Mother Nature offers up a cacophony of diverse sounds. But after examining the calls of hundreds of species from cricket chirps to chimp hoots, scientists have found they aren't so different from one another.
Their research on the calls made by nearly 500 animal species has led to simple mathematical models that can predict an animal's sounds based on the rate at which that individual takes up and uses energy.
"Our results indicate that, for all species, basic features of acoustic communication are primarily controlled by individual metabolism, which in turn varies predictably with body size and temperature," said James Gillooly, a biologist at the University of Florida Genetics Institute. "So, when the calls are adjusted for an animal's size and temperature, they even sound alike."
Their analyses included species of insects, fishes, reptiles, amphibians, birds and mammals.
"This seems to provide unifying principles for acoustic communication that can be applied to virtually all species. In terms of producing sounds, we use vocal cords, but other mechanisms of sound production exist, such as insects that rub their legs together," said study researcher Alexander Ophir, a zoologist at Oklahoma State. "Until now, these sounds have been treated differently. But by providing a general mathematical framework — a baseline — we have a reference point to compare those differences."
Ophir added, "So if we say one animal's call is loud, we can provide a predictive reference point to say whether it is truly loud when compared with other animal sounds."
The finding, reported in today's Proceedings of the Royal Society B, will help scientists understand how acoustic communication evolved across species, and could also help to predict what dinosaurs and other extinct animals may have sounded like compared with other animals when alive.
"These findings say if you give me information about an animal of a certain body size and the mechanisms it uses to make sounds, I can give you a rough idea of what it sounds like," said Jeffrey Podos, a biologist at the University of Massachusetts Amherst, who did not participate in the study.