A Rare Frog Species in China Enters the Record Books as the First Known Amphibian Capable of Ultrasonic Communication.
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Amolops tormotus |
Until now, only a few mammal species—such as bats, whales, and dolphins—are known to use ultrasonic sounds for communication.
The frog species Amolops tormotus may have developed this mechanism to hear sounds over bubbling water. They inhabit fast-flowing streams in Anhui Province, China. During the rainy season, water levels rise rapidly, creating sounds that drown out the calls of small animals.
A. tormotus distinguishes itself in the chaotic soundscape by emitting ultrasonic sounds (above 20 kilohertz) that exceed the auditory range of the entire area. The calls of this frog are quite unique. While most of their calls are either high-pitched or low, they utilize a range of ascending and descending sounds that resemble the calls of birds, whales, or primates.
A research team led by American professor Albert Feng visited the Tao Hua River branch in China to study this frog species. They initially heard a melodic chirping they thought was from a bird hiding in the bushes. Ultimately, it turned out to be the song of a male frog from the species they were researching.
Dr. Feng wondered whether other frogs of the same species could hear and respond to this sound or if they were merely showcasing their abilities. He conducted an experiment, recording the frog’s calls, breaking them down into different frequencies, and testing the responses of frogs in their natural habitat.
The team found that most frogs reacted to the ultrasonic sound range, with half of them responding back with ultrasonic calls. Only the male frogs were tested, and it remains unknown whether the females, which have a different ear structure, utilize ultrasonic communication as well.
“Nature has its own way of developing mechanisms that facilitate communication in various situations,” Feng noted. “One of those ways is tuning frequencies above the background sound range. Mammals like bats, whales, and dolphins do this—using ultrasound to communicate. Frogs have never been thought to have that capability.”
Dr. Feng believes that the ability to respond to ultrasonic sounds may also be found in other bird and amphibian species.
M.T.
