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Home/Species/ Round-tailed Ground Squirrel

Xerospermophilus tereticaudus

(Baird, 1858)

Round-tailed Ground Squirrel

G5Secure Found in 5 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
Identity
Unique IDELEMENT_GLOBAL.2.103413
Element CodeAMAFB05160
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassMammalia
OrderRodentia
FamilySciuridae
GenusXerospermophilus
Synonyms
Spermophilus tereticaudusBaird, 1858
Other Common Names
round-tailed ground squirrel (EN)
Concept Reference
Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/.
Taxonomic Comments
Recent molecular phylogenetic studies suggest that the traditionally recognized genera Marmota (marmots), Cynomys (prairie dogs), and Ammospermophilus (antelope ground squirrels) render Spermophilus paraphyletic, potentially suggesting that multiple generic-level lineages should be credited within Spermophilus (Helgen et al. 2009). As a result, ground squirrels formerly allocated to the genus Spermophilus (sensu Thorington and Hoffman, in Wilson and Reeder 2005) are now classified in 8 genera (Notocitellus, Otospermophilus, Callospermophilus, Ictidomys, Poliocitellus, Xerospermophilus, and Urocitellus). Spermophilus sensu stricto is restricted to Eurasia.

Xerospermophilus mohavensis and X. tereticaudus hybridize along a small, narrow, stable contact zone (Helendale, Coyote Dry Lake) that coincides with a Wisconsinan pluvial barrier; the two taxa exhibit a consistent difference in diploid number (Hafner and Yates 1983, Hafner 1992).
Conservation Status
Review Date1996-11-06
Change Date1996-11-06
Range Extent Comments
This species has a patchy distribution in southwestern North America, including southern Nevada, southeastern California, and southwestern and south-central Arizona south into eastern Baja California and the northwestern mainland of Mexico, at elevations ranging from 70 meters below sea level in Death Valley to 1,190 meters above sea level (Ernest and Mares 1987, Wilson and Reeder 2005).
Ecology & Habitat

Habitat

Habitat includes low flat areas with desert shrubs, most often with sandy soils. This ground squirrel also occurs in areas with coarse hard-packed sand and gravel, ans alkali sink and creosote bush communities. It avoids rocky hills. Burrows usually are at the bases of shrub. Round-tailed ground squirrels are basically terrestrial but climb well (Wilson and Ruff 1999).

Ecology

Semicolonial but maintains individual burrows during much of year. Reported average population density ranges up to about 210/ha (early May). Home range in southern Arizona was estimated at 0.3 ha; home ranges of females may overlap greatly (Ernest and Mares 1987). Apparently, vagility is low (Hafner 1992).

Reproduction

Breeds January-April; abundant winter rain may result in early breeding and increased litter size. Gestation lasts about 4-5 weeks. Produces one litter averaging 6-7 young annually. Young are weaned at 5 weeks, disperse June-July, sexually mature at 10-11 months (Ernest and Mares 1987).
Terrestrial Habitats
DesertPlaya/salt flatSand/dune
Other Nations (1)
United StatesN5
ProvinceRankNative
CaliforniaSNRYes
ArizonaS5Yes
NevadaS5Yes
Roadless Areas (5)
Arizona (5)
AreaForestAcres
Catalina St. Pk. Roadless AreaCoronado National Forest951
Happy ValleyCoronado National Forest7,972
Middle Romero WSRCoronado National Forest60
Oracle RoadlessCoronado National Forest22,365
Santa RitaCoronado National Forest6,078
References (26)
  1. American Society of Mammalogists (ASM). 2024. The Mammal Diversity Database (MDD). Online. Available: www.mammaldiversity.org
  2. Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, Canada. 438 pp.
  3. Burt, W. H. and R. P. Grossenheider. 1964. A field guide to the mammals. Houghton Mifflin Company, Boston.
  4. Drabek, C. M. 1973. Home range and daily activity of the round-tailed ground squirrel, <i>Spermophilus tereticaudus neglectus</i>. American Midland Naturalist 89:287-93.
  5. Ernest, K. A., and M. A. Mares. 1987. Spermophilus tereticaudus. Mammalian Species 274:1-9.
  6. Evans, F. C., and R. Holdenried. 1943. A population study of the Beechey ground squirrel in central California. Journal of Mammalogy 24:231-260.
  7. Hafner, D. J. 1992. Speciation and persistence of a contact zone in Mojave Desert ground squirrels, subgenus <i>Xerospermophilus</i>. Journal of Mammalogy 73:770-778.
  8. Hafner, D. J., and T. L. Yates. 1983. Systematic status of the Mojave ground squirrel, <i>Spermophilus mohavensis</i> (subgenus <i>Xerospermophilus</i>). Journal of Mammalogy 64:397-404.
  9. Hall, E. R. 1946. Mammals of Nevada. The University of California Press, Berkeley, California.
  10. Hall, E. R. 1981a. The Mammals of North America, second edition. Vols. I &amp; II. John Wiley &amp; Sons, New York, New York. 1181 pp.
  11. Harris, J. H., and P. Leitner. 2004. Home-range size and use of space by adult Mohave ground squirrels, <i>Spermophilus mohavensis</i>. Journal of Mammalogy 85:517-523.
  12. Helgen, K. M., F. R. Cole, L. E. Helgen, and D. E. Wilson. 2009. Generic revision in the holarctic ground squirrel genus <i>Spermophilus</i>. Journal of Mammalogy 90(2):270-305.
  13. Ingles, L. G. 1965. Mammals of the Pacific States. Stanford University Press, Stanford, California.
  14. Johnson, K. 1981. Social organization in a colony of rock squirrels (<i>Spermophilus variegatus</i>). Southwestern Naturalist 26:237-242.
  15. Mammalian Species, nos. 1-604. Published by the American Society of Mammalogists.
  16. Morton, M. L., C. S. Maxwell, and C. E. Wade. 1974. Body size, body composition, and behavior of juvenile Belding ground squirrels. Great Basin Naturalist 34:121-134.
  17. Murie, J. O. 1973. Population characteristics and phenology of a Franklin ground squirrel <i>(Spermophilus franklinii)</i> colony in central Alberta. American Midland Naturalist 90:334-40.
  18. Murie, J. O., and G. R. Michener, editors. 1984. The biology of ground-dwelling squirrels: annual cycles, behavioral ecology and sociality. Univ. Nebraska Press, Lincoln. xvi + 459 pp.
  19. Murie, J. O., and M. A. Harris. 1978. Territoriality and dominance in male Columbian ground squirrels (<i>Spermophilus columbianus</i>). Canadian Journal of Zoology 56:2402-12
  20. Olson, G. S., and B. Van Horne. 1998. Dispersal patterns of juvenile Townsend's ground squirrels in southwestern Idaho. Canadian Journal of Zoology 76:2084-2089.
  21. Owings, D. H., M. Borchert, and R. A. Virginia. 1977. The behaviour of California ground squirrels. Animal Behaviour 25:221-30.
  22. Recht, M. A. 1977. The biology of the Mohave ground squirrel (<i>Spermophilus mohavensis</i>): home range, daily activity, foraging and weight gain, and thermoregulatory behavior. Ph.D. dissertation, University of California, Los Angeles. 117 pp.
  23. Slade, N. A., and D. F. Balph. 1974. Population ecology of Uinta ground squirrels. Ecology 55:989-1003.
  24. Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/.
  25. Wilson, D. E., and D. M. Reeder (editors). 2005. Mammal species of the world: a taxonomic and geographic reference. Third edition. The Johns Hopkins University Press, Baltimore. Two volumes. 2,142 pp. [As modified by ASM the Mammal Diversity Database (MDD) at https://www.mammaldiversity.org/index.html]
  26. Wilson, D. E., and S. Ruff. 1999. The Smithsonian book of North American mammals. Smithsonian Institution Press, Washington, D.C. 750 pp.