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Cheryl Knott
Grantee: Cheryl Knott, Anthropologist
Borneo, Indonesia

Time spent by research team:
More than 50,000 hours over the past decade

Gunung Palung National Park, Borneo, Indonesia

Park's orangutan population:
About 2,500

Worldwide population:
15,000 to 24,000 in the wild

Dangers for orangutans: By some estimates more than 80 percent of all orangutan habitat has been destroyed. Since 1996 legal and illegal logging has consumed about five million acres (two million hectares) of forest each year.

Spreading awareness:
"Through our educational outreach programs and awareness campaigns around the park, we are drawing public attention to the orangutans' plight and helping to make a difference. It would be tragic to let these great apes slip away."


Learn More

Gunung Palung Orangutan Project
Visit Dr. Cheryl Knott's website featuring her orangutan research in Gunung Palung National Park, Borneo, Indonesia.

Balikpapan Orangutan Society–USA
Learn more about these red apes at this website, which includes education resources and things you can do to help protect orangutans.

Orangutans Online
This website contains frequent updates on topics related to orangutan conservation.

Global Forest Watchenglish/indonesia/
A World Resources Institute initiative, this network provides information on forests throughout the world, including Indonesia.


Felton, Annika M., and others. "Orangutan population density, forest structure and fruit availability in hand-logged and unlogged peat swamp forests in West Kalimantan, Indonesia." Publication forthcoming in Biological Conservation
(November 2003), 91-101.

Jepson, Paul, and others. "The End for Indonesia's Lowland Forests?" Science (May 4, 2001), 859-61.

Knott, Cheryl D. "Orangutan Behavior and Ecology." In The Nonhuman Primates, ed. P. Dolhinow and A. Fuentes. Mayfield Publishing Company, 1999.

Knott, Cheryl D. "Changes in orangutan diet, caloric intake and ketones in response to fluctuating fruit availability." International Journal of Primatology (1998), 1061-79.

Matthews, Emily, ed. The State of the Forest: Indonesia. Forest Watch Indonesia and Global Forest Watch, 2002. Available online at

Van Schaik, Carel P., and Cheryl D. Knott. "Geographic Variation in Tool Use on Neesia Fruits in Orangutans." American Journal of Physical Anthropology (April 2001), 331-42.

Van Schaik, Carel P., and others. "Orangutan Cultures and the Evolution of Material Culture." Science (January 3, 2003), 102-5.


Field Dispatch: Borneo

Photographs by Tim Laman

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This Week's Questions. Click on a question for a full response.

1.   What do they eat, where do they sleep, and what kind of noises do they make? 4.   What natural predators do orangutans, have other than tigers?

2.   Is the Sepilok center actually doing
conservation work or is it just a public relations front?
5.   Do the orangutans live in the trees, or are they ground dwellers? Also, what type of wood is being harvested?
3.   Is there anything we can do other than give money? That is, lobby our legislators to pressure the international community?




Name: Mrs. Nemeth's third grade class  
Question 1:
What do they eat, where do they sleep, and what kind of noises do they make?
The orangutans' preferred food is fruit, which often includes seeds. When fruit is plentiful, this is all they eat. However, there are many periods when there is not much fruit to eat and they must rely partly on leaves, bark, pith (herbaceous vegetation), and insects, particularly termites.

Each adult orangutan builds a nest in the trees each night to sleep in. The nest is made by bending over branches with leaves attached and inserting them under other branches until they've made what literally looks like a huge bird's nest.  This takes about five minutes to do on average. Occasionally they will sleep in an old nest and they sometimes make nests to rest in during the day. Babies and juveniles sleep with their mothers in her nest until they are about eight years old and have a younger sibling or have started to become more independent. 

Orangutans make a number of different noises or vocalizations. The most famous is the "long call" produced by large, prime males. This call can last for several minutes and carries very far in the forest. This is the way that these big male orangutans alert other orangutans
to their presence. Orangutans also make other sounds such as the "kiss-squeak," the "lork," and a "grumph" sound when they are disturbed. Juveniles make whining noises to their mother's when, for example, they can't cross over a gap and need the mother's help. There may be other softer noises they make to each other that we can't hear following them on the forest floor.
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Name:  Glenn F.  
Question 2:
I visited the center at Sepilok several years ago and was struck by the following dilemma. The center helps rehabilitate orangutans and hopes to return them to the wild. However, it is run by the forestry commission, which means that there is a vested interest in harvesting the forest itself. If habitat destruction is the major threat to the orangutans' survival, is the Sepilok Center actually doing conservation work, or is it just a public relations front?
I have also visited the Sepilok Center, but I'm afraid I can't really answer this one for you. I don't know what other work they are doing and how the Malaysian government balances forestry and conservation. I do know that in Indonesia, where I work, different branches of the Forestry Department are responsible for forest conservation and assigning forestry contracts. You may want to contact one of the NGOs working on orangutan conservation in
Malaysia such as World Wildlife Fund.
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Name:  Chanin C.  
Question 3:
Is there anything we can do other than give money?  That is, lobby our legislators to pressure the international community?
This is one of the most important questions—What can an individual do? Yes, you can lobby local and national government officials to let them know this should be a top concern within the international community. You can tell your American congressional representatives that you support the Great Ape Conservation Act and wish to see U.S. funds allocated to great ape conservation. You can also provide funds to organizations that support orangutans such as National Geographic's Conservation Trust and the Balikpapan Orangutan Society—USA, among others. And you can volunteer for an organization
supporting orangutan conservation either here or in Indonesia or Malaysia.
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Name:  Becky C.  
Question 4:
What natural predators do orangutans have other than tigers?
Tigers may be a threat, but only in Sumatra because they aren't found on Borneo. There are also some smaller cats, such as the clouded leopard, that may be a threat to an infant or juvenile who is alone. However, these smaller individuals would never be alone except if their mother died. Some rehabilitated juvenile orangutans that were released into the wild have reportedly been killed by clouded leopards. But this has not been reported in wild
orangutans. In fact, I know of no published reports of wild orangutans killed by any natural predator. However, most cats hunt at night, thus this is not likely to be observed by researchers and perhaps it does happen on occasion.
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Name:  Tim K.  
Question 5:
Do the orangutans live in the trees or are they ground dwellers? Also, what type of wood is being harvested?
Orangutans predominantly live in the trees. In fact, they are the largest animals that spend most of their time in the canopy. Females come to the ground very rarely.  The much larger males sometime travel on the ground or eat insects or plants found there. But both sexes spend more than 90 percent of their time in the trees, although there are population and individual differences.

There are many different types of wood that are being harvested. In our area the number one species has been ramin.
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