Townsend's Ground Squirrel

Townsend's ground squirrel is found in the Great Basin and the Columbia Plateau. Its range includes south-central Washington, eastern Oregon, southern Idaho, western Utah, most of Nevada, and extreme eastern California. The subspecies are distributed as follows:

Urocitellus townsendii artemesiae – south-central Idaho U. t. canus (Merriam's ground squirrel) – eastern Oregon; northeastern corner of California; northwestern corner of Nevada U. t. idahoensis – southwestern Idaho U. t. mollis (Piute ground squirrel) – eastern California; southeastern Oregon; southern Idaho; western Utah; Nevada; most widely distributed subspecies U. t. nancyae – south-central Washington U. t. townsendii – south-central Washington U. t. vigilis – Snake River Canyon bottomlands of east-central Oregon and west-central Idaho Townsend's ground squirrels typically inhabit arid grasslands and shrub-grasslands. Malheur ground squirrels, however, inhabit the relatively mesic and fertile Snake River Plain. …

Townsend's ground squirrels consume mainly green vegetation and some seeds and insects. Green grasses are apparently a staple from late winter until just prior to grass senescence and Townsend ground squirrel estivation, when seeds become the primary diet item. Seeds are an important source of calories just prior to estivation. Where present, winterfat is browsed heavily, but only light browsing of other shrubs has been reported. From March through May on the Arid Land Ecology Reserve in eastern Washington, the Townsend's ground squirrel diet is 49% Sandberg bluegrass, 11% western yarrow (Achillea millefolium var. occidentalis), 8% pinnate tansymustard (Descurania pinnata) seed, 31% other plant species (mostly forbs), and 1% insects. On a big sagebrush-crested wheatgrass community in southeastern Idaho, 80% of Townsend's ground squirrels trapped in June had consumed crested wheatgrass, and Townsend's ground squirrels became dormant after the crested wheatgrass senesced. Cheatgrass (Bromus tectorum) is an important food item in some years. As an annual with wide year-to-year swings in productivity, however, it is not a reliable food source. Adult cannibalism of unweaned young has been observed in the Townsend's ground squirrel.