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Abel Satisfies Her Huge Appetite

October is fruiting season in Kehje Sewen, when the forest is teeming with an array of delicious foods. The fruit of Lithocarpus sp., a favourite among orangutans, is found in abundance during this period and Abel, who was released to the southern part of the Kehje Sewen Forest in July, particularly loves this fruit, and is often observed eating it.

Lithocarpus sp.

Our PRM team recently caught up with Abel one morning, and watched her devour Lithocarpus fruits, one after the other, for around two hours, occasionally remembering to glance around to monitor her surroundings. Interestingly, orangutans favour the seeds of this particular fruit, and will usually discard the flesh. With their strong teeth and jaws, orangutans can easily break the endocarp of hard fruits to reveal the seeds inside.


After a satisfying Lithocarpus sp. fruit meal, Abel went back to exploring the forest, and stopped when she came to a Baccaurea sp. tree.  Slowly, Abel started to pick and eat the young leaves. After a good back scratch, she moved on to find more young leaves. That day, Abel spent most of her waking hours eating.

Able was so preoccupied with eating, she forgot to build herself a night nest before it started to turn dark. Sensing the evening was about to catch her unprepared, she quickly located the nest she had used the previous night and packed it with more leaves for comfort. After she finished her renovations she settled down for the night, bringing her day of feasting to an abrupt end.

We were happy to have caught up with Abel and monitor her day’s activities. She seems to be adapting very well to her new forest home.

See you again soon, Abel! Keep satisfying that healthy appetite!

Text by: PRM team in Camp Nles Mamse, Kehje Sewen Forest

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[Breaking News] BOS Foundation’s Nyaru Menteng Team Rescues 2 Baby Orangutans in 2 Days!

Today, just a day after rescuing a 3-year old female, a joint rescue team from BOS Foundation and the Central Kalimantan BKSDA rescued yet another baby orangutan, this time a 6-8 month old male from Sigi Village, Bukit Goha, Kahayan Sub-District, Pulang Pisau Regency, Central Kalimantan. Our attending Vet, Arga Sawung Kusuma, reported that the infant is severely dehydrated and malnourished.

The infant is now on his way to the BOS Foundation Orangutan Rehabilitation Center at Nyaru Menteng for urgent medical attention and 24-hour intensive care. This poor little boy is the 19th baby orangutan rescued by Nyaru Menteng this year.

Text by: BOS Foundation Communication Team 

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[Breaking News] BOS Foundation’s Nyaru Menteng Team Rescues the 18th Baby Orangutan in 2017

Today, a joint rescue team from BOS Foundation and the Central Kalimantan BKSDA rescued another baby orangutan, who we estimate to be 3 years old, from Teluk Nyatu village, Kuala Kurun Sub-District, Gunung Mas Regency, Central Kalimantan. This baby has reportedly been held captive by local people for around 3 years, meaning they have had her since a very young age.

The accompanying vet from BOS Foundation-Nyaru Menteng, Lia Kristina, was on hand to provide immediate medical care and, from initial reports the baby orangutan is in a relatively stable condition, though very underweight. She is now on her way to Nyaru Menteng for a thorough health examination and some much needed 24-hour care.

This little girl is the 18th baby orangutan rescued by Nyaru Menteng this year.

Text by: BOS Foundation Communication Team 

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Bungan’s Big Appetite

A heavy downpour last Sunday morning prevented the Camp Nles Mamse PRM team from making an early start. It took a while for the rain to ease up, but when it eventually did, the team set off for Simpang Tawon transect to look for orangutan, Ung.

After trekking along the transect for an hour, there was still no sign or signal for Ung. The team continued the search across the swamp, when they saw a sudden movement in the trees. Spotting the approaching silhouette of an orangutan, the team quickly checked for signals, and found none. The foliage parted and revealed Bungan, who was released in December 2015. This likely explained why she wasn’t emitting a signal, as the battery in her transmitter had probably expired. Bungan moved from tree to tree to explore the forest, as the team observed her from below.

Bungan sit on the tree

Bungan went about her way foraging and feeding, too busy to worry about the team’s presence. She climbed down to pick and eat some shoots: This was clearly just an appetiser, as Bungan quickly climbed back up into the trees to dine on other forest fare – Anthocepalus fruits, shorea, and young fig leaves and figs. She lazily fed whilst resting on a big tree branch, reaching out for more fruits nearby without even needing to get up. How convenient!

Bungan climb down to pick and eat some shoots

After two hours of ‘culinary observations’, our team tried again to locate Ung’s signal, but were still unable to detect it after several attempts. So they returned to camp to make preparations to search for Ung the next day.

Everyday is a new adventure and although the team didn’t find Ung on that day, they did have the pleasure of seeing Bungan in good form and with a very healthy appetite!

Text by: PRM team in Camp Nles Mamse, Kehje Sewen Forest

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Sofi and Compost: The Very Best of Friends

Orangutans are the only great apes known to spend the majority of their lives in solitude. While gorillas and chimpanzees live in social groups, orangutans maintain a solitary existence in their own home ranges, which they will often defend if trespassed by other non-related individuals. However, there are some exceptions – like Compost and Sofi.

Gentle-natured Compost was released in February 2015, and during her first six months in the forest was observed spending time with other orangutans, who were released at the same time. In April 2016, the BOS Foundation released more orangutans, including Sofi, a shy and nervous female. Compost encountered Sofi in the forest and the two were observed spending a lot of time together. This was beneficial for Sofi, who became more confident in the calming company of Compost.



These two beauties began exploring the forest together, sharing food, and grooming one other. It was clear from the very beginning that the two enjoyed being together: They often built their nests in the same tree and napped at the same time.

Then, one day, our post-release monitoring team found Compost alone without Sofi. On the next day however, the team saw branches in a nearby tree move and quickly checked radio tracking signals to detect who it was. To their surprise and delight, Sofi had come back to her friend! At first, Sofi seemed shy and hesitant, but Compost soon approached her, and after a few minutes the two started grooming one another. They then spent a long time feeding on the same piece of bark before continuing on their way together.

While Compost and Sofi are expected to spend most of their lives individually, we hope the two friends will continue to meet again in the Bukit Batikap Conservation Forest and enjoy moments in each other’s company.


Text by: Alizee Martin, PRM Coordinator in Batikap

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Angely, Leonie Spend Time Together in Kehje Sewen

Our PRM team recently set out from Camp Nles Mamse early in the morning to conduct observations on several released orangutans, including Angely. After walking along the river and following transects, the team eventually found her sitting in the top of a tree, and were surprised to discover that she was not alone. She was with Leonie!

The team first spotted Angely slowly moving around lianas, with Leonie following close behind. After travelling through several trees, Angely stopped for a rest. Leonie caught up and sat next to her. It was amazing to witness the closeness between the two and they even had a hug! They conducted their activities together, and took time out to give each other a scratch on the back.



Shortly after this encounter, the two moved away through the forest to forage. Angely stopped every now and then along the way to grab some shoots; but Leonie kept bustling her along, as if she wanted to maintain momentum. Leonie, who was released to the Kehje Sewen Forest a few months before Angely, seemed to have knowledge of certain areas of the forest abundant in natural foods.

Angely continue exploring the forest

Finally, in an area a few kilometers away from the initial point of our observations, Leonie started to slow down. It appeared she had reached her intended destination – an area rich in natural food sources – and happily began to forage. Clever girl! Angely continued to explore the forest and also forage, but didn’t roam too far away from her friend.

It was great to see Angely and Leonie thriving and supporting each other in the forest. We can’t wait to catch up with them again!

Text by: PRM team in Nles Mamse Camp, Kehje Sewen Forest

You can support our monitoring team. DONATE NOW to the BOS Foundation!



Bogor, October 1st 2017: Borneo Orangutan Survival (BOS) Foundation has teamed up with its worldwide partners to launch a free competition to raise awareness for #Orangutanfreedom.

Designed to highlight the importance of this year’s goal to reintroduce 100 orangutans to safe natural forest, and release 100 onto pre-release islands to complete their forest training before reintroduction, BOS Foundation together with its global partners today launched a campaign, which offers the opportunity to win the trip of a lifetime.

The campaign website invites people around the globe the chance of winning an amazing prize of witnessing the release of an orangutan. «The lucky winner and a companion will take a trip to Borneo and connect with this unique species in a new way – by witnessing orangutan freedom first-hand», said Dr. Jamartin Sihite, CEO of BOS Foundation.

A featured website divides this year’s freedom approach into three key focal areas – Threats, Solution and Freedom. Visitors can learn more about the main threats orangutans face, gain insights on the organisation and its efforts, and learn how to become part of the freedom solution. The campaign also aims to actively engage audiences to understand the link between giving orangutans back their freedom and the survival of this iconic species. «Everybody can join by using and exploring the hashtag #Orangutanfreedom. The more people who join our movement, the wider we can spread awareness on the critical need to protect these unique beings in the wild», said Jacqueline L. Sunderland-Groves, Deputy CEO of BOS Foundation.

To enter the competition is quick and easy. Eligible contestants can register online by filling in the entry form. The competition ends on 11:59 p.m. UTC/GMT plus 7 hours on October 31, 2017. The winner will be picked randomly and announced at the beginning of November 2017.

The #Orangutanfreedom Press Kit provides you with instant access to photos and one campaign teaser. To learn more about the campaign, please contact Paulina Laurensia Ela,  a non-profit Indonesian organization dedicated to the conservation of Bornean orangutans and their natural habitat, working together with local communities, the Ministry of Environment and Forestry of the Republic of Indonesia, and international partner organizations.

BOS Foundation currently cares for more than 600 orangutans in two rehabilitation centres, with support from 440 highly dedicated staff and experts in the fields of primatology, biodiversity, ecology, forest rehabilitation, agroforestry, community empowerment, communications, education, and orangutan welfare.



BOS Foundation has declared 2017 as the «Year of Freedom, with the immediate aim to give back freedom to 200 orangutans under their direct care. These are orangutans which are either ready for reintroduction to natural habitat; ready for release to pre-release islands; or working through the rehabilitation process. The challenges BOS Foundation faced in the past, including securing safe and suitable release forests and pre-release islands have been overcome.

For further information, please visit



[BABY BULLETIN] It’s Milk Time!

Orangutans learn many things in Forest School, but they do need breaks from their busy forest activities. For our younger orangutans, who still need a lot of hands on care and love, milk time is looked forward to by everyone including Jacqui and Jengyos, who can be seen here enjoying their milk!

Text by: BOS Foundation HQ Communication Team 

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Rafli: King of Kehje Sewen

During a recent early morning patrol, our Kehje Sewen Post-Release Monitoring (PRM) team happened upon Rafli in the forest. The team followed Rafli – the 49th orangutan released to the Kehje Sewen Forest – and began to observe him. Rafli soon realized the PRM team’s presence, and promptly emitted three loud kiss-squeaks to show his displeasure at being watched over. The PRM team decided to give Rafli space, and observed him from a further distance.

Rafli in the Kehje Sewen Forest

 Ficus tree; natural orangutan food in the Kehje Sewen Forest, and Rafli’s favourite!

A year after his release, Rafli has become a dominate figure in the Kehje Sewen. His roaming area is very wide, reaching 3.5 km. The PRM team often hears Rafli’s long calls when they are undertaking monitoring duties in the forest, indicating that Rafli is marking his territory to other orangutans, as well as trying to attract female orangutans.

An avid explorer, Rafli has been observed in good health, and has become a wonderful forager. His favourite food source is the ficus tree. He likes all parts of the ficus tree, including young leaves, the fruit, and even its bark. Rafli also likes to eat Etlingera shoots (of the Zingiberaceae family).

We are delighted to see Rafli adapting well to life in the Kehje Sewen Forest. Well done, Rafli!

Text by: PRM team in Camp Lesik, Kehje Sewen Forest

You can support our monitoring team. DONATE NOW to the BOS Foundation!