Thank you as always to the incredible team who worked on this project!

If logging and deforestation continue at current rates, chimpanzees may soon lose access to their forest pharmacy, leaving them vulnerable to previously treatable pathogens.

These results not only have relevance for our understanding of chimpanzee medicinal repertoires, they also have implications for chimpanzee habitat conservation.

Based on these findings, the fact that tree bark is used in traditional medicine across the world, and our recent pharmacological discoveries, we propose that the function of bark in chimpanzee diets should be reconsidered.

Lastly, we found that individuals travel unusually long distances and into high-risk areas to access the bark of certain species.

We also observed several cases of chimpanzees prioritizing bark over high-value food items like meat, suggesting the bark of certain species plays an important role in the diet.

Many of these same species were targeted in very small quantities, making it unlikely they are targeted for nutrition alone.

First, the bark of several tree species are targeted by the chimps during periods of food abundance, rather than periods of scarcity, suggesting they are not fallback resources. A few of these species are targeted most frequently during months when respiratory infections peak.

Our results suggest that the barks of several tree species serve as medicinal resources for the Budongo chimpanzees, based on four lines of evidence:

For years, tree bark has been considered a ‘fallback food’ for chimpanzees—in other words, a food that is eaten opportunistically when there is no better option. In our paper, we call this assumption into question, investigating the role bark plays in wild chimpanzee diets.

Thanks to the amazing team who worked on this project, and of course the incredible field staff at the Budongo Conservation Field Station!

📊These findings add compelling evidence that chimpanzees seek out specific plants for their medicinal effects. 💊 The medicinal knowledge gained from observing other species in the wild underscores the urgent need to preserve these forest pharmacies for future generations.

🦠 Excitingly, Dr. Fabien Schultz
and his team found that 88% of the plant extracts inhibited bacterial growth, and 33% had anti-inflammatory properties.

🔬To investigate, we monitored the behavior of two chimpanzee communities over the course of 8 months, and collected 17 plant samples from 13 species of trees and herbs suspected of being used by chimpanzees for self-medication. Many of these were eaten by ill or injured chimps.

Wild chimpanzees eat a variety of plants, some of which have medicinal compounds which may help treat or lessen symptoms of illness. But do they self-medicate intentionally or consume these plants passively as medicinal foods?