A troop of chimpanzees in Zambia has revived an ancient trend with a new twist. Over a decade after a female chimp named Julie initiated the practice of inserting grass into her ear, a different group of chimps at the Chimfunshi Wildlife Orphanage has adopted the behavior.
Jake Brooker, a psychologist and great apes researcher at Durham University in England, expressed astonishment at the resurgence of this trend and the innovative modifications made by the new chimps. These chimpanzees have been observed inserting grass and sticks into their ears and anuses, leaving them in place for no apparent reason.
A recent study published in the journal Behavior sheds light on how social-cultural trends propagate and evolve among our primate relatives, mirroring human cultural dynamics.
Researchers suspect that the chimps may have learned the ear-inserting behavior from humans, as both chimp groups displaying this behavior do not interact with each other but share common human caretakers who occasionally use similar tools for ear cleaning.
The trend was traced back to a male chimp named Juma, who introduced the variation of inserting grass into their rear ends, possibly to enhance their attractiveness to potential mates. Similar to human cultural practices, the chimps seem willing to endure discomfort for the sake of fashion, with the behavior resembling the act of getting ears pierced.
Primatologist Julie Teichroeb from the University of Toronto suggests that the chimps may be innovating ways to adorn themselves, similar to humans, with the behavior possibly serving as a form of social display.
The study highlights the striking parallels in cultural behaviors between humans and primates, illustrating the shared kinship and evolutionary connections between the two. This phenomenon of adopting and modifying social trends among chimpanzees mirrors similar behaviors observed in other animal species and underscores the intricate social dynamics within primate societies.
Brooker noted that this study, though peculiar, is not the most surprising behavior exhibited by chimpanzees, recalling a previous observation of post-conflict fellatio among male chimps. Such behaviors continue to intrigue researchers and emphasize the remarkable diversity and complexity of chimpanzee social interactions.
