Urocitellus washingtoni (A. H. Howell, 1938)

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Sciuridae, Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona: Lynx Edicions, pp. 648-837 : 800-801

publication ID

https://doi.org/ 10.5281/zenodo.6840226

DOI

https://doi.org/10.5281/zenodo.6818974

persistent identifier

https://treatment.plazi.org/id/064D0660-FF91-ED6D-FA6A-F603FEA5F22A

treatment provided by

Diego

scientific name

Urocitellus washingtoni
status

 

203. View On

Washington Ground Squirrel

Urocitellus washingtoni View in CoL

French: Spermophile du Washington / German: Washington-Ziesel / Spanish: Ardilla terrestre de Washington

Taxonomy. Citellus washingtoni A. H. Howell, 1938 ,

“Touchet, Walla Walla Co., Washington, USA.”

This species in monotypic.

Distribution. E Washington and NE Oregon (USA).

Descriptive notes. 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.

Habitat. 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.

Food and Feeding. 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.

Breeding. 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.

Activity patterns. 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.

Movements, Home range and Social organization. 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.

Status and Conservation. 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.

Bibliography. Betts (1990, 1999), Greene et al. (2009), Hayssen et al. (1993), Rickart & Yensen (1991), Thor ington et al. (2012).

Kingdom

Animalia

Phylum

Chordata

Class

Mammalia

Order

Rodentia

Family

Sciuridae

Genus

Urocitellus

Loc

Urocitellus washingtoni

Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier 2016
2016
Loc

Citellus washingtoni

A. H. Howell 1938
1938
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