The Kehje Sewen Forest has welcomed a new resident! Following confirmation from our veterinarian in October last year that Lesan was pregnant, we are thrilled to announce that she has since given birth!

Lesan was last seen around Camp Lesik at the end of 2022 with an enlarged stomach. Shortly after, she disappeared for some time, so our team suspected that she had already given birth. And they were right! Lesan and her firstborn, Ayu, were recently spotted around Camp Lesik, but they were not alone this time: Lesan was holding Ayu’s baby sibling, her second offspring born in the forest.

The second-time mum clearly illustrated her protective maternal instincts and affection through her behaviour around the newborn. When our team attempted to take photos, Lesan turned away to hide the baby. Even big sister Ayu went into protective mode and attempted to scare off our team members by shaking the trees and approaching them with her teeth exposed. Lesan and Ayu did a great job teaming up to protect their newest family member from the prying eyes of human observers.

Lesan clearly shows her protective maternal instincts and affection

A reintroduction success story
Lesan, a rehabilitated orangutan who BOS reintroduced to the forest in 2012, is a success story not only for her ability to survive in the wild and reproduce but also for raising Ayu to forage on her own and build nests in nearby fruiting trees. According to observational data made by our Post-Release Monitoring team in the field, Lesan’s ability to socialise with other orangutans, act accordingly when encountering humans, explore her ranging area, and copulate to help create a new generation of forest-born orangutans demonstrates the success of the reintroduction programme.

We need orangutans in the wild
Orangutans are endemic to the islands of Borneo and Sumatra and are on the verge of extinction. Thus, various efforts are being made to protect them, including the BOS Foundation’s rehabilitation and release programme.

As an umbrella species that plays a vital role in forest sustainability, orangutans are desperately needed in the wild. We need them to remain in Kalimantan’s forest ecosystems, their true home. Therefore, we must prevent them from being exploited and protect them at all costs.

Will you help us by donating to our work or adopting one of our orphaned orangutans?

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

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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