Data from: Ultrasonic vocalizations emitted by flying squirrels

Anecdotal reports of ultrasound use by flying squirrels have existed for
decades, yet there has been little detailed analysis of their
vocalizations. Here we demonstrate that two species of flying squirrel
emit ultrasonic vocalizations. We recorded vocalizations from northern
(Glaucomys sabrinus) and southern (G. volans) flying squirrels calling in
both the laboratory and at a field site in central Ontario, Canada. We
demonstrate that flying squirrels produce ultrasonic emissions through
recorded bursts of broadband noise and time-frequency structured frequency
modulated (FM) vocalizations, some of which were purely ultrasonic.
Squirrels emitted three types of ultrasonic calls in laboratory recordings
and one type in the field. The variety of signals that were recorded
suggest that flying squirrels may use ultrasonic vocalizations to transfer
information. Thus, vocalizations may be an important, although still
poorly understood, aspect of flying squirrel social biology.