Biologist and ethologists have long noticed that some nonhuman animals, such as bears, elephants, or bees have the capacity to self-medicate. However, until recently, no evidence has emerged that animals are also able and willing to assist other suffering members of their species.
In November 2019 though, Alessandra Mascaro, a volunteer at the Ozouga Chimpanzee Project – a research organization investigating chimpanzee behavior in Gabon, Central Africa – observed a female chimpanzee inspecting a wound on the foot of her adolescent son. Next, the mother was seen catching an insect out of the air, putting it in her mouth, and then applying it onto her son’s wound.
After this extraordinary event, which Mascaro managed to capture on video, the Ozouga team started to monitor the chimpanzees for such wound-tending behavior. Over the next 15 months, they documented 76 more cases.
According to the researchers, these acts of applying insects to others’ wounds are clear examples of prosocial behavior, in which the chimpanzees act in the best interest of others rather than just themselves.
“This is, for me, especially breathtaking because so many people doubt prosocial abilities in other animals,” said study co-author Simone Pika, a cognitive biologist at the Osnabrück University in Germany. “Suddenly we have a species where we really see individuals caring for others.”
Further research is needed to clarify which types of insects the chimpanzees use in order to tend one another’s wounds, and what therapeutic properties these insects have.
“Humans use many species of insect as remedies against sickness – there have been studies showing that insects can have antibiotic, antiviral, and anthelmintic functions,” said Dr. Pika. One theory, which still needs to be tested, is that some of the insects used by chimpanzees may also provide pain relief.
“Studying great apes in their natural environments is crucial to shed light on our own cognitive evolution,” said study senior author Tobias Deschner, a primatologist at the Max Planck Institute for Evolutionary Anthropology. “We need to still put much more effort into studying and protecting them and also protecting their natural habitats.”
The study is published in the journal Current Biology.