Otospermophilus douglasii
| Douglas's Ground Squirrel
(Otospermophilus douglasii) | |
|---|---|
| Range | |
 | |
| Taxonomic classification | |
| Order: | Rodentia |
| Suborder: | Sciuromorpha |
| Family: | Sciuridae |
| Subfamily: | Xerinae |
| Tribe: | Marmotini |
| Genus: | Otospermophilus |
| Binomial details | |
| Otospermophilus douglasii (J. Richardson, 1829) | |
| Other resources | |
| Full taxonomic details at MDD | |
The Douglas's Ground Squirrel (Otospermophilus douglasii) is a bushy-tailed ground squirrel found in a variety of habitats in northern California, Oregon, and southern Washington.
Description
From Long and Smith (2023): "The distinguishing traits of Otospermophilus douglasii include ventral fur that is light brown to cream-colored, a long, bushy tail, and white rings around the eyes (Eder and Ross 2005)."
Museum specimens
External measurements
Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.
| Part of range | Reference | Total length | Tail length | Hindfoot length | Ear length | Mass |
|---|---|---|---|---|---|---|
| Oregon | Verts & Carraway (1998) | females: 415–489 (n=27); males: 394–510 (n=27) | females: 52–63 (n=27); males: 42–66 (n=27) | females: 247–703 (n=27); males: 466–843 (n=27) |
Skull
Similar species
Comparison with Otospermophilus beecheyi
From Long and Smith (2023): "Despite their similar color variation, the medial stripe of O. douglasii is darker than that of O. beecheyi (Allen 1874). The charcoal to blackish-brown triangular patch extending from the nape of neck to about midway down the back, the lighter colored brown shoulders, and the dense, silvery hairs that are often present on the lateral margins of the nape and the shoulders are the major characteristics that distinguish O. douglasii from O. beecheyi. The upper forelegs and tail of O. douglasii typically have lateral hairs tipped with white; this contrasts with the buffy wash seen on the lateral hairs in O. beecheyi. These differences between O. douglasii and O. beecheyi are most apparent in adults and may not be as discernable in immature individuals (Allen 1874; Thorington et al. 2012)."
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Douglas's Ground Squirrel (Otospermophilus douglasii) observed by Jonathan Eisen. The charcoal to blackish-brown triangular patch extending from the nape of neck to about midway down the back help to distinguish this species from other ground squirrels. -
California Ground Squirrel (Otospermophilus beecheyi) photographed by Nathan Petersen near Pasadena, California. © Nathan Petersen
Comparison with Otospermophilus variegatus
From Long and Smith (2023): "The grayish brown fur with speckled white spots on the dorsum of O. douglasii distinguishes it from O. variegatus, the rock squirrel. Specifically, in addition to having grayish brown fur, the dorsum of O. variegatus typically includes a mixture of cinnamon buff and light brown to bone to dark blackish-brown fur (Thorington et al. 2012). In some instances, the entire dorsum of O. variegatus is black, a feature that is absent from O. douglasii (Thorington et al. 2012)."
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Douglas's Ground Squirrel (Otospermophilus douglasii) observed by Jonathan Eisen. The charcoal to blackish-brown triangular patch extending from the nape of neck to about midway down the back help to distinguish this species from other ground squirrels. -
Common Rock Squirrel (Otospermophilus variegatus) observed by Tim Healy at the Grand Canyon in Arizona.
References
Allen JA. 1874. On geographical variation in color among North American squirrels with a list of the species and varieties of the American Sciuridae occurring north of Mexico. Proceedings of the Boston Society of Natural History 16:276–296.
Eder T, Ross G. 2005. Mammals of California. Lone Pine Publishing, Auburn, Washington, USA.
Long DJ and Smith JE. 2023. Otospermophilus douglasii (Rodentia: Sciuridae). Mammalian Species 55(1034):1–13.
Phuong MA, Lim MCW, Wait DR, Rowe KC, Moritz C. 2014. Delimiting species in the genus Otospermophilus (Rodentia: Sciuridae), using genetics, ecology, and morphology. Biological Journal of the Linnean Society 113(4):1136-1151. https://doi.org/10.1111/bij.12391
Phuong MA, Bi K, Moritz C. 2017. Range instability leads to cytonuclear discordance in a morphologically cryptic ground squirrel species complex. Molecular Ecology 26(18):4743-4755. https://doi.org/10.1111/mec.14238
Thorington Jr. RW , Koprowski JL, Steele MA, Whatton JF. 2012. Squirrels of the world. Johns Hopkins University Press, Baltimore, Maryland, USA.