Chimpanzees exhibit a knack for drumming with a consistent rhythm on tree trunks, as highlighted in a recent study. These rhythmic skills suggest that a shared ancestor of chimps and humans, who diverged about 6 million years ago, possibly utilized rhythmic beats as a means of communication. According to Cat Hobaiter, a primatologist from the University of St Andrews and co-author of the study, the capability to create rhythm and integrate it into social interactions appears to be an ancestral trait pre-dating early humans.
Earlier studies have indicated that chimpanzees possess unique drumming patterns. A comprehensive assessment of 371 drumming episodes by chimpanzees has confirmed that they consistently produce regular rhythms on tree trunks, a natural percussion instrument of sorts. Henkjan Honing, a researcher in music cognition from the University of Amsterdam, supported these findings, emphasizing the characteristic way chimps produce these rhythms. Although he did not partake in the study, Honing acknowledged the significance of these findings.
In their natural jungle environment, chimpanzees often drum on the tall buttress roots of rainforest trees, generating low-frequency sounds that travel over a kilometer through dense foliage. This drumming is considered a long-distance communication method, possibly signalling other chimps about the location or intended path of an individual. Hobaiter explains that this activity serves a social function, acting as a ‘check-in’ method, with each chimp possessing its own distinctive drumming style that can be recognized by others.
The study also revealed regional variations in drumming styles among chimpanzee populations across Africa. Chimps from the western regions tend to adhere to a steady beat, while those in eastern regions demonstrate more varied rhythmic intervals. These findings were publicized by the journal Current Biology. Beyond the use of tools like rocks for cracking nuts or sticks for fishing termites, tree roots serve an acoustic purpose, selected for their ability to transmit sound efficiently in lush environments. Catherine Crockford, a primatologist affiliated with the CNRS Institute for Cognitive Sciences in France and co-author of the study, noted the chimpanzees’ selective choice of roots to achieve effective sound projection.
The study underscores the importance of drumming as a contact method for chimpanzees. Additionally, a separate research effort documented in Science Advances examined how chimps utilize a complex array of vocalizations, more intricate than previously understood. By combining different sounds, such as those used for resting and play, chimps can convey new meanings, like inviting others to nest together at night. This discovery suggests that researchers might have underestimated the sophistication and adaptability of animal communication. Crockford, involved in both studies, highlighted this reevaluation of communication abilities as a pivotal advancement.