Abbie’s Forest

Kehje Sewen Forest, June 29, 2012

Abbie was transported by road to Kehje Sewen approximately a week after the other five had been released. So she was the last one to arrive at Mount Belah. But make no mistake, even as a newcomer, Abbie is as bold as ever. She keeps demonstrating her marvelous ability to quickly master the vast terrain of Kehje Sewen. She can travel 1-3 kilometers daily. She even visits places that have never been visited by the other five orangutans; nor by us.

Her extensive cruising area is growing every day, making observation not only difficult but also absolutely exhausting. She challenges us to climb hills of 800-900 meters above sea level (asl) to follow her. Following Abbie is always a thrilling and fantastic experience. Once, we even had to climb a steep hill for half an hour non-stop for fear that if we stopped, we’d lose her.

Abbie has a unique ability to walk on the forest floor without a sound and without leaving a trace in the trees or shrubs in her path. We are fooled numerous times and end up losing her.

Just 4 days after she was released, Abbie made a nest at the summit of a hill, at around 900 m-asl, approximately 2 kilometers away from the acclimatization enclosures at Mount Belah. That day, we only managed to follow her until midday, after which we lost her. Since then, we kept searching for Abbie to no avail. We could not see her, nor pick up her radio telemetry signals. She was simply gone.

Abbie, quietly observing the observers

Unexpectedly, 3 weeks later Abbie was seen sitting on a big rock across Soh River while observing our team who at that time was following Mail. Abbie’s location was around 4.2 kilometers from the acclimatization enclosures. For an orangutan entering adulthood like Abbie, it is quite normal to travel this far. An adult female Bornean orangutan’s home range is between 0.5 km2 to 5 km2.

It was like seeing an old friend. Without thinking, we plunged into the wild rapids of Soh River, ignoring the risks of drifting or drowning, just to get a closer look of Abbie. It seemed that Abbie missed us, too! She actually let us follow her into her private ‘home’ across the river, without giving us any of her usual ‘disappearing tricks’. So far, Abbie is the only orangutan who has managed to reach the forest across the Soh River.

The spectacular Abbie’s Forest

Abbie looked healthy and well toned with stunning reddish-brown hair, indicating her success in adapting with her new environment. She obviously found a favorite place, which is the virgin forest across the river that has not been touched by her five friends. We were so excited to see her. All of our fear and anxiety disappeared. We know from now on, Abbie will be just fine. And we have come to an unspoken agreement to name the forest that extends from across the Lembu River all the way to across the Soh River, Abbie’s Forest.


Siesta with Mail

Kehje Sewen Forest, June 19, 2012

These past five days, not one drop of rain falls on Kehje Sewen. It feels good! Because we don’t have to do our work while soaking wet, no walks on puddles, no damped and muddy feet, no slipping down the hills and, most importantly, no leeches!

The beautiful Soh River

Today, observer Masino and researcher Wulan get their turn to follow and observe Mail. It was a sunny warm day of 24º Celsius and relative humidity of 78% (daily temperature data of Camp 103). And knowing that Mail usually cruises along Soh River, this observation task is exciting for us because the riverbanks of Soh are blessed with stunning panorama.

Kehje Sewen is indeed a watershed and a drainage area. So there are many creeks and clear whitewater rivers with exotic scenery, among which are Lesik River, Lembu River, Soh River and Mount Belah River.

Mail is lazy this morning, just laying around in his nest, having slept at around 6.30 pm yesterday evening, which is considered quite late for an orangutan. Mail was too busy foraging along the Soh River yesterday, so he came back late to his nest that is also located on the bank of Soh. The fact that Mail lives by the river gives us double advantages. In addition to enjoying the beautiful landscape, we are also able to observe and follow Mail without having to climb up and down any hill. Haha!

Mail, lazily sunbathing in his nest

At 7 am, Mail still has not moved anywhere. He is still laying lazily in his nest while chewing stalks of Piper aduncum fruits (in the same family of betel leaf). Mail, too, seems to enjoy the sunshine, which is rare in a tropical rainforest like Kehje Sewen. Our mornings are usually adorned with low-hanging clouds and heavy rain. So Mail is obviously content just sitting around and occasionally nodding off in the warm morning sun.

Mail eventually gets bored… at around 12 noon! The sun is high. It is no longer warm, but stinging hot! Mail then moves downstream, exploring the vegetation along Soh River. And we have to follow him in the hot midday sun. Fortunately, the scenic river does cool our hearts, though it does not cool our bodies. But we can’t complain. After all, Mail has allowed us a half-day siesta with him all morning.

Casey’s Disadvantage is a Blessing in Disguise

Mount Belah, Kehje Sewen Forest, June 13, 2012

Good food does not necessarily look appetizing and is not always easy to get. Just like Casey’s favorite food, the young shoots of rattan trees.

The “cruel” rattan trees

Rattan tree is a plant from the Calamae family, closely related to decorative palm trees that you normally find at an office’s front yard as well as at roadsides in many big cities in Indonesia. In contrast to palm trees though, rattan vines are equipped with barbed hooks that function as a tool for attaching to other trees and protection from herbivores. Rattan tree is often found on Mount Belah because the world’s largest rattan trees population – 70% of all population – is in Indonesia, especially in the tropical forests of Borneo Island.

The rattan thorns do not only stretch on the stems, but also on the vine leaves and young tendrils. Even the young shoots are already equipped with barbed hooks. Obviously we are often accidentally injured when passing a rattan grove. Our clothes are often torn apart and our skins are sores for many days. So we give this plant a new name, “the cruel tree”.

Casey uses her two crooked fingers to hook a shoot

But despite all of its ‘cruelty’, the prickly rattan tree is Casey’s favorite food.

While other orangutans prefer to search for other types of food and only hunt for rattan shoots when absolutely necessary, Casey spends half of her time every day to beat the evil thorns and gather the delicious rattan shoots for lunch, and she always has fun doing it!

Then, she uses her teeth and mouth to yank the shoot

We are amazed at how Casey conquers the rattan thorns. Apparently, the fact that she only has 2 fingers on her right hand becomes a blessing in disguise. Casey uses her two crooked fingers to hook young shoots that are of course surrounded by thorns. After that, she will use her teeth and mouth to yank them. Then, all she has to do is grab the yanked shoots with her normal left hand. She gathers the shoots diligently and saves them for lunchtime. So by using fewer body parts, Casey faces less chances to get hurt. The rattan tree has hooks, so does Casey!

Clever and inspiring Casey

This behavior is repeated over and over again, so we are sure that it is not a coincidence. Casey consciously turns her disadvantage and drawback into a more effective tool. Usually, orangutans will eat the young shoots directly using their mouths as a tool. But Casey with her two fingers can squeeze into the shoots, hook them, and ultimately make them a delicious meal without having to bear the risks of injuries on her face or her hands.

We are so inspired by Casey. Having a disadvantage does not mean she loses out. Instead she turns it into a unique and amazing advantage. Bravo, Casey!

Tasting Lesan’s Favorite Exotic Fruits

Kehje Sewen Forest, June 5, 2012

Being an orangutan observer is an experience that opens up an exciting new scientific discourse, especially in botanical science, and at the same time, is very “filling”! The forest managed by Restorasi Habitat Orangutan Indonesia (RHOI) covers 86,450 hectares and stores amazingly rich and impressive flora, including a wide variety of orangutan food. There are many species that the observers are not familiar with, do not know the names and even have found for the very first time. When they finally figure out the scientific names for some fruits, they are still having a hard time figuring out the common names.

Diospyros sp. trees with ripe fruits – one of orangutan’s favorites in the forest

A Diospyros sp. fruit

One example is Diospyros sp. This fruit is similar to Kesemek – a fruit that can be found in traditional markets in Indonesia. But it is not quite a Kesemek. It is also in the same family with imported Persimmon and Plum that we usually find in supermarkets in Indonesia’s major cities. Diospyros sp. is one of orangutan’s favorite fruits in Mount Belah. So much so that the observers named one of the hills “Berlian’s and Lesan’s Diospyros Hill” because there are two Diospyros sp. trees where Berlian and Lesan often “hang out” in.

This morning, observer Sam Edri and observer Putri were forced to go down the hills of Mount Belah to follow Lesan who was looking for Diospyros sp. fruits because the ones in Mount Belah are not yet ripe. Lesan is a young female orangutan with remarkable capabilities in navigation and food identification. Just by looking from the top of a tree in the hills of Mount Belah, she was able to spot some Diospyros sp. trees growing 700 meters on the edge of the River Soh. Sure enough, it turned out there were many ripe Diospyros sp. fruits that were still untouched by her other orangutan friends. This is an extraordinary talent! It almost seems like Lesan is equipped with a GPS application that can accurately point the location of her favorite food sources.

Lesan can spot her favorite fruits from high up in the trees

Arriving at the tree, Lesan spent almost 30 minutes partying there. The Post Release Monitoring (PRM) Team observing her underneath the tree were hoping against hope that a fruit would fall so they too could taste it. Finally – either it was because Lesan generously decided to share her fruits or because one simply slipped from her grasp – a fruit did fall to the ground. And the observers immediately tasted this exotic fruit and found out that the only consumable part of the fruit was the thin meat that surrounded its black seeds. There were quite a few seeds; a fruit generally contains 5 to 6 seeds. What does it taste like? Well, it has a buttery taste with a tinge of sweetness and a bitter aftertaste. It is truly an exotic fruit.

Lesan, having a lunch party of Diospyros sp. fruits

This is why we say that being an orangutan observer is sometimes a “filling” experience. Almost every day, we get to taste different types of fruits that we have never found anywhere else in the world. And we have encountered various flavors and textures – bitter, sticky, sweet and sour, bland, minty, greasy and syrupy – some are delightful in the tongue, some are simply horrible. What a wonderful culinary experience!

We still need support, funds, gifts in kind to support
our Post Release Monitoring Team.
If you can help please contact us at

Going Home with Mail

Kehje Sewen Forest, June 3, 2012

The distance between Camp 103 to Mount Belah is about 2 km. That’s how far the Monitoring Team has to travel – twice a day – which takes about 30 minutes each way. They leave every day at around 4:30 AM to monitor all of the six former “students” who are now living freely in the Kehje Sewen Forest. They need to ensure the orangutans can adapt well to their new home. Although this is not an easy task, it is still a very enjoyable routine.

Mail is one of the orangutans whom they have to observe. Mail usually roams around the acclimatization enclosures and from Mount Belah River to Soh River. When the Monitoring Team travels on transect lines around the mentioned areas, they inadvertently will meet Mail.

Mail’s predictable routine makes him a favorite among the observers. As soon as morning comes Mail wakes up and immediately explores the valleys and hills of Mount Belah in search of food. But in the afternoon, Mail will change his direction, heading down the Mount Belah River all the way to Soh River, which is a river that runs behind our main camp.

The Monitoring Team notes that Mail may like this route because there are a lot of his favorite food, which are the Zingiberaceae plants (a type of wild ginger). These plants grow widely on the slopes and the cliffs near the river. Obviously, the team loves to follow Mail because not only he makes it easy for the team to monitor and observe him, he will also eventually lead them home almost to the doorstep of Camp 103, saving a trip back to camp after dark. Thanks, Mail!

We still need support, funds, gifts in kind to support
our Post Release Monitoring Team.
If you can help please contact us at

The Release Video is Ready!

After carefully converting, selecting and editing more than 500 GB worth of excellent footages, the full version video of the first release of three orangutans (Casey, Lesan and Mail) from BOSF East Kalimantan Orangutan Reintroduction Project at Samboja Lestari to the Kehje Sewen Forest on April 22, 2012, is now ready! Enjoy!

You can also watch it on Vimeo:

Hamzah, a Reliable and Experienced Guide!

Kehje Sewen Forest, June 1, 2012

Do you want to explore limitless forest with a reliable and highly experienced guide? Be an observer or a researcher of an orangutan named Hamzah.

Hamzah, the forest explorer.

Hamzah is a teenage male orangutan. Like most teenage boys, Hamzah is courageous, adventurous and always curious to try new things. His ability to roam the forest is a lot more advanced compared to other orangutans at Mount Belah. He never hesitates to go into new areas that even observers and researchers have not set foot in.

Hamzah once traveled very far from the acclimatization area, off the established transect lines, and into a Protected Forest upstream the River Soh, which is located around 2 kilometers from the Main Camp (Camp 103), or about 5 kilometers from the acclimatization area, making the observer and researcher who followed him terribly exhausted!

Hamzah’s unique qualities include his remarkable speed and agility. He can unexpectedly move from one tree to another without being noticed by observers. Observer Masino and researcher Fitri are often fooled by him. Although Masino and Fitri feel that they never take their eyes off Hamzah, he can simply vanish from sight, without any sign of movement and without a sound.

Hamzah will guide you deep into the forest, then safely lead you back home!

This particular quality amazes Masino and Fitri. Even tree branches would sway if blown by the wind. Yet sometimes when Hamzah swings among trees, nothing moves; not a broken twig, not even a fallen leaf. Next thing they know, Hamzah is found far away from where they are.

After exploring the forest of Mount Belah and the surrounding areas, Hamzah always tends to return to the acclimatization area. It’s like he invites the observers to venture deep into the heart of the Kehje Sewen Forest with him as their personal guide. After that, he will lead them back to the acclimatization area, enabling the observers to return to Camp safe and sound. Truly a fun and reliable traveling friend and a highly experienced guide!