On 16 May this year, the BOS Foundation successfully conducted its 25th orangutan release in East Kalimantan. After the release, our Post-Release Monitoring (PRM) team conducted nest-to-nest observations on the five released orangutans for over a month, with particular attention paid to Mayer and Elaine. 

Three PRM team members and one veterinarian split into two teams to monitor Mayer and Elaine's recent activities. Their task began early in the morning, so they could locate Mayer and Elaine as they rose from their night nests. When rehabilitated orangutans are released into the forest, nest-to-nest monitoring is conducted to collect behavioural data. This data is evaluated and then used to assist with future releases. Nest-to-nest monitoring of rehabilitated orangutans also helps ensure individuals are adjusting to their new surroundings.

Our PRM team discovered Mayer and Elaine in an area known as persemaian. The two were seen moving through the trees and enthusiastically socialising together, as they engaged in many brief copulations. Between the action, both were seen consuming young leaves and the cambium beneath the bark of various lianas.

Read also: FIVE MORE ORANGUTANS HAVE ARRIVED IN KEHJE SEWEN

Elaine seemed to be aware of our PRM team's presence but did not appear to be bothered by it. Mayer, on the other hand, was disturbed by our PRM team members and tried to scare his human observers away by shaking branches. Mayer was seen and heard sneezing a few times, likely due to the cooler weather from recent rainfall and lower temperatures in the forest.

One day when returning to monitor Elaine and Mayer, the technicians discovered that the two orangutans were no longer at their last known point. The team remained for a while at that location before moving on to check Transects #29 and #41. They then decided to split up and search for signs that could indicate Mayer and Elaine's location, but they were unsuccessful. As the temperature dropped and the rain returned, our PRM team was forced to return to camp and finish the day's monitoring early.

Mayer and Elaine have yet to be found again and our PRM team believes the two orangutans have moved deeper into the forest. We can't wait to catch up with Mayer and Elaine sometime in the near future!

Text by: PRM Team at Camp Nles Mamse, Kehje Sewen Forest, East Kalimantan