Primatology
The high intelligence levels of orangutans have long been recognized, in part due to their practical skills such as using tools to crack nuts and forage for insects. However, recent research suggests that these primates possess another remarkable ability: applying medicinal herbs.
Scientists have observed a male Sumatran orangutan treating an open facial wound with sap and chewed leaves from a plant known to have anti-inflammatory and pain-relieving properties. This discovery marks the first time a wild animal has been seen using a substance with medicinal properties to treat open wounds.
While the use of self-medication has been observed in other animals, such as Bornean orangutans rubbing chewed leaves on their arms and legs to alleviate muscle soreness, this is the first documented instance of a wild animal intentionally using a plant with known medical properties.
Dr. Caroline Schuppli, the senior author of the research conducted at the Max Planck Institute of Animal Behavior in Germany, highlights the significance of this finding. She points out that it offers valuable insight into the origins of human wound care, a practice that dates back to a medical manuscript from 2200 BC.
The study suggests that the cognitive capacities required for such behavior were present in our last common ancestor, indicating that the use of medicinal plants for wound healing extends far back in our evolutionary history.
The team made the discovery while working in a protected rainforest in Indonesia. They observed a male Sumatran orangutan named Rakus with a fresh facial wound, likely the result of a skirmish with another male. Three days later, Rakus was feeding on the stem and leaves of a type of liana climbing vine called Fibraurea tinctoria.
What happened next was unexpected. Thirteen minutes following Rakus began feeding on the liana, he started chewing the leaves without swallowing them. He then used his fingers to apply the plant juice from his mouth directly onto his facial wound. Rakus repeated this process and eventually covered the entire wound with the chewed leaves. Within five days, the wound had closed, and within a few weeks, it had completely healed, leaving only a small scar.
The plant used by Rakus, as well as related liana species, is known to contain substances with various beneficial properties, including antibacterial, anti-inflammatory, anti-fungal, antioxidant, pain-killing