Transcript:

BULLFROGS CALLINGmusic; ambience: bullfrogLegend has it that if you make a wish when you hear the first frog of spring, your wish will be granted. I'm Jim Metzner, and this is the Pulse of the Planet.In India, people once believed frogs to be the physical incarnation of thunder. That's not surprising when you hear the bellow of a male bullfrog. What these amphibians lack in size they make up in volume. The croaks that we're hearing now are said to be the loudest sounds made by a cold-blooded animal in the Northeastern United States, and they can be heard up to half a mile away. So why isn't this bone-shaking sound too loud for the bullfrog who's doing the calling? Well, scientists think it has something to do with the unusual design of their ears. The frog's eardrums and lungs are connected, and they vibrate at the same time. This produces a pressure system that seems to protect the frog's hearing.Now that's a good thing, because it's advantageous for them to have as loud a croak as possible. They're trying to attract potential mates, of course, and a louder call increases their chances because more frogs can hear it. Not only that, but females seem to prefer a hardy call from their mates. Once the male frog has found a partner, he'll grasp her in a hug that could last for days. The female lays up to 20,000 eggs, and they're fertilized by the male as they're extruded from the female's body. Less than a week later, the eggs will hatch into tiny, swimming tadpoles, although far less than 20,000 will ever become full adult frogs.So here's a wish for enough frogs in the future to grant all of our wishes.I'm Jim Metzner, and this is the Pulse of the Planet.