Japanese Macaques Floss Teeth

Earlier this year, I blogged about long-tailed macaques (Macaca fascularis) in Thailand using human hair as dental floss to clean their teeth. This behavior gives us an insight to culture transfer as mothers were observed teaching their infants how to floss repeatedly.

In Kyoto, Japan, a Japanese macaque (Macaca fuscata) name Chonpe was observed flossing her teeth using her own hair. She perfected not one, but three flossing techniques.

Lead author Jean-Baptiste Leca told Discovery News that dental flossing could have been a fortuitous yet "accidental byproduct of grooming." Leca, a post-doctoral fellow at Kyoto University's Primate Research Institute, explained that "Japanese macaques sometimes bite into hair or pull it through their mouths to remove external parasites." The hair might have become stuck in Chonpe's teeth, and as she drew the hairs out, "she may have noticed the presence of food remains attached to them". "The immediate reward of licking the food remains off the hair may have encouraged her to repeat the behavior for the same effect in the future," he added.

Chonpe is a middle ranking female with no children. Her only close kin is her mother and her sibling, therefore diffusion of knowledge is somewhat limited to her only sibling. She was observed flossing her teeth about four years ago and had only recently seen this behavior spread among Chonpe's troop. Chonpe was also observed her rolling small stones in her hand while attempting to remove a spine stuck in her palm, so she might be particular an innovative individual, the researchers added.

Chonpe flossing her teeth. Photo by Jean-Baptiste Lena on Discovery News.

Read about the article from Discovery News, Tidy Monkey Flosses Teeth and The first case of dental flossing by a Japanese macaque (Macaca fuscata): implications for the determinants of behavioral innovation and the constraints on social transmission on the journal Primates.