An international team of scientists have recorded the first footage of a great ape using medicine made from mashed up leaves to treat an open head wound, in an act of human-like behavior.
It may sound like a scene from Tim Burton’s 2011 movie Rise of the Planet of the Apes, but this impressive show of intelligence seemingly isn’t the result of a sudden evolutionary leap forward. Instead, the scientists behind the new discovery have suggested that the great ape’s medicinal accumen may instead be rooted in an underlying evolutionary ability to recognise medicinal substances that exists in both humans, and their closest living relatives.
The footage was captured in 2022 in an Indonesian rainforest nature reserve, after an international team of scientists noticed a Sumatran orangutan named Rakus tending to a facial wound inflicted by a fellow great ape some three days earlier. Rakus could be seen selectively picking out and chewing leaves from a native Akar Kuning liana plant, which is used in traditional medicins owing to its various medicinal, antibacterial, and pain relieving properties. The orangutan then applied the juice to the wound before covering it with the remaining leafy mash.
Researchers have observed a Sumatran #orangutan in the wild repeatedly treating its own wound with a plant with several known medicinal properties - the first scientific record of this behaviour in a wild animal https://t.co/p37Bs4vots @IsabelleLaumer @carolschuppli… pic.twitter.com/hELCGQW0P4
— Max Planck Society (@maxplanckpress) May 2, 2024
“The behavior of Rakus appeared to be intentional as he selectively treated his facial wound on his right flange, and no other body parts, with the plant juice,” said Isabelle Laumer, first author of the new study from the Max Planck Institute of Animal Behavior in Germany. “The behavior was also repeated several times, not only with the plant juice but also later with more solid plant material until the wound was fully covered. The entire process took a considerable amount of time.”
Incredibly, Rakus’ makeshift medicine appeared to work, staving off infection, and allowing the large wound to close up after a mere five days following the treatment. So how did the orangutan know to use that particular leaf to treat the wound? Well, the evolutionary and cognitive biologists behind the new study appearing in the journal Scientific Reports have some theories.
First the authors admit that its entirely possible that Rakus may have simply come up with the treatment himself in a moment of primate brilliance after feeding on the plant and noticing its pain relieving qualities. It’s also possible that Rakus could have picked up the behavior from another ape. However, the paper notes that in over 21 years and 28,000 hours of observation, researchers had never observed another orangutan self medicating in this way. There also exists a third explanation for the canny plant selection, which is rooted in the evolutionary history of both humans and apes.
“As forms of active wound treatment are not just human, but can also be found in both African and Asian great apes, it is possible that there exists a common underlying mechanism for the recognition and application of substances with medical or functional properties to wounds,” explained the study’s senior author Caroline Schuppli, also of the Max Planck Institute. “And that our last common ancestor already showed similar forms of ointment behaviour.”
Moving forward the team are on the lookout for further examples of self medicating apes. If super intelligent primates are your thing then why not check out our article detailing how to watch The Planet of the Apes movies in chronological order ahead of the cinematic release of Wes Ball’s Kingdom of the Planet of the Apes on May 10. Finally, be sure to catch up on IGN’s 2020 interview with legendary conservationist Dr Jane Goodall DBE, where she shares details on her lifelong fight to protect the natural world.
Image credit: Isabelle Laumer.
Anthony is a freelance contributor covering science and video gaming news for IGN. He has over eight years experience of covering breaking developments in multiple scientific fields and absolutely no time for your shenanigans. Follow him on Twitter @BeardConGamer
