Xerospermophilus mohavensis

Mohave Ground Squirrel
(*Xerospermophilus mohavensis*)
Mohave Ground Squirrel (Xerospermophilus mohavensis)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Sciuromorpha
Family:	Sciuridae
Subfamily:	Xerinae
Tribe:	Marmotini
Genus:	Xerospermophilus
Binomial details
	Xerospermophilus mohavensis (C. H. Merriam, 1889)
Other resources
	Full taxonomic details at MDD

The Mohave Ground Squirrel (Xerospermophilus mohavensis) is a small ground squirrel found in the Mojave Desert of California.

Description

From Best (1995): "The Mohave ground squirrel is a brown-colored ground squirrel, without stripes or conspicuous markings on the body, but with a short, broadly haired tail (Grinnell and Dixon, 1918). In unworn winter pelage (March), upperparts are uniform pale drab, with a tinge of pale vinaceous-cinnamon that is strongest on the forehead. Front feet are pale pinkish-cinnamon, and hind feet are pale buff, washed with pale pinkish-cinnamon or pinkish buff. Dorsally, the tail is fuscous, overlaid with creamy white. Ventrally, the tail and underparts are creamy white. In summer pelage (May), upperparts are drab or yellowish (Howell, 1938)."

Museum specimens

Holotype: USNM 186469. Xerospermophilus mohavensis . Adult male. Mohave River, San Bernardino County, California. Collected 29 June 1886.
Holotype: USNM 186469. Xerospermophilus mohavensis . Adult male. Mohave River, San Bernardino County, California. Collected 29 June 1886.

Distribution

From Best (1995): "The Mohave ground squirrel inhabits a 20,000-km2 area in the northwestern corner of the Mojave Desert (Hafner, 1992). The range of mohavensis includes parts of Inyo, Kern, Los Angeles, and San Bernardino counties, California (J. R. Gustafson, in litt.; Hall, 1981; Zembal and Gall, 1980). The Mohave ground squirrel occupies the lower Sonoran life zone in the Mojave Desert at elevations of 610-1,800 m (Grinnell, 1933; Grinnell and Dixon, 1918; J. R. Gustafson, in litt.; Howell, 1938; Ingles, 1965)."

Distribution of the Mohave Ground Squirrel (Xerospermophilus mohavensis) based on Best (1995), Bell et al. (2010), and Leitner (2015).

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)	210–230	57–72	32–38		85–130

Skull

Holotype: USNM 186469. Xerospermophilus mohavensis . Adult male. Mohave River, San Bernardino County, California. Collected 29 June 1886. Dorsal view of the skull.
Holotype: USNM 186469. Xerospermophilus mohavensis . Adult male. Mohave River, San Bernardino County, California. Collected 29 June 1886. Ventral view of the skull.
Holotype: USNM 186469. Xerospermophilus mohavensis . Adult male. Mohave River, San Bernardino County, California. Collected 29 June 1886. Lateral view of the skull.
Holotype: USNM 186469. Xerospermophilus mohavensis . Adult male. Mohave River, San Bernardino County, California. Collected 29 June 1886. Dorsal view of the mandible.
Holotype: USNM 186469. Xerospermophilus mohavensis . Adult male. Mohave River, San Bernardino County, California. Collected 29 June 1886. Lateral view of the mandible.

Similar species

Comparison with Ammospermophilus leucurus

From Best (1995): The range of "mohavensis lies completely within the distribution of Ammospermophilus leucurus (Bartholomew and Hudson, 1960). Compared with mohavensis, A. leucurus has distinctive white stripes on the sides (Jameson and Peeters, 1988)."

Mohave Ground Squirrel (Xerospermophilus mohavensis) photographed by kliewer in Kern County, California.
White-tailed Antelope Squirrel (Ammospermophilus leucurus) photographed by lonnyholmes in Clark County, Nevada.

Comparison with Otospermophilus beecheyi

From Best (1995): Compared with "beecheyi (total length, 357-500 mm), mohavensis (total length, 210-230 mm) is smaller, upperparts are plain and not variegated, and upper incisors are slender and not distinctly recurved (Hall, 1981)."

Mohave Ground Squirrel (Xerospermophilus mohavensis) photographed by kliewer in Kern County, California.
California Ground Squirrel (Otospermophilus beecheyi) observed by Rick Overson and Laura Steger.
Holotype: USNM 186469. Xerospermophilus mohavensis . Adult male. Mohave River, San Bernardino County, California. Collected 29 June 1886. Lateral 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.

Comparison with Xerospermophilus tereticaudus

From Best (1995): "Compared with tereticaudus, mohavensis is most easily distinguished by its tail, which has a white undersurface, is shorter, and is more broadly haired (flatter) than in tereticaudus. Claws of mohavensis are stouter, cheeks are brownish instead of white, quantity of winter pelage is greater, and general tone of coloration always is decidedly dark (Grinnell and Dixon, 1918). [Xerospermophilus] mohavensis also is significantly larger than tereticaudus in 18 of 20 cranial characters (except postorbital and interorbital breadths)." See Leitner (2015) for more detailed information on where the two species co-occur in California.

Mohave Ground Squirrel (Xerospermophilus mohavensis) observed by Venkat Sankar in San Bernardino County, California. Notice the that the underside of the tail is creamy white.
Round-tailed Ground Squirrel (Xerospermophilus tereticaudus) observed by dumplingbug in Pima County, Arizona. Notice the that the underside of the tail is tan.
Range of the Mohave Ground Squirrel (Xerospermophilus mohavensis) (purple) and the Round-tailed Ground Squirrel (Xerospermophilus tereticaudus) (green). These two species are sympatric (co-occur) in San Bernardino County, California.

References

Bell KC, Hafner DJ, Leitner P, Matocq MD. 2010. Phylogeography of the ground squirrel subgenus Xerospermophilus and assembly of the Mojave Desert biota. Journal of Biogeography 37(2): 363-378.

Best TL. 1995. Spermophilus mohavensis. Mammalian species (509): 1-7.

Grinnell J. 1933. Review of the Recent mammal fauna of California. University of California Publications in Zoology 40:71-234.

Grinnell J, Dixon J. 1918. Natural history of the ground squirrels of California. Monthly Bulletin of the State Commission of Horticulture 7:597-708.

Hafner DJ. 1992. Speciation and persistence of a contact zone in Mojave Desert ground squirrels, subgenus Xerospermophilus. Journal of Mammalogy 73:770-778.

Hall ER. 1981. The mammals of North America. 2 vols. John Wiley and Sons, New York.

Howell AH. 1938. Revision of the North American ground squirrels, with a classification of the North American Sciuridae. North American Fauna 56: 1-256.

Ingles LG. 1965. Mammals of the Pacific states: California, Oregon, and Washington. Stanford University Press, Stanford, California, 506 pp.

Jameson Jr EW, Peeters HJ. 1988. California mammals. University of California Press, Berkeley, 403 pp.

Leitner P. 2015. Current status of the Mohave ground squirrel (Xerospermophilus mohavensis): a five-year update (2008–2012). Western Wildlife 2: 9-22.

Zembal R, Gall DC. 1980. Observations on Mohave ground squirrels, Spermophilus mohavensis, in Inyo County, California. Journal of Mammalogy 61:347-350.