Thirteen-Lined Ground Squirrel (Spermophilus tridecemlineatus)

County List:

Rule:

Mixed Forested/Nonforested or Nonforested Landscapes

      Fields/Pasture
      or Coastal Dunes
      or Residential

Habitat List:

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Literature:

This species prefers short grass that it can easily see over without standing up. Consequently, the thirteen-lined ground squirrel is at home in areas such as mowed lawns, manicured golf courses, and well-grazed pastures. It occasionally lives in weedy areas adjacent to highways or railroads, and it always avoids the woods.

Vegetation dominates the diet but this rodent is omnivorous. Caterpillars, grasshoppers, and beetles are common animal food, although it also takes small vertebrates and bird eggs and readily consumes carrion. It eats the leaves of grass and clover, but prefers seeds; in fact, the name means seed lover. It relishes seeds from crabgrass, sunflower, chickweed, thistle, ragweed, and vetch, as well as corn, wheat, and oats.

Distribution: The thirteen-lined ground squirrel is widespread in both the tall-grass and short-grass prairies of central United States and south-central Canada.

In presettlement days, the forested regions centered around the western Great Lakes all but excluded prairie plants and animals. After the 1820 Land Law was enacted, however, settlement of the Michigan area expanded and Lower Peninsula lumbering which began before the mid-nineteenth century reached a high level in the 1870s. The pine forest and much of the beech-maple woodlands were removed, and the resulting cleared lands were burned repeatedly. This clearing allowed for the eastern and northern spread of plants (both native and introduced) and animals having open-land affinities. The thirteen-lined ground squirrel, which may actually have occurred in early times in sandy openings in the southwestern part of the Lower Peninsula, was one of the species which rapidly moved northward. Ultimately, the thirteen-lined ground squirrel moved into cleared and/or cultivated areas in all Lower Peninsula counties.

Habitat Preferences: The thirteen-lined ground squirrel occurs in a variety of grass/weed environments mostly in sandy soils and in dry well-drained locations. Although the animal can be found in tall vegetation, it prefers areas where its view is not impaired, such as grassy fields, pastures, hay meadows, and along weedy/grassy fence lines between cultivated fields. The species generally avoids plowed fields. Urban dwellers are most apt to notice these animals scurrying across well-mowed lawns of estates, cemeteries, parks, and on campus grounds. The species may have been encouraged in its rapid spread throughout the Lower Peninsula by the building of railroad embankments and road rights-of-way. Beach habitat and dry pine barrens are also acceptable living areas.

Food Habits: The thirteen-lined ground squirrel is a true omnivore, with a liking for both plant and animal foods. Vegetable foods include cultivated plants (oats, wheat, corn, currants, peas, sugar beets, melons, and other garden crops) and roots, herbage, and seeds of such wild species as goosefoot, knotweed, sunflower, ragweed, black locust, dandelion, vetch, and various grasses. Seeds are usually stuffed in the internal cheek pouches for easy transportation to underground caches. Animal foods consumed consist mostly of insects, including grasshoppers, crickets, ants, caterpillars, beetle larvae and adults, cockroaches, stoneflies, leaf hoppers, and hemipterous insects. Whitaker reported that in Indiana they ate earthworms and diplopods. The thirteen-lined ground squirrel also consumes, as the opportunity is presented, assorted kinds of vertebrates; these include bird eggs, young birds, lizards, young chickens, small snakes, short-tailed shrews, young eastern cottontails, and small rodents. They are also known to eat their own young and the bodies of others crushed on paved roadways.