Can elephants hear with their feet?
The sound waves come from the animals’ huge vocal cords, and distant elephants “hear” the signals with their highly sensitive feet.
Elephants perceive vibrations through the soles of their feet. Vibrations travel up through their bones to their head. They are then amplified by the skull’s bones and transmitted to the ossicles of the ear. The elephant pounds the earth to alert others of danger. Such messages can be perceived at a distance of up to 18.5 mi. (30 km).
To test the theory that elephants transmit and receive underground messages, O'Connell-Rodwell and her colleagues previously conducted several novel experiments with pachyderms in Africa, India and at a captive elephant facility in Texas.
"We went to Etosha National Park in Namibia and recorded three acoustic calls commonly made by wild African elephants," she says. "One is a warning call, another is a greeting and the third is the elephant equivalent of 'Let's go!'"
The researchers wanted to find out if elephants would respond to recordings played through the ground, so they installed seismic transmitters at a tourist facility in Zimbabwe where eight trained, young elephants were housed.
The idea was to convert audible "Greetings," "Warning!" and "Let's go!" calls into underground seismic waves that an elephant could feel but not hear directly through the air.
"We used a mix of elephant calls, synthesized low-frequency tones, rock music and silence for comparison," says O'Connell-Rodwell.
"When the 'Warning!' calls were played, one female got so agitated she bent down and bit the ground," she notes. "That's very unusual behavior for an elephant, but it has been observed in the wild under conditions of extreme agitation."
The young female had the same agitated response each time the experiment was repeated. Researchers also played recorded calls to seven captive males.
"The bulls reacted, too, but their response was much more subtle," notes O'Connell-Rodwell.
"We think they're sensing these underground vibrations through their feet," she adds. "Seismic waves could travel from their toenails to the ear via bone conduction, or through somatosensory receptors in the foot similar to ones found in the trunk. We think it may be a combination of both."
Picture Credit : Google