Sumatran orangutan facts for kids
Quick facts for kids Sumatran orangutan |
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| Male at Leipzig Zoological Garden, Leipzig | |
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| Female with infant at the Tierpark Hellabrunn, Munich | |
| Conservation status | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Primates |
| Suborder: | Haplorhini |
| Infraorder: | Simiiformes |
| Family: | Hominidae |
| Genus: | Pongo |
| Species: |
P. abelii
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| Binomial name | |
| Pongo abelii Lesson, 1827
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| Distribution in Indonesia | |
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The Sumatran orangutan (Pongo abelii) is one of three amazing species of orangutans. These special apes are found only in the northern part of the Indonesian island of Sumatra. They are considered Critically endangered because there are so few left in the wild.
The name "orangutan" comes from two Malay words: orang, meaning 'people' or 'person', and hutan, meaning 'forest'. So, an orangutan is truly a 'person of the forest'!
Contents
- Sumatran Orangutans: Forest People
- Who Hunts Orangutans?
- See also
Sumatran Orangutans: Forest People
What Do Sumatran Orangutans Look Like?
Male Sumatran orangutans can grow to be about 1.7 meters (5.6 feet) tall and weigh around 90 kilograms (198 pounds). Females are smaller, usually about 90 centimeters (3 feet) tall and weighing about 45 kilograms (99 pounds).
Compared to their cousins, the Bornean orangutans, Sumatran orangutans are generally thinner and have longer faces. Their hair is also longer and a lighter shade of red.
How Sumatran Orangutans Evolved
Scientists have studied ancient orangutan fossils found in Sumatra from a time called the Pleistocene era. These fossils show that orangutans back then ate similar foods to those today, mostly soft fruits. We know this by looking at tiny marks on their teeth!
Life in the Trees: Behavior and Habits
Sumatran orangutans love to eat fruit, especially figs and jackfruits. They also enjoy eating insects. Sometimes, they will even eat bird eggs and small animals. They spend less time eating tree bark compared to Bornean orangutans.
Clever Tool Users
Wild Sumatran orangutans have been seen using tools! For example, an orangutan might break off a tree branch, remove the twigs, and chew one end to make it frayed. They use this stick to dig into tree holes to find termites. They also use sticks to poke into bee nests to get honey.
They even use tools to eat tricky fruits! The Neesia fruit has seeds that orangutans love, but these seeds are surrounded by hairs that feel like fiberglass and are painful to eat. So, orangutans make special tools to carefully remove these hairs before enjoying the seeds. If a tool works well, they often save it for later, creating a collection of "toolboxes."
Moving Through the Forest
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Orangutans are the heaviest mammals that travel mostly through trees. They move slowly and carefully, using many different ways to hold onto branches. They can even sway trees back and forth to help them move, saving energy.
Sumatran orangutans spend more time in trees than Bornean orangutans. This might be because there are large predators, like the Sumatran tiger, on the ground in Sumatra. They move by using all four limbs and by swinging from branch to branch.
In April 2026, a Sumatran orangutan was filmed using a handmade rope bridge to cross a road in Indonesia. This clever solution helped connect parts of their habitat that had been separated by human roads.
How Orangutans Communicate
Orangutans use many different gestures to communicate with each other. Scientists have identified 64 different gestures, and 29 of these seem to have specific meanings that other orangutans understand most of the time. These gestures can mean things like "let's play," "stop that," "look at this," "share food," "let's move together," or "move away." Sumatran orangutans mostly use gestures and do not rely on sounds for communication, even for danger signals.
In 2024, a wild Sumatran orangutan named Rakus was seen doing something amazing. He applied a paste made from chewed leaves of the Fibraurea tinctoria plant to a wound on his face. Weeks later, the wound appeared to be healed! This was the first time scientists observed a wild animal treating its own wound with medicine.
The Life Cycle of a Sumatran Orangutan
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Sumatran orangutans go through five main stages in their lives, each with different looks and behaviors.
- Infancy (Birth to about 2.5 years): Babies weigh 2 to 6 kilograms (4.4 to 13 pounds). They have lighter skin around their eyes and mouth, with darker skin on the rest of their face. Their hair sticks out around their face. Infants are always carried by their mothers, depend on them for food, and sleep in their mother's nest.
- Juvenilehood (2.5 to 5 years): Juveniles weigh 6 to 15 kilograms (13 to 33 pounds) and look similar to infants. They are still mostly carried by their mothers but start to play with other young orangutans and explore a little, always staying close to their mother. Towards the end of this stage, they build their own nest near their mother's.
- Adolescence (5 to 8 years): Orangutans weigh 15 to 30 kilograms (33 to 66 pounds). The light patches on their face start to disappear, and their face becomes darker. They still stay in touch with their mothers but spend more time playing in groups with other young orangutans. They are cautious around adult males.
- Sub-adulthood (Males, 8 to 13-15 years): Males weigh 30 to 50 kilograms (66 to 110 pounds). Their faces are completely dark, and they start to develop wider cheeks (called cheek flanges). Their beard grows, and the hair around their face shortens. At this stage, males can reproduce, but they are still socially developing and avoid adult males.
- Adulthood (Males, 13-15 years and older; Females, 8 years and older): Adult males are very large, weighing 50 to 90 kilograms (110 to 198 pounds). They have full beards, fully developed cheek flanges, and long hair. They are fully mature and usually travel alone. Females are considered fully developed at 8 years old and begin to have their own babies.
Female Sumatran orangutans typically live 44–53 years in the wild, while males can live a bit longer, 47–58 years. Females can have babies up to 53 years old. Even in old age, they are usually healthy, with good hair growth and strong cheek pads.
Sumatran orangutans are more social than their Bornean relatives. They sometimes gather in groups to eat large amounts of fruit from fig trees. These groups are usually made up of female orangutans and a preferred male partner. Adult males generally avoid other adult males. Young males might try to reproduce with females, but mature females usually prefer to mate with fully grown males.
Female orangutans usually have a baby about every 9.3 years. This is one of the longest times between births for any great ape! Young orangutans stay very close to their mothers for up to three years, and even after that, they often stay connected. Both Sumatran and Bornean orangutans can live for more than 50 years.
Some orangutans have lived to be very old in zoos. Puan, an orangutan at Perth Zoo, was believed to be 62 years old when she passed away, making her the oldest recorded orangutan. Currently, Bella, a female orangutan at the Hagenbeck Zoo, is thought to be the oldest at 61 years of age.
What Sumatran Orangutans Eat
Sumatran orangutans mainly eat fruit. They especially like fruits with a large seed surrounded by soft flesh, like durians, lychees, jackfruit, breadfruit, and figs. Insects are also a big part of their diet, especially ants.
Their diet can be divided into five main groups: fruits, insects, leaves, bark, and other small food items. Studies in Indonesia showed that orangutans ate over 92 different kinds of fruit, 13 types of leaves, and 22 other plant parts. They also ate at least 17 different kinds of insects. Sometimes, they even eat small amounts of soil from termite mounds. When ripe fruit is scarce, Sumatran orangutans might eat the meat of a slow loris, which is a small, nocturnal primate. They get water from natural pools in trees or by licking rainwater from their arms.
Occasional Meat-Eaters
Eating meat is rare for Sumatran orangutans. Research in the Ketambe area has shown a few cases of wild Sumatran orangutans eating slow lorises. This usually happens when there isn't enough fruit available, suggesting they eat meat as a backup food source during lean times. Like many primates, mothers might share meat with their infants.
Understanding Orangutan Genes
| Ploidy | diploid |
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| Genome size | 3,441.24 Mb |
| Number of chromosomes | 24 pairs |
| Year of completion | 2011 |
| Genome browser (UCSC) | |
Orangutans have 48 chromosomes. The complete genetic map (genome) of a Sumatran orangutan was first studied in January 2011, using a female orangutan named Susie. This made the Sumatran orangutan the third great ape, after humans and chimpanzees, to have its entire genome sequenced.
Scientists also studied the genes of ten wild orangutans, five from Borneo and five from Sumatra. They found that Bornean orangutans (Pongo pygmaeus) have less genetic variety than Sumatran orangutans (Pongo abelii), even though there are many more orangutans in Borneo. This research also showed that these two species separated about 400,000 years ago, which is more recent than scientists first thought.
Protecting Sumatran Orangutans
Sumatran orangutans face many dangers that threaten their survival.
Dangers They Face
One of the biggest threats is the loss of their forest home. Forests are cut down for wood (logging), or cleared to make space for farms and palm oil plantations. Roads also cut through their habitat, breaking it into smaller pieces. Palm oil companies often clear large areas of forest, which is where Sumatran orangutans live. In the 1990s, it was estimated that forests supporting at least 1,000 orangutans were lost every year in just one area called the Leuser Ecosystem.
As of 2017, most Sumatran orangutans (about 82.5%) lived in the northern part of Sumatra, in the Aceh Province. There are very few, if any, orangutans found further south. One population in Pakpak Barat is thought to be the only one that can survive long-term, given all the changes to their habitat and human activities.
While hunting is not a huge problem for Sumatran orangutans today, some local hunting has happened in the past for food. Farmers sometimes see orangutans as pests if they damage or steal crops, leading to them being targeted. In the past, there was also a demand for live or dead orangutans from zoos and institutions in Europe and North America during the 20th century.
Their Conservation Status
The Sumatran orangutan lives only in the north of Sumatra. In the wild, they are mainly found in the province of Nanggroe Aceh Darussalam (NAD). They used to live in more places further south in the 19th century.
There are smaller groups in the North Sumatra province, especially near the Lake Toba forests. A study in the Lake Toba area found them in only two places: Bukit Lawang (which has an animal sanctuary) and Gunung Leuser National Park. Bukit Lawang is a village about 90 kilometers (56 miles) northwest of Medan. In the 1970s, a Swiss group set up an orangutan sanctuary there to help orangutans rescued from the logging industry. Rangers taught them jungle skills and provided extra food. However, in recent years, the extra feeding has stopped because the program was successful, and the orangutans are now fully rehabilitated. The forest is full, so the sanctuary no longer takes new orphaned orangutans.
Since 2000, the Sumatran orangutan has been listed as critically endangered on the IUCN Red List. This means they face a very high risk of disappearing forever. From 2000 to 2008, they were even named one of "The World's 25 Most Endangered Primates."
A study published in March 2016 estimated that there were about 14,613 Sumatran orangutans left in the wild, which was double previous estimates! A 2004 study had estimated around 7,300. The 2004 study also found that orangutans lived in an area of about 20,552 square kilometers (7,935 square miles), but only about 8,992 square kilometers (3,472 square miles) had permanent populations. Some are protected in five areas within Gunung Leuser National Park; others live in unprotected areas. A successful breeding program has also been started in Bukit Tiga Puluh National Park.
Two main ways to help save this species are: 1) helping orangutans that were once pets or displaced to return to the wild, and 2) protecting their forest homes from threats like deforestation and hunting. Protecting their habitat is seen as the best way to ensure orangutans survive in the long term. The World Wide Fund for Nature and other groups are working to stop the clearing of forests near Bukit Tigapuluh National Park.
Orangutans need large areas of forest to live in, and they don't live very close to each other. This makes conservation difficult. They move between different forest areas throughout the year to find fruits. When forests are cut down or broken up, it stops them from moving freely. Sumatra currently has one of the fastest rates of deforestation in the world.
Who Hunts Orangutans?
Potential predators of Sumatran orangutans in the Sikundur Monitoring Post include Sumatran tigers, Sunda clouded leopards, large snakes like pythons, and grey-headed fish eagles.
See also
In Spanish: Orangután de Sumatra para niños
- Ah Meng
- Bonobo
- Environmental issues in Indonesia
- Fauna of Indonesia
- Mountain gorilla
