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Neotamias sonomae

(Grinnell, 1915)

Sonoma Chipmunk

G4Apparently Secure Found in 2 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
Least concernIUCN
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.101465
Element CodeAMAFB02080
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicendemic to a single state or province
KingdomAnimalia
PhylumCraniata
ClassMammalia
OrderRodentia
FamilySciuridae
GenusNeotamias
Synonyms
Tamias sonomae(Grinnell, 1915)
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
See Patterson and Norris (2016) for a revised classification of Marmotini (Sciuridae: Xerinae), based on Thorington et al. (2012), Ge et al. (2014), and Patterson and Norris (2016); the three chipmunk lineages should be recognized as three distinct genera, namely, Tamias Illiger, 1811, Eutamias Trouessart, 1880, and Neotamias A. H. Howell, 1929. Thorington and Hoffmann (in Wilson and Reeder 2005) noted that chipmunks could be legitimately allocated to one (Tamias), two (Neotamias, Tamias), or three (Tamias, Neotamias, Eutamias) genera; they chose to adopt the single-genus (Tamias) arrangement.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-08-06
Change Date2025-08-06
Edition Date2025-08-06
Edition AuthorsGundy, R. L. (2025)
Threat ImpactUnknown
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
This species has a limited range in northwestern California. Little is known about the population, but many occurrences are protected on conservation land, no threats are known, and the population is presumably stable.
Range Extent Comments
This species is endemic to northwestern California. It is found from northern San Francisco Bay area north to Siskiyou County in the Upper Sonoran and Transition life zones, from near sea level to 2100 m (Johnson 1943, Best 1993). Using Global Biodiversity Information Facility (GBIF) (2025) records, range extent is estimated to be 65,743 km² (RARECAT 2025).
Occurrences Comments
Applying a 5 km separation distance to GBIF (2025) records, 123 occurrences are estimated (RARECAT 2025).
Threat Impact Comments
No threats are known at this time.
Ecology & Habitat

Habitat

Dense chaparral, brushy clearings in forests, and streamside thickets; often associated with black oak, ponderosa pine, digger pine, Douglas-fir, white fir, redwood, sticky laurel, incense cedar, madrone, manzanita, and serviceberry; associated with tan oak on high ridges in Trinity and Humboldt counties, with whitethorn, chokecherry, serviceberry, and silk tassel in large warm tracts of brush in Trinity County (see Best 1993). A tree nest was on a limb 15 m up in a large Douglas-fir at the base of a forested slope (see Best 1993). Often uses elevated perches such as stumps, rocks, or lower limbs of trees.

Ecology

Males disperse as juveniles; females tend to stay near natal site (see Best 1993).

Reproduction

Breeds once a year in spring. Young are born during May-July; timing of reproduction varies with elevation. Litter size is 3-5 (usually 4). Female raises litter alone; remains with young for at least 3 weeks after young emerge. Weaned young may stay together for some weeks after separation from mother.
Terrestrial Habitats
Woodland - HardwoodWoodland - ConiferWoodland - MixedShrubland/chaparral
Palustrine Habitats
Riparian
Other Nations (1)
United StatesN4
ProvinceRankNative
CaliforniaSNRYes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined———

—

Roadless Areas (2)
California (2)
AreaForestAcres
ChinquapinShasta-Trinity National Forest22,040
Snow MountainMendocino National Forest14,457
References (28)
  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. Best, T. L. 1993. Tamias sonomae. Am. Soc. Mamm., Mammalian Species No. 444:1-5.
  5. Broadbooks, H. E. 1970a. Home ranges and territorial behavior of the yellow-pine chipmunk, <i>Eutamius amoenus.</i> Journal of Mammalogy 51:310-26.
  6. Broadbooks, H. E. 1970b. Populations of the yellow pine chipmunk, <i>Eutamias amoenus</i>. American Midland Naturalist 83:472-488.
  7. Brown, J. H. 1971. Mechanisms of competitive exclusion between two species of chipmunks. Ecology 52:305-311.
  8. Elliot, L. 1978. Social behavior and foraging ecology of the eastern chipmunk (<i>Tamias striatus</i>) in the Adirondack Mountains. Smithsonian Contributions to Zoology No. 265. 107 pp.
  9. Gashwiler, J. S. 1965. Longevity and home range of a Townsend chipmunk. Journal of Mammalogy 46:693.
  10. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  11. 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.
  12. Ingles, L. G. 1965. Mammals of the Pacific States. Stanford University Press, Stanford, California.
  13. Jackson, H. H. 1961. Mammals of Wisconsin. University of Wisconsin Press, Madison. 504 pp.
  14. Jameson, E. W., Jr. 1999. Host-ectoparasite relationships among North American chipmunks. Acta Theriologica 44:225-231.
  15. Johnson, D.H. 1943. Systematic review of the chipmunks (genus EUTAMIAS) of California. University of California, Publications in Zoology, 48(2):63-148.
  16. 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.
  17. Levenson, H., et al. 1985. Systematics of the Holarctic chipmunks (<i>Tamias</i>). J. Mammalogy 66:219-242.
  18. Oxley, D. J., M. B. Fenton and G. R. Carmody. 1974. The effects of roads on populations of small mammals. Journal of Applied Ecology 11: 51-59.
  19. Patterson, B. D., and R. W. Norris. 2016. Towards a uniform nomenclature for ground squirrels: the status of the Holarctic chipmunks. Mammalia 80(3):241-251.
  20. Piaggio, A. J., and G. S. Spicer. 2001. Molecular phylogeny of the chipmunks inferred from mitochondrial cytochrome b and cytochrome oxidase II gene sequences. Molecular Phylogenetics and Evolution 20:335-350.
  21. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  22. Roberts, D. R. 1962. Rodent movements in a cutover forest of the Sierra Nevada, California. Ph.D. thesis, University of California, Berkeley.
  23. Sheppard, D. 1972. Home ranges of chipmunks (<i>Eutamias</i>) in Alberta. Journal of Mammalogy 53:379- 380.
  24. Storer, T. I., F. C. Evans, and F. G. Palmer. 1944. Some rodent populations in the Sierra Nevada of California. Ecological Monographs 14:166-192.
  25. Sutton, D. A. 1992. Tamias amoenus. Am. Soc. Mamm., Mammalian Species No. 390:1-8.
  26. Wadsworth, C. E. 1972. Observations of the Colorado chipmunk in southeastern Utah. Southwestern Naturalist 16:451-454.
  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]