Urocitellus washingtoni
Creators: name: Wilson, Don E.
name: Thomas E. Lacher, Jr
name: Mittermeier, Russell A.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Sciuridae
Urocitellus
Urocitellus washingtoni

description: 203. Washington Ground Squirrel <i>Urocitellus washingtoni</i> <b>French:</b> Spermophile du Washington / <b>German:</b> Washington-Ziesel / <b>Spanish:</b> Ardilla terrestre de Washington <b>Taxonomy.</b> Citellus washingtoni A. H. Howell, 1938, “Touchet, Walla Walla Co., Washington, USA.” This species in monotypic. <b>Distribution.</b> E Washington and NE Oregon (USA). <b>Descriptive notes.</b> Head-body 185-245 mm, tail 32-65 mm; weight mean 210 g. Dorsal pelage of the Washington Ground Squirrel is pale smoke-gray washed with a pinkish buff, with small cream to buff flecks, and ventral pelage is grayish white washed with pinkish buff. Feet are white to buff and tail is frosted with white to buff, with a grizzled gray suffused with cinnamon on dorsal side and a pinkish cinnamon on ventral side. Chromosome complement of the Washington Ground Squirrel is 2n = 36, FN = 66. Karyotype consists of eight pairs of metacentric autosomes, eight pairs of submetacentric autosomes, a pair of acrocentric autosomes, a submetacentric X chromosome, and an acrocentric Y chromosome. <b>Habitat.</b> Shrub steppe areas of the Columbia River Basin. The Washington Ground Squirrel is more abundant in areas of extensive grass cover on deep soils with high clay content. <b>Food and Feeding.</b> Diet is composed mainly of succulent grasses and herbs, including cultivated plants, roots, bulbs, and seeds. Insects and other animal matter are consumed when available. <b>Breeding.</b> Females become ready to breed a few days after emergence and give birth in February to March to a litter of 5-11 young,after a gestation of ¢.23-30 days,inside the burrow. <b>Activity patterns.</b> The Washington Ground Squirrel is diurnal and terrestrial. After accumulating fat stores, adults enter estivation that grades into hibernation from late May to early June; juveniles enter estivation 1-2 months later. Adults emerge in January to mid-March. Young emerge from natal burrow in late March or April and reach adult size by late May to early June. <b>Movements, Home range and Social organization.</b> The Washington Ground Squirrel is highly social, with females apparently forming coalitions within colonies. Annual mortality rates are high, exceeding 60%, and maximum life span is less than five years. Juvenile males typically disperse ¢.880 m, with a maximum dispersal distance registered of 3-5 km. <b>Status and Conservation.</b> Classified as Near Threatened on The IUCN Red List. The total remaining area of occurrence of the Washington Ground Squirrel is not much greater than 20,000 km®. It is endangered in Oregon, USA, and is a candidate for protection under the US Endangered Species Act. Current population trend is decreasing. About two-thirds of the population resides on United States federal land with remaining portion of the population inhabiting privately-owned land. Major threats are habitat loss and fragmentation, mainly due to conversion of grasslands and sagebrush (Artemisia, Asteraceae) steppes into croplands and due to urban development. It is not hunted or trapped, although historically it was a target of recreational shooting. <b>Bibliography.</b> Betts (1990, 1999), Greene et al. (2009), Hayssen et al. (1993), Rickart &amp; Yensen (1991), Thor ington et al. (2012).
description: Published as part of <i>Don E. Wilson, Thomas E. Lacher, Jr &amp; Russell A. Mittermeier, 2016, Sciuridae, pp. 648-837 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions</i> on pages 800-801, DOI: 10.5281/zenodo.6840226