Elephant communicate without a sound?

Elephants may be able to communicate over long distances but it’s hard to tell, because they’re not talking. Instead, they may be transmitting infrasonic signals through the ground with seismic waves. Gunther et al. studied the range of low-frequency vocal sounds made by African elephants and suggest that the signal’s two kilometer [one mile] range can propagate further than the animals’ airborne vocalizations.

Their study suggests that it is possible for elephants to communicate over longer distances than can be heard, although they propose that it is unlikely that the seismic waves are the primary mode of elephant communication. The researchers found that normal elephant rumblings can be heard at distances between four and five kilometers [two and three miles] under normal atmospheric conditions, but that the ground waves could be useful for communicating a warning or the herd’s location during a storm or adverse conditions that would block the airborne sound waves.

Title: Seismic waves from elephant vocalizations: A possible communications mode?