Borneo Orangutan Survival Foundation



Leonie and Teresa’s Friendship in the Kehje Sewen Forest

Recently, three members from our PRM team in Nles Mamse Camp – Jani, Usup, and Rizal – located Leonie and Teresa around Transect 7. These two female orangutans were released in September and December 2015 respectively and it was great to have the chance to record behavioural data on them in the Kehje Sewen Forest: Both have covered an extensive range since their release, and have been difficult to track.

The team arrived at Transect 7 early and quickly spotted Leonie waking in her nest. She was hungry, and immediately climbed down from her nest to start feeding on the forest floor.


Leonie waking up in her nest


Leoni eating shoots

As the team were observing Leonie, Teresa arose from her nest located nearby. Teresa joined Leonie and the two fed together.


Teresa eating shoots

Shortly after, Leonie and Teresa climbed a tree and started moving through the forest together, taking their time to rest and eat forest fruits along the way. The team had to keep their distance, as both females expressed displeasure when they became aware of human presence.


The two actively moved through the trees, only descending occasionally to eat different food items. The pair kept moving toward the hills as the sky began to darken: Following them, the fading light and challenging terrain forced the team to end data collection for the day. But it was great to have observed these two magnificent females thriving in the forest.

The next day, the team caught up with the two again. As on the previous day, the two did everything together.


Compared to other orangutans released in 2015, Leonie and Teresa have continued to range widely across the Kehje Sewen Forest. They appear to be in great health and skilful foragers.

Text by: Jani, PRM team member from Nles Mamse Camp, Kehje Sewen Forest

The year 2016 marks the BOS Foundation’s 25th anniversary! Celebrate 25 years of ever-challenging, dedicated work in the field of orangutan conservation by showing your support and help save orangutans! DONATE NOW



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