Transcript:

Alarm CallsAmbience: alarm call, Stellar's JayGreene: Monkeys, birds, insects, fish, salamanders. Lots of animals give signals of various sorts in response to their predators.Is that a hawk flying overhead? Sound the alarm! I'm Jim Metzner and this is the Pulse of the Planet.Greene: Imagine you're a bird out in the woods and you see a dangerous predator. You'd think that maybe the best thing to do would be to just keep quiet and hide in the bushes. That's really not what happens. Most animals we know about, if they see a predator, give what we call alarm calls.Erick Greene is a biology professor at the University of Montana whose been studying alarm calls. Right now we're listening to the alarm calls of a Stellar's JayGreene: Alarm calls are sounds of various types that have a very specific meaning. They are essentially telling other animals that there's danger in the area. Most birds that have been studied give alarm calls when they see a predator, be it a snake, a leopard, a hawk, another bird that's a predator. Alarm calls can travel surprisingly fast. We can have microphones placed throughout large chunks of habitat that allow us to map out these acoustic landscapes. What we've discovered much to our astonishment is that alarm calls can travel at over a hundred miles an hour and they get passed from one bird to the next. if you think about it, this is pretty amazing because this wave of information about predators is traveling far faster than hawks are flying, for example. That information is going about twice as fast as the predator moving through the environment. We'll hear more on alarm calls in future programs. Pulse of the Planet is made possible in part by Virginia Tech, inventing the future through a hands-on approach to education and research.