A new study reveals that chimpanzees drum with a regular rhythm when striking tree trunks, a practice that may date back to a common ancestor with humans and represent one of the oldest forms of social communication.
According to the researchers, chimpanzees and humans shared a common ancestor around six million years ago. This ability to produce a structured rhythm could therefore predate the very emergence of the human species. "Our ability to produce rhythm—and to use it in social contexts—appears to predate humanity," explains Cat Hobaiter, a primatologist at the University of St Andrews and co-author of the study.
Analysis of 371 chimpanzee drumming sequences revealed a notable regularity in the beats, according to Henkjan Honing, a music cognition specialist at the University of Amsterdam, who was not involved in the study. Chimpanzees use the root buttresses of tropical trees, striking them repeatedly to produce low-pitched sounds that can be heard more than a kilometer across the jungle.
This practice is believed to be used as a means of long-distance communication, signaling an individual's location or direction of travel. "It's a way of socializing," Hobaiter said, adding that each chimpanzee has a distinct rhythmic signature that is recognizable by its peers.
The study, published Friday in Current Biology, also indicates regional differences: chimpanzees from western Africa adopt a more regular rhythm, while those from eastern Africa prefer more varied sequences, with alternating short and long beats. These preferences could reflect cultural traditions rooted within groups.
The researchers also highlight the chimpanzees' selective nature in choosing which roots they strike, with certain species and shapes producing sounds that carry more through dense vegetation. "Roots can be considered tools in their own right," says Catherine Crockford, a primatologist at the CNRS Institute of Cognitive Sciences in France.
In parallel, another study published in Science Advances demonstrates the unsuspected complexity of vocal communication in chimpanzees. By combining different types of calls—for example, a call to rest with an invitation to play—they create new messages, such as an invitation to nest together for the night.
These recent discoveries shed light on the extent and sophistication of communication among our closest cousins, revealing abilities far more elaborate than previously thought.
