(SOUNDBITE OF CRICKET CHIRPING)
AILSA CHANG, HOST:
Male tree crickets advertise their availability by rubbing their wings together to chirp. And larger, louder males find more favor with the females.
MARY LOUISE KELLY, HOST:
But smaller, less desirable males do have a trick to juice up their prospects - they amplify their chirps by punching a hole in a leaf and sticking their head through it. Rittik Deb of India's National Center for Biological Sciences described it like this.
RITTIK DEB: You know those collars that they put on dogs when they're putting some vaccine or something on the dogs? It looks something like that.
CHANG: This technique, known as baffling, can more than double the volume of a cricket's mating call. Ed Baker of the Natural History Museum in London says the leaf works sort of like a loudspeaker.
ED BAKER: You effectively increase the size of the wing, which makes the sound appear to be louder.
KELLY: Here are two recordings - same cricket. First, without the leaf.
(SOUNDBITE OF CRICKET CHIRPING)
CHANG: All right, now with the leaf.
(SOUNDBITE OF CRICKET CHIRPING)
CHANG: Whoa. I got to turn down my headphones now.
(LAUGHTER)
KELLY: This phenomenon was first documented in the mid-1970s. But what Deb's team found is it has real consequences for small crickets. His team estimates quieter males can go from zero dates a night to three simply by cranking the volume of their calls up to about 11.
CHANG: And once female crickets are reeled in, they hang around longer, too, which gives smaller males a better chance at passing on their genes. The results were published by the Royal Society.
KELLY: A question, though - if baffling works so well, why don't all crickets use it? Deb says loud males don't have much to gain.
DEB: The loud males are already getting the optimal number of mates they can mate with within a night.
CHANG: (Laughter) And though we might think of primates or crows as the smart tool-using animals, Deb says crickets deserve some credit, too.
DEB: The have the tiniest of all the brains that is possible, and yet they produce such complex behaviors.
CHANG: The chance of finding a mate, it seems, is all it takes to turn crickets into audio engineers.
(SOUNDBITE OF THE MIDNIGHT SONG, "YOUTH") Transcript provided by NPR, Copyright NPR.
