Transcript:

A Birdlike Trill Here's a program from our archives. Ambience: American toads trillingJM: Throughout the United States, it's one of the signature sounds of Spring - do you know what's making it? I'm Jim Metzner, and this is the Pulse of the Planet. Serrao: When you look at a toad, it's hard to believe the sound so beautiful could come from such a creature.It varies year to year, depending upon the weather, but in the Northeastern United States, this time of year is the breeding season for American Toads. Naturalist and author John Serrao tells us more.Serrao: It's a bird like trill that may last for twenty or thirty seconds and it's the kind of a sound that you could make if you hum and whistle at the same time, but like all sounds it's main reason is not to thrill humans, but to attract the females of the species, and the females will hear that sound, travel to the pond where the toads are, or maybe even a drainage ditch where there is some water, and the toads get together and the eggs are fertilized, long curly strings, or ribbons, they look like, and they come out of the female toad. Ten thousand from a single female toad can come out in a long curly string; and they are fertilized outside as with all frogs and toads, and just a few days later the eggs hatch, and just a couple weeks later those tadpoles that came from those eggs become baby toads and come out of the water for the first time, and at that time they look like tiny crickets, they're very, very small, and they all come out at the same time and you see thousands and thousands of little tiny toads coming out of the water almost simultaneously.We will hear more on American Toads in future programs. To hear about our new CD visit pulseplanet.com. Pulse of the Planet is presented by the National Science Foundation. I'm Jim Metzner.