Mystery Sound
Here’s a program from our archives.
This month, the animal that we’re listening to is just beginning to sing its annual cycle of songs. See if you can guess what animal this is. Multiple choice: is it song sparrow, meadowlark, a mockingbird, or none of the above. I’m Jim Metzner, and this is the Pulse of the Planet.
Well, the answer is – none of the above. We’re listening to a recording of… a humpback whale. The recording has been speeded up thirty times.
The song of the male humpback whale can travel hundreds of miles across the ocean, but as it does, the upper frequencies fall away, and only the lower frequencies remain. In this timelapse recording, remember that what we hear as chrps are actually those lowest frequencies of the whale’s voice, speeded up to become audible. Chris Clark is director of Cornell University’s Bioacoustics Research Program.
Clark: Certainly you hear the songlike quality. The birdlike quality to it. But now you have to realize, this is the voice that is almost so low that you and I can’t perceive it. This is the part of the song that’s for the long distance phone call.”
And just like songbirds, the male humpbacks could be using their songs – especially that low frequency long distance call – to attract females.
Clark: Now, when females are having to choose mates are they using song as a criteria? That’s been one of the big questions. Or is song really for males? Just as male sheep use their horns to joust with each other and determine a hierarchy. Maybe Humpbacks use their songs as acoustic jousting to determine mating hierarchy. It’s still very much of an open question.
We’ve been listening to a program from our archives. If you want to hear more, check out our podcast. I’m Jim Metzner.