- Researchers in Gabon’s Loango National Park observed chimps applying insects to their own wounds, as well as the wounds of other individuals.
- Researchers identified 76 instances of this behavior being repeated on 22 different chimps.
- Experts say these findings could help guide conservation efforts for not just these endangered great apes, but also their entire ecosystem.
When Alessandra Mascaro first recorded a video of a chimpanzee (Pan troglodytes troglodytes) catching something in the air, putting it in its mouth, and then putting it on the wound of another chimp, she and her colleagues had to watch the footage multiple times to make sense of it. At the time, in November 2019, Mascaro was a volunteer for the Ozouga Chimpanzee Project in Gabon’s Loango National Park, and no one on her team had ever seen anything like it.
“At the moment I didn’t realize what was going on, but I noticed that there was something very cool because other chimpanzees came to observe,” Mascaro told Mongabay over video call. “This is the way [chimps] learn behavior.”
Mascaro felt that she was watching something like a “chimp doctor” at work, much like how humans go to doctors when they’re sick. She added that if this was the case, then it would illustrate that humans aren’t as unique as we may think. But there were still unanswered questions: Was this just a one-time thing? And what was it that the chimp had caught from the air and applied to the wound?
The team only had to wait one week before they saw it happen again. Mascaro said she was closely observing another chimp with an injury. The chimp, which the researchers had named Freddy, appeared to catch something on a branch, put it in his mouth and then reapplied it to his wound three times. After these two incidents, the team observed this behavior more than 20 times. This suggested that, at least for this group of chimps, insects were being used as a form of medication. They published their findings in the journal Current Biology.
The team at Ozouga Chimpanzee Project still haven’t been able to identify which insect the chimps are using. By the time the chimps are done with the insects, there’s not much left, Simone Pika, one of the directors of the Ozouga Chimpanzee Project, told Mongabay. But they’re in talks with entomologists to explore ways to get to the bottom of this mystery.
Once they’ve identified the insect, they’ll be able to determine whether the insect has any chemicals that help heal open wounds — which could confirm that this behavior is medicinal in nature.
For Pika, one of the more interesting parts of the team’s observations is that it might reveal new things about chimps’ social interactions: chimps have been observed self-medicating before, but they’ve never been observed medicating another chimp.
Pika said she finds the role of the recipient of the treatment particularly interesting. “If you think you have a wound and it’s hurting you, then who do you let help you?” she said. “What we see here is that if animals are friends and have a very strong social bond, then they communicate differently with each other. They groom differently. And it also seems that then they [let them] treat their wounds.”
These kinds of questions can help people realize there’s still a lot we don’t know about the “diversity and flexibility of chimpanzee behavior,” she added. And that may help call attention to the importance of conserving endangered species like Gabon’s chimps.
Jacobus C. de Roode, professor of biology at Emory University in the U.S., researches self-medication in animals, and his own work has focused on self-medication in monarch butterflies. Though we still don’t know if the insects used by chimps actually help their wounds heal, he told Mongabay these kinds of studies still have important implications for how we think about the way animals live within their broader ecosystems.
“When you think about conservation biology, or preserving a particular habitat, just the fact that [an animal’s] food is in there isn’t enough,” he said. “So I think that appreciation helps with people understanding the overall importance of biodiversity is so much more than just food or shelter. It’s this whole pharmacy that we need to preserve.”
Mascaro, A., Southern, L. M., Deschner, T., & Pika, S. (2022). Application of insects to wounds of self and others by chimpanzees in the wild. Current Biology, 32(3), R112-R113. doi:10.1016/j.cub.2021.12.045
Editor’s note: This article was amended to correct the number of times chimpanzees were observed applying insects to wounds.
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