A group of chimpanzees in Zambia has revived an old trend with a unique twist. Fifteen years after a female chimpanzee named Julie first inserted a blade of grass into her ear, sparking a trend among her peers at the Chimfunshi Wildlife Orphanage, a new group of chimpanzees at the sanctuary has adopted the practice.
Psychologist and great apes researcher Jake Brooker from Durham University in England expressed surprise at the resurgence of this behavior. The chimpanzees have taken the trend a step further by also inserting grass and sticks into a different orifice.
These chimpanzees have been observed placing blades of grass and sticks into both their ears and anuses, leaving them there without a clear purpose. A recent study published in the journal Behavior sheds light on how social and cultural trends spread and evolve among our primate relatives, mirroring human behavior.
Researchers speculate that the chimps may have learned the behavior from humans, particularly the ear-insertion aspect. Despite having no direct contact, the two groups of chimps exhibiting this behavior share some human caretakers who occasionally use tools like matchsticks or grass to clean their ears while working at the sanctuary.
The trend seems to have originated with a male chimp named Juma, who introduced the grass-in-butt variation, which quickly spread to his companions. Similar to Julie’s group, where the grass-in-ear trend started, the behavior continued even after Julie’s passing, with her son and another chimp still displaying the behavior.
Brooker noted that the chimps appear willing to endure discomfort for the sake of fashion, likening the behavior to getting ears pierced. Primatologist Julie Teichroeb from the University of Toronto suggested that the chimps may be using these behaviors to attract potential mates, with females displaying a swelling on their rear ends as a signal of receptiveness.
The presence of human caretakers providing food to the chimps at Chimfunshi may afford them more time to develop purely social trends. Teichroeb emphasized the shared kinship and similarities in cultural behaviors between humans and animals, highlighting the pointlessness of some cultural ideas that become viral trends.
Brooker drew parallels with orcas observed wearing salmon on their heads, likening the behavior to a resurgence of trends like flared jeans. He noted that such behaviors could be linked to environmental factors, such as changes in food availability over time.
While the chimpanzee behaviors may seem unusual, Brooker mentioned that observing chimpanzees engaging in post-conflict fellatio was even more surprising, showcasing the continuous intrigue these animals provide researchers.
