How Long Do Orangutans Stay With Their Mothers? Facts

Why orangutan childhood lasts so long

An adult orangutan has to find enough food in a vast forest where fruit appears unevenly, often in different places from month to month. Surviving alone means knowing hundreds of food plants, the locations of fruit trees, how to open spiny or hard fruits and how to build a safe nest every night. Learning all this takes years.

Long-term field studies in Borneo and Sumatra have shown that young orangutans do not become fully independent until they are around 7 to 9 years old, and that infant survival is very high when they stay that long. Researchers describe orangutans as having the slowest life history of all the great apes: long childhoods, late first births and long gaps between babies.

Stages of an orangutan’s childhood

Ages vary between individuals and species, and Sumatran youngsters often stay longer than Bornean ones.

Nursing and learning to eat

Orangutan mothers nurse for many years. Studies at long-term research sites have recorded young orangutans still suckling at 6 to 8 years of age, longer than in any other wild mammal for which reliable data exist. Milk becomes less important as the youngster grows, but it is a safety net during fruit shortages.

Infants watch their mothers closely while they feed, and they often take scraps of food from her mouth or hands. Through this, they learn which fruits, leaves and insects are good to eat. By the time they are weaned, young orangutans eat almost the same range of foods as their mothers. They also pick up skills that differ from place to place, such as particular ways of using sticks or leaves, which researchers see as a form of culture. Read more in what do orangutans eat?

Learning to build a nest

Every adult orangutan builds a new sleeping nest each evening, and this is a skill that takes years to perfect. Infants sleep in their mother’s nest and watch her bend and weave branches. From about 6 months old they start “playing” at nest building on their own, and they become skilled at it by about 3 years. Even so, most young orangutans keep sharing their mother’s night nest until they are weaned or a younger sibling arrives.

Long gaps between births

Because a mother looks after one youngster for so long, she does not usually become pregnant again until it is almost independent. As a result, wild orangutans have the longest interval between births of any great ape, about 6 to 9 years. Long-term studies have found average intervals of around 7 to 8 years in Bornean orangutans, with Sumatran orangutans averaging close to 9 years at some sites.

Female orangutans usually give birth for the first time at about 15 years of age. Combined with the long intervals, this means a mother may raise only four or five offspring in her lifetime. This slow breeding is one reason orangutan populations recover so slowly from losses, as explained in why are orangutans endangered?

How orangutans compare with other apes

Humans have short gaps between births but a very long childhood, because parents and other relatives share the work of raising children. Orangutan mothers do it alone, which is why each youngster takes so long. Compare with Africa’s apes on the chimpanzee page.

What happens after leaving mother?

Young orangutans usually drift away gradually rather than leaving suddenly. Adolescents may still meet their mothers and travel with them now and then, and they often seek out other young orangutans to play and travel with. Daughters commonly settle near their mother’s home range, while sons wander farther and may take many years to establish themselves. Learn more about the species on the Bornean orangutan page.