Sound familiar? Well, if you watch the movies, you’ve heard these frogs before. And, at this time of year you can hear them in real life, too. And even tell the temperature by them. I’m Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.
“Thanks to Hollywood, when people think of frogs calling, this is what they think of. This is the Pacific Tree Frog. It’s the one you always hear in the background in movies. The Pacific Tree Frog is a common frog in southern California where the movie studios are, and somebody went down on the back lot one time and made a recording and from then on, that has been the frog call in movies. These frogs, however, only exist along the west coast of the United States from British Columbia down into Baja California. So if you see a movie taking place in the jungle someplace and you hear ‘ribbit’ in the background, don’t be fooled.”
Frank Awbrey is a retired Professor of Biology from San Diego State University. He tells us that on the west coast, Pacific Tree Frogs can be commonly heard at this time of year. It’s their breeding season, and we’re hearing the males calling for a mate. Now, if you knew the voices of these frogs well, you can actually tell the temperature by them.
“Pacific Tree Frog calls change with temperature. These things are basically the result of chemical reactions, as are everything that goes on in animals. And when it get’s cold, chemical reactions slow down. So do frog calls.”
ambience: frog call at 42 degrees F
“This is a Pacific Tree Frog calling at about 42 degrees Fahrenheit. Now, one month later, we recorded the same frog at 50 degrees Fahrenheit,
ambience: (A 24) frog call at 50 degrees Farenheit
and the next night we recorded the same frog again at 63 degrees Fahrenheit.
ambience: (A 27) frog call at 63 degrees Farenheit
You can hear how everything in the call speeds up.”
Pulse of the Planet is presented by the American Museum of Natural History. I’m Jim Metzner.