Orangutans are a species of great apes like gorillas and chimpanzees. They belong to mammals and are the closest relatives of humans. In nature, they live only on two large islands in Asia: Sumatra and Borneo. There are three species of orangutans: the Bornean orangutan, the Sumatran orangutan, and the Tapanuli orangutan. The word “orang” means “man”, and the word “utan” means “forest”. Together, this results in something like “Forest Man”.
Orangutans are up to five feet long from head to bottom. The females reach 30 to 50 kilograms, the males about 50 to 90 kilograms. Their arms are very long and significantly longer than their legs. The body of the orangutan is better suited for climbing trees than that of the gorillas and chimpanzees. Orangutans’ fur is dark red to red-brown with long hair. Older males in particular get thick bulges on their cheeks.
Orangutans are critically endangered. The main reason: people are taking more and more habitats away from them by clearing the jungle because the wood can be sold at high prices. But people also want to plant plantations. A lot of primeval forests are cut down, especially for palm oil. Other people want to eat orangutan meat or keep a young orangutan as a pet. Researchers, poachers, and tourists are infecting more and more orangutans with diseases. This can cost the orangutans their lives. Their natural enemy is above all the Sumatran tiger.
How do orangutans live?
Orangutans always look for their food in trees. Over half of their diet is fruit. They also eat nuts, leaves, flowers, and seeds. Because they are so strong and heavy, they are very good at bending branches down towards them with their strong arms and eating from them. Their diet also includes insects, bird eggs, and small vertebrates.
Orangutans are very good at climbing trees. They almost never go to the ground. It’s too dangerous for them there because of the tigers. If they do have to go to the ground, it is usually because the trees are too far apart. However, orangutans do not support themselves with two fingers when walking like gorillas and chimpanzees. They support themselves on their fists or on the inner edges of their hands.
Orangutans are awake during the day and sleep at night, much like humans. For each night they build a new nest of leaves on a tree. They rarely sleep twice in a row in the same nest.
Orangutans live mostly on their own. An exception is a mother with her cubs. It also happens that two females go together in search of food. When two males meet, they often get into arguments and sometimes a scuffle.
How do orangutans reproduce?
Reproduction is possible all year round. But it only happens if the animals find enough to eat. Mating occurs in two ways: Roving males force sex with a female, which in humans would be called rape. However, there is also voluntary mating when the male is settled in his own territory. There are about the same number of young in both species.
Pregnancy lasts about eight months. That’s how long a mother carries her cub in her stomach. Usually, she only gives birth to one cub at a time. There are very few twins.
A baby orangutan weighs about one to two kilograms. It then drinks milk from its mother’s breasts for about three to four years. At first, the cub clings to its mother’s belly, later it rides on her back. Between the ages of two and five, the cub begins to climb around. But it only goes so far away that its mother can still see it. During this time it also learns to build a nest and then no longer sleeps with its mother. Between the ages of five and eight, it distances itself more and more from its mother. During this time, the mother can become pregnant again.
Females have to be around seven years old before orangutans can give birth themselves. However, it usually takes about 12 years before a pregnancy actually occurs. Males are usually around 15 years old when they first mate. It doesn’t take that long for any other great apes. This is also one reason why orangutans are so endangered. Many female orangutans only have two to three cubs in their lifetime.
Orangutans live to be around 50 years old in the wild. In a zoo, it can also be 60 years. In zoos, most animals also get much heavier than in the wild.