Cited research: Curr. Biol. doi:10.1016/j.cub.2010.03.069 (2010)

Vertebrates living on plants can communicate through not only sound and visual displays, but also by vibrating the plants on which they perch.

Michael Caldwell at Boston University in Massachusetts and his colleagues studied such behaviour in wild male red-eyed tree frogs (Agalychnis callidryas). These creatures defend their territories and compete for females by rapidly shaking their hind ends.

The researchers also staged contests between pairs of males. They found that shaking was the most frequently displayed signalling behaviour, with victorious males tending to shake more than their opponents. Experiments using a robotic frog, an electronic shaker and sound recordings showed that the frogs shake in response only to plant vibrations, and not to the shaking model frog or vibrational sounds. J.F.