Female orangutan with a baby
All living things, including orangutans, have the drive to meet their biological needs: water, oxygen, food, shelter – and the opportunity to reproduce. When it comes to wild orangutans, who live a semi-solitary life, the reproduction process can be pretty interesting, to say the least.

It can be difficult to tell once an orangutan reaches reproductive maturity. While fully mature male orangutans develop cheek pads later in life, they can father offspring many years before they have cheek pads. Female orangutans, just like humans, can conceive offspring once their menstrual cycle begins, but this can be very challenging for human observers to spot.

Male orangutans living in captivity will reach reproductive maturity at around 8-10 years, slightly faster than wild male orangutans. Female orangutans can reach reproductive maturity as early as seven years of age, while on average, their wild counterparts are first fertile between 9-11 years of age.

Orangutans have the longest interbirth interval of any mammal.

Researchers have discovered that mature male and female orangutans will occasionally live side-by-side for a few days (known as ‘consortship’), which can lead to mating, also known as copulation. It is the female orangutan who can control when these associations begin or end.

The female is in charge

One study even found that male orangutans were more tolerant of sexually active females taking food from them because if they denied them, the female was more likely to make loud vocalisation and end the association by the end of that same day. So, while passively sharing their food did not mean direct mating for the male, if they did not, the female may bring their time together to an end and therefore deny the male any chance for copulation.

The peak of sexual behaviour in orangutans is when copulation between a male and female orangutan occurs. Prior to copulation, a male orangutan will typically inspect the female’s vulva or genitals with his fingers or lips. Not all of these investigations end in copulation, but ‘ideal copulation’ is achieved when ejaculation occurs, and there is a chance for a baby orangutan to be conceived.

With the interbirth interval of orangutans sitting around 7-8 years – the longest of any mammal on Earth! – we want as many orangutan babies born to wild mothers as possible. We aren’t ashamed to admit we have orangutan “baby fever,” so here’s to hoping for some romance in the trees and many more orangutan copulations!

You can support our work here. No donation is too small to make a difference in an orangutan’s life.

How Can You Help

There are lots of ways you can support orangutans and help ensure the survival of this precious ape.

Adopt an Orangutan

Adopt an Orangutan

Orangutans are endangered and at risk of extinction. Habitat destruction results in hundreds of orphaned orangutans, who rely on our care every year. You can help by adopting one. Their dedicated ‘nannies’ teach them everything they need to know for when it’s time to release them back to the wild. You can follow their progress through Forest School.

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Make a Donation

Make a Donation

Please help the Orangutans in their struggle for survival. Your donation is important and goes directly to BOS Indonesia. By donating, you are helping bring this noble yet endangered species back from the brink of extinction and on a path to freedom - from rescue to rehabilitation and release.

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Visit Our Shop

The perfect gift for any occasion! Choose from our selection of instant gifts that directly support our orangutans. You can buy a wheelbarrow, provide food for an orangutan for two months or lots more. You will receive a certificate, personalised with the name of your choice - perfect gift for you or a friend.

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