How do chimps make ‘rock’ music? The answer is simple — the reason isn’t, study says

Why do chimpanzees in some parts of West Africa sometimes hurl rocks against trees, often accompanied by loud hoots?

It’s a question scientists have been trying to answer for a few years now, but a new study published in Biology Letters provides at least a few more clues.

To test the acoustic qualities of the trees favored by chimps for their rock-hurling, researchers chucked some rocks of their own and analyzed the resulting racket, Science Alert reported.

“It was quite fun, I have to say,” said Ammie Kalan, chief rock-thrower and a primatologist at the Max Planck Institute for Evolutionary Anthropology in Germany, Science magazine reported.

Researchers discovered the apes seem to prefer trees that produce a “lower, longer-lasting sound,” according to the publication.

An initial 2016 report on the curious behavior suggested the rock-throwing might be some kind of ritualized behavior, Newsweek reported.

After the latest analysis, though, Kalan — who also headed up the 2016 study — thinks the apes may be trying to communicate over long distances, Science Alert reports.

Or they might just like the sound it makes.

Kalan also notes that researchers have yet to catch a chimp changing rock-hurling targets, making it harder to figure out why they might prefer one tree over another, Science magazine says.

This story was originally published December 19, 2019 at 5:53 PM with the headline "How do chimps make ‘rock’ music? The answer is simple — the reason isn’t, study says."