The human race is not the only one who plays the role of doctor and patient chimpanzees do as well

The research team focuses on the social dimension of the behavior, such as who the main actors and recipients of therapy are, as well as the social learning processes that allow for its transmission.

A research team from Germany's Osnabrück University and the Ozouga Chimpanzee Project observed - for the first time in 2019 - a chimpanzee that treats its own wounds and wounds by using insects.

The researchers investigated the behavior of a community of about 45 chimpanzees living in a 1,550 square kilometer savanna called Loango National Park located in western Gabon, with a particular focus on their social relationships, interactions and disagreements with other groups, hunting behavior, tool use and skills. Cognitive and communicative.

Recently, the results of the research were published under the title "Application of insects to wounds of self and others in chimpanzees in the wild" in the journal Current Biology on February 7.

It has never been documented before

This park is home to the Chimpanzee Ozoja project led by Dr. Tobias Deschner and Professor Simone Becca, a cognitive biologist at the University of Osnabrück.

Alessandra Mascaro , an emerging evolutionary biologist who volunteered for the project, recalls her first observation, "I was following a female chimpanzee named Susie, and I watched her lean on the injured foot of her teenage son Sia. It seems that She had something between her lips and then she applied it to the wound on Sia's foot."

Later that evening, I rewatched my videos and saw that Susie first reached out to pick up something she had placed between her lips and then placed it directly on an open wound on Sia's foot. Discussing these observations and the potential function of the behavior with team members, we realized that we We have never witnessed such behavior and it has not been documented before."

Looking at her shots, Mascaro realized that Susie had grabbed the spot treatment right from the underside of the leaf, and it looked like a small, dark bug. A week later, Lara Southern, a PhD student on the research team, watched an adult chimpanzee pull a paper from its mouth, pick up an insect with its lips, and hold it with its thumb and forefinger. Then he applied what he had extracted from the bush to a one-day-old wound in the crease of his arm.

By discussing these observations and the possible function of the behavior with team members, they realized that they had never seen such behavior and that it had not been documented before, and Mascaro and her colleagues began to observe it regularly.

As a report in Science Alert notes, over the next 15 months, chimpanzee project researchers carefully documented 20 other similar events on the west coast of Africa. Most of the time, chimpanzees treated their wounds with unidentified insects, but there were several occasions when they helped each other as well.

Self-medication

"Self-medication, in which individuals use plant parts or non-food items to combat pathogens or parasites, has been observed across multiple animal species including insects, reptiles, birds and mammals," says biologist Becca.

"Chimpanzees and bonobos, for example, ingest the leaves of plants with antihelminthic properties and chew the bitter leaves, which have chemical properties to kill intestinal parasites."

Despite decades of observations of chimpanzees in Africa, this is the first time that similar behavior has been observed among their societies, and this indicates that humankind is not the only one playing the role of doctor and patient.

Chimpanzees are known to display many seemingly social behaviors on the surface, including sharing food, adoption, cooperative hunting, and swallowing the leaves of medicinal plants to help ward off intestinal infections, but the topical application of insects as a drug is a new discovery.

The topical application of the treatment to the wounds of another chimpanzee strengthens the idea that humans are not the only ones who can act in someone else's favour. Studying chimpanzees can help us further understand how these social behaviors first began to develop and what their evolutionary benefits are.

It is known that humans themselves use insects in a very similar way, as the small bodies of some invertebrates have medicinal properties. Written records, for example, indicate that "maggot therapy" has been used by humans to treat wounds for thousands of years around the world.

Prof. Becca returns, "It is particularly remarkable to see that individuals heal not only their own wounds but those of others who are not related. Such examples of prosocial behaviors evident in non-human species are seldom observed."

Next step

As a next step, the researchers aim to recover the remaining insect parts to identify their species and conduct biological tests to check for potential pharmaceutical properties. Furthermore, the team will focus on the social dimension of behaviour, such as who are the main actors and recipients of 'treatment' as well as the social learning processes that allow its transmission.

"Our observations provide the first evidence that chimpanzees regularly pick up insects and place them on open wounds," concludes Dr. Deschner. "Our study shows that there is still much more to explore, so we still need to do more to protect them in their natural environment."