Believe it or not, the sounds we’re listening to are made by an elephant– and they may hold the key to an aspect of the elephant’s behavior which has long puzzled scientists. I’m Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.
Many elephant calls are so low in frequency that human ears can’t detect them. This recording has been speeded up five times, to place the entire call within the range of human hearing. Scientists feel that the sounds may be able to explain one of the mysteries of elephant behavior: why is it that groups of elephants– too distant to see or smell each other– nevertheless seem to be able to synchronize their movements across the landscape.
“The movements are coordinated in the sense that the families without meeting one another will keep within three or four kilometers of each other, often closer, but they are not converging. If you look at a tracking record for a number of days you may see parallel movements and then changes of direction at the same time.”
Katy Payne is the author of Silent Thunder: In The Presence of Elephants. She tells us that throughout the day, African elephants often pause and stand motionless for a moment, as if intently listening to some silent communication. Well, now Ms. Payne and her colleagues believe that that’s exactly what the elephants are doing with those low-frequency calls.
“Low frequency sound travels much, much better than high frequency sound and it can go through all kinds of obstacles. And the African investigators who had spent many decades already looking at the behaviors of elephants had often wondered among themselves how it was that elephants seemed to be coordinating their societies over longer distances than would make sense given ordinary forms of communication.”
Additional funding for Pulse of the Planet has been provided by the National Science Foundation. I’m Jim Metzner.