Today we write about a chimpanzee study that shows our close relatives have gesture dialects that differ among groups of chimpanzees.
According to Phys.org the report was recently published in Scientific Reports. Chimpanzees have long been known to use gestures. Those gestures include pointing and touching as among humans. What is different is the discovery that bands of chimps develop different dialects of leaf tearing that vary among bands.
Chimpanzees tear leaves to make sounds or pluck leaves to make a display. This was understood before too. What is new is the discovery that different bands can make different “leaf-modifying” behaviors. The behaviors are consistent in a group and slightly different from another group’s modifications.
Apparently a common use of gestures is the equivalent of flirting in humans. Male chimps will signal interest in a female and then tear leaves in a specific way to “flirt.” Females who traveled between troops were able to understand the slightly different gesture both groups used.
“Like human dialects, the different forms of gestures used by the two communities are used in the same contexts and seem to have the same meaning. It makes me think of the song ‘you say Potayto, I say Potaato’; it’s the same word, with the same meaning, but with a different pronunciation.”
Chimpanzees have also recently been observed doing behaviors that look like medicine. Observers found them crushing and using specific insects and applying them to each other. It is thought the behavior may be a form of medical treatment. More study in underway.
On a sad note, leprosy has been discovered in wild chimps for the frst time. The discovery is worrisome to scientists but appears to be somewhat localized.