Roadless Areas
Home/Species/ Piute Ground Squirrel

Urocitellus mollis

(Kennicott, 1863)

Piute Ground Squirrel

G5Secure Found in 1 roadless area NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
Identity
Unique IDELEMENT_GLOBAL.2.102074
Element CodeAMAFB05200
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicendemic to a single nation
KingdomAnimalia
PhylumCraniata
ClassMammalia
OrderRodentia
FamilySciuridae
GenusUrocitellus
Synonyms
Spermophilus mollisKennicott, 1863
Other Common Names
Great Basin Ground Squirrel (EN) Piute ground squirrel (EN)
Concept Reference
Jones, C., R. S. Hoffman, D. W. Rice, M. D. Engstrom, R. D. Bradley, D. J. Schmidly, C. A. Jones, and R. J. Baker. 1997. Revised checklist of North American mammals north of Mexico, 1997. Occasional Papers, Museum of Texas Tech University 173:1-20.
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.

Urocitellus canus and U. mollis formerly were included in U. townsendii. Baker et al. (2003) and Thorington and Hoffmann (in Wilson and Reeder 2005) recognized the three taxa as distinct species, noting their distinct cytotypes and lack of hybridization.
Conservation Status
Review Date1998-11-09
Change Date1998-11-09
Range Extent20,000-2,500,000 square km (about 8000-1,000,000 square miles)
Range Extent Comments
Washington, north of the Yakima River and west of the Columbia River and, disjunctly, southeastern corner of Oregon, southern Idaho (Snake River Valley) southward through Nevada (except extreme southern Nevada), extreme eastcentral California, and western Utah.
Threat Impact Comments
Decline in the late 1980s in the Snake River Birds of Prey Area in southwestern Idaho was due to widespread conversion of desert shrublands to exotic annual-dominated communities by wildfires (Yensen et al. 1992).
Ecology & Habitat

Habitat

Mainly in high desert (sagebrush, shadscale, greasewood). In southwestern Idaho, highest densities were in winterfat-Sandberg's bluegrass communities, with intermediate densities in big sagebrush-dominated communities and lowest densities in shadscale communities; scarce in communities dominated by exotic annuals (Yensen et al. 1992). Generally occurs in well-drained soils, especially embankments. Often around desert springs and irrigated fields. Makes extensive burrow systems. Young are born in a nest chamber in an underground burrow.

Ecology

Population density in southern Idaho was estimated at 3-32/ha, excluding juveniles; density estimates ranging up to 331/ha (including juveniles) may be inaccurate. Mean home range was estimated at 1357 sq m. May form colonies but families and individuals live separately. Compared to other ground squirrels, has high fecundity and low adult survivorship and is short-lived (Rickart 1988).

Reproduction

Breeds late January-early March, depending on locality. Drought may suppress breeding. Gestation lasts 24 days. Litter size typically is 5-10; 1 litter per year. Males mature as yearlings or as 2-year-olds; females breed as yearlings (Rickart 1987)
Terrestrial Habitats
Shrubland/chaparralGrassland/herbaceousDesertCropland/hedgerow
Other Nations (1)
United StatesN5
ProvinceRankNative
CaliforniaS3Yes
IdahoS4Yes
UtahS4Yes
OregonSNRYes
NevadaS4Yes
Threat Assessments
ThreatScopeSeverityTiming
2 - Agriculture & aquaculture——High (continuing)
2.1 - Annual & perennial non-timber crops——High (continuing)
2.3 - Livestock farming & ranching——High (continuing)

—

Roadless Areas (1)
Nevada (1)
AreaForestAcres
South SchellHumboldt-Toiyabe National Forest125,614
References (29)
  1. American Society of Mammalogists (ASM). 2024. The Mammal Diversity Database (MDD). Online. Available: www.mammaldiversity.org
  2. Baker, R. J., L. C. Bradley, R. D. Bradley, J. W. Dragoo, M. D. Engstrom, R. S. Hoffman, C. A. Jones, F. Reid, D. W. Rice, and C. Jones. 2003a. Revised checklist of North American mammals north of Mexico, 2003. Museum of Texas Tech University Occasional Papers 229:1-23.
  3. Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, Canada. 438 pp.
  4. Dalquest. W. W. 1948. Mammals of Washington. University of Kansas Museum Natural History Publ. 2:1-444.
  5. 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.
  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. Hall, E. R. 1946. Mammals of Nevada. The University of California Press, Berkeley, California.
  9. 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.
  10. 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.
  11. Ingles, L. G. 1965. Mammals of the Pacific States. Stanford University Press, Stanford, California.
  12. Johnson, K. 1981. Social organization in a colony of rock squirrels (<i>Spermophilus variegatus</i>). Southwestern Naturalist 26:237-242.
  13. Jones, C., R. S. Hoffman, D. W. Rice, M. D. Engstrom, R. D. Bradley, D. J. Schmidly, C. A. Jones, and R. J. Baker. 1997. Revised checklist of North American mammals north of Mexico, 1997. Occasional Papers, Museum of Texas Tech University 173:1-20.
  14. Jones, J. K., Jr., R. S. Hoffman, D. W. Rice, C. Jones, R. J. Baker, and M. D. Engstrom. 1992a. Revised checklist of North American mammals north of Mexico, 1991. Occasional Papers, The Museum, Texas Tech University, 146:1-23.
  15. 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.
  16. 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.
  17. 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.
  18. 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
  19. 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.
  20. Owings, D. H., M. Borchert, and R. A. Virginia. 1977. The behaviour of California ground squirrels. Animal Behaviour 25:221-30.
  21. 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.
  22. Rickart, E. A. 1987. Spermophilus townsendii. Mammalian Species 268:1-6.
  23. Rickart, E. A. 1988. Population structure of the Piute ground squirrel (SPERMOPHILUS MOLLIS). Southwest. Nat. 33:91-96.
  24. Rickart, E. A., R. S. Hoffman, and M. Rosenfeld. 1985 [1987]. Karyotype of SPERMOPHILUS TOWNSENDII ARTEMESIAE (Rodentia: Sciuridae) and chromosome variation in the SPERMOPHILUS TOWNSENDII complex. Mammailan Chromosome Newsletter 26:94-102.
  25. Schooley, R. L., B. Van Horne, and K. P. Burnham. 1993. Passive integrated transponders for marking free-ranging Townsend's ground squirrels. J. Mamm. 74:480-484.
  26. Slade, N. A., and D. F. Balph. 1974. Population ecology of Uinta ground squirrels. Ecology 55:989-1003.
  27. 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/.
  28. 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]
  29. Yensen, E., D. L. Quinney, K. Johnson, K. Timmerman, and K. Steenhof. 1992. Fire, vegetation changes, and population fluctuations of Townsend's ground squirrels. American Midland Naturalist 128(2):299-312.