Scientists watch an orangutan treat its own wound with medicinal plants for the first time
Scientists have become the first in the world to observe a wild orangutan applying medicine to its own wound.
A Sumatran orangutan named Rakus was seen chewing leaves of a medicinal plant, making a pulp and applying the substance to a wound near its eye.
Scientists were not only amazed that the orangutan knew the plant had medicinal powers, but they had also never seen a monkey treating its wounds before.
After two months, the wound had healed and the orangutan’s face showed few signs that it had ever been injured.
Researchers spotted a male orangutan named Rakus with a facial wound on June 22, 2022. Two days later he chewed leaves and applied the paste to the wound.
About two months later, on August 25, 2022, Rakus showed virtually no signs of being injured
The surprising sighting was made last summer in Gunung Leuser National Park in South Aceh, Indonesia.
Researchers have been studying Rakus since they first saw him in 2009, but noticed on June 22, 2022 that he had suffered some sort of injury to his face.
Although it is unknown how the wound occurred, the team noted that male orangutans often sustain such injuries in fights with other dominant males.
After the initial sighting, the team returned three days later and found Rakus leaves of the plant that locals call Akar Kuning (scientific name Fibraurea tinctoria).
That was already unusual, since orangutans almost never eat the plant.
People have long used Akar Kuning to treat many conditions, including diabetes, dysentery and malaria.
But they had never seen a monkey use it.
The team observed Rakus chewing the leaves for about 13 minutes, then collecting the pulp with his finger and placing it around his eye until the wound was completely covered.
And for the next half hour Rakus ate leaves from the vine.
The next day he ate the leaves again for a few minutes.
Researchers monitored him for several days later to see if an infection would develop from the wound, but nothing had happened.
The leaves of Akar Kuning (left), a plant used by people in Indonesia to treat dysentery, diabetes and malaria. The orangutan Rakus (right) eats the leaves.
Rakus shows off a mouthful of Akar Kuning leaves. The wound on his face is visible, gaping but not infected.
On June 30, just eight days after the monkey treated itself, the wound was closed.
“On July 19, 2022, the wound appeared completely healed, leaving only a faint scar,” the team wrote in their study published in the journal Scientific reports.
Researchers took pictures of the time the wound healed, but unfortunately they didn’t take any pictures of him sticking the leaves to his wound.
Scientists have seen orangutans self-medicate before, but never like this.
For example, orangutans with intestinal parasites sometimes eat the leaves of medicinal plants known to have antiparasite properties.
A young orangutan with serious wounds was once seen eating wild ginger, a plant used by locals to treat inflammation and fight infections.
They estimate that Rakus was born in the late 1980s, making him somewhere in his mid-30s.
Male orangutans can live up to 58 years in the wild, but on average their lifespan is closer to 40 years.
“To our knowledge, this study is the first systematic documentation of putative active wound treatment with a biologically active plant substance in great apes and other non-human species,” the study authors wrote in the study published in
Researchers took pictures of Rakus from June 22 (top left), when they first saw the wound, to August 5 (bottom right), when it had healed.
Rakus is seen here on July 5, 10 days after treating his wound
People have been treating wounds for thousands of years – as far back as 2200 BC.
“Among the earliest known wound care products used by the Sumerians, Greeks, Mayans and Egyptians were oil, herbs, maggots, beer, vinegar, wine, green paint containing copper and honey,” the study authors wrote.
Like any case of an animal apparently self-medicating, this case raises an important question: Did Rakus know what he was doing?
According to the study authors, it appears that this was the case. They base this conclusion on three factors:
He applied the plant only to his wound, not to the rest of his body, and repeated the behavior several times, first by juicing them with pulp.
And third, it took him a significant amount of time to complete the task.
Perhaps, they concluded, he had brought the behavior from its native range.
When male orangutans reach adulthood, they move elsewhere and leave their home range.
Although researchers have never seen orangutans do this, it is possible that it is a habit learned at home.
If we go back even further, perhaps Rakus shows that there is something in our ancestral minds that tells us to put medicine on our wounds.
‘Since forms of active wound treatment are not only universal to humans, but also occur in both African and Asian great apes, it is possible that there is a common underlying mechanism for the recognition and application of substances with medical or functional properties to wounds. and that our last common ancestor already exhibited similar forms of ointment behavior,” the authors wrote.