Possible Romance between Lesan and Hamzah?

As usual, monitoring activity started early that day. At five in the morning, the PRM team were already up and ready to follow Lesan, a female orangutan who was released into Kehje Sewen Forest back in April 2012. After venturing the forest for an hour, we finally found Lesan at six. She already started a healthy breakfast of macaranga fruit, or mahang as the locals call it, her favourite fruit.

The agile Lesan moved from one tree to another, devouring fruits as she swung. She stayed in the trees all the time, didn’t touch the ground even once.

At eight, we heard a cracking sound from the trees nearby and Hamzah appeared. He approached Lesan and it seemed that Lesan didn’t mind his company. This area was actually a place where they usually meet and play together. And of course, not long after, the party began!

They enjoyed macaranga fruits which were abundant around them while we watched from a distance. We saw them playing together, and apparently, Hamzah was interested in courting Lesan because he kept following her. Sometimes he would also ask for fruit from Lesan and Lesan would happily give it to him. When rain fell by midday, they took shelter under an impromptu umbrella made from a branch with big leaves. That was quite a romantic moment that we felt a little bit embarassed watching them!


In wild orangutans, it has been discovered that female orangutans of Lesan’s age are not usually attracted to young adult males like Hamzah. It is possible that Lesan only tolerates Hamzah because she looks at him as a brother or a really good friend instead of a potential mate. But considering that Lesan and Hamzah grew up together in the BOS Foundation’s rehabilitation center instead of in a forest like wild orangutans, their behaviors may slightly differ. Observing and recording these differences is one of the many reasons of post-release monitoring.

It didn’t take long for Lesan to leave the romantic setting, however. She wasn’t romantically interested in Hamzah after all. Right after the rain stopped she tried to leave Hamzah behind and to go on her own way, but Hamzah was insisting on following her. Tailing them was the monitoring team who had to keep up with their amazing speed and agility. They finally separated in a hill where Lesan went to the north and Hamzah decided to go south instead.

You might have heard that the process of orangutan reintroduction does not stop with them being released into the forest. Post release activity for orangutan is called PRM or Post-Release Monitoring, where a team must monitor each individual for at least 1 year to ensure their reintroduction is successful. PRM aims at monitoring the orangutans’ ability to adjust and survive in their new home. We monitor their forest skills, including whether or not they can find food during non-fruiting season. PRM results become a valuable evaluation material for the development or improvement of rehabilitation program.

Text and photo: Rio Ardie – Restoration Coordinator


Following the Monitoring Team Following Orangutan

It was 4 am and the day was still dark, but some of our friends in Camp 103 were already up preparing orangutan monitoring activity for the day.

Orangutan monitoring is an activity to follow, observe, and record data on orangutan’s behaviors, from the time they wake up in the morning in their nest until they build a new nest and finally rest for the night.

Today, my curiosity was finally answered when I was allowed to follow the Monitoring Team following an orangutan. As a beginner, they suggested that I’d join the team that would follow Casey, because the location was relatively near from camp (around 30 – 45 minutes on foot) and Casey does not usually move too quickly nor travel very far. Unlike, for example, Hamzah who is very agile, very quick and travels deep into unfamiliar areas within the Kehje Sewen Forest.

So we began walking towards Casey’s nest that morning with only the light from our headlamps guiding us on the muddy and wet road. About half way, we came off the main road and started to track a small trail into the forest. Because it was still dark and the trail was slippery, I fell behind many times, but Yosua and Wulan patiently waited for me and accompanied me all the way to location.

When we arrived at an area called “Blue Tent”, there was a sudden change of plan. A few meters from the Blue Tent, Wulan saw Hamzah in a tree. Wulan quickly asked me, whether I still wanted to follow Casey, or followed Hamzah instead. Considering that Hamzah had disappeared from radar detection and was found again only a few weeks ago, and he was just right there in front of us, of course I decided to follow Hamzah.

Hamzah moved smoothly

Hamzah moved smoothly

Hamzah just woke up and barely came out from his nest when we arrived. But just like what the team had warned me, Hamzah suddenly moved fast with impressive agility in total silence! Without any broken or fallen branches, Hamzah moved from the top of a tree to another tree top smoothly. Luckily, Hamzah did make a stop from time to time to eat. Today in particular, he seemed to be into the fruits of Macaranga sp., or known as the Mahang tree or Pioneer tree. It was indeed the fruiting season for Macaranga sp.

Enjoying Macaranga for breakfast

Enjoying Macaranga for breakfast

We crossed a small river to watch Hamzah from a better position. Meanwhile, Wulan was busy with her pen, diligently recording monitoring data. She noted everything down – the time when Hamzah woke up and left his nest, the types of food he ate, which directions he moved, his physical conditions, etc. Absolutely everything was recorded. What a job!

Yosi had to cross small river for better view

Yosua had to cross small river for better view

Wulan and Yosi

Wulan and Yosua

Wulan ready with form to note Hamzah activity

Wulan ready with form to note Hamzah activity

It was a great experience following the monitoring team. It certainly gave me a new perspective on all the knowledge of orangutans and conservation that I had learned so far. It’s like connecting dots. I finally understood the magnitude as well as the importance of orangutan reintroduction programs. And forever now I salute and give my utmost respect to all orangutan monitoring teams out there, particularly of course our post-release monitoring team in Kehje Sewen Forest!

Text and photos by: Iwan Pribadi