Bornean Orangutan Profile
Borneo is a large island right in the centre of the Southeast Asian Island groups, directly intersected by the equator. It is the third-largest island in the world and is home to some of the oldest rainforests in the world.
This forest may be over 140 million years old, and in that time, it’s accrued and distributed an unfathomably diverse and unique range of species.
Most of these species of animal cannot be found anywhere else in the world, and the Bornean Orangutan is one of the most endangered.
Bornean Orangutan Facts Overview
| Habitat: | Rainforest canopy |
| Location: | Borneo |
| Lifespan: | Around 45 years in the wild, 50+ in captivity |
| Size: | Up to 1.5m (5ft) |
| Weight: | Up to 100kg in the wild |
| Colour: | Orange |
| Diet: | Generalist omnivores: mostly plants, some insects, few mammals |
| Predators: | Humans |
| Top Speed: | Slow, relaxed |
| No. of Species: | 1 |
| Conservation Status: | Critically endangered (IUCN) |
These are the largest tree-dwelling mammals, likely pushed into the canopy to avoid a fearsome ancient predator.
Known in the local Indonesian language as the “Man of the Forest”, the Bornean orangutan matches the description with its apparent wisdom, gentle nature and kindly, welcoming eyes.
Sadly, they’re in great danger from habitat destruction and direct hunting by humans and without dramatic changes in land usage on their native island in Indonesia, we may well lose them altogether.
Interesting Bornean Orangutan Facts
1. They’re smart
Despite sharing up to 97% of their DNA with humans, orangutans show remarkable intelligence. They seem to be more thoughtful than most, moving mindfully and with intention and are known to use tools for various things from back scratchers to toilet paper.
Interestingly, orangutans use tools less than their more terrestrial cousins like chimps and gorillas, and researchers believe that this is not a sign that they’re less intelligent, instead, it’s a product of their almost exclusively arboreal lifestyle.
This insight sheds light on the role and evolution of tool use in early humans, too!
But that’s not the limit of their smarts. Orangutans have a wide vocal repertoire that’s still being understood. They’re capable of mimicking human speech and using leaf instruments, perhaps to fool predators. 1 2
2. They like tattoos
If you’re ever lucky enough to meet an orangutan, you’ll find it impossible to deny just how gentle, inquisitive and seemingly ‘knowing’ they are.
In Barcelona Zoo, there are examples of one of the young resident orangutans thoroughly enjoying a magic trick involving cups.
There’s a similar video featuring the now deceased Rajang at Colchester Zoo, and while this clip is actually fake, in his lifetime at the zoo, Rajang would show incredible curiosity toward visitors with tattoos or pregnant bellies, often prompting them for a closer look by pointing. 3 4
3. They can bite
It’s commonly touted that orangutans are between five and seven times as strong as an average man – on par with a chimpanzee – though accurate strength testing is difficult to accomplish, let alone rarely necessary to measure.
Still, bite force is a common important metric for measuring or investigating various elements of evolution and ecology, and it’s been shown that orangutans can bite at least as hard as the much larger gorilla; this is far greater even than a tiger.
This is probably because they commonly feed on hard seeds and nuts and need to be able to crush the shells. In fact, a strong bite force allows an ape to access food sources previously unavailable to them and likely played a significant role in the evolution of diversity among great apes.
They also have very powerful hands, partially because they spend so long navigating branches with them, but likely also to help tear and break into woody plant foodstuffs.
These are powerful animals, and, like chimps, have the strength to tear off all your soft bits and bite you to pieces. But unlike chimps, that’s just not in their nature. 5 6
4. They’re solitary-ish
These gentle giants are far more interested in living their best lives, far from conflict, just cruising about in the canopy. Orangutans are far less social than most other apes, including people, but they appear to be significantly more tolerant.
What’s particularly magical about orangutan society is that despite not showing any particular interest in socialising, they’re not usually bothered about others being around. They’ll even tolerate humans and have been seen approaching casually and offering gifts.
Females will stay with their young for up to around eight years, and they do know and interact with their peers to some extent, but for the most part, these thoughtful creatures like their alone time. 7
5. They’re almost exclusively arboreal
There was once likely a terrifying terrestrial predator on the island of Borneo. Ancient artworks and local legends depict a tiger that so far, has not been found in fossils or remains, but would have been a significant threat to any ground-dwelling ape.
In Sumatra, this predator still exists, and consequently, the Sumatran orangutan has evolved to spend its entire life in the tree canopy.
In Borneo, orangutans are no longer threatened on the ground and will occasionally touch base, but old habits die hard, and they remain one of the most arboreal species of great ape as a consequence. 8
6. And trees are the problem
Being so exclusively reliant on trees puts these incredible animals in direct competition with farmers, who want to use the land for crops.
The major crop of concern is oil palm, a crop which has been the subject of a lot of controversy over the previous decade. Vast swathes of forest are removed to produce this palm, and it is sold worldwide as an additive in over half of all packaged food products worldwide.
As a result of this habitat destruction, orangutan populations have halved over the past 60 years.
Not all of this comes from Borneo; the largest amount comes from Sumatra, where another species of orangutan species is even more highly endangered. So, this may act as an omen for things to come for the Bornean orangutan, if palm oil isn’t done right.
7. Palm oil can be done right
Ridding the world of palm oil isn’t the solution. Palm oil is an exceptionally efficient oil crop, producing up to 11 times the amount of oil for the same amount of land as a sunflower oil crop.
The issue is that the climate that oil palm requires is the same one where all the ancient rainforests are. Finding a solution to sustainable palm oil is likely the way forward unless an equally efficient option can be found that grows elsewhere.
A mutually beneficial solution is being sought by organisations like the Roundtable on Sustainable Palm Oil and new research suggests that tree islands can boost biodiversity and yield by interrupting monocultures, which should reduce the pressure on ancient forest to provide the space for more oil palm crops.
All of these should help to protect the habitat of the orangutans, but there are other threats to their population to worry about too. 9
8. Some are killed for meat
Illegal hunting is a major contributor to their decline. Several thousand are killed for meat each year, and this is a far greater rate than can be sustained by an animal that reproduces this slowly.
A smaller number are hunted as pets, and conservation projects need to address all forms of illegal hunting as well as habitat protection in order to guarantee the future of the species.
Bornean Orangutan Fact-File Summary
Scientific Classification
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Primates |
| Family: | Hominidae |
| Genus: | Pongo |
| Species: | Pygmaeus |
Fact Sources & References
- Aline Reynolds (2009), “Study: Orangutans Play Leaf Instruments to Fool Predators”, Discover Magazine.
- Ellen J.M. Meulman (2013), “Orangutan tool use and the evolution of technology”, Research Gate.
- CBS News (2016), “Baby orangutan flips out over magic trick”, YouTube .
- Colchester Zoo (2017), “Orangutan Rajang gets gets up close to another baby bump…his keepers!”, YouTube.
- Carolyn M. (2013), “Bite force and occlusal stress production in hominin evolution”, Sci Hub.
- Cheryl D. Knott (2019), “Possible Male Infanticide in Wild Orangutans and a Re-evaluation of Infanticide Risk”, Scientific Reports.
- Primatforskning (2012), “Strong Fingers”, YouTube.
- (2018), “Why Do Orangutans …”, Smithsonian’s National Zoo & Conservation Biology Institute.
- Delphine Clara Zemp (2023), “Tree islands enhance biodiversity and functioning in oil palm landscapes”, nature.