About Orangutans

Morphology

Orangutans share many features with African great apes, including large body, no tail, building nests for sleeping, and long, slow lives. Their most distinctive feature is their red-orange color—other great apes are black. read more…

Life History and Development

Orangutans live life in the slow lane. They grow and breed slower than any other land mammal, even elephants, and whales. read more…

Diet

Orangutans are frugivores, or fruit eaters. 50-60% of their foods are fruits. Fruits are poor in proteins and fats, so they eat many other items too: leaves, flowers, honey, shoots, stems, seeds, fungus, pith, bark, soil, insects, eggs, and small mammals. They eat lower quality items as when fruit is scarce. Some of their foods are medicinal: they protect against malaria, control parasites, or treat diarrhea. Orangutans also use leafs as topical medicines; they rub special leaves on their skin to soothe sore muscles and joints.

Distribution and Habitat

In Sumatra, orangutans remain only in the northern tip. They are found across Borneo, but not everywhere. Orangutans live in tropical rainforests, mostly lowland and swamp forests rich in biodiversity. read more…

Individual Behavior

A typical orangutan day starts at dawn around 6:00 am, waking in the nest where they slept the night. Then they eat, rest, travel, and (rarely) socialize. read more…

Communication

Orangutans are known as quiet, but they communicate desires, needs, and intentions by vocalizations, gestures, postures, and facial expressions. read more…

Social Life

Orangutans are semi-solitary—or semi-social. It is adults who prefer solitude, especially adult males. Adult males range alone and are so intolerant of one another that they may fight to the death if they meet. Adult females are semi-social, usually living with one or more offspring. Offspring leave their mother at adolescence but females stay near their mother's range while males move farther away. Immatures are more sociable, traveling and playing with family or friends for days on end. read more…

Intelligence

Orangutans, like other great apes, are the most intelligent nonhuman primates and the nonhuman species most similar, mentally, to humans. read more…

Conservation

On IUCN's Red List of Threatened Species Borneans are endangered, at very high risk of extinction in the near future. Sumatrans are critically endangered, among the world's 25 most endangered primates. Humans cause their greatest threats: habitat loss, hunting and disease. Clearing forests is often the first phase of development. It destroys orangutan habitat because the forests humans want are often those orangutans need. Logging, oil palm plantations and natural resource industries have cleared vast tracts of Bornean and Sumatran forest. Development is also at the root of fires that have eradicated much forest, even if natural droughts set the stage. Humans hunt orangutans for food, as pests and to sell to the illegal wildlife trade. Development enables hunting by making forest foods scarce. Orangutans leave the forest seeking food, often raid farms or plantations, and become easy targets. Development also increases disease threats. Orangutans are susceptible to many human diseases, even tuberculosis, polio, and hepatitis.