Smart Orangutan Uses Medicinal Plant To Heal Wound

A Sumatran orangutan named Rakus has stunned researchers by treating a cheek wound with a medicinal plant. The male primate, believed to be about 35 years old, lives in Gunung Leuser National Park in northern Sumatra, Indonesia. The protected rainforest is home to over 750 animal species, including 150 orangutans.

Dr. Isabelle Laumer and her team at Max Planck Research first noticed the primate's wound on June 22, 2022. They believe it was most likely the result of a fight with another orangutan. Three days later, they caught Rakus chewing on the stems and leaves of a tropical vine called liana. The plant is known to locals for its healing properties.

Since Sumatran orangutans rarely eat the plant, the scientists were intrigued and decided to observe and document Rakus' behavior. The orangutan spent the first 13 minutes eating the plant. He then dedicated another seven minutes to chewing the leaves and rubbing the juice on his injury. When flies began hovering around the cut, the clever primate covered it with the leaves. Within five days, the wound had closed. By July 19, 2022, it was completely healed — only a scar remained.

"This case represents the first known case of active wound treatment in a wild animal with a medical plant," Laumer told NPR.

The researchers revealed their findings in the journal Scientific Reports on May 2, 2024. They state that in addition to being a good nurse, Rakus was also a great patient. The day after applying the healing juice to his wound, the orangutan returned to the plant to eat more leaves. He also rested more than usual to allow his body to heal.

Sumatran orangutans are a critically endangered species, with only about 14,600 left in the wild. The primates can only be found in the northern tip of the island of Sumatra in Indonesia. Their numbers have plummeted due to the widespread conversion of rainforests into oil palm plantations and other agricultural development. Also, despite being legally protected, the animals are often captured for food or to be kept in households as status symbols. Since females give birth to just one infant at a time every eight or nine years, their populations are susceptible to even very low levels of hunting.

Resources: NPR.com, Smithsonianmag.com, worldwildlife.org