One morning, after the Post Release Monitoring (PRM) team finished their 2-day phenology activities in Mount Belah, they continued to patrol in the area of Kali Tengah to search for Sayang and her pregnant mother, Yayang (read full story here: Yayang is Expecting a Baby!).
On the first day of patrol, we did not detect any signal and only managed to locate a used nest in the hillside area of Kali Tengah, which we presumed was Yayang’s. The next day, we went back patroling in Kali Tengah, but this time we follow a different transect. From Kali Tengah, we walked up to Berlian Hill. Every 100 meters, we stopped to try and detect any orangutan signals around the area. When we reached the ridge on the way to Berlian Hill, we finally detected Yayang’s signal and tried to decide the direction of its source. Initially, we suspected that it came from another hill across the valley, which is very far. But we soon learned that we were wrong.
We slowly climbed up Berlian Hill to get better reception. When we arrived at the top, we discussed the possibilities and decided to head down to Mobil Mogok transect. We guessed that Yayang was somewhere near that transect. On our way, Yayang’s signal grew stronger and it came from a valley on our left. So we took a shortcut down the valley following the direction of the signal.
At one point, the signal was very strong indicating that Yayang was near. We slowed down and walked as silently as possible while looking for Yayang. It did not take us long to finally spot Yayang up in a tree with her daughter Sayang, eating the fruits of Lithocarpus sp. (a genus of trees related to the oaks).
Yayang has A Baby!
After only around two minutes of observation, someone in our team shouted excitedly, “Yayang already gave birth!” The team then realized that a small baby was clinging on Yayang’s belly. We do not know who the father was, but Yayang had been observed in the past mating with some of the males in Kehje Sewen, including Noel and Acul. In the life of this mostly solitary primate, the mother entirely bears the burden of childcare.
That moment, we were all strucked with a sense of undescribable happiness. This is the first natural birth in the Kehje Sewen Forest; the first wild-born from one of our rehabilitated orangutans, giving a real hope to our goal of reviving wild orangutan population in Borneo, particularly in this case, in East Kalimantan.
During observation, Yayang was very relaxed and ate a lot of forest fruits. Due to Yayang’s protective nature as a new mother, we decided to observe from a distance and therefore have not been able to identify the infant’s gender. We will do so in a few weeks, as soon as the baby is a little bit older and Yayang is more approachable.
With the company of an older sister and an experienced mother, we can safely hope that this baby will have a bright future as a wild orangutan.
We all wish Yayang and her two children a prosperous life living in their true home, the Kehje Sewen Forest, East Kalimantan.
Text by: Tim PRM di Camp Lesik, Hutan Kehje Sewen
You can support our team and its monitoring activities too. DONATE NOW to the BOS Foundation and keep our spirits high!