Elephant Seismic Detection – Underground

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Ambience: elephant rumble

You remember that classic moment in old Westerns where someone puts their ear to the railroad track and hears the sound of a train in the distance being transmitted through the rails? Well, it looks like elephants might do something similar– hearing far away sounds propagated through the ground. I’m Jim Metzner and this is the Pulse of the Planet.

“Elephants are capable of making several different kinds of vocalizations. The most interesting vocalization in terms of long distance communication is called the rumble.”

Caitlin O’Connell Rodwell studies elephant communication as a research associate at Stanford University. She recorded these sounds of low frequency elephant rumbles.

“What’s interesting about this rumble is that it also propagates in the ground. We’ve measured that as an elephant rumbles, there’s so much energy in this rumble that it couples with the ground and travels along the surface of the ground. And it has physical properties that allow it to travel further than airborne vocalizations, such that if elephants can detect these rumbles in the ground, they could communicate at much further distances than they could in the air.”

Rodwell says that elephants usually make this kind of low frequency call as a warning to other elephants. Now, she and her colleagues have done a number of tests to see if the animals responded the same way to rumbling calls played through the ground, as through the air.

“I had originally recorded these warning call rumbles, to see if you could chase elephants out of farmer’s fields. And then came back this past year and played those same rumbles back through the ground. And watched the elephants responses, at a water hole in the wild. And in fact they did increase their vigilant behaviors. They clumped up into tight clusters, which is a sign of vigilance.”

The question is how do the elephants detect these underground rumbles? We’ll hear about that in future programs. Pulse of the Planet is made possible by the National Science Foundation.

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Elephant Seismic Detection - Underground

If you feel the ground shake, perhaps you'd better do as the elephants do: listen DOWN.
Air Date:09/20/2011
Scientist:
Transcript:

Music
Ambience: elephant rumble

You remember that classic moment in old Westerns where someone puts their ear to the railroad track and hears the sound of a train in the distance being transmitted through the rails? Well, it looks like elephants might do something similar-- hearing far away sounds propagated through the ground. I'm Jim Metzner and this is the Pulse of the Planet.

"Elephants are capable of making several different kinds of vocalizations. The most interesting vocalization in terms of long distance communication is called the rumble."

Caitlin O'Connell Rodwell studies elephant communication as a research associate at Stanford University. She recorded these sounds of low frequency elephant rumbles.

"What's interesting about this rumble is that it also propagates in the ground. We've measured that as an elephant rumbles, there's so much energy in this rumble that it couples with the ground and travels along the surface of the ground. And it has physical properties that allow it to travel further than airborne vocalizations, such that if elephants can detect these rumbles in the ground, they could communicate at much further distances than they could in the air."

Rodwell says that elephants usually make this kind of low frequency call as a warning to other elephants. Now, she and her colleagues have done a number of tests to see if the animals responded the same way to rumbling calls played through the ground, as through the air.

"I had originally recorded these warning call rumbles, to see if you could chase elephants out of farmer's fields. And then came back this past year and played those same rumbles back through the ground. And watched the elephants responses, at a water hole in the wild. And in fact they did increase their vigilant behaviors. They clumped up into tight clusters, which is a sign of vigilance."

The question is how do the elephants detect these underground rumbles? We'll hear about that in future programs. Pulse of the Planet is made possible by the National Science Foundation.

music