Elodie Freymann: Wild chimpanzees use forest ‘first aid’

Elodie Freymann PhD, EC50 Class of 2025, in collaboration with researchers from the University of Oxford, has published a study highlighting observed self-directed and ‘other-directed’ wound care, snare removal, and medicinal hygiene behaviors in the Sonso and Waibira chimpanzee communities of the Budongo Forest in Uganda. The research underscores the importance of continued study and protection of these populations, their behaviors, and their environments.

Published in Frontiers in Ecology and Evolution, the study provides “insights into the origins of medicinal knowledge, the identification of specific medicinal resources used for health maintenance, and the emergence of prosocial healthcare capacities.”

Elodie and her collaborators conducted two four-month observation periods in the Budongo Forest, studying two populations of wild chimpanzees. The team also analyzed archival records from thirty years of observations at the Budongo Conservation Field Station (BCFS), as well as videos recorded by previous researchers, part of the Great Ape Dictionary (GAD) video database—which contains over 13,800 catalogued videos of the Budongo chimpanzee populations.

During their fieldwork, the researchers observed chimpanzees licking and applying leaves and chewed plant material to their own wounds, as well as successfully removing a snare. The team also documented chimpanzees using leaves to wipe themselves, interpreted as hygienic self-care.

For the first time in Budongo, Elodie and her team observed chimpanzees treating the wounds of other chimps. In some cases, a chimp would chew leaves and apply them to another’s injury—whether they were family members or not.

These observations suggest that the chimpanzees’ prosocial healthcare is more widespread across populations than previously recognized.

The research team collected and identified the plants that the chimpanzees were using for suspected self-medication. Several of the plants being used have been shown to exhibit antibacterial, antifungal, anti-inflammatory, and analgesic properties. 

The study highlights the need for more long-term investigations into healthcare behaviors at free-ranging chimpanzee sites, to protect the resources chimpanzees use to stay healthy and protect them against anthropogenic risks. 

The full paper can be found in Frontiers of Ecology and Evolution here.

Learn more about Elodie Freymann, EC50 Class of 2025, and the rest of the members of the EC50 here.