Here is Doctor Orangutan, the monkey cures himself: the story of Rakus

He had injured his cheek, Rakus. So he obtained some leaves of Akar Kuning (in botanical jargon Fibraurea tinctoria), a climbing plant used in traditional medicine to treat injuries – but also against dysentery, diabetes and malaria – he chewed them creating a sort of paste and applied them to her face right on the sore spot. A classic self-medication scene, except that the protagonist is not a man, but a monkey. And it is the first time ever that he has been reported an ‘orangutan doctor’ in action. A sign that even primates practice self-medication.

Rakus is a wild male Sumatran orangutan (I ask abelii). Experts who observed him in action believe he was treating his wound using a plant with known medicinal properties. A report of this unprecedented behavior for a primate is published in the journal ‘Scientific Reports’, because it would be the first time that a wild animal has been caught intent on self-care. Before this study, the authors explain, several species of wild primates had been observed swallowing, chewing or rubbing plants with medicinal properties, but without applying them to fresh wounds.

Scientist Isabelle Laumer and fellow biologists from the Max Planck Institute of Animal Behavior in Konstanz, Germany and the Universitas Nasional of Indonesia observed the male orangutan in June 2022, in the Suaq Balimbing research area in Gunung Leuser National Park , Indonesia.

Rakus chewed the stem and leaves of Akar Kuning and applied the liquid ‘ointment’ repeatedly for 7 minutes thus generated over a wound on his right cheek, a wound he had sustained 3 days earlier. Rakus then spread the chewed leaves until it completely covered the lesion and continued to feed on the plant for over 30 minutes. The authors report that there were no signs of infection at the treated site in the following days. And within 5 days the wound had closed, only to heal completely within a month. Since Rakus repeatedly applied the plant material to his wound and nowhere else on his body, and the entire process took more than half an hour, it is likely that he intentionally treated his facial wound with Akar Kuning, the researchers.

Previous research has identified antibacterial, anti-inflammatory, antifungal and antioxidant properties in Akar Kuning and the chewed leaves may have helped reduce the pain and inflammation caused by Rakus’ wound and aided healing. The authors do not know whether this was the first time Rakus treated one of his wounds or whether he had already learned this behavior from other orangutans in his native area. Since Rakus appears to have intentionally treated his wound, this suggests that the behavior may have originated in a common ancestor shared by humans and great apes, experts reason.

“Rakus’ behavior – confirms Laumer – seemed to be intentional since he selectively treated the wound and no other part of the body, with the juice of the plant. The behavior was also repeated several times, not only with the juice of the plant, but also subsequently with more solid plant material”. Finally, the authors point out that they have not currently observed other orangutans in the research area ‘self-medicating’ their wounds. However, this may be due to the fact that researchers rarely encounter injured specimens.

“The site’s orangutans rarely eat the plant – explains Caroline Schuppli, senior author of the study – However they can accidentally touch their wounds while feeding on this plant and therefore unintentionally apply the juice of the plant on the lesions. Since Fibraurea tinctoria has powerful analgesic effects, they may feel immediate pain relief, which may cause them to repeat the behavior several times.”

“The treatment of wounds in humans was probably first mentioned in a medical manuscript dating back to 2200 BC – Schuppli remarks – It is possible that there is a common underlying mechanism for the recognition and application of substances with medical properties or functional to wounds and that our last common ancestor already exhibited similar forms of behavior.”