Like humans, chimpanzees touch the drum with distinctive rhythms, and two subspecies that live at the opposite extremes of Africa have their own characteristic styles, according to a study published Friday in Current Biology magazine.
The idea that the percussion of apes could contain clues about the origins of human musicality has fascinated scientists for a long time, but collecting enough reliable data in the middle of the jungle cacophony had been difficult until now.
“Finally, we were able to measure that the chimpanzees touch the drum rhythmically; they do not do it at random,” one of the authors of the study told AFP, Vesta Eleuteri, from the University of Vienna.
The findings reinforce the theory that the basic components of human music already existed before our evolutionary separation of chimpanzees six million years ago.
Previous studies showed that chimpanzees hit the huge roots of the trees of the tropical jungle to emit low frequency sounds through the dense foliage. Scientists believe that these rhythmic signals help transmit information at short and long distances.
For the new study, Eleuteri and his colleagues – among them, Catherine Hobaiter, from the University of St. Andrews (United Kingdom), and Andrea Ravignani, from La Sapienza University (Rome) – gathered more than a century of observational data.
After analyzing the ambient noise, the team was concentrated in 371 good quality drummering samples registered in 11 chimpanzees communities of six groups in Eastern and Western Africa, both of tropical jungle habitats and Sabana.
His analysis showed that the chimpanzees drummers with a defined rhythmic intention: the synchronization of their blows is not random.
Social dynamics
Distinctive differences between subspecies also emerged: the Chimpanzees of Western Africa tended to produce more uniform rhythms, while those of East Africa alternated more frequently between shorter and longer intervals.
In the west, they also drummed more frequently, maintained a faster tempo and used the earlier drum in their vocalizations, composed of gasps and branches.
Researchers still do not know the cause of differences, but suggest that it could indicate differences in social dynamics.
The fastest and predictable pulse of the west chimpanzees could account for greater social cohesion, according to the authors, who observe that these are often less aggressive towards individuals external to the group.
On the contrary, the variable rhythms of the East Apes would be associated with a greater number of nuances, useful to locate or notify colleagues in a more dispersed habitat.
Hobaiter would now like to study the data in greater depth to understand if there are intergenerational differences between the rhythms within the same groups.
“Music is not just a difference between diverse musical styles, but a musical style such as rock or jazz will evolve in itself,” he said.
“We are going to have to find a way to distinguish between group differences and intergenerational differences to address the issue of whether you are socially learned or not,” he explained. “Could it be that someone appears with a new musical style and the next generation adopts it?”
