Tree frogs convey aggression using body vibrations

Washington, May 21 (ANI): Researchers at the Smithsonian Tropical Research Institute in Panama have discovered that male red-eyed tree frogs communicate with one another in aggressive contests by using vibrations they send through their plant perches.

"In the case of red-eyed treefrogs, tremulation displays in which the frogs shake their entire bodies convey information about the status and aggressive intent of the signaler," says Michael Caldwell of Boston University.

"They also appear to carry information about the size of the signaler."sing experiments involving a mechanical shaker and a robotic frog, the researchers found that plant-borne vibrations generated by the shaking display of the vertebrates act as a signal and are both necessary and sufficient to elicit tremulations by other treefrogs in response.

These tremulations or responses depend on the size of the treefrog and the context. Their other signaling behaviours, such as their acoustic calls, also generate strong and stereotyped vibrations that travel through plants and might carry information.

Unlike earlier studies where the researchers observed the treefrogs under white light, in this study, they used infrared source of light.

"When we attached vibration-sensitive accelerometers to the plants and looked at the frogs under infrared light, we saw a whole new range of fascinating behaviors," Caldwell said.

"Studies on frogs, birds, and primates have formed the core of our understanding of vertebrate communication," the researchers write, "yet we know almost nothing about vibrational signaling in these species. The further study of vibrational communication among arboreal vertebrates presents important unexplored opportunities to improve our comprehension of the behavioral ecology of these species, and of animal communication as a whole."

The study was published online on May 20th in Current Biology, a Cell Press publication. (ANI)