Planet Earth

Reach Out and Stomp Someone

By Jocelyn SelimJul 1, 2001 12:00 AM

Newsletter

Sign up for our email newsletter for the latest science news
 

When threatened, an elephant will stomp its feet menacingly. And Stanford biologist Caitlin O'Connell-Rodwell says the tooth-rattling toe work isn't just for show; it is also a call for assistance. Her insight came while she was studying the penetrating low-frequency vocal rumblings elephants use to keep in touch with the rest of the herd. Whenever a listening elephant perked up its ears, it would also lift one foot off the ground. "It seemed peculiar, and I realized that their feet must be sensitive to something," she says.

O'Connell-Rodwell rigged up a system of sensors and microphones and learned that elephant calls travel better through earth than through air. "When an elephant rumbles a certain call, an exact replica of that pressure wave is created in the ground," she explains. Sound waves in air dissipate in three dimensions, like a widening sphere, but ground waves spread out in two dimensions, like ripples, so they remain detectable much farther away. For the best long-distance communication, elephants therefore send and receive vibrations with their feet. O'Connell-Rodwell predicts elephants should be able to sense underground signals at distances of up to 20 miles. "That is more than sufficient to pick up warning calls and stomping signals from other herd members or even neighboring herds," she says.

1 free article left
Want More? Get unlimited access for as low as $1.99/month
Already a subscriber? Log In or Register
1 free articleSubscribe
Want unlimited access?

Subscribe today and save 70%

Subscribe

Already a subscriber? Log In or Register
More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Join
Our List

Sign up for our weekly science updates.

 
Subscribe
To The Magazine

Save up to 70% off the cover price when you subscribe to Discover magazine.

Copyright © 2021 Kalmbach Media Co.