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The Townsend's ground squirrel (''Urocitellus townsendii'') is a species of rodent in the Sciuridae family. It is found in high desert shrublands in several areas of the United States. ==Distribution== The 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:〔Hall, E. Raymond. 1981. The mammals of North America. 2nd ed. Vol. 2. New York: John Wiley and Sons ISBN 1-930665-31-8〕 *''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.〔 Plant communities in which Townsend's ground squirrels occur include crested wheatgrass (''Agropyron cristatum''), big sagebrush (''Artemisia tridentata'') wheatgrass,〔 rabbitbrush (''Chrysothamnus'' spp.), shadscale (''Atriplex confertifolia''), and winterfat (''Kraschenninikovia lanata'') grasslands.〔Nydegger, Nicholas C.; Smith, Graham W. 1986. Prey populations in relation to Artemisia vegetation types in southwestern Idaho. In: McArthur, E. Durant; Welch, Bruce L., compilers. Proceedings – symposium on the biology of Artemisia and Chrysothamnus; 1984 July 9–13; Provo, UT. Gen. Tech. Rep. INT-200. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station: 152–156〕 In southeastern Idaho, the density of Townsend's ground squirrel burrows is highest on winterfat-Sandberg bluegrass (''Poa secunda''), intermediate in big sagebrush-Thurber needlegrass (''Stipa thurberiana''), and lowest in shadscale-Indian ricegrass (''Oryzopsis hymenoides'') and thread grass (''Stipa comata'') . Burrow densities were highly variable in mixed exotic annual communities, and negatively correlated with cheatgrass (''Bromus tectorum'') . They increase with increasing native grass cover, but the populations are unstable when native grass cover is overly high.〔Knick, Steven T. 1993. Habitat classification & the ability of habitats to support populations of Townsend's ground squirrels and black-tailed jackrabbits. In: Steenhof, Karen, ed. Snake River Birds of Prey National Conservation Area research and monitoring annual report: 1993. (ID ): U.S. Department of the Interior, Bureau of Land Management, Boise District: 237–263〕〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Townsend's ground squirrel」の詳細全文を読む スポンサード リンク
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