You might think a mouse can make little more than a squeak and a scuffle. However, new research says they actually charm their mates with ultrasonic mating calls using a mechanism only seen before in jet engines.
It’s well established that mice and other rodents use ultrasonic communication for territorial and mating purposes. These “songs” are such a high-frequency, they can’t be heard by the human ear.
An international team of researchers has now shown that mice vocalization is even more bizarre than previously thought. Their study, based at the University of Cambridge, was recently published in the journal Current Biology.
"Even though mice have been studied so intensely, they still have some cool tricks up their sleeves,” said senior author Dr Coen Elemans, from the University of Southern Denmark, in a statement.
“Mice make ultrasound in a way never found before in any animal,” added lead author Elena Mahrt, from Washington State University.
You can listen to the mice in the study above
They filmed mice singing with an ultra-high-speed camera at 100,000 frames per second and noticed that their vocal folds remained completely motionless. This is pretty strange, as it was previously assumed the mechanisms was caused by the vibration of the vocal cords, just like human vocalizations.
But it turns out, the mice actually point a small jet of air from the windpipe against the inner wall of the larynx. The result is a chirpy (but inaudible to human) ultrasonic whistle, more akin to military technology than little furry mammals.
“This mechanism is known only to produce sound in supersonic flow applications, such as vertical takeoff and landing with jet engines, or high-speed subsonic flows, such as jets for rapid cooling of electrical components and turbines,” added Dr Anurag Agarwal, study co-author and head of the Aero-acoustics laboratories at Cambridge’s Department of Engineering.