The use of medicinal plants by orangutans to treat wounds is of interest to scientists

The use of medicinal plants by orangutans to treat wounds is of interest to scientists

A male Sumatran orangutan named Rakus suffered a facial wound below his right eye, apparently during a fight with another male orangutan at the Suaq Balimbing research site, a protected rainforest area in Indonesia. What Rakus did three days later really caught the attention of scientists.
The orangutans chew plant leaves to produce a liquid that Rakus applies repeatedly to wounds and then applies the chewed plant material directly to the injury, much like a wound plaster given by a doctor, according to primatologist and cognitive biologist Isabelle Laumer of the Max Planck Institute for Animal Behavior in Germany.

Ravens also eat the plant, an evergreen vine commonly called Yellow Root – scientific name Fibraurea tinctoria, added Laumer, lead author of the study published in the journal Scientific Reports, opens a new tab. These plants are rarely eaten by orangutans in this area of peat swamp forest, home to about 150 critically endangered Sumatran orangutans.

“To our knowledge, this is the first documented case of active wound treatment with a plant species with medicinal properties by a wild animal,” said study senior author Caroline Schuppli, an evolutionary biologist at the institute.

Rakus, believed to have been born in 1989, is a lipped male, with large cheek pads on both sides of his face – a secondary male sexual characteristic. Rakus is one of the dominant men in the area.

The researchers say that the orangutan’s self-healing of wounds does not appear to have occurred by chance.

“His behavior seemed deliberate. He selectively treated his facial wound on his right lip with plant juice, and no other part of the body. The behavior was repeated several times, not only plant juice but later also denser plant material was used. until the wound completely shut down. The whole process took quite a while,” said Laumer.

The wound never showed signs of infection and closed within five days, the researchers said.

“Observations show that the cognitive capacity required for the behavior – active wound treatment with plants – may be as old as the last common ancestor of orangutans and humans,” said Schuppli. “However, what this cognitive capacity actually is remains to be investigated. Although these observations show that orangutans are able to treat their wounds with plants, we do not know how well they understand the process.”

The last common ancestor of orangutans and humans lived about 13 million years ago.

Orangutans are one of the world’s great apes – humans’ closest living relatives – along with chimpanzees, bonobos and gorillas. Orangutans are the least closely related to humans but still share about 97% of our DNA, opens a new tab.

“It is possible that the treatment of wounds with Fibraurea tinctoria emerged through accidental individual innovation. Individuals may accidentally touch their wounds while eating Fibraurea tinctoria and thus accidentally apply the plant’s juice to their wounds,” said Laumer.

“But it’s also possible,” Laumer added, “that Rakus learned this behavior from other orangutans in his native area.”

This plant, widely distributed throughout China, Indonesia, Malaysia, Thailand, Vietnam and other parts of Southeast Asia, is used in traditional medicine to treat diseases such as malaria.

Orangutan means “forest person” in Indonesian and Malay, and this ape is the largest arboreal mammal in the world. Orangutans, adapted to live in trees, live more alone than other great apes, sleeping and eating fruit in the forest canopy and swinging from branch to branch.

“Orangutans have high cognitive abilities, especially in the field of physical cognition,” said Schuppli. “They are known to be excellent problem solvers. Wild orangutans acquire their skill sets through observational social learning, and skills are passed down from generation to generation. These observational populations are known for their rich cultural repertoires, including tool use. in different contexts .”

Researchers on Thursday described observing how Rakus appears to treat wounds using a plant known for its pain-relieving properties and supporting wound healing due to its antibacterial, anti-inflammatory, anti-fungal and antioxidant qualities.