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Home/Species/ Trowbridge's Shrew

Sorex trowbridgii

Baird, 1858

Trowbridge's Shrew

G5Secure Found in 1 roadless area NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
Identity
Unique IDELEMENT_GLOBAL.2.103809
Element CodeAMABA01220
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassMammalia
OrderEulipotyphla
FamilySoricidae
GenusSorex
Other Common Names
Musaraigne de Trowbridge (FR) Trowbridge's shrew (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/.
Conservation Status
Rank MethodExpertise without calculation
Review Date2016-04-05
Change Date1996-11-01
Range Extent20,000-2,500,000 square km (about 8000-1,000,000 square miles)
Rank Reasons
Widely distributed in a variety of habitats; often the most abundant shrew where it occurs.
Range Extent Comments
Coastal southwestern British Columbia south of Burrard Inlet south through western Washington and Oregon to northwestern California, south through coast ranges to Santa Barbara County, east to Warner Mountains (northeastern California), south through Sierra Nevada to Kern County, California (George 1989). Sea level to 1820 m.
Threat Impact Comments
No documented threats. One study showed a decline following logging, but another showed an increase, indicating that dominant vegetation structure may not be responsible for regulating abundance (Verts and Carraway 1998).
Ecology & Habitat

Diagnostic Characteristics

See Carraway (1995) for a key to western North American soricids based primarily on dentaries.

Habitat

Mature forest (dry or moist) with abundant ground litter; forested canyons and ravines, and swampy woods; deep rank grass near salmonberry thickets (Destructioin Island off Washington); riparian fringe areas (but not streamside); under chaparral (at southern edge of range); cut forest if sufficient ground cover present (George, in Wilson and Ruff 1999; George 1989).

Ecology

Maximum life-span estimated at about 18 months. Populations decline after forest wildfires. Fall population tends to be about double spring population (George 1989).

Reproduction

Pregnant females recorded March-May in Washington; 3-4 embryos. Breeds February-early June in Sierra Nevada; average of 5 embryos; post-partum pregnancy probably common. Average of 3.9 embryos in Oregon. Age of sexual maturity less in areas with warmer climate.
Terrestrial Habitats
Forest - ConiferForest - Mixed
Palustrine Habitats
Riparian
Other Nations (2)
United StatesN5
ProvinceRankNative
CaliforniaSNRYes
OregonS4Yes
WashingtonS5Yes
NevadaS2Yes
CanadaN3
ProvinceRankNative
British ColumbiaS3Yes
Roadless Areas (1)
California (1)
AreaForestAcres
Snow MountainMendocino National Forest14,457
References (15)
  1. American Society of Mammalogists (ASM). 2025. Mammal Diversity Database (Version 1.13) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.10595931. Online. Available: https://www.mammaldiversity.org/
  2. Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, Canada. 438 pp.
  3. Bradley, R.D., L.K. Ammerman, R.J. Baker, L.C. Bradley, J.A. Cook. R.C. Dowler, C. Jones, D.J. Schmidly, F.B. Stangl Jr., R.A. Van den Bussche and B. Würsig. 2014. Revised checklist of North American mammals north of Mexico, 2014. Museum of Texas Tech University Occasional Papers 327:1-28. Available at: http://www.nsrl.ttu.edu/publications/opapers/ops/OP327.pdf
  4. Buckner, C. H. 1969. Some aspects of the population ecology of the common shrew, <i>Sorex araneus</i>, near Oxford, England. Journal of Mammalogy 50:326-332.
  5. Carraway, L. N. 1995. A key to Recent Soricidae of the western United States and Canada based primarily on dentaries. Occasional Papers of the Natural History Museum, University of Kansas (175):1-49.
  6. Churchfield, S. 1992. The Natural History of Shrews. Cornell University Press, Ithaca, New York. 192 pp.
  7. George, S. B. 1988. Systematics, historical biogeography, and evolution of the genus <i>Sorex</i>. J. Mammalogy 69:443-461.
  8. George, S. B. 1989. <i>Sorex trowbridgii</i>. Am. Soc. Mamm., Mammalian Species No. 337:1-5.
  9. Hawes, M. L. 1977. Home range, territoriality and ecological separation in sympatric shrews, <i>Sorex vagrans</i> and <i>Sorex obscurus</i>. Journal of Mammalogy. 58:354-367.
  10. Ingles, L. G. 1961. Home range and habitats of the wandering shrew. Journal of Mammalogy 42:455-462.
  11. Jackson, H.H. 1928. A taxonomic review of the North Americanlong tailed shrews (genera Sorex and Microsorex). N. Amer. Fauna. 51:1-238.
  12. Jackson, H. H. 1961. Mammals of Wisconsin. University of Wisconsin Press, Madison. 504 pp.
  13. van Zyll de Jong, C.G. 1983. Handbook of Canadian mammals. 1. Marsupials and insectivores. National Museum of Natural Sciences, National Museums of Canada, Ottawa, Canada. 210 pp.
  14. Verts, B. J., and L. N. Carraway. 1998. Land mammals of Oregon. University of California Press, Berkeley. xvi + 668 pp.
  15. 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/.