Chimpanzees seen using bug juice as medicine for the first time
Capturing insects and smashing them onto your pal’s flesh may not seem helpful, but for chimpanzees it may be just what the doctor ordered.
In what many scientists have called a genuine show of empathy between primates, chimpanzees were seen catching insects to apply them to a mate’s open wound — presumed by researchers to be a sort of medicine.
A team of scientists with the Ozouga Chimpanzee Project, whose goal is to study the social bonds and interactions of chimpanzees, tracked a community of an estimated 45 chimpanzees at the Loango National Park in Gabon, CNN reported.
Many animal species, “including insects, reptiles, birds and mammals,” are already known to self-medicate against illness, according to cognitive biologist Simone Pika, whose co-authored study was published on Monday in Current Biology.
Indeed, chimps, one of humans’ closest animal relatives, have been observed swallowing and chewing leaves with anti-parasitic properties to ward off invading organisms, Pika pointed out.
And certain bugs, too, may have antiseptic or anti-inflammatory properties — as early humans have known at least as far back as 1,400 BC, researchers said.
But up until now, scientists haven’t observed chimps seeking out these buggy remedies to use on themselves and on other chimps.
“Chimpanzees eat insects but we did not know that they catch and use them to treat their wounds,” Pika said. “Hence, they not only have an understanding of their food species (plants, insects, monkeys, birds, reptiles) but probably also about characteristics of other animal species that help to act against injuries.”
The observation was made between mother and son chimps in 2019, when chimp Suzee appeared to tend to young Sia’s injured foot.
Project volunteer Alessandra Mascaro recalled the interaction.
“I noticed that she appeared to have something between her lips that she then applied to the wound on Sia’s foot,” Mascaro said. “Later that evening, I rewatched my videos and saw that Suzee had first reached out to catch something which she put between her lips and then directly onto the open wound on Sia’s foot.”
Over the course of the next year, researchers kept their eyes peeled for other signs of insect-based medical aid between chimps, and recorded 76 cases total between November 2019 to February 2021, including one between adult male Littlegrey, who suffered a gashed shin, and adult female Carol.
Doctoral student Lara Southern added in her report that Carol “suddenly reached out to catch an insect. “What struck me most was that she handed it to Littlegrey, he applied it to his wound and subsequently Carol and two other adult chimpanzees also touched the wound and moved the insect on it,” said Southern.
It’s the empathetic behavior that is particularly novel, according to Pika. These acts, called “pro-social behavior,” she explained, “have long posed a problem for evolutionary theory, because it was not immediately clear why organisms might help others in the face of selection operating in the interest of self.”
“This is, for me, especially breathtaking because so many people doubt pro-social abilities in other animals,” Pika said. “Suddenly we have a species where we really see individuals caring for others.”
The comparative biocognition expert added that they can’t be sure that what they saw was genuine empathy, but it does “increase the welfare of another animal,” which suggests an inherent benefit to the one performing the good deed.
“There are examples of chimpanzees adopting and rescuing other chimpanzees,” Pika added, “which may involve empathy.”