutan to learn in order to survive. The babies nurse until they are about six years of age. The young males may stay close by their mothers for a few more years but the females may stay until they are into their teens, allowing them to observe mothering skills as they watch their younger sibling being raised by the mother. Orangutan females only give birth about once every 8 years – the longest time between births of any mammal on earth. (This results in only 4 to 5 babies in her lifetime.) This is why orangutan populations are very slow to recover from disturbance.
Do orangutans use tools? Orangutans make umbrellas for themselves out of big leaves when it rains, and use sticks to get honey from beehives.
How many orangutans are there in the wild? 100 years ago there were thought to be 315,000 orangutans in the wild. There are now less than 6,600 left in Sumatra, and less than 54,000 in Borneo.
It is thought that Sumatran orangutans may be the first Great Apes to become extinct unless people help to protect them.
Orangutans are losing their homes as tropical rainforests are being cut down for wood to make paper and furniture and the land is cleared to grow palm oil, an ingredient in lots of foods. Baby orangutans are also taken from their mothers to be sold as pets.
Population decline of 40% in last two decades
Orang-utans in Sabah and Sarawak live mainly in lowland rainforests but are also found in tropical, swamp and mountain forests. Sarawak has about 1,300 orang-utans, almost all in the Lanjak-Entimau Wildlife Sanctuary and Batang Ai National Park to the south bordering West Kalimantan, Indonesia. In Sabah, there are about 11,000 individuals today, the population having declined by over 40% in the last 20 years due mainly to planned conversion of forests to plantations in the eastern lowlands. Drought and forest fires, especially during the El Nino events of 1982-83 and 1997-98, but also 1987 and 1991, contributed to the decline.
Destruction of natural forests and unreliable food sources
Wild orang-utan populations need a reliable source of a variety of fruits and young leaves to survive. They can survive only in extensive natural forests. The availability of food all year round means not all forests can support long-term breeding populations. We now know that this gentle ape can survive only in lowlands - where fertile soils and constant water availability allow steady food production - or where there are several forest types with different fruiting and leaf-producing seasons. There is little point in putting orang-utans where they have historically not existed, as lack of food supply may eventually cause them to die. There are six areas in Malaysia with quite large populations but this does not mean that any one of these places is unimportant. There is always the risk that one or more populations could be devastated by disease, drought or fires.
Maintaining natural forests with viable wild breeding populations and restoring degraded forests is vital for the continued survival of orang-utans in Malaysia. Hence, the Sabah government’s initiative to retain the largest orang-utan population in the Ulu Segama-Malua Forest Reserves under sustainable forest management (SFM) deserves full support. The Deramakot forest management model, which produces controlled amounts of timber for international auction, certified according to international standards since 1997, shows what can be done. SFM could reduce forest damage and provide enough time for the forest to regenerate. In SFM, reforestation is necessary to ensure the forest rehabilitation or restoration take place in any sustainably managed forest. In the Lower Kinabatangan, various isolated forest patches need to be joined through restoration.
