July 29, 2004
Apart from the calls of bats, little is known about the use of ultrasound in the animal world. Until, that is, David R. Wilson and James F. Hare watched Richardson’s ground squirrels (Spermophilus richardsonii) apparently screaming warnings to one another, but only producing faint rushes of air. Further investigation showed that these warnings contain pure ultrasonic frequencies of around 50 kilohertz, far above the range detectable by the human ear. In the July 29, 2004 Nature, the authors suggest that this may be the first record of the detection of ultrasonic alarm calls in any animal group.
Abstract © 2004 Nature
“Ground squirrel uses ultrasonic alarms,” David R. Wilson, James F. Hare, Nature, July 29, 2004
James F. Hare, University of Manitoba, Winnipeg, Canada