| Since the massive conversion of land in the Columbia Basin to agriculture, the Washington Ground Squirrel has been in decline. During the 1980s, the number of localities where they were known to occur dropped from 179 to 35, all small in size. Because many of these localities are isolated from one another, the species cannot naturally recolonize even the best habitats if a local population goes extinct. The species is classified as Vulnerable by the International Union for the Conservation of Nature. These ground squirrels are among the smaller members of the genus. Like most other Spermophilus species, they spend as much as eight months of the year underground, estivating to escape summer heat and hibernating to escape winter cold.
Males are larger than females.
Howell, A.H., 1938. Revision of the North American ground squirrels, with a classification of the North American Sciuridae, p. 69. North American Fauna, 56:1-256.
Mammal Species of the World
Mammalian Species, American Society of Mammalogists' species account
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