"Grass-in-the-ear" new fad amongst 'copycat' chimps

A new study has revealed that Chimpanzees are copycats and, in the process, they form new traditions that are often particular to only one specific group of these primates, as "grass-in-the-ear" has become a new trend.

According to the researchers, a female chimp named Julie repeatedly put a stiff, strawlike blade of grass for no apparent reason in one or both of her ears and left it there even when she was grooming, playing or resting, after which other chimpanzees also followed suit.

The research team, including Zambians who monitor the chimpanzees daily, collected and analyzed 740 hours of footage that had been shot during the course of a year of 94 chimpanzees living in four different social groups in the sanctuary. Only two of these groups could see one another.

The research team found that only one of the four groups regularly performed this so-called "grass-in-the-ear" behavior. In one other group one chimpanzee once did the same. Eight of the twelve chimpanzees in Julie's group repeatedly did so.

The observations show that there's nothing random about individual chimpanzees sticking grass into their ears. They spontaneously copied the arbitrary behavior from a group member. Chimpanzees have a tendency to learn from one another - clearly a case of "monkey see, monkey do" in fact.

The study was published in Springer's journal Animal Cognition.