Recently, our monitoring team conducted nest-to-nest observations on Desi, a female orangutan residing on Juq Kehje Sewen, one of BOS Foundation’s pre-release islands in East KalimantanThe team, consisting of Aluna, Ubay, Rustam, and Erik, had been preparing since early morning to head to the nest Desi had built and slept in the night before. They didn’t want to miss watching the moment the female woke up. But things did not go according to plan.

Desi was not in her nest and last known location. After searching for quite some time, the team finally found her sitting on a branch, observing the humans below who had been looking for her.

On that day, Desi followed after our PRM team, which ended up dividing into two groups. Our team members presumed that Desi was hungry at the time and seeking food from her human observers. Therefore, they had to retreat quickly and hide to avoid her to be able to continue their observations.

Desi dangles silently, waiting for the technicians to deliver food.

Desi also acted peculiarly, she appeared to try to make a mat out of twigs, dry leaves, and bushy branches that she had yanked off the tree she was in. She compiled all the materials and then sat on them. Clearly uncomfortable, she soon got up to rearrange her seating pad and sat back down again when satisfied. Desi repeated this reorganising of her materials several times while our PRM team members held back their laughter at her comical routine. 

Throughout the day, Desi sought suitable trees to explore and rest. She dangled silently for a while, waiting for technicians to pass by in a boat to deliver food. When our monitoring team finally brought the supplementary food delivery, Desi immediately rushed over, took the fruit, and ate with gusto. Of course, the first thing she devoured was the mango, her favourite!

A little rest on a branch before sunset.

After finishing lunch, our split team swapped shifts to take turns observing Desi. They saw her also nibbling on some natural leaves and plant fibres, and after eating enough, she climbed up into the trees to dangle. 

Our team decided to stay a little longer into the late afternoon to confirm where the female was nesting. Half an hour passed, with no sign of Desi preparing to build her night nest. Instead, she lay down on the branch of a Ficus benjamina treethe same one she had been waiting in earlier. With the sun setting, our team had already observed Desi for twelve hours, yet she still had not built a nest for the night. Still, it had been a productive day, and it was time to return to camp. 

Keep on enjoying your time on the island, Desi!

You can support Desi and the other orangutans in our care here.