In the wild, monkeys known as macaques drum by shaking branches or thumping on dead logs.

Similar behavior has been seen in non-human primates — for instance, gorillas beat their chests and clap their hands, while chimpanzees drum on tree buttresses.

In the lab, scientists noted that rhesus macaque monkeys drummed using artificial objects such as cage doors by shaking them vigorously or slapping or banging them against surfaces, often with accompanying threatening sounds, postures and facial expressions.

Only the largest and dominant monkeys drummed, suggesting that drumming was used to communicate messages about power and status — the louder the drumming, the bigger and stronger the macaque likely is.

Past research had uncovered areas of the brain linked with vocal communication in monkeys, findings that hint at the roots of vocal communications in primates. The discovery of drumming in rhesus macaques offers a way to examine what brain regions were linked with nonvocal communication, such as music in humans. Humans and macaques are thought to have had a common ancestor about 25 million years ago.

Investigators at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, scanned monkey brains while the rhesus macaques listened to either drumming or monkey calls. They found overlapping networks activated in the temporal lobe, which in humans is key to processing meaning in both speech and vision. Christoph Kayser, a neuroscientist at the Max Planck Institute, states:

\"Monkeys respond to drumming sounds as they would to vocalizations. Hence, drumming originated as a form of expression or communication, possibly in an ancestral species common to apes and old-world monkeys, early during primate evolution.\"