PREVIEW

An incredible study has found that orangutans are the first animal to be observed treating its own wounds.
Researchers from the Max Planck Institute of Animal Behavior in Germany and Universitas Nasional in Indonesia reveal groundbreaking evidence of self-medication behavior in a wild male Sumatran orangutan, shedding light on the evolutionary origins of wound treatment in humans.
The study, led by Caroline Schuppli and Isabelle Laumer, was made in the protected rainforest of Suaq Balimbing in Indonesia, home to a critically endangered population of Sumatran orangutans. During routine observations, researchers witnessed a male orangutan named Rakus actively tending to a facial wound.
“During daily observations of the orangutans, we noticed that a male named Rakus had sustained a facial wound, most likely during a fight with a neighboring male,” says Laumer.
Remarkably, three days post-injury, Rakus engaged in deliberate wound treatment. He selectively plucked leaves from a liana known as Akar Kuning (Fibraurea tinctoria), chewed them, and applied the resulting juice precisely onto the wound for several minutes before covering it entirely with the chewed leaves. The plant, renowned for its medicinal properties in traditional Southeast Asian medicine, contains compounds with antibacterial and anti-inflammatory effects conducive to wound healing.
Laumer adds: “This and related liana species that can be found in tropical forests of Southeast Asia are known for their analgesic and antipyretic effects and are used in traditional medicine to treat various diseases, such as malaria. Analyses of plant chemical compounds show the presence of furanoditerpenoids and protoberberine alkaloids, which are known to have antibacterial, anti-inflammatory, anti-fungal, antioxidant, and other biological activities of relevance to wound healing.”


Notably, observations revealed no signs of infection, and within five days, the wound had healed substantially.
This unprecedented behaviour prompts intriguing questions about its intentionality and emergence. Rakus's meticulous and repeated application of the plant material suggests deliberate action rather than mere coincidence. Schuppli suggests that such behaviour might stem from individual innovation.
She adds: “It is possible, that wound treatment with Fibraurea tinctoria by the orangutans at Suaq emerges through individual innovation.
“Orangutans at the site rarely eat the plant. However, individuals may accidentally touch their wounds while feeding on this plant and thus unintentionally apply the plant’s juice to their wounds. As Fibraurea tinctoria has potent analgesic effects, individuals may feel an immediate pain release, causing them to repeat the behavior several times.”
Importantly, this discovery challenges previous assumptions about non-human animals' capacity for self-medication. It offers a rare glimpse into the sophisticated cognitive abilities of our closest relatives and hints at shared evolutionary mechanisms underlying wound management across species.
Schuppli emphasises the potential implications of this finding, suggesting that understanding the origins of wound treatment behaviors could illuminate the broader evolutionary history of medicine.
“The treatment of human wounds was most likely first mentioned in a medical manuscript that dates back to 2200 BC, which included cleaning, plastering, and bandaging of wounds with certain wound care substances,” she explains. “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 and that our last common ancestor already showed similar forms of ointment behaviour.”
As the first documented case of active wound management with a biologically active substance in a great ape species, Rakus's remarkable behavior opens new avenues for exploring the depths of animal cognition and its implications for human health.