Largest of Asia: Orangutans are the largest primates in Asia.
They are sexually dimorphic - the males are twice the size of the females. The males can be around four and a half feet tall, and 130-200 pounds; the females are around two and a half feet and 90-110 pounds, in the wild. In zoos, animals tend to be heavier than animals in the wild.
Large and hairy: In addition to long hair and long arms, orangutans have curved hands and feet which are very useful as they spend a lot of time climbing through treetops. Their hands have small thumbs. The orangish-red-brown hair is longer on the males than the females, and the males also grow cheek pads that resemble plates on either side of his head.
Man of the woods: As stated above, the Malay meaning of their name is "man of the woods"... and indeed with their expressive faces and soulful eyes, these apes certainly do sometimes resemble a stockier, hairier human!
The ability to stand like a man: Though orangutans spend most of their time high above the ground in trees, they also have the ability to walk on two feet, though they generally choose to use four. Perhaps the Malay people who first sighted orangutans caught them while standing on two feet and looking like a small hairy man, therefore leading to their name 'man of the woods''!
Daydreamers: Orangutans have been called "the loners and the daydreamers of the great apes". Unlike most of the other great apes like chimps, gorillas and bonobos that live in groups and interact often while looking for food, playing or socializing, orangutans are very solitary animals, living, eating and traveling alone. Highly intelligent, it seems that these apes have become very reflective and inward since they are only in the company of themselves.
Sit and think: It's been said that they have a more internal approach to tasks. They have been observed to sit in a tree canopy for hours, and then suddenly go over to a batch of fruit that it discovered simply by sitting still, whereas other apes for the same task would go from tree to tree in search.
Follow the fruit-eaters: Sometimes they do slowly climb through the forest in search of fruit, but again they are thoughtful in their approach; they may find fruit by following movements of other fruit-eaters like hornbills. Once an extremely prolific tree with lots of fruit is found, orangutans will spend hours feeding on the ripe fruit.
The arboreal ape: Orangutans are the most arboreal of the great apes, spending nearly all of their time in the trees, making a new nest in the trees every night (though they will occasionally reuse a nest).
Older orangutans are very careful climbers, using all four limbs to climb and always making sure that they are holding on to something with at least two of them. Younger orangutans are less careful, sometimes brachiating (swinging hand over hand).
Intelligent tool-users: Like the other great apes, orangutans are remarkably intelligent. Although tool use among chimpanzees was documented by Jane Goodall in the 1960s, it wasn't until the mid-1990s that one population of orangutans was found to use feeding tools regularly.
Honey-termite sticks: Researchers have observed orangutans using sticks as tools to obtain termites and honey for food.
Mirror, mirror...Like the other great apes, orangutans can recognize themselves in the mirror and have the ability to learn sign language. Some people consider orangutans of equal or above average intelligence to chimpanzees. Orangutans developed earlier than both chimpanzees and gorillas.
Hide and seek : At zoos, orangutans are sometimes given manmade tools for enrichment - and can be viewed using combs to groom their long hair! Many orangutans in the zoo tend to be very playful, hiding under blankets, boxes, and then showing themselves for their keepers or other orangutans.
Relaxed, and get it on the first try: Orangutans have a unique relaxed approach to most problems solving - again different than other primates. For example, a chimp given a situation with many shaped holes and an oddly shaped peg that will fit in only one, will right away try putting the peg in different holes attempting to find the correct one. An orangutan will not act immediately.. in fact, it has reacted by staring into space, or simply scratching itself with the peg. After some time, it will then place the peg into the correct hole on the first try - while looking at something else that has interested the meditative orangutan!
Long motherhood: The exception to the orangutan's solitary life is the orangutan mother. Orangutan young stay with their mother longer than any other great ape. Females do not give birth often compared to other primates, on average once every eight years. The young may nurse until six years and the young will stay with their mothers until the next baby is born; therefore the young orangutan is often between age 8 and 10 years old by the time they leave their mother.
Babies in the fur: Infants will cling to their mother's fur for years, and their mothers are very devoted and loving with them; cuddling, cleaning and nursing them.
The long childhood: The reason for this long childhood (the longest of any of the great apes) is probably because unlike the other great apes, they don't have a group around them to give them more lessons as young adults. Instead, young orangutans have to learn everything before setting off in the world alone - finding fruit, building night nests and other tasks they need to survive without help.
Peaceful females: Despite their usual solitude, females will also occasionally encounter other females with young at a particular fruit tree in overlapping territories. Usually these females and their young will peacefully feed within their overlapping ranges.
Aggressive males: Males are not so accommodating - they will accept females ranges overlapping into theirs, but never a male. If any male happens to wander too far into another male's territory, a booming roar will immediately be emitted to scare him away.
Vocalizations: Calls are also used during mating season to invite females within earshot. Male grunts can be heard 3000 feet away! Orangutans have between 13-15 observed vocalizations, including screaming when scared, lip smacking, and teeth grinding when frustrated.
Young aggression: Although orangutans are generally passive, aggression toward other orangutans is very common; they are solitary animals and can be fiercely territorial. Immature males will try to mate with any female, and may succeed in forcibly copulating with her if she is also immature and not strong enough to fend him off. Mature females easily fend off their immature suitors, preferring to mate with a mature male.
Indonesian apes in different kinds of forests: Two subspecies of orangutans survive today, both which are in Indonesia, a country in Southeast Asia - more specifically on the islands of Borneo and Sumatra. They live in several types of forests, which include forests of low altitudes, mountainous forests and thickly wooded swamps.
Fruity apes: The main part of an orangutan's diet is fruits of the forest. These include: jackfruits, mangos, figs, lychees, durians and others. Fruit trees are spread throughout the forests where orangutans live, and the fruit ripens and flowers and different times. Young orangutans adopt a mental map of the layout of the forest so they can go to the section that has ripe fruit.
The rest of their diet is made of leaves and shoots, with occasionally insects, tree bark, small animals and soil.
Orangutans using boats! Remarkable observers, orangutans have been known to watch villagers cross waterways using boats... then when the villagers are gone, the orangutans have come, untied the boat and repeated the same thing!
Master escape artists: At zoos, they also are very clever at going where they shouldn't. One particular orangutan at the San Diego Zoo was a master escape artist. Using his fingers he would unscrew bolts, unlatch hooks and hinges and find ways to get out of his enclosure. When his keepers figured out his escape route and orangutan-proofed it, this cunning orangutan would find another way to get out. According to the zoo, he didn't seem to mind being caught and being led back to his enclosure, but actually seemed to like the challenge of finding a new way out!
Helping orphans: Wild orangutans are known to visit human-run facilities for orphaned young orangutans released from illegal captivity, interacting with the orphans and probably helping them adapt in their return to living in the wild.
Meditative orangutans in trouble: Orangutans are highly endangered in the wild. Orangutan habitat destruction due to logging, mining and forest fires has been increasing rapidly in the last decade. Much of this activity is illegal, occurring in national parks that are officially off limits to loggers, miners and plantation development. There is also a major problem with the illegal trapping of baby orangutans for sale into the pet trade; the trappers usually kill the mother to steal the baby. Major conservation centers in Borneo include those at Semenggok in Sarawak, and Sepilok near Sandakan in Sabah. There are also organizations, like the Orangutan Foundation International, that are trying to protect these rare, amazing primate cousins and enforce laws against poaching.
- Genus Pongo
- Bornean Orangutan (Pongo pygmaeus)
- Pongo pygmaeus pygmaeus - northwest populations
- Pongo pygmaeus morio - northeast and east populations
- Pongo pygmaeus wurmbii - southwest populations
- Sumatran Orangutan (P. abelii)
Bonobos | Chimpanzees |Gorilla | Humans | Gibbons
Apes| Monkeys| Prosimians