10 NEBRASKAland • DECEMBER 2016
A Mammal Brief
By Lindsay Rogers
Once limited to prairies, the thirteen-lined
ground squirrel (Ictidomys tridecemlineatus)
can now be found in well-grazed pastures,
cemeteries, mowed roadsides, golf courses,
parks and even urban backyards. They are
easily distinguished from tree squirrels and
other ground squirrels by their smaller
size (6-12 inches long) and their
characteristic stripes extending along
their backs.
They are quick and small, but if you are
fast you can often see them standing on hind
legs surveying the land. Once spotted, they quickly
jump into their burrow to escape. They can also be heard giving alarm calls when in danger from predators
including hawks, snakes and weasels. Because they are an important food source for so many species, most
young do not make it through the first year and adults rarely live more than a few years.
In fall, thirteen-lined ground squirrels rapidly gain weight to sustain themselves through winter hibernation.
In mid to late September, they enter true hibernation, meaning they allow their body temperature to drop just
above freezing and their heart rate to drop from 200 beats per minute to just 20 beats per minute. They arouse
from hibernation in March with males emerging first. ■
Thirteen-lined
Ground Squirrel
Lindsay Rogers is an outdoor
education specialist with the
Nebraska Game and Parks
Commission.
JOEL
SARTORE/
NATIONAL
GEOGRAPHIC
PHOTO
T
ARK ARK
RK
