orangutan It is one of the largest primates in the world and is the only member of its family that lives outside of Africa. Humans share 96,4% of our DNA with these apes.

Bornean orangutan (Pongo pygmaeus)
Bornean orangutan (Pongo pygmaeus)


There are three species of orangutans that live in the humid jungles of the islands of Borneo and Sumatra: the Bornean orangutan (Pongo pygmaeus), the Sumatran orangutan (Pongo abelii) and Tapanuli orangutan (I put tapanuliensis).

The Bornean orangutan species is much more widespread and more numerous than the Sumatran orangutans. It has three different subspecies that are distributed in different geographical areas of the island. The three subspecies are very similar in behavior and appearance. Unfortunately, all three are classified as endangered animals by IUCN on its Red List.


The orangutan has a large and strong body, a thick neck, very long and strong arms, short, bowed legs, and no tail. The body is covered by long hair of a reddish color. The Sumatran orangutan has much less hair and is a lighter color. Some males grow hair on their faces, giving them a small mustache.

The species has sexual dimorphism, that is, males and females have small differences between them. Females are typically 115cm tall and weigh 37kg, while males are 137cm tall and weigh 75kg. The arm of a male can reach up to 2 m.

Spending most of its life up in trees, so it has developed special adaptations to easily survive among trees.

To move between trees they are too heavy to jump like monkeys do, so they use their long arms to swing from branch to branch. This is also possible thanks to the fact that the fingers of both extremities (hands and feet) are adapted to be agile and skillful.

There are some differences between species, the Bornean orangutan is much larger than the Sumatran, which is lighter in color and has a longer beard than its cousin. Tapanuli oranguntans are similar to Sumatrans but the hair is more frizzy, the head is smaller and the face is flatter. As males mature, they develop fleshy pads on the cheeks.

All three species have a bag in their throat that is used to make calls that echo through the forest.

Because of its shiny red and orange fur, it has earned the nickname the "red monkey." Besides being the largest ape, he is also one of the smartest. It is able to create mind maps to remember where the best fruit trees are and when they will bear fruit. They are also able to create their own tools to extract honey from honeycombs or to capture ants and termites from inside trees. It seems that intelligence is distributed individually and not by species, so some are able to go further and have been seen using leaves as umbrellas and as "gloves" to protect themselves from thorny vegetation.

Close-up of a male orangutan
Close-up of a male orangutan


Among orangutans they are the opposite of all apes. They are solitary and spend their entire lives high up in the trees. Each orangutan owns a small fragment of the forest, but they are not excessively territorial and even tolerate feeding with others around trees with a great abundance of food. Although the Sumatran orangutans are the most social.

Despite this sociability, males compete with each other to mate with females, producing long and loud calls using their throat bags in order to intimidate the rival male.

They spend a lot of time roaming the forest trees in search of food, such as fruit. You make nests to sleep at night high in the treetops, bending branches and creating a mattress using leaves to ensure a comfortable night.


The habitat of the orangutan is restricted to the wide dense tropical forests in the lowlands where there is a varied and wide food supply.

In addition to hillside forests, valleys and peat swamps, there are a number of isolated populations on both islands that inhabit the high mountain forests at much higher altitudes.


The orangutan has a limited distribution bought with other animals of its genus, although in the past they were distributed throughout the islands of Indonesia. Currently they are only distributed on the island of Borneo and Sumatra. Both islands are located in Southeast Asia.

Like the species names themselves, the Bornean orangutan is distributed over three areas of Borneo, and the Sumatran orangutans are found north of Sumatra. Most individuals are found in an area of ​​about 1.000 km2.


The orangutan is an omnivorous animal, that although it eats vegetables and animals, it widely prefers to consume fruit. Their large size and frugivorous nature have turned them into semi-solitary animals, since they must spend much of their time eating.

They eat both ripe and immature fruits, such as: mangoes, lychees, durian and figs, which grow in abundance to the point that several members can come together to feed. Sometimes, if there is a source of fresh water, drink it by joining your hands (in the form of a cup), raising them and drinking it as it falls. You generally don't drink a lot, as you get the water you need from the food you eat.


The orangutan has as its main predators two big cats, tigers and clouded leopards. They can also be victims of crocodiles, and sometimes the great Asiatic black bear.

The great deforestation of Malaysia and Indonesia means that the number of predators is even more threatened than the orangutans themselves. Humans are probably the biggest predator of orangutans today, as they threaten the few remaining populations by hunting them and capturing their young to be sold as exotic pets.

It is likely that orangutans from Borneo and Sumatra historically were forced to leave the ground due to large carnivorous predators.


The orangutan is a viviparous animal. The gestation period lasts for nine months, at the end of the female she gives birth to a single young in a nest built in a tree. The young orangutan clings to its mother's hair to stay safe while its mother searches for food.

It will take three years until they are fully weaned. They will still remain with their mother for another seven or eight years, as they need to learn the skills that will allow them to survive in the forest. These skills include which plants to consume, where to find them, and the use of various tools such as sticks and leaves to make life easier.

The development of the orangutan is extremely slow, since they begin to reproduce between 12 - 15 years. Each female usually has 3 offspring in her entire life, this greatly hinders the recovery of the species in areas where they are in danger.

Female orangutan with her calf at a US zoo
Female orangutan with her calf at a US zoo

State of conservation

All three species of orangutan are currently classified in the IUCN registry. Both the Bornean orangutan, the Sumatran orangutan and the Tapanuli orangutan are included as endangered animals.

About 15.000 Borneo orangutans, 5.000 Sumatran orangutans and only 800 Tapanuli orangutans are thought to remain in the rain forests. Despite the prohibitions by law, an estimated 5.000 orangutans die each year. If something is not done about it, it is estimated that they will disappear in the wild in a decade.

To prevent its extinction, there are several rehabilitation and reintroduction projects in Borneo and Sumatra. Some projects have been successful and 70 recovered poachers were reintroduced into Sumatra's national parks.

Relationship with humans

About 40.000 years ago the first modern humans arrived in the Indonesian archipelago. Since then the number of orangutans has been declining, due to hunting and habitat loss.

They were originally hunted for meat, but things got worse during the XNUMXth century, when zoos around the world demanded orangutans and the babies were captured for sale. Beyond improving, the thing however with the demand for exotic pets. To achieve this, the mother must be killed, as she tries to defend her young with great violence.

Other problems suffered by humans, is the illegal logging of tropical timber and land clearing to obtain palm oil.

Popular culture

The orangutan has been represented in numerous cultural works, whether in literature, cinema or video games. Perhaps the most famous orangutan in the world is King Louie, a orangutan, who offers Mowgli a deal to stay in the jungle in Disney's animated film "The Jungle Book."

List of other interesting animals

The bat's wings are membranous.