A team of Dartmouth College researchers have discovered that male lebinthine crickets now use a high-frequency call as a means of startling females in order to determine their location.
"The origins of communication signals have long fascinated evolutionary biologists, and multiple potential mechanisms for these origins have been proposed," Hannah ter Hofstede, co-author of the study, said in a press release. "Our results demonstrate how sensory exploitation of anti-predator behavior can also evolve into a classic communication system that benefits both senders and receivers, and that this unexpected origin might be more common than previously appreciated."
The researchers examined a group of male crickets that produced unusually high-frequency calls and found that females do not walk to calling males as they should. Instead, their whole body vibrates in response to these high frequency calls, allowing the males to locate the females based on these vibrations. This response likely evolved as a startle reflex in response to the loud, high frequency calls.
In addition to examining the cricket's behavior, the researchers also conducted neurophysiological recordings and discovered that the female crickets in this high frequency group lacked the auditory neuron for coding the low frequency sound that allows them to move in response to sounds, which likely stems from the shift in tuning to high-frequency sounds to adapt to the increase in the frequency of male calls.
The study was published in the Dec. 10 issue of the journal Cell Press.
