ambience: bullfrogs
A menacing predator lurks in the waters of the American Southwest, gulping everything that can fit down its throat. Sounds like a grade B science fiction movie, but it happens to be true. I’m Jim Metzner, and this is the Pulse of the Planet. The southwestern United States is home to whole lot of frogs – American bullfrogs to be exact – and no one knows quite what to do about them. Weighing in at up to two pounds and measuring up to seven inches long, the common bullfrog was introduced by humans to the West over a century ago and has now become a major environmental threat in states such as Arizona and California. Cecil Schwalbe with the U.S. Geological Survey at the University of Arizona tells us about the bullfrog’s innocent beginnings.
“The bullfrog evolved in North America – it naturally occurred from Florida to Canada, and then west – it got on its own about as far as eastern New Mexico. It could not cross the desert until we humans got involved. And the first bullfrogs were actually imported into California in 1898. They’ve since been introduced throughout the west and they have created some problems for us with their veracious appetite. The bullfrog will eat, literally, almost anything small enough to swallow. And, at one of our study sites in Southeastern Arizona, we have found every class of vertebrate that occurs in Cochise county Arizona inside bullfrogs stomachs. Such diverse items as red winged blackbirds, cotton rats, six species of snakes, five species of lizards. We even have a couple of bats in the stomachs. They eat other frogs, snakes, turtles, fish. It’s there, they eat it.”
We’ll hear more on bullfrogs in future programs. Pulse of the Planet is presented by DuPont, bringing you the miracles of science, with additional support provided by the National Science Foundation. I’m Jim Metzner.
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