Islands of Sumatra and Borneo in Southeast Asia


Rain forest

Red apes of the forest

Orangutans, whose name means “people of the forest,” live in tropical and swamp forests on the Southeast Asian islands of Borneo and Sumatra. These shaggy red apes are the largest arboreal mammal and the only great ape found in Asia. The other great apes—gorillas, chimpanzees, and bonobos—are all native to Africa.

All arms

Long, flowing, reddish hair covers most of an orangutan’s gray skin. Its stocky body has a flexible pelvis, a thick neck, and bowed legs. The orangutan's arms are longer than its legs, reaching nearly to its ankles when the ape stands up. Like other apes, orangutans don't have a tail.

Orangutans spend most of their life in the trees, swinging confidently from branch to branch. Their long fingers and toes can easily grasp branches and vines. With arms longer than their body and long, strong fingers and prehensile feet, life in the trees works well for them. In fact, orangutans look a bit awkward on the ground, using their arms as we might use a pair of crutches or lifting those arms high above their head when they walk. Adult male orangutans are much larger than the adult females.

If you think orangutan arms look long, you’re right. Their arms stretch out longer than their bodies—over 7 feet (2 meters) from fingertip to fingertip.
Skilled tool users, wild orangutans strip leaves from twigs and use them to reach into holes for termites. San Diego Zoo keepers often put honey in the orangutans’ manmade termite mounds to give them the same opportunity.
Orangutans have been known to watch villagers use boats to cross the local waterways and then untie a boat and ride it across the river on their own.
Orangutans are the largest fruit-eating animals on Earth.
Wild orangutans have more than 300 types of fruit available to them in their rain forest home.

Orangutans are the only great apes species with a native habitat outside of Africa.
Orangutans have the slowest breeding rate of all mammals. They reproduce only every seven or eight years, the longest interval of all land mammals.

Ever-fascinating orangutans have been delighting San Diego Zoo guests since 1928. Over the years, we’ve had both Bornean and Sumatran orangutans and have celebrated 30 births at our facility.

The famous Ken Allen
Orangutans are known for their clever ability to get into places they’re not supposed to go! One of the Zoo’s most famous orangutans was Ken Allen, a Bornean orangutan known for his creative escape techniques. He would unscrew bolts with his fingers, reach around to unlatch things, climb up a steep incline by the back of his enclosure to slip over a wall, and so on. Every time keepers figured out one of his escape routes, he would discover a new one. He never seemed to mind being led back into his enclosure—he just seemed to enjoy the challenge of finding a new way out! Ken Allen became a San Diego Zoo legend, with his own fan club and T-shirts, bumper stickers, and songs created in his honor. Many people were saddened when this gentle, mischievous ape developed cancer and passed away in December 2000.

Ape exhibit
Today, our orangutans share their exhibit with playful siamangs, the largest of the gibbons, which inhabit the same forest of Indonesia and Malaysia as the orangutans. Their exhibit includes climbing structures that are joined by ropes and cargo nets, a man-made “termite mound” that is often filled with tasty treats for the orangutans to retrieve, rocky caves, and vertical “sway poles,” which are sturdy poles that gently bend like tree branches and help create aerial pathways through the exhibit, and provide entertainment for both apes and Zoo visitors who come to watch their antics.

Some of the orangutans stay right up close to the exhibit glass, observing their human visitors and interacting with them any way they can. They might want to show off their newest enrichment item, such as a burlap sack that can be worn quite smartly as a shawl, or they might want to just look at you as enrichment!

Our orangutans
Our current group of orangutans includes adult male Satu and females Indah, Karen, and our newest member, Aisha, who was born on October 25, 2013. The only member of the group to be hand-raised as an infant, spunky Karen survived a widely publicized open-heart surgery in 1994. Karen has a LOT of personality and is a guest favorite. She can be stubborn and willful, but keepers love her, too! Look for Karen: she likes to roll around on the ground and twirl around on the sway poles.

Watch our orangutan gang daily on Ape Cam!

Unfortunately, these highly intelligent red apes are now extinct in much of Asia. Most of their forest habitat has been destroyed to make palm oil plantations. On top of that, poachers often kill orangutan mothers and sell their young to the illegal pet trade. In those cases, the orangutan orphan is usually doomed to a short and depressing life unless it is rescued by an orangutan organization that takes care of orphans in special reserves. Many of these organizations have programs to educate loggers and local people about the need to protect their rare red neighbors and to help enforce the laws against poaching.

Indonesia is the top supplier of wood products and paper pulp in the world, and at least 70 percent is illegally logged. The world operates on the law of supply and demand, so we need to lessen the demand and carefully manage the supply. Conserve and recycle: we hear this often, but it really is an important part of the answer for helping wild orangutans.

San Diego Zoo Global is working to raise awareness of the dangers all great apes face. We provide financial funding and support various conservation projects via the Association of Zoos and Aquarium’s Ape Taxon Advisory Group’s Conservation Initiative.

Studies identifying levels of genetic variation between the two orangutan species have provided information that can be used for habitat conservation efforts. Comparing the genomes of five Bornean and five Sumatran orangutans with DNA provided from our Frozen Zoo® identified that both species have high levels of genetic diversity but contrasting histories of population growth and decline. Previous studies conducted by our geneticists identified chromosomal differences between Bornean and Sumatran orangutans. This information helps build the Association of Zoos and Aquarium’s Species Survival Plan programs for these apes.

San Diego Zoo Global is also a member of the Roundtable on Sustainable Palm Oil (RSPO), which was started to promote a sustainable palm oil industry to limit the destruction of rain forests. Look for products that are RSPO-designated as containing certified sustainable palm oil.

You can help us bring orangutans back from the brink by supporting the San Diego Zoo Global Wildlife Conservancy. Together we can save and protect wildlife around the globe.