First Observation of an Orangutan Using Medicinal Plant to Heal a Wound

Rakus, an orangutan male from Sumatra (Pongo abelii), was observed in the Suaq Balimbing research area in Indonesia applying a plant with known medicinal properties to a wound under his eye. This behavior, never before seen in a wild animal, involved Rakus eating and repeatedly applying the sap of the climbing plant Akar Kuning (Fibraurea tinctoria) to his wound, which he also covered with chewed leaves. Akar Kuning is known for its analgesic and antipyretic effects and is used in traditional medicine to treat wounds and various conditions like dysentery, diabetes, and malaria.

Researchers from the Max Planck Institute for Animal Behavior and Universitas Nasional observed Rakus’ behavior in June 2022. It was noted that Rakus intentionally treated his facial wound with the plant’s juice, suggesting a shared common ancestor between humans and orangutans in terms of medical treatment for wounds. Previously, wild primate species were observed consuming or chewing plants with medicinal properties, but not applying them to fresh wounds.

Rakus had sustained a wound on his face, likely from a fight with another male orangutan. Three days after the injury, he selectively chewed Akar Kuning leaves and applied the juice to his wound, continuing this behavior for several minutes. The wound healed within five days and was completely cured in a month. This behavior raises questions about the intentionality of self-medication in non-human animals and how it arises.

The researchers suggested that the wound treatment behavior with Fibraurea tinctoria may have been absent in the behavioral repertoire of the Suaq orangutan population until Rakus demonstrated it. Since Rakus was not born in the research area, it is possible that this behavior could be shown by other individuals from his natal population outside the research area. This groundbreaking behavior provides insights into self-medication in great ape species and the evolutionary origins of wound treatment.