Chimpanzees spark new wild fashion trend with grass and stick accessories—Just like humans

Chimpanzees Spark New Wild Fashion Trend with Grass and Stick Accessories (Image: Canva)

At a sanctuary in Zambia, some chimps are making headlines. But not for what they eat or how they climb. It’s their surprising taste in accessories.

A Behaviour That Started with One Female
Researchers at the Chimfunshi Wildlife Orphanage Trust first noticed something odd in 2010. A female chimp was seen dangling blades of grass from her ear. It didn’t seem to serve a purpose. Yet others soon followed, copying her without hesitation.

The chimps weren’t in distress or trying to scratch. They looked relaxed and calm, said Ed van Leeuwen, a behavioural biologist at Utrecht University. His team has studied the chimps for years.

The behaviour spread through the group like a social trend. A decade later, another group nine miles away began doing the same. This time, some chimps even inserted twigs or grass into their rectums. The scientists were intrigued.

Human Influence and Viral Traditions
Van Leeuwen suspected human influence may have played a role. Carers on one side of the sanctuary had a habit of cleaning their ears with matchsticks. The chimps may have been watching and learning.

Later, when those same carers worked with the second group, the chimps there began to adopt similar habits. It suggests the behaviour passed between chimps and humans and then from one chimp to another.

“This is social learning,” said Van Leeuwen. “It’s a trend that goes viral among them.”

Such behaviours mirror human customs. In one zoo in the Netherlands, a female chimp began walking like she was holding a baby. Others copied her—even newcomers, who adopted the faster walk, were accepted quicker.

More Leisure Time, More Room for Trends
At Chimfunshi, chimps don’t face predators or food shortages. That leaves them with more time to rest, groom, and invent. It’s during these moments that such playful habits tend to emerge.

Van Leeuwen believes wild chimps could show similar creativity. But their lives are busier, and such moments may go unnoticed in the wild.

The next step for Van Leeuwen’s research is to explore how chimps develop new ways to forage. He wants to see if they can build on shared knowledge over time, much like human culture.

Elodie Freymann from the University of Oxford, who wasn’t involved, called the findings “mind-blowing.” If chimps can copy humans, she wonders, could they also mimic other animal species?

“It’s an exciting time for primatology,” Freymann said.