Recordings show some ‘mute’ animals communicate vocally

PARIS: More than 50 animal species previously thought to be mute actually communicate vocally, according to a study published on Tuesday which suggested the trait may have evolved in a common ancestor over 400 million years ago.

The lead author of the study, evolutionary biologist Gabriel Jorgewich-Cohen, told AFP he first had the idea of recording apparently mute species while researching turtles in Brazil´s Amazon rainforest.

“When I went back home, I decided to start recording my own pets,” Jorgewich-Cohen said. That included Homer, a turtle he has had since childhood. To his great excitement, he discovered that Homer and his other pet turtles were making vocal sounds. So he started recording other turtle species, sometimes using a hydrophone, a microphone for recording underwater.

“Every single species I recorded was producing sounds,” said Jorgewich-Cohen, a researcher at Zurich University in Switzerland. As well as 50 species of turtle, the study published in the journal Nature Communications also included recordings from three “very strange animals” considered mute, he said.

They include a type of lungfish, which has gills as well as lungs that allow it to survive on land, and a species of caecilian -- a group of amphibians resembling a cross between a snake and a worm.