Orangutan observed using medicinal herbs to heal wounds

Biologists from the Max Planck Institute of Animal Behavior, Konstanz, Germany and Universitas Nasional, Indonesia observed a large male orangutan self-medicating: topically using a paste of chewed plants to heal a large wound on his cheek. It is essentially a wild animal that seems to deliberately make its own medicinal ointment.

A peer-reviewed study was published on Thursday Scientific reportsThis is the first time scientists have observed this specific behavior in an orangutan. The biologists first saw the behavior in 2022, when the orangutan was seriously injured. Rakus is an orangutan who lives in Gunung Leuser National Park in Sumatra, and when he was injured with a gaping hole in his cheek, he sprang into action and behaved in a way that scientists have never seen before in a non-human have seen.

Lead researcher Dr. Isabelle Laumer, a primatologist and behavioral biologist, confirmed the findings High times. “We observed a male Sumatran orangutan (Pongo abelii) who suffered a facial wound,” researchers wrote. “Three days after the injury, he selectively tore off the leaves of a vine with the common name Akar Kuning (Fibraurea tinctoria), chewed it and then applied the resulting juice to the facial wound repeatedly. As a final step, he completely covered the wound with the chewed leaves.” Here, watch the orangutan the first time it behaved this way. (Laumer et al., 2024 Scientific reports)

The researchers saw no signs of infection and the wound closed within five days. After a month, Rakus’ wound was completely healed.

Fibraurea tinctoria is a plant with anti-inflammatory and antibacterial properties and can be used topically to treat malaria and diabetes. Humans have used medicinal ointments for thousands of years, but this behavior is rarely seen in wild animals.

“The treatment of human wounds was most likely first mentioned in a medical manuscript dating back to 2200 B.C., which included cleaning, plastering and dressing wounds with certain wound-care substances,” says Dr. Caroline Schuppli, a senior author of the article. , the Natural History Museum said. “Since African and Asian great apes also actively treat wounds, it is possible that we share a common underlying mechanism for recognizing and applying medical agents to wounds. This may have developed in a common ancestor, who may already have exhibited similar forms of ointment behavior.” (Laumer et al., 2024 Scientific reports)

CBS News reports that gorillas, chimpanzees and bonobos swallow certain bitter-tasting leaves whole to remove stomach parasites. The rough texture of the leaves can scrape away their digestive systems. It seems that the monkeys only eat these types of bitter leaves when they need help with their digestive tract.

Researchers said we can learn about ourselves from these findings. “They are our closest relatives and this again highlights the similarities we share with them. We are more alike than we are different,” said biologist Dr. Isabella Laumer of the Max Planck Institute in Germany BBC news.

Orangutan intelligence

Orangutans exhibit remarkable intelligence, and some researchers think it could surpass the intelligence of chimpanzees. For example, psychologist Robert Deaner of Grand Valley State University in Michigan sifted through hundreds of cognition studies and created “The Hierarchy of Primate Intelligence.” According to Deaner’s hierarchy, orangutans are smarter than chimpanzees, and the smartest primates after humans, and spider monkeys are the fourth smartest primates after orangutans and chimpanzees, while gorillas are the fifth smartest.

Orangutans can perform several tasks that most monkeys cannot do. Researchers at Leipzig Zoo in Germany have observed “calculated reciprocity” – meaning they “weigh the costs and benefits of exchanging gifts.” They have also been observed causing distractions by stealing food from each other, which is essentially pickpocketing. They have also been seen using leaves to amplify the sounds, holding them to their mouths when they squeaked, allowing them to trick each other into sounding like a larger monkey. Scientists claim that this behavior makes them one of the most self-aware wild animals ever observed.

Orangutans can learn up to forty hand gestures to communicate in sign language, and can do the same with their feet.

Medicinal plants used by animals

The Natural History Museum reports that the use of medicinal plants by animals – known as zoopharmacognosy – is believed to be used by a variety of different species to treat their diseases and injuries to some extent. But in most cases it is unclear whether it is motivated by instinct and not learned behavior.

For example, blue-headed parrots often lick clay, which allows them to absorb the toxins from unripe fruits they have eaten. Galápagos finches have been observed rubbing the leaves of the Galápagos guava tree on their feathers. These are rich in chemicals that repel mosquitoes and fly larvae.

Wild animals have been seen eating cannabis, but it is unclear why they are attracted to it. In the wild, mice and rats eat sprouted hemp seeds, while moles, rabbits, foxes, deer and dogs eat hemp leaves and stems. Not to mention insect pests that regularly eat cannabis leaves.

Even insects eat various foods that have medicinal properties. Cordyceps and yeast infections are a nightmare (and the inspiration for The last of us video games and series), but ants have been observed to normally eat unwanted food that wards off fungal infections.

The new findings about the behavior of orangutans show how little we know about the intelligence of apes.