The Post Release Monitoring (PRM) Team in Kehje Sewen has faced a huge challenge since the radio telemetry receivers suddenly stopped working last October. New equipment has been ordered and we are eagerly awaiting its arrival. But in the interim the team must monitor orangutans manually; that means using all of their skills and knowledge related to orangutan range behavior. Instead of relying on technology, they must rely on all their experience to search for orangutan signs such as broken branches, opened canopy, reasonably new nests, traces of urine or feces, and food leftovers, and ultimately pinpoint their locality. Finding orangutans that have been well schooled to be wild is understandably hard. It was almost mission impossible.
Fajar & Frangki searching for signs of orangutans (photo by: Arif)
Inge in particular – our 100th orangutan – seemed to have changed location and had not been seen since the second day of her release. She quickly disappeared into the forest, leaving no trace for the technicians to follow. Siwie was the same. The newest residents of Kehje Sewen, Yayang and her daughter Sayang, were also nowhere to be found. Fortunately, the team spirit remains high. “When we work together as a team and we don’t lose hope, we can do it,” they said.
And they did it! Not only did they find Inge, Siwie, Yayang and Sayang, there is apparently love growing in the forest between Noel (released back in October) and Diah (also a new resident, released together with Yayang and Sayang in December). The following short stories are from our technicians in Kehje Sewen that we have loosely translated.
Yayang & Sayang Return
Text by: Agus and Awal
Two of our very first cross-province releases, Yayang and Sayang, had not been seen since the third or fourth day of their release. The mother-daughter pair seemed to be exploring the forest far beyond the reach of our team. But on December 28, 2013, they returned! We spotted them playing in the trees right in front of our camp.
A couple of technicians, who were on their day off quickly geared up and followed them. The pair weren’t too happy seeing the team, kiss-squeaking and throwing branches at them. Obviously, they didn’t return to meet us. Keeping a safe distance from them, we continued to follow them while keeping a low profile to let them know that we were not a threat. We simply wanted to make sure that they were okay. They finally seemed to relax. That day they made a nest at around 5.30 pm in a mahang tree (Macaranga pearsonii).
Agus, Bowo and Iwan monitoring Yayang and Sayang. (photo by: Rini)
Because we had very little data on Yayang and Sayang, we decided to do nest-to-nest monitoring for the following six days. Unfortunately, on the first day of the nest-to-nest follow, we lost them again at around 3 pm. Sayang was startled by something and fearfully fled, followed by her mum. They moved so quickly it was impossible to keep up and hence we lost track of them. But on the first day of the New Year, they were spotted again in front of our camp. This time the whole camp saw them. Three of us hurried to follow them, determined not to lose them again. It was late afternoon and soon enough Yayang and Sayang made their nest, only 400 meters from camp.
Nest-to-nest activities resumed the following day. Leaving camp at 5 am every morning, we waited for them to wake up and followed them all day through the forest. Sayang usually woke up first and started swinging around the nest, probably to wake her mother up. Mum, on the other hand, took her time. We could only see her arms stretching lazily, before she finally got out of the nest. Thirty minutes later, she approached Sayang, sat with her on a branch, and started to nurse her young. It was a heartwarming sight.
Yayang and Sayang Return! (photo by: Agus)
Yayang and Sayang look healthy and have adjusted wonderfully to life in their true forest home. They eat a variety of forest foods, such as mahang fruits, the cambium of lianas, young leaves of mahogany (Aglaia sp.), and fruits of bayur tree (Pterospermum sp.), gambier tree (Uncaria glabra), as well as jackfruits (Artocarpus sp.). They play high up in the canopy like wild orangutans and rarely come down to the ground, except once when we saw them drinking water from a spring. They are also never too happy seeing humans getting too close for comfort.
Also, we found out that Yayang has not forgotten her friend, Diah. These two East Kalimantan orangutans (Pongo pygmaeus morio) grew up together in Nyaru Menteng, Central Kalimantan, went to forest school together, and spent time on a pre-release island together. The friendship is apparent as Diah often pays a visit. Yayang welcomes her friend warmly and they are often seen playing and feeding together.
Diah pays Yayang and Sayang a visit. (photo by: Agus)
Nest-to-nest activities of Yayang and Sayang have concluded successfully. We will repeat nest-to-nest follows in two months, but for now, we wish them well and hope that they don’t travel too far, at least until the new radio telemetry receivers arrive.
Diah & Noel: Love is in the Air
Text by: Agus
On January 7, 2014, while we were monitoring Yayang and Sayang, Diah came over to spend some time with Yayang. For a while, they were feeding in a tree, feasting on an abundance of fruit. Suddenly, Noel showed up and it was clear that he was looking for Diah. Diah, too, seemed happy to see him.
Love was in the air and the pair were recorded mating.
Diah and Noel hit it off under the watchful eyes of Yayang and Sayang. (photo by: Agus)
This was the second time we witnessed these two hit it off. But the first time they were more discreet and it happened so quickly we didn’t have time to record the event. This behavior is very encouraging as it is the sole reason why we reintroduced them into the forest; to establish a new viable orangutan population of truly wild orangutans. We are crossing our fingers for Diah and Noel. We hope love stays in the air and a little Noel or little Diah will soon arrive.
Inge & Siwie: The Rulers of Kali Tengah
Text by: Fajar, Frangki and Arif
Inge and Siwie were both released in the Gunung Belah area, around 1.5 kilometers from camp. But days and days of searching on Gunung Belah did not provide us any clues as to where they had gone. On January 10, 2014, however, we remembered that Asep – our maintenance man – recently reported two orangutans crossing in front of him while he was fixing a part of the road damaged by a landslide. This location is quite far from camp in an area locally called Kali Tengah, which literally means the Middle River because it is located roughly halfway between Pelangsiran (the nearest community to our camp) and Camp 103, or around 9-10 kilometers from camp.
We decided to search the area and follow up on this information. After we passed the landslide, we rested on the roadside. Our rest only lasted a few seconds as Arif saw an orangutan foraging in the trees on a nearby hill. Instantly, Fajar got up and ran towards the hill with Arif and Frangki following not far behind. We had to go around a steep cliff to get there and had to watch our step and keep an eye on the orangutan at the same time. But it all paid off and once we got there, we found little Miss Clean, Inge – the 100th orangutan released by the BOS Foundation – feeding on the fruits of a matico (Piper aduncum) tree.
Inge, our 100th orangutan, now lives in Kali Tengah area. (photo by: Arif)
Startled by our arrival, Inge stopped eating for a minute or two, as if ensuring that we were not there to bother her. Then she continued eating. A few minutes later, we saw movements to the west, not far from where Inge was. It was Siwie!
We immediately split up. Two of us followed Inge and the other followed Siwie. In the end, we all met up again because Inge and Siwie decided to join together; they were obviously close friends. They played together and at least for now, seem to be using the same home range. At the end of the day, they even made nests in the same tree.
Siwie is never too far from Inge. (photo by: Arif)
Since then, we have conducted nest-to-nest monitoring on Inge and Siwie. By the time this story was written, we had been following them for three days. Both looked healthy and were feeding well, mostly matico fruits that were found in abundance in that area. For now, Inge and Siwie seem to have found a piece of the forest they call home. They never traveled too far from Kali Tengah. We call them the Rulers of Kali Tengah.
Searching for Leo & Titin
Text by: Fajar
Not all of our searches were successful. Leo and Titin, too, have not been seen for a while and we are anxious to see whether their romance last year continues. But in addition to not having the radio telemetry receivers, searching for these two poses another challenge; the raging Lembu River. Lembu is a big river with fast currents and rapids that often floods. And sure enough, it flooded again on the morning of December 29, 2013 after an overnight rain.
Using the sling to cross the Lembu River. (photo by: Arif)
But we didn’t give up. We crossed the river using the sling that we used to transport Leo, Titin and Juminten across the river to their release site. Then we patrolled the area from the release site up to the foot of a big hill far in the north. Late in the afternoon, we found two old nests; both located close to each other in two neighboring trees. Moving forward, we found two more nests – newer, possibly around 1-2 days old – also close to each other. One was a huge nest, fit for a big adult male of Leo’s size. The other was smaller.
All of the sudden, we heard a long call followed by two more. The sound was far from the forested hill. We debated whether it was Emerson’s long call. But Emerson was released on the other side of Lembu River, far from Leo as to avoid competition. And the sound of the raging river was too loud. It was impossible that we could hear Emerson’s long call all the way from here. So whose long call was it? Was it Leo? Whose nests were they? Were they Leo’s and Titin’s? Are they still together?
We only found several nests. (photo by: Fajar)
We could not provide the answer. It was late and we couldn’t risk crossing the Lembu River in the dark. Since then, we have not been able to continue our search because the rainy season is officially here. It rains almost non-stop every day and the Lembu River is too dangerous to cross, even by sling. We can only hope that it really was Leo that we heard and that he still travels together with Titin. We will let you know once it is safe to cross the river and hopefully we will have the technology (radio telemetry) on our side by then.
Here at the Headquarters in Bogor, we are proud of our PRM team in Kehje Sewen. They have proven their monitoring skills, even without the latest technology. Although there are still many orangutans that they need to search for, they have managed to find some of the orangutans we have not seen for a while and witnessed the promising romance between Diah and Noel. The beginning of 2014 seems to be bringing new blessings. We hope the blessings continue as well as your support for the orangutans, for more releases and to support our amazing PRM team.