for National Geographic News
Male field crickets on the Hawaiian island of Kauai have given up singing in order to survive (Hawa- i'i map).
The crickets can no longer trill or chirp because of a recent evolutionary adaptation that has changed the structure of their wings over the course of just a dozen or so cricket generations.
The silent lifestyle protects male crickets from a deadly parasitic fly that locates its victims by sound, researchers say.
But the muted males can no longer perform the nightly serenades thought to be essential for attracting female crickets and ensuring reproduction.
So the insects employ a sneaky technique: Hang around males who can chirp to attract females and then intercept a mate.
Robin Tinghitella is a graduate student who participated in the research, which was led by Marlene Zuk of the University of California, Riverside.
Tinghitella says that the mutation seems to have been accompanied by looser standards on the part of the female crickets.
In other cricket populations, she notes, silent males are rejected.
"Without some sort of relaxation in how choosy females are, the mutation never would have taken off," Tinghitella said.
The team's research, which was partially funded by the National Geographic Society, appears in the online edition of the journal Biology Letters.
(National Geographic News is part of the National Geographic Society.)
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