ambience: Rattlesnake rattle
The rattle of a rattlesnake spells danger. How dangerous is it? Well, the sound itself can give us clue. I’m Jim Metzner, and this is the Pulse of the Planet, presented by DuPont. “A snakes rattle consists of a series of specialized scales, multi-lobe segments that interconnect with one another, so that when a snake shakes its tail, the segments are clacking against one another. It, it’s not like a baby rattle where you have something inside a chamber that’s rattling around.” Don Owings, a professor at the University of California in Davis, says that, as you might expect, a larger rattlesnake has a louder, deeper rattle. This, for example, is a small rattlesnake… ambience: Small snake rattle And here’s a larger rattlesnake… ambience: Large snake rattle Snakes are not able to produce their own body heat, like mammals do. Consequently, a rattlesnakes temperature fluctuates a great deal, and so does the sound of its rattle. “And when snakes cool down, they slow down, and since a rattling sound consists of a series of closely related clicks (makes clicking sounds), uh, when a snake gets cold and starts slowing down, its rattle slows down and the individual clicks get farther apart.” Now here’s one rattlesnake, recorded first when it was very cool, then at intervals as it gradually warmed up… ambience: Snake rattle The larger and warmer a rattlesnake is, the more dangerous it is — it has more venom, and can strike faster and hold on to its victims longer. So, by listening to the sound of its rattle, you can tell how dangerous a rattlesnake is, and in our next program, we’ll hear how some of the rattlesnake’s prey use this knowledge to their advantage. 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.