Mardianto’s 15-Year-Challenge

You might have seen the #10YearChallenge on social media, where people upload two photos of themselves, taken ten years apart. The ‘challenge’ typically highlights just how much an individual’s appearance has, or has not, changed over a decade. Inspired by this, we have created our own #15YearChallenge for Mardianto, a male orangutan who now lives wild and free in the forest.

Mardianto was rescued in 2005 and started his rehabilitation process at our Nyaru Menteng Rehabilitation Centre. He successfully graduated from Forest School in 2012 and was placed on Bangamat Pre-release Island. He learned to live more independently and was easily recognised for his flat and wide forehead, short dark hair and distinctive face.

In 2015, ten years after his rescue, Mardianto was finally released to his true wild home in the Bukit Batikap Protection Forest in Central Kalimantan. In the years following his release, our Post-Release Monitoring (PRM) team has managed to find him quite often and was able to collect ample behavioural data on his adjustment to his new environment.

Mardianto loves to explore the forest and meet other individuals, especially females. We often see him following or eating with his adult female companions in the canopy. And he doesn’t seem to mind the presence of our PRM team members as they observe his activities.

Now 18 years old, Mardianto has undergone some extreme physical changes. No longer a juvenile, he has transformed into a handsome adult male with a wider face, thanks to his impressive, growing cheek-pads.

During observations, the PRM team has noted that Mardianto is now attempting to make long calls. He is only just starting out and still sounds a little awkward. Even though he gives it his all, he cannot call very loud or far yet.

Since he has lived in the forest for many years, we are not able to track Mardianto by his transmitter signal any more, as the battery died back in 2018. However, we can still locate him from time to time along the riverbanks as he forages and searches for his next female companion.

Mardianto’s evolution over 15 years is quite remarkable, and we are very proud of our handsome red cousin.