A Sumatran orangutan in Indonesia has self-medicated using a paste made from plants to heal a large wound on his cheek, say scientists. It is the first time a creature in the wild has been recorded treating an injury with a medicinal plant. After researchers saw Rakus applying the plant poultice to his face, the wound closed up and healed in a month. Scientists say the behavior could come from a common ancestor shared by humans and great apes.
A research team in the Gunung Leuser National Park, Indonesia spotted Rakus with a large wound on his cheek in June 2022.They believe he was injured fighting with rival male orangutans because he made loud cries called "long calls" in the days before they saw the wound. The team then saw Rakus chewing the stem and leaves of a plant called Akar Kuning - an anti-inflammatory and anti-bacterial plant that is also used locally to treat malaria and diabetes.
Armas Orangutan Rakus with a medicinal leaf in his mouth ArmasScientists saw Rakus chewing a medicinal leaf into a paste. He repeatedly applied the liquid onto his cheek for seven minutes. Rakus then smeared the chewed leaves onto his wound until it was fully covered. He continued to feed on the plant for over 30 minutes.
The paste and leaves then appear to have done their magic - the researchers saw no sign of infection and the wound closed within five days. "He repeatedly applied the paste, and he later also applied more solid plant matter. The entire process lasted really a considerable amount of time - that's why we think that he intentionally applied it," explains Dr Laumer. The researchers also saw Rakus resting for much longer than usual - more than half of the day - suggesting he was trying to recover after the injury.
