Otospermophilus beecheyi

California Ground Squirrel
(*Otospermophilus beecheyi*)
California Ground Squirrel (Otospermophilus beecheyi)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Sciuromorpha
Family:	Sciuridae
Subfamily:	Xerinae
Tribe:	Marmotini
Genus:	Otospermophilus
Binomial details
	Otospermophilus beecheyi (J. Richardson, 1829)
Other resources
	Full taxonomic details at MDD

The California Ground Squirrel (Otospermophilus beecheyi) is a bushy-tailed ground squirrel that occupies a wide variety of habitats, but most often occurs in open grasslands, oak savannah, oak woodland, nearshore rocky outcrops, and on agricultural lands (Smith et al., 2016).

Description

From Smith et al. (2016): "The pelage of Otospermophilus beecheyi is laterally and dorsally grayish brown speckled with white spots. Its distinguishing traits include a yellowish white to light brown venter, a bushy tail, and white rings around the eyes."

Museum specimens

Holotype: USNM 29318/41385. Otospermophilus beecheyi fisheri. Adult male. Kern Valley, Kern County, California. Collected 6 July 1891.
Holotype: USNM 29318/41385. Otospermophilus beecheyi fisheri. Adult male. Kern Valley, Kern County, California. Collected 6 July 1891.

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
California	Jameson & Peeters (2004)	375–500	135–195	50–64	17–22	300–650

Color variation

This section shows some of the color variation present in Otospermophilus beecheyi. The location is provided for reference only. The individual shown does not necessarily represent the only color variant within the local population.

Otospermophilus beecheyi photographed by Nathan Petersen near Pasadena, California. © Nathan Petersen
Otospermophilus beecheyi photographed by RJ Adams in Pacific Grove, California.
Otospermophilus beecheyi photographed by Rick Overson and Laura Steger in Jalama Beach County Park, California.

Skull

Holotype: USNM 29318/41385. Otospermophilus beecheyi fisheri. Adult male. Kern Valley, Kern County, California. Collected 6 July 1891. Dorsal view of the skull.
Holotype: USNM 29318/41385. Otospermophilus beecheyi fisheri. Adult male. Kern Valley, Kern County, California. Collected 6 July 1891. Ventral view of the skull.
Holotype: USNM 29318/41385. Otospermophilus beecheyi fisheri. Adult male. Kern Valley, Kern County, California. Collected 6 July 1891. Lateral view of the skull.
Holotype: USNM 29318/41385. Otospermophilus beecheyi fisheri. Adult male. Kern Valley, Kern County, California. Collected 6 July 1891. Dorsal view of the mandible.
Holotype: USNM 29318/41385. Otospermophilus beecheyi fisheri. Adult male. Kern Valley, Kern County, California. Collected 6 July 1891. Lateral view of the left mandible.

Similar species

Comparison with Otospermophilus douglasii

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)."

California Ground Squirrel (Otospermophilus beecheyi) photographed by Nathan Petersen near Pasadena, California. © Nathan Petersen
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.

Comparison with Otospermophilus variegatus

From Smith et al. (2016): "O. beecheyi differs from O. variegatus, the rock squirrel, in that O. variegatus has a dark grayish dorsum mixed with cinnamon buff. The dorsum of O. variegatus may also be light brown to bone brown to dark blackish brown; its head and shoulders are often black. The eye ring of O. variegatus is sometimes white like that of O. beecheyi, but O. variegatus has a buff or tawny dorsum and a grayish white to cinnamon buff venter (Thorington et al. 2012)."

California Ground Squirrel (Otospermophilus beecheyi) photographed by Nathan Petersen near Pasadena, California. © Nathan Petersen
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.

Long DJ and Smith JE. 2023. Otospermophilus douglasii (Rodentia: Sciuridae). Mammalian Species 55(1034):1–13.

Smith JE, Long DJ, Russell ID, Newcomb KL, Muñoz VD. 2016. Otospermophilus beecheyi (Rodentia: Sciuridae). Mammalian Species 48(939):91-108.

Thorington Jr. RW , Koprowski JL, Steele MA, Whatton JF. 2012. Squirrels of the world. Johns Hopkins University Press, Baltimore, Maryland, USA.