Chimpanzees drum with regular rhythm when they beat on tree trunks, a new study shows.

Approximately 6 million years ago, chimpanzees and humans shared a common ancestor. Researchers believe this ancient forebear likely used drumming as a form of communication.

“The ability to create rhythm and incorporate it into our social interactions appears to date back to before humans evolved,” explained study co-author Cat Hobaiter, a primatologist at the University of St Andrews.

Prior studies have revealed that chimpanzees have distinct drumming styles. A recent analysis of 371 instances of chimp drumming shows they “clearly play their instruments—the tree trunks—with regular rhythms,” according to University of Amsterdam music cognition researcher Henkjan Honing, who was not part of the study.

When bounding through the jungle, chimps will often grab hold of the tall buttress roots of rainforest trees. Sometimes they pound them several times to create low-frequency sounds that can be heard for a kilometer or more through the forest.

Scientists believe that the drumming is a form of long-distance communication, perhaps to alert other chimps where one chimp is waiting or the direction it is traveling.

“It’s a way of socially checking in,” said Hobaiter, adding that each chimp has its own “individual signature — a pattern of beats that allows you to recognize who’s producing that drumming.”

The new work showed that chimps from different regions of Africa drum with distinctly different rhythms, with western chimps preferring a more even beat while eastern chimps used varied short and long intervals between beats. The research was published Friday in the journal Current Biology.

It’s well-known that chimps use tools such as rocks to crack open nuts and sticks to “fish” termites from their mounds. Tree roots can also be tools, the researchers say.

Chimps are selective about which roots they pound, said co-author Catherine Crockford, a primatologist at the CNRS Institute for Cognitive Sciences in France. Certain shapes and wood varieties create sounds that travel well through dense jungle.

The drummings are likely “a very important way to make contact,” she said.

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