A male Sumatran orangutan in Indonesia appeared to heal a wound to its face using specific leaves in a rare instance of animal self-medication in the wild, a study published Thursday showed.
Rakus the orangutan — born sometime in the 1980s — was observed in the Gunung Leuser National Park in South Aceh, Indonesia, selectively eating the stem and leaves of the climbing plant Fibraurea tinctoria, locally known as Akar Kuning/Akar Palo/Yellow Root, on June 25, 2022, according to the study. Rakus also repeatedly rubbed the plant juice from its mouth onto a fresh open wound on its flange just below its right eye within thirteen minutes.
Rakus possibly got the wound from a fight with some other male orangutans, as there were sounds of fighting before the observation, the scientists reported in the study. When flies bothered his facial wound, Rakus covered it all up with the green plant pulp from its mouth, according to the study, which was published in the high-impact journal Nature.
Rakus ate the leaves of the plant again the next day, the study revealed. The great ape also had a wound in its mouth, as observed when he made a call.
By Jun. 30, the facial wound had closed, and two weeks later, the wound appeared completely healed with only a scar left, according to the study.
Rakus rested for more than half of each day during this period, which also might have facilitated the healing process “as growth hormone release, protein synthesis and cell division are increased during sleep,” the scientists reported in the study. Rakus reportedly rested less after the facial wound healed. (RELATED: Orangutan Straight Up Yeets Possum As Onlookers Scream In Horror)
The plant Akar Kuning has antibacterial, hypotensive, anti-inflammatory, anti-fungal, antioxidant, analgesic and other properties, and some people in Indonesia traditionally use it to treat dysentery, diabetes, and malaria, among other diseases, according to the study.
While there have been reports — some anecdotal — of apes appearing to similarly self-medicate using certain plants and insects, the overall evidence remained limited, according to the study.
“To the best of our knowledge, this study is the first systematic documentation of the putative active wound treatment with a biologically active plant substance in great apes and other non-human species,” the seven scientists from Germany and Indonesia wrote in the study report.
The study was a non-invasive, observational one, with no interaction between the scientists and Rakus, the scientists wrote, adding that they had been studying the area for 21 years.