This orangutan in Sumatra self-medicates with herbs

Male orangutan Rakus suddenly had an ugly deep wound under his right eye, which poses a significant risk of infection in the unforgiving wilderness of Sumatra. Behavioral biologists saw this to their horror when they made their daily observations of the wild orangutans in the Suaq Balimbing research area, where they have been observing the population since 1994. That area is located in the vast Gunung Leuser National Park on the Indonesian island of Sumatra.

Three days after the researchers first saw the injury in Rakus, something special happened, the researchers describe in the scientific journal Scientific Reports. They saw him selectively plucking the leaves of a type of vine known as akar kuning (Fibraurea tinctoria). He chewed it and then applied the released juice repeatedly to the wound on his face. As a final step, Rakus covered the wound completely with the chewed leaves, as a kind of compress. Unfortunately, there are no photos or film recordings of this self-care, the researchers write. We have to make do with the description.

Regardless, the treatment seems to have helped Rakus well. After a week the wound was closed and after a month it had healed to such an extent that almost nothing was visible anymore.

Akar kuning and related liana species, which grow in the tropical forests of Southeast Asia, are also used in traditional herbal medicine. According to the researchers, preparations from these plants are known for their analgesic, antipyretic and diuretic effect. They are used to treat dysentery, diabetes and malaria, among other things. Chemical analysis of the plant previously showed that it contains certain terpenoids and alkaloids, substances known to have antibacterial, anti-inflammatory, antifungal and antioxidant effects, all of which benefit wound healing.

“This represents the first systematically documented case of active wound treatment with a plant species known to contain biologically active compounds by a wild animal,” the researchers write. They go one step further: “This offers new insights into the origins of human wound care.”

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