Orangutan, Heal Thyself

Scientists observed a wild male orangutan repeatedly rubbing chewed-up leaves of a medicinal plant on a facial wound in a forest reserve in Indonesia.

It was the first known observation of a wild animal using a plant to treat a wound, and adds to evidence that humans are not alone in using plants for medicinal purposes.

The male orangutan, Rakus, lives in the Gunung Leuser National Park on the island of Sumatra and is thought to be around 35 years old. For years researchers have followed orangutans like him on his travels through the forest, threading his way through the canopy in search of fruits to eat.

Scientists within the Suaq Balimbing research area of the park first noticed a wound on his face on June 25, 2022, when they saw his self-medication behavior begin.

“Once I heard about it, I got extremely excited,” said Isabelle Laumer, a primatologist with the Max Planck Institute of Animal Behavior in Germany, in part because records of animals medicating themselves are rare — even more so when it comes to treating injuries. She and colleagues detailed the discovery in a study published Thursday in the journal Scientific Reports.

The plant Rakus used, known as akar kuning or yellow root, is also used by people throughout Southeast Asia to treat malaria, diabetes and other conditions. Research shows it has anti-inflammatory and antibacterial properties.

Orangutans rarely eat the plant. But in this case, Rakus ingested a small amount and also coated the wound several times. Five days after the wound was noticed, it had closed, and less than a month later “healed without any signs of infection,” Dr. Laumer said.

Michael Huffman, a visiting professor at the Institute of Tropical Medicine at Nagasaki University in Japan,