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Lesan’s Baby is a Girl!

It had been a couple of weeks since our PRM team from Camp Lesik had seen Lesan and her baby, when they finally caught up with them a few days ago. The team managed to observe Lesan’s activities over a whole day – from the moment she woke in the morning, until she built her night nest in the evening.

We departed from Camp Lesik at 6 a.m. in search of Lesan’s nest. After searching for a while, we detected movements in a tree, which turned out to be Hamzah and Casey rising for the day. We remained focused on Lesan’s nest, however, until just after 7 a.m. when she finally appeared.

After waking, Lesan and her baby moved to a fig tree, with Casey following. Lesan ate some bark and then moved to another tree to eat cinnamon stems. Lesan took her time feeding with Casey trailing her wherever she went.

During the middle of the day, Lesan spent more time on the ground. She was observed kissing her baby and rubbing its hair as the infant suckled. This was the moment we were able to determine the sex of the baby – it’s a girl!

We discovered that Lesan’s baby is a girl!

Still hungry, Lesan moved to feed on nearby bamboo. She then retired to her morning nest to take a rest, but soon ventured out to feed again. After nearly an hour of eating, Lesan collected some twigs and fresh leaves to improve the construction of her morning nest and then rested there with her daughter. Meanwhile, Casey, who had been following them all morning, moved on to the trial called Transect Martin.

This is not the first time we have seen Lesan sharing her food sources with others – we once observed her sharing papaya with Juminten  (read the full story here: Peace and Papayas Among Friends) and it seems to this day she is still happy to share with Casey.

Clearly, Lesan is a good mother, as she and her baby daughter both appear to be in good health and thriving in the Kehje Sewen Forest.

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

The year 2016 marks the BOS Foundation’s 25th anniversary! Celebrate 25 years of ever-challenging, dedicated work in the field of orangutan conservation by showing your support and help save orangutans! 


Latest News from Napri and Yutris

You may recall the two orphaned, male baby orangutans that came into the BOS Foundation’s care in 2015 named Napri and Yutris.

Napri was rescued from a forest-fire affected area in Hiang Bana Village, Katingan Regency (Read the full story: Orangutan Rescue Operations), and Yutris was rescued from Madara Village, South Barito Regency, in a joint effort with the Central Kalimantan BKSDA (Read the full story here: Yutris, the Newest Orphaned Orangutan to Arrive at Nyaru Menteng). After passing the quarantine phase and routine health tests, the boys were moved to the Nyaru Menteng Nursery Group where they now spend their days learning and playing with their peers.

Yutris Loves Rambutan

In the group for orangutans under four years of age, 2-year-old Yutris is very active and spends most of his time up in the trees. He loves to play with Valentino and Momot – the three are inseparable!

Valentino, Yutris, and Momot

Out of these three, Yutris seems to enjoy taunting babysitters and his peers the most. His adorable and entertaining behaviour, however, makes it difficult for anyone to be upset with him. Among the various fruits served to the nursery group, rambutan is by far Yutris’ favourite! He often approaches the babysitters in a bid to get more rambutan fruits.

Yutris, Madara and Valentino are building on their survival skills daily. Their foraging skills are improving and all three are currently having a love affair with ehang fruit!

Napri and his Favourite Doll

While Yutris prefers to be in the company of friends, Napri is somewhat of a loner. At the tender age of one year, Napri has yet to gain much self-confidence. He still prefers to play alone with his favourite doll, which he lugs around everywhere.

Napri dan his doll

Babysitters have tried to encourage Napri to climb trees, but he always seems to get cold feet. He often moves away from the group to play in the enrichment hammock or on the feeding platform alone. Whenever a friend tags him to play, Napri retreats quickly to the arms of his babysitter.

Orangutans orphaned at a young age are robbed of the opportunity to receive first-hand knowledge from their mothers on how to survive in the wild. Left to fend for themselves without their mother’s care and guidance, only one in five orphaned orangutans will survive to adulthood. This is where our babysitters play a vital ‘surrogate mother’ role.  Our dedicated babysitters nurture and guide the baby orangutans in their care to become independent and survive in the wild. The orangutan reintroduction programs in both Nyaru Menteng and Samboja Lestari would not be as successful without our team of loving and devoted babysitters.

Yutris and Napri still have a long way to go before they become true, wild orangutans. Time will tell how long it takes these gorgeous boys to hone their skills and self-confidence. Stay strong and keep learning, lads!

Text by: Communication Team of BOSF Nyaru Menteng

The year 2016 marks the BOS Foundation’s 25th anniversary! Celebrate 25 years of ever-challenging, dedicated work in the field of orangutan conservation by showing your support and help save orangutans! 


Orangutan Food Aplenty in the Kehje Sewen Forest

The biggest challenge in releasing orangutans back to the wild is finding suitable forest habitats for them to live in. In order to determine the viability of a forest as a potential release area, we first need to conduct a thorough phenology survey to ensure the area has a sufficient amount of natural food available all year round.

A phenology survey involves recording data on all fruiting trees in the forest, as well as other food sources for orangutans, such as edible tree bark, shoots, foliage and insects. The survey also records the fruiting season of each fruit-tree species to ensure food availability over the changing seasons.

Some of the natural orangutan foods found in the Kehje Sewen include:

Ardisia sp. fruit, locally known as lampeni or rempeni, which resembles cherries – red, round and small.

Ardisia sp.

Artocarpus sp., a variety of jackfruit related to cempedak and breadfruit.

Artocarpus sp.

Durian, which is known as the ‘king of fruits’. The durian variety found in the Kehje Sewen Forest has a reddish skin and is a great source of carbohydrate, fat, protein and minerals for orangutans.


Various types of forest flowers, including Ficus aurataLithocarpus gracilis, and Macaranga gigantea.

Certain plant shoots, such as rattan and forest-ginger shoots.

Raymond eating a ginger root (Etlingera sp.)

Termites, which are especially high in protein, found in weathered pieces of wood.

Angely eating termites

The Kehje Sewen Forest is an 86,450-hectare primary forest area rich in food sources for orangutans. From our phenology survey – which also involved tagging every fruiting tree in certain transects and recording data on their numbers and density – we discovered that almost 200 plant species grow there.

The Kehje Sewen Forest is rich in nutritious orangutan food and can sustain orangutan populations and other fauna. The difficulty involved in finding suitable release habitats for rehabilitated orangutans has forced the BOS Foundation to ‘rent’ forest areas under the Ecosystem Restoration Concession scheme since 2010. With 700 orangutans still under our care, we hope that support from the central and provincial governments of Indonesia will help the BOS Foundation secure more forest release areas.

Text by: PRM team in Kehje Sewen Forest

The year 2016 marks the BOS Foundation’s 25th anniversary! Celebrate 25 years of ever-challenging, dedicated work in the field of orangutan conservation by showing your support and help save orangutans! 


Raymond Encounters Bungan in the Kehje Sewen Forest

Our PRM team from Camp Nles Mamse recently monitored Raymond’s activities over several consecutive days to see how he was adapting to life in the Kehje Sewen Forest following his release on May 28.

Raymond was observed eating a variety of forest fruit species, including jackfruit (Artocarpus sp.), Ficus sp., and a ginger root (Etlingera sp.) He was actively foraging and moving through the trees and lianas, clearly enjoying his new life.

After climbing down to grab some a ginger root, he busied himself building a couch-like mattress made from piles of twigs and leaves. He rested comfortably on his ‘couch’ for a while before returning to the trees to explore.

The next day, the team caught up with Raymond and followed him again, this time interrupted by unfavourable weather and rainfall. Raymond cleverly grabbed several leafy branches to cover his head, just like an umbrella.

After the rain stopped, Raymond returned to foraging and kiss-squeaked every now and then to show his displeasure with human presence.

Suddenly, the team noticed movements in the forest and quickly checked telemetry signals to find out if it was another orangutan approaching. The movements turned out to be from Bungan, a female the BOS Foundation released in December 2015.

Raymond did not appreciate the company and quickly departed. However, Bungan seemed determined to get to know Raymond and chased him for a few hours. The team followed them until Raymond finally made peace with Bungan’s presence, and they both stopped to sit in the same tree. They then hugged and sat together to eat forest fruits.

They were still together the following day, and stayed close to one another. When Raymond started to build his nest for the night, Bungan chose to build hers in a nearby tree.

We are delighted to see this friendship develop between Raymond and Bungan, and hope it will result in another natural birth in the Kehje Sewen Forest.

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

The year 2016 marks the BOS Foundation’s 25th anniversary! Celebrate 25 years of ever-challenging, dedicated work in the field of orangutan conservation by showing your support and help save orangutans! DONATE NOW

Dewi and Her New Baby

We quickly picked up transmitter signals for Mardianto and Compost – two of our more recently released orangutans, who had been observed spending time together over the past few weeks. Our luck didn’t stop there, however. A short way upriver from this happy pair we detected a strong signal for Dewi, a 21-year-old female who was released just over a year ago.

What good fortune, I thought, since Dewi hadn’t been tracked for several months. Jagau and I set out on foot to find her, which was rather unfortunate for Jagau as he had expected to stay in the boat all day and had failed to bring shoes! After some searching, we found Dewi in a sangkuangtree happily munching on its small fruits. I was so excited to find such an elusive orangutan and so invested in taking detailed notes on her position and initial reaction to seeing people, that I didn’t notice the tiny orange bulge half-hiding behind her head: A new infant!

When Jagau spotted the infant, we shouted with joy at the new discovery and Dewi stared intently down at us, seemingly waiting to see whether she needed to be alarmed by those calls. Lucky for us, she only turned away from us, hiding her young baby from our sight. It will take us some time before we can determine the sex of the baby. The baby’s face is still very pink, and we estimated it is around four months old.

Long-time followers of the BOS Foundation’s released orangutans in Batikap will remember that Dewi, along with two other females from the 10th release group, was observed mating with flanged male Tarzan soon after finding freedom in the forest. Whether Dewi continued to copulate with Tarzan or mated with another released orangutan remains unknown, but we believe it is more likely that this infant is Tarzan’s offspring. This would make the newborn a product of a first-released and tenth-released orangutan pair.

During that first day of observation, Dewi and her new baby mainly kept to themselves in the trees. Dewi ate while the infant was watching us with its big brown eyes, occasionally pulling the fruits from Dewi’s mouth to try for itself and instantly spitting them back out (Dewi is a tolerant mother indeed). We lost sight of them that day, when Dewi disappeared through a thick of spikey rattan and could no longer be tracked until her transmitter turned back on the following morning.

The next day I went back, accompanied by Nanggau. Unfortunately, Dewi wasn’t so tolerant of being observed this time around. She frequently descended from the trees and moved towards us, alternating between quadrupedal and bipedal walking as the baby clung on tightly to her neck and back. Even from a distance, we could tell the that infant already had a tight grip.

We lost sight of them after backing away a little too far, but the mother-infant pair was quite easy to relocate as the baby began crying incessantly! We rushed over to see what caused the commotion and were greeted by Dewi again moving back down from the trees and coming towards us, this time at a much faster pace. We backed off again and later returned to find them in a large tree overhanging the river. Her baby continued crying while Dewi alternated between slapping her body, rubbing her back against the trunk of the tree, and pulling at her and the poor baby’s hair – an ant attack! Somewhere along the way, they must have bothered an ant nest and had become covered in its angry inhabitants. Having done the same thing in the field several times, I could surely sympathize with the baby’s cries and Dewi’s frantic scratching. I can only imagine how much harder it must be to brush ants out of that long red hair!

It took more than an hour for the baby to finally calm down and return to peacefully watching Dewi go about her day from upon her shoulder. Dewi remained wary of our presence after the episode, however, and continued to descend and advance toward us bipedally whenever she caught sight of us.

Dewi was not known to prefer bipedal movement beforehand. Perhaps her hands were sore from the bites? Perhaps she was still adjusting to the difficulty of carrying a baby – for although his grip appeared tight, the baby’s preferred resting positions were somewhat awkward. It seemed to stick close to Dewi’s head and shoulders, and at one point flopped completely over her face, just managing to catch onto her mouth with its feet. Dewi seemed unperturbed though; she simply flopped the baby back over and continued eating.

We stayed with Dewi and her baby until they nested for the night, high up in the trees. Just beforehand, however, we heard the tell-tale rustling and branch breaking of someone else setting up nest for the night in the trees nearby. Could it have been Compost or Mardianto, who we had seen along the river earlier? Could it be Tarzan, who still frequents the area, checking in on one of his mates and his potential offspring? We can’t say for sure just yet what dynamic is at play here, but we will definitely keep our eyes peeled over the coming weeks.

Text by: Coral, PRM Team volunteer in Batikap Conservation Forest

The year 2016 marks the BOS Foundation’s 25th anniversary! Celebrate 25 years of ever-challenging, dedicated work in the field of orangutan conservation by showing your support and help save orangutans!  DONATE NOW 

Peace and Papayas Among Friends

Suddenly, movements could be heard coming from up in the trees. The team tried to identify the approaching individual by telemetry signal, but were unable to pick up a signal – this could indicate an orangutan released quite some time ago with an exhausted transmitter. Through observing the approaching orangutan’s physical characteristics, the team soon discovered it was none other than Juminten (with her round face and distinguishable hairline)!

Released in 2013, Juminten was last seen by our team on July 8 last year, when she was observed hanging out with Mona, another adult female released the same year (Read the full story here: A reunion with Mona and Juminten).


Juminten looked very interested in the papaya that Lesan and her baby were eating, and she moved cautiously closer. Lesan remained calm and seemed unfazed by larger Juminten’s presence – so much so, she gave her the chance to join them.


Juminten eating papaya

Lesan played with her baby nearby while Juminten ate the fruit.

Lesan playing with her baby after getting her papaya fill

After finishing her papaya, Juminten approached Lesan and her baby again and spent some time with them before continuing her journey through the forest alone.

Juminten spending time with Lesan and her baby

Lesan then took her baby and climbed up in the trees to build a nest and rest together.

This friendly and peaceful interaction between released orangutans indicates to us they are living happily and comfortably in the Kehje Sewen Forest.

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


The year 2016 marks the BOS Foundation’s 25th anniversary! Celebrate 25 years of ever-challenging, dedicated work in the field of orangutan conservation by showing your support and help save orangutans!  DONATE NOW 

HOPE (Help Orangutans, Protect Earth)

The recent reclassification of the bornean orangutan from ‘endangered’ to ‘critically endangered’ by the IUCN indicates that the hard work we have been doing is still not enough. Wild orangutans are constantly being pushed out of their natural habitats. Meanwhile, we are caring for hundreds more in our rehabilitation centres who are waiting to be released to safe habitats. The BOS Foundation asks for more dedication and commitment to help save orangutans. Let’s join hands and work harder to save this umbrella species and keeper of the forest. We still live in HOPE – Help Orangutans, Protect Earth.


Growing Up in Batikap

When I arrived at Totat Jalu Camp in March, I immediately saw Lesta and Lewis, a mother-and-son pair released to the Batikap Conservation Forest in February 2013. The pair could be seen in and around the camp, and they appeared to be very healthy and active. That day, I joined the PRM team to observe Lesta and Lewis and it was a priceless experience.

I watched Lewis as he hid among clumps of bamboo. He then approached us alone, but it seems Lewis has already learned a lot about survival in the wild from his mother, Lesta, because he immediately started kiss squeaking to express his displeasure at my presence.


Shortly after this interaction, Lesta spotted me and like a wild orangutan mother should, she grabbed her son and clutched him tightly to her belly, then quickly moved high through the trees of the Batikap Forest so we were unable to follow them.


Lesta and Lewis have been living in Batikap for almost four years now. Lewis is now a healthy 4-year-old and has started displaying some independence, through Lesta is still on hand to provide her motherly support and supervision. Young orangutans usually start to live apart from their mothers at the age of 6-8 years, so Lewis still has a few more years to learn from his Mum.

It is amazing to witness the dedicated love and care of a mother orangutan in preparing her son for independence. We believe Lewis will grow to be an awesome male figure in the Batikap Conservation Forest.

Angely Enjoys Her New Life in the Kehje Sewen Forest

Our PRM team from Camp Nles Mamse has been tracking Angely and is happy to report she is adapting well to her new home in the Kehje Sewen Forest. Angely has been observed feeding well on breadfruit (Artocarpus sp.) and ficus fruits, which seem to be among her chosen favourites.

From the moment she leaves her nest in the morning, Angely goes in search of forest foods. She spends hours in the trees eating which is very encouraging to see.

Angely feeding on breadfruit

Arthocarpus sp., Angely’s favourite fruit

After feeding, Angely will travel deeper into the Kehje Sewen Forest. She is quick and agile, and more often than not, our team has to make a fast dash just to catch up with her and keep monitoring her activities. At midday, Angely usually builds herself a nest to rest in for a couple of hours.

Angely resting in her nest

Our PRM team have noted that Angely starts building her night nests from about 4.30 p.m. daily and cleverly stocks them with ficus fruits before retiring for the night. At sunrise, she eats her already prepared fig breakfast in bed before leaving her nest for another day in the forest.

Angely ready to explore more of Kehje Sewen

It is heart-warming to see Angely living in the Kehje Sewen Forest. We hope the other orangutans in our care at Samboja Lestari and Nyaru Menteng will have the same opportunity to live happily in the wild, just like Angely.

Vote BOS Foundation as Your Favourite Organisation!

Saleduck Asia is a Dutch internet-based company established in 2012. Based in Amsterdam, Saleduck Asia offers access to smart, cost-effective online shopping by providing sales codes and discount coupons.

Saleduck Asia has organised a charity campaign, and the BOS Foundation has been selected as one of the NGOs to benefit from the campaign.

The campaign will run from July 1, 2016 until January 31, 2017. Saleduck Asia will donate 15 million Rupiah in total among the nominated NGOs. Voting will determine how much money will reach the BOS Foundation, so help us become the most liked organisation by accessing this link and please vote for the BOS Foundation!