Thirteen-lined Ground Squirrel

Spermophilus tridecemlineatus

Description

The thirteen-lined ground squirrels are small, slender gopher-like rodents with alternate longitudinal stripes of tan (or white) and dark brown extending from the nape to the tail. They grow to be about 11 inches long, including a 4 inch long black striped tail.  Dark brown stripes are wider than the lighter stripes and have a line of white spots in the middle of each dark stripe. There are seven dark brown stripes and six bands of tan/white stripes (this can also be found as a reversed pattern) to equal 13 stripes. This species has very short ears and a thin tail that is mildly bushy. A common posture for thirteen-lined ground squirrels is sitting erect with the head pointed up. Other than size, there is no sexual dimorphism (telling male from female by observation), male thirteen-lined ground squirrels weigh about five ounces while females weigh about nine ounces. All rodents have ever-growing incisors with enamel on the front and sides only, because this ground squirrel is a rodent it has these incisors.

Habitat

They were originally found in the prairies of the central United States but have now moved to the northeast as far as Ohio, as far west as Montana and Arizona, anywhere some grasslands exist. Thirteen-lined ground squirrels prefer open areas of short grass and sandy or loamy soils to dig burrows in. They avoid wooded areas and some common habitats of this species include; pastures, parks, and golf courses. They live in underground burrows of sandy and loamy soils. These burrows consist of a shallow blind-end emergency burrow and also a deeper underground burrow/s for nesting and hibernation.

Feeding Behavior and Diet

Thirteen-lined ground squirrels are omnivorous, mainly eating seeds (“spermophilus”=seed lover), leaves, and grass. They hoard plant material underground, transporting the material in their cheek pouches. They also consume insects, small birds, lizards and the flesh of dead/decaying animals.

Reproduction

Thirteen-lined ground squirrels mate in early spring, after emerging from hibernation. Males breed with only one female and litters of about 8 young are born a month after mating occurs. Females sometimes will have a second litter later in summer.

Months and Times of Activity

This species is diurnal, most activity occurring midday. These ground squirrels hibernate from August until March. This species is a true hibernator, which means it allows its body temperature to drop just above freezing, their heart rate will also drop (from 200 beats per minute to 20 beats per minute) and periodically arouse during the length of hibernation to raise body temperature. Males emerge from hibernation in March, before females, in order to search for breeding partners.

Special Features, Stories, Relationships

• These squirrels have 13 stripes- seven dark stripes separated by six lighter stripes.
• Thirteen-lined ground squirrels rub glands around their mouth on objects to leave scent marks.
• These ground squirrels greet each other by touching noses or lips, it appears as if they are kissing.
• This animal is the mascot for the University of Minnesota’s “Golden Gophers!”
• For legends featuring thirteen-lined ground squirrels visit: http://www.turtletrack.org/Issues02/Co09212002/CO_09212002_Arrowheads.htm
• Children’s book featuring a thirteen-lined ground squirrel: Earnest, the Moose Who Doesn’t Fit  by Catherine Rayner

References

Petrella, S. 1999. "Spermophilus tridecemlineatus" (On-line), Animal Diversity Web. Accessed November 04, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Spermophilus_tridecemlineatus/

."Thirteen-lined Ground Squirrel." Dnr.state.us. Department of Natural Rescouces, n.d. Web. 30 Jan. 2013.