Nature. 2004 Jul 29;430(6999):523.
.
Abstract
Apart
from echolocation and the pursuit of prey by bats, the function of
ultrasound in animal communication is poorly understood. This is mainly
because of the broad range of responses that it can evoke and the widely
varied contexts in which it is used (for example, in rodents of the
Muridae family it may indicate distress
in infants or a sexual or predatory encounter in adults). Here we find
that a purely ultrasonic signal is produced in the wild by a rodent of
the Sciuridae
family, Richardson's ground squirrel, and show that its function is to
warn conspecifics of impending danger. To our knowledge, ultrasonic
alarm calls have not previously been detected in any animal group,
despite their twin advantages of being highly directional and inaudible
to key predators.
