In an impressive display of animal smarts, Rakus, a male Sumatran orangutan, used natural medicine to heal a wound he got during a fight with another orangutan in June 2022. This happened at the Suaq Balimbing research site in Indonesia, a protected rainforest where Sumatran orangutans live. Rakus hurt his face below his right eye and was seen using leaves from the Akar Kuning plant, scientifically known as Fibraurea tinctoria. This plant is not usually eaten by orangutans, but it is known for its healing properties, like fighting bacteria and reducing inflammation. Rakus chewed the leaves to get their juice, which he then put on his wound, and he also ate some of the leaves.

The researchers, Isabelle Laumer and Caroline Schuppli from the Max Planck Institute of Animal Behavior, published their study in the journal Scientific Reports. They said Rakus’ treatment was careful and focused only on the hurt part. He kept doing it until his wound was completely healed in five days. This shows how smart orangutans are and hints at their abilities to solve problems, which might go back millions of years to when humans and orangutans had a common ancestor. The researchers think Rakus might have learned this behavior by being around other orangutans or by just figuring it out by chance.