squirrels have many vocalizations, some audible to humans, some not.
More research is required in this field of study. The source of the
calls are difficult to locate for mere humans and likely some predators - good thing for the squirrel, and likely
designed by nature to be this way.
Southern flying squirrels are, generally, much more vocal by sheer
power than their much larger northern counterparts. Northerns may
broader menu of vocalizations.
Flying squirrel ears are the same in structure as other squirrels' ears
- except for one difference. Flying squirrel ears possess a larger
ear cavity, which allows them to hear better than other squirrel species.
This adaptation is likely due to their nocturnal behaviour, but no one
knows for sure.
Loud things come in small packages! Southerns have a very loud, sharp
"tseep" vocalization, up to down in scale. The "tseep" call is
considered to be an alarm, or caution
call, designed to notify other flying squirrels within earshot of
something in the forest that may be, or is, a threat. Southerns also
have a "chittering" vocalization, usually following, or framed by, an
alarm call. Another vocalization from southerns is a snorting sound
when challenging a flying squirrel of the same sex but of lower ranking
in the hierarchy. They can "chucke" too.
Northerns utilize a very low-volume
We have monitored, with a parabolic microphone, the vocalizations of
northern flying squirrels for a period of time. One thing we have
that this "seep" call is employed by a family group,
usually consisting of a mother and her offspring. We speculate this is
to notify group
members that all is well, and to let other group members know
where each other is in the immediate area. Northerns, like the
southerns, share a "chittering" sound, usually following, or framed by,
an alarm call. Northerns also have a chuckle or "chuck chuck"
sound. Another vocalization is a long chortling sound, often when
running (along branches or up tree trunks). They'll also, on occasion,
make a soft sputtering sound when grooming themselves.
Both species have an assortment of audible squeaks, snorts and squawks,
especially in a nest full of juvenile flyers or when the natal nest is
under threat from a predator. As Nancy Wells says, if some of these
sounds were translatable, some would certainly not get a G rating!
Some vocalizations are made by adult flying squirrels during their
glides, and these sounds are also made by juveniles during their
glides. No one knows why.
Some sounds that flying squirrels make
inaudible. These ultrasonic sounds produce sound waves with a frequency
above the upper limit of human hearing. Many mammals are able to hear
sound frequencies much higher than humans can. Ultrasonic sounds do not
Conversely, some mammals, such as whales and giraffes, can communicate
employing infrasonic sound frequencies that are lower than the limit of
human hearing. Infrasonic sounds can travel great distances.
Ultrasonic sounds have been documented in the natal nest, and may be
used by the mother to communicate to her offspring. The fact that these
sounds have been noted opens up a pandora's box. Do they communicate in
ultrasound as adult to adult? Do they employ a type of sonar similar to that which
bats employ for echolocation/navigation purposes? Preliminary research
finds that ear design does not compare to that of a bat, but much more
research is required in this field.
Some sounds we have described are, well, impossible to describe! We'll
be adding more sounds later to help you understand what we are talking