WASHINGTON - On the western side, they dance to quick, consistently paced rhythms. In the eastern part, it leans towards a more spontaneous and flowing style.
Similar to humans, chimpanzees also beat out distinctive rhythms when they drum—and two different subgroups residing at opposite ends of Africa each have their unique rhythmic patterns, as reported in a recent issue of Current Biology.
The notion that apes' drumming could provide insights into the roots of human music has captivated researchers for a long time. However, gathering sufficient clear data amidst the chaotic sounds of the forest had remained difficult—until recently.
"The study shows that chimpanzees can drum rhythmically — not just hit drums haphazardly," said lead researcher Vesta Eleuteri from the University of Vienna in an interview with AFP.
These discoveries add new strength to the idea that the basic elements of human music existed even prior to our divergence from chimps about six million years ago.
Earlier studies demonstrated that chimpanzees bang the large flared base roots of rainforest trees to produce deep-pitched thuds that travel through thick vegetation. Researchers think these repetitive sounds aid in conveying messages over short as well as extended ranges.
For the latest research, Eleuteri along with her team — which includes lead researchers Catherine Hobaiter from the University of St. Andrews in the UK and Andrea Ravignani from Sapienza University in Rome — gathered over a hundred years' worth of observation records.
Following the elimination of background noise, the researchers concentrated on 371 top-notch drumming instances documented from 11 chimpanzee groups spread across six different populations inhabiting both rainforest and savanna woodland environments stretching from eastern to western Africa.
Their study revealed that chimpanzees drum with clear rhythmic purpose—their hits follow a pattern rather than occurring randomly.
Significant variations were observed among the subspecies as well: western chimpanzees often created beats with more consistent timing, whereas eastern chimpanzees more commonly switched between shorter and longer intervals.
West African chimpanzees also drummed more often, maintained a faster rhythm, and started drumming sooner during their characteristic vocalizations, which consist of quick panting sounds and hooting noises.
The researchers have not yet determined what is causing these differences, but they suggest it could indicate variations in social interactions.
The rapid and consistent heartbeat of Western chimpanzees could indicate or support stronger social bonding, according to the researchers, who also observe that these groups tend to be less hostile towards unfamiliar individuals.
On the other hand, the varying tempos of the eastern apes might convey additional subtleties — useful for finding or communicating with fellow apes when their groups are spread out over larger areas.
Next, Hobaiter mentions that she wants to delve deeper into the data to explore if there are variations across different generations regarding the rhythms observed within those groups.
As she pointed out, music isn’t just about distinguishing various musical genres; even specific styles such as rock or jazz tend to transform gradually with time.
She mentioned that they will need to figure out a method to distinguish between group and generational variations in order to address the question of whether this phenomenon is acquired through social learning.
"Is there one person who arrives with a fresh style, and then the upcoming generation adopts it?" - AFP