Archives: May 2015

An afternoon at Siwie Hill with Yayang & Sayang

May 26, 2015. Posted in Article

After a full week of rain in Kehje Sewen Forest, today’s patrol was blessed with beautiful sunshine. Yosi, Bariyo and I were tasked to patrol along transect Wani, down to Tyo River. The other two Post Release Monitoring (PRM) teams were assigned to patrol along transect Mount Belah and transect Martin. We departed together from Camp Lesik until we reached Mount Belah, then went our separate ways towards our assigned transects.

Yosi, Bariyo and I headed to transect Wani. As usual, we checked for signals of orangutans every 100 meters using radio telemetry equipment. But we didn’t detect any orangutan in the area. We even climbed a nearby hill in the attempt to detect signals from a higher spot. The result was the same. No orangutans were detected.

ribbet 30-01-2014 Fajar_Arif_Frangky (22)

After a while, we decided to continue along the main ex-logging road towards Tyo River since we had recently received information that some local residents saw an orangutan near the river.

These last few weeks, it has consistently rained at around midday. Unfavorable weather doesn’t discourage us from continuing our work. However, the radio telemetry equipment can’t be used in the rain because it is not waterproof. So we continued our search for orangutans by employing traditional techniques, i.e. by searching for broken branches, food leftovers or feces that may indicate the presence of orangutans around the area.

Fortunately, the rain didn’t last very long. After the rain subsided, we were informed by one of the other teams on our hand held radio that they had detected Yayang’s signal from the direction of Siwie Hill. After a quick discussion with all three teams via the radio, we agreed to search for Yayang together with each team coming in from different directions. But this joint effort still didn’t yield the expected result. Yayang was nowhere to be found. So we split up again and returned to each of our assigned transects.

Yosi, Bariyo and I continued our patrol by following the ridge along Siwie Hill. By late afternoon, we finally located Yayang who was sitting on the forest floor, happily feeding on forest ginger and termites.


Not far from where Yayang was sitting, we also spotted her daughter Sayang high up in the trees. Seeing us, Sayang immediately showed her dissatisfaction at our presence by loudly kiss-squeaking (a call indicating distress or displeasure made by sucking sharply between the lips or against the palm of the hand).


We kept our distance from Sayang so she calmed down. From our observations, pregnant Yayang looked very healthy and had a good appetite. Both she and her daughter Sayang ate a lot of forest fruits and young leaves.

Sayang and Yayang

After observing them for two hours and taking photos, we left them in peace. We pray that Yayang stays healthy throughout her pregnancy and will soon deliver Kehje Sewen’s first wild-born baby orangutan who will hopefully be as strong and active as her sister, Sayang.

Text by:Agus Purniawan, PRM Team at Camp Lesik, Kehje Sewen Forest

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Lembu River Phenology and an Encounter with Juminten

May 19, 2015. Posted in Article

Our schedule to collect phenology data in the Lembu River area was hampered by bad weather and repeatedly flooded rivers. The survey that was supposed to be conducted on 24th-25th of each month had to be postponed by a week. And by the time we gained access into the area, still we experienced heavy downpours, so initially were only able to set up a temporary camp. We had to once again delay the phenology survey and wait for the rain to end.

The rain finally stopped and on May 4th we were at last able to leave the camp and conduct the phenology survey.

Some trees were bearing fruits, and these attracted bees, such as Aporosa benthamiana, Garcinia sp., Gardenia sp., Baccaurea tetrandra, Polyalthia sumatrana, and many more whilst others were in flower, soon to bear fruit

ribbet IMG_4241 - Aporosa benthamiana by Jafar
Aporosa benthamiana
Garcinia sp
Garcinia sp

Data collection that day went well with the additional bonus of encountering a forest deer.

On the May 5th, before sunrise at 5.20 AM, we were delighted to find that there was an orangutan nearby. We vaguely saw that this individual was just waking up and was about to start the day. But we had to wait for the light to improve to visually identify the orangutan.


The sun rose and finally we could see that the individual was Juminten, a female adult we released back in 2013. Some of the team observed her for a couple of hours, while the rest prepared breakfast.


After two hours we finished observations and concluded that Juminten was in good condition, healthy and active. She seemed to move actively through trees and eat well, especially forest kedondong, which is a type of fruit that Indonesians frequently use as an ingredient for rujak, a local form of fruit salad. We were delighted to see her because Juminten is one the most rarely encountered individuals. She is doing very well and has now lived in the forest for more than a year, so is a successfully reintroduced orangutan.

After that brief time with Juminten, we continued the phenology data collection. Dark clouds covered the sky the entire day, but thankfully the rain held off a moment before sun down. During the survey we also encountered wild hogs, deers, horn bills and several bird species. We were glad that when the rain started to fall, we had already finished our task and headed back to Camp Lesik.

Text by: Agus P, Camp Lesik PRM team, Kehje Sewen Forest

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Casey Joins Our Patrol Team

May 14, 2015. Posted in Article

At sun rise, we depart daily on our regular patrols to track our reintroduced orangutans and see how they are getting on. This time our efforts were focused in the area of Gunung Belah and every 100 meters we stopped to check our radio tracking receiver to see if we could detect any of our orangutan signals.

As we drew nearer to the transect close to our habituation enclosure, we detected Casey’s signal. It did not take long for Casey to come down from the tree she was in and try to approach us, so we kept our distance.

IMG_3936 - Casey by Handoko

From the habituation enclosure transect we headed to Bukit Acul, but did not pick up any other orangutan signal apart from Casey’s.  Then we realized that she was following us.

IMG_3937 - Casey by Handoko

We tried to encourage her to move away, but Casey would still continued to follow  us until we reached Gunung Belah.  There we did not detect any other orangutan signals either, and decided to take a break for lunch.

Seeing us resting, Casey left after she too found something to eat in the trees.

IMG_3935 - Casey by Handoko

As the night began to draw in, it was time for us to return to Camp Lesik. We did not encounter any other orangutans that day, but we were glad to see Casey well and have her company during our patrols. Thanks a lot, Casey!

Text by: Camp Lesik PRM team, Kehje Sewen Forest

Photo by: Handoko, Camp Lesik PRM team, Kehje Sewen Forest

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Berlian and Agus

May 5, 2015. Posted in Article

A couple of weeks ago, residents of Pelangsiran – a small transit town on the border of Kehje Sewen Forest – reported sightings of an orangutan. The following day, two members of our Post-Release Monitoring (PRM) team, Handoko and Gunawan, went straight to the location to check it out.

Arriving in Pelangsiran, we detected strong signals for Berlian, a female orangutan reintroduced back in April 2012. She was hanging out by the banks of Telen River, not far from Pelangsiran.  Seeing us, she quickly moved away, so Handoko and Gunawan decided to stay in Pelangsiran and plan to relocate Berlian the following day.

Three days passed, but Handoko and Gunawan did not manage to get close enough to Berlian to attempt a evacuation effort. Both had tried every trick they know, but Berlian showed no interest in approaching the two technicians at all. So Handoko and Gunawan finally decided to return to Camp Lesik to discuss the situation and seek some advice from the rest of the team.

On the fourth day, our phenology team consisting of Agus, Bowo and Jafar just returned from their monthly data collection duty in the southern area of Pelangsiran. They stopped at Pelangsiran to rest and saw Berlian eating fruits up in a tree. To everyone’s surprise, Berlian suddenly stopped eating, came down from the tree and approached the team. Apparently, she seemed to recognize one of our team members, Agus. Agus tried to get Berlian to enter a travel cage that had already been prepared by Handoko and Gunawan before they had left.  But Berlian was only willing to enter if Agus entered the cage with her.

After several failed attempts, Agus chose to just carry Berlian on his back. The team feared that the longer Berlian stayed in Pelangsiran, there was a potential for human-orangutan conflict to occur. They had planned to relocate Berlian to the area of Lembu River, several kilometers north of Camp Lesik. However, no cars were available to take them back to Camp Lesik, so the team decided to walk slowly back to Camp Lesik with Berlian on Agus’ back.

During the trip back to Camp Lesik, Berlian was only willing to be next to or to be carried by Agus. We don’t know why she was so focused on Agus, but as long as she willingly came with us, we were totally up for it. Nevertheless, one-third of the way to Camp Lesik, Agus started to feel very tired. The 60-something kilogram orangutan was not easy to carry. She kept moving, changing positions and generally making it difficult for Agus to walk. So around the area of Muara Soh, Agus and the team stopped to rest a bit. But Berlian did not seem to approve of this plan. She started to whine trying to get the team to keep walking. She eventually got so impatient that she left them.

Berlian climbed a tree on a steep hill and quickly moved away. The team tried to follow her, but orangtuans can move quickly through the forest when they want to and it wasn’t long before she had left the team behind. They spent some time trying to find her but without radio tracking equiment, which they didn’t bring as were doing phenology, it was impossible.

So the team decided to leave Berlian alone for now. Muara Soh is also an area often visited and inhabited by some of our reintroduced orangutans so we are sure that Berlian will be fine, but we’ll keep an eye on her in this area. After all, Berlian is one of the first six residents of Kehje Sewen and she has been living here and thriving for over three years. We just hope that she does not decide to return to Pelangsiran again. Take care, Berlian!

Text by: PRM Team, Camp Lesik

You can support our team and its monitoring activities too. Donate now to the BOS Foundation and keep our spirits high!

Breaking News: Yayang is Expecting a Baby!

May 1, 2015. Posted in Article

Last week we shared with you a story of Yayang’s daughter Sayang, who has started to live independently in Kehje Sewen Forest. This week we have even more exciting news from this pair; Sayang is about to have a baby sister or a brother!

Foto Yayang

Since their release back in December 2013, both Yayang and Sayang have shown excellent ability at adjusting to their new lives in the forest. They are very active and prefer to spend the majority of their time high up in the trees.  Yayang is very good at finding forest foods, not only fruit, but also leaves, bark and termites. Sayang has learned a lot of foraging skills from her mother (read more here: Motherly Love Goes a Long Way

And this week, we received great news about Yayang from the Post-Release Monitoring (PRM) Team at Camp Lesik.  Based on several observations, the team had suspected that Yayang may be pregnant.  Early morning on April 22, 2015, the team collected a urine sample from Yayang and tested it.  Sure enough two pink stripes appeared confirming her pregnancy. Unconvinced, the PRM team took another sample in the afternoon. The result was the same. The next day, on April 23, 2015, they repeated the test one more time, just to sure. And yes! Yayang is indeed pregnant!


Since then, the PRM team conducted a 6-day series of nest-to-nest observations on Yayang. She consumed plenty of forest fruits such as kedondong (Spondias dulcis), mangosteen, and ginger. Although she is now relatively less active than usual, in general she is very healthy. It is quite normal for a pregnant orangutan to be less active; she needs to conserve her energy.

Foto yayang lagi makan

While there have been three births in our Central Kalimantan’s reintroduction site (Bukit Batikap Conservation Forest), this is the first recorded pregnancy in Kehje Sewen Forest, so naturally we are all very excited and have high hopes for Yayang who is already an excellent mother to Sayang. We hope for a smooth pregnancy for Yayang and safe delivery of the first wild-born baby orangutan in Kehje Sewen Forest.

Foto Yayang lagi gelantungan

Text by: BOS Foundation’s Communication Team at the Headquarters

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