BOB HIRSHON (host):
What price, reproduction? I’m Bob Hirshon and this is Science Update.
Animals have a strong drive to mate in order to pass on their genes. But sometimes sex can kill, according to sensory ecologist Stefan Greif of the Max Planck Institute for Ornithology in Germany. He says when house flies mate, they emit a buzzing sound like this: (sfx: buzzing flies). Suspecting this might attract hungry bats, he and his colleagues recorded the sounds and played them back through speakers on the ceilings of barns, where both bats and flies congregate. Greif says, sure enough, the bats tried to attack the speakers as if they were tasty flies. But he says in the absence of the sounds, the flies were invisible to the bats.
STEFAN GREIF (Max Planck Institute for Ornithology):
People have been wondering for 85 yrs now if copulations might pose a risk to animals. So we now show for the first time that increased conspicuousness is one of the factors that makes copulation dangerous.
He says 5% of the flies are actually killed when they mate. I’m Bob Hirshon, for AAAS, the science society.