Chimps observered using plants to perform first aid

By Stephen Beech

Chimps in the wild use medicinal leaves to perform "First Aid" on their friends and family, reveals new research.

They also use leaves to clean themselves after sex - which may help prevent infections, say scientists.

Researchers observing the primates in Uganda's Budongo Forest recorded them not just treating their own injuries, but caring for others too.

They say their findings, published in the journal Frontiers in Ecology and Evolution, could shed light on how our ancestors first began treating wounds and using medicines.

While chimps have been observed elsewhere helping other community members with medical problems, the research team believes the "persistent presence" of such behavior in Budongo could suggest that medical care among chimpanzees is much more widespread than previously realized.

Study first author Dr. Elodie Freymann, of the University of Oxford, said: “Our research helps illuminate the evolutionary roots of human medicine and healthcare systems.

“By documenting how chimpanzees identify and utilise medicinal plants and provide care to others, we gain insight into the cognitive and social foundations of human healthcare behaviors.”

The researchers studied two communities of chimpanzees in the Budongo Forest - Sonso and Waibira.

Like all chimps, the research team explained that are "vulnerable" to injuries - whether caused in fights, accidents, or snares set by humans.

Around 40% of all the chimps in Sonso have been seen with snare injuries.

The research team spent four months observing each community, as well as drawing on video evidence from the Great Ape Dictionary database, logbooks containing decades of observational data, and a survey of other scientists who had witnessed chimps treating illness or injury.

Any plants that the chimps were seen using for external care were identified.

Several of the plants turned out to have chemical properties which could improve wound healing and relevant traditional medicine uses.

During the observation period, the scientists recorded 12 injuries in Sonso, all of which were likely caused by in-group conflicts.

In Waibira, five chimps were injured - one female by a snare, and four males in fights.

The research team also identified more cases of care in Sonso than in Waibira.

Dr. Freymann said: “This likely stems from several factors, including possible differences in social hierarchy stability or greater observation opportunities in the more thoroughly habituated Sonso community.”

The researchers recorded 41 cases of care overall: seven cases of care for others - known as "prosocial care" - and 34 cases of self-care.

The cases often included multiple types of care, which the research team said might be treating different aspects of a wound, or might reflect a chimpanzee’s personal preferences.

Dr. Freymann said: “Chimpanzee wound care encompasses several techniques: direct wound licking, which removes debris and potentially applies antimicrobial compounds in saliva; finger licking followed by wound pressing; leaf-dabbing; and chewing plant materials and applying them directly to wounds.

"All chimpanzees mentioned in our tables showed recovery from wounds, though of course we don’t know what the outcome would have been had they not done anything about their injuries.

“We also documented hygiene behaviors, including the cleaning of genitals with leaves after mating and wiping the anus with leaves after defecation - practices that may help prevent infections.”

Of the seven instances of prosocial care, the researchers found four cases of wound treatment, two cases of snare removal assistance, and one case where a chimpanzee helped another with hygiene.

Care wasn’t preferentially given by, or provided to, one sex or age group.

On four occasions, care was given to genetically unrelated individuals.

Dr. Freymann said: “These behaviors add to the evidence from other sites that chimpanzees appear to recognize need or suffering in others and take deliberate action to alleviate it, even when there's no direct genetic advantage."

She added: "While we documented plants used in healthcare contexts, further pharmacological analyses are needed to confirm their specific medicinal properties and efficacy.

"Also, the relative rarity of prosocial healthcare makes it challenging to identify patterns regarding when and why such care is provided or withheld.

"These limitations highlight directions for future research in this emerging field.”

The findings follows a study published last year showing an ape treating a wound using a medicinal plant for the first time.

In a world first, the male Sumatran orangutan known as Rakus was observed applying chewed leaves from Akar Kuning - a climbing plant used in traditional medicine - to a wound on his cheek.

The findings, published in the journal Scientific Reports, were the first report of wound treatment by a wild animal using a plant with known medicinal properties.