Science News brings attention to male shortcomings and the gender’s creativity in overcoming them with a story about crickets who use leaves as megaphones, amplifying their mating calls to make lady crickets think they’re bigger:
Some male crickets make their own megaphones by cutting wing-sized holes into the center of leaves. With their bodies stuck halfway through this vegetative speaker, male Oecanthus henryi crickets can more than double the volume of their calls, allowing naturally quiet males to attract as many females as loud males, researchers report December 16 in Proceedings of the Royal Society B.
It’s a rare example of insect tool use that “really challenges you to think about what it takes to produce complex behavior,” says Marlene Zuk, an evolutionary biologist at the University of Minnesota in St. Paul who wasn’t involved in the study.
Biologists first spotted crickets creating leaf-speakers, called baffles, and singing from them, or baffling, in 1975. Since then, the baffling behavior has been reported in two other species, but wasn’t clear exactly how it benefits individual crickets.
Rittik Deb, an evolutionary ecologist now at the National Centre for Biological Sciences in Bangalore, India, was stunned when he first witnessed an O. henryi male baffling in 2008. “It was mind-bogglingly beautiful,” he says, “I had to understand why it was happening.”
Do females fall for their inflated calls? Yes, according to lab experiments. When given a choice, females overwhelmingly prefer louder calls, even when these come from baffling males. Baffling essentially evens the playing field, allowing quiet males to attract just as many females as louder males.
Females dictate how much sperm they accept by how long they retain the spermatophore. With larger males, it’s about 40 minutes, compared with only 10 minutes for small males. But when Deb artificially boosted the calls of small and quiet males, females treated them like large males, retaining their spermatophores for longer. “That really surprised us,” Deb says. “It’s as though the females are in some sense being deceived.”
You can read Deb’s original research article here.