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BC Conservation Data Centre: Species Summary


Sorex cinereus
Cinereus Shrew

 
Scientific Name: Sorex cinereus Kerr, 1792
English Name: Cinereus Shrew
English Name Synonyms: Common Shrew
Masked Shrew
 
Classification / Taxonomy
Scientific Name - 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/.
Classification Level: Species
Taxonomy Comments: FORMERLY MASKED SHREW
Species Group: Vertebrate Animal
Species Code: M-SOCI
Kingdom Phylum Class Order Family
Animalia Craniata Mammalia Eulipotyphla Soricidae
   
Conservation Status / Legal Designation
Global Status: G5 (Apr 2016)
Provincial Status: S5 (Jan 2024)
BC List: Yellow
Provincial FRPA list:   
Provincial Wildlife Act:
COSEWIC Status:
SARA Schedule:
General Status Canada: 4 - Secure (2005)
   
Ecology & Life History
General Description: A medium-sized shrew (adults usually 9-11 cm total length, tail 35-45 mm, 3-6 g) with a sharply pointed snout, beady eyes, and small ears nearly hidden in the fine soft pelage; dorsal pelage varies from dark brown to gray, depending on the season and location; five small unicuspidate teeth behind the upper incisors (the fifth is minute, the fourth generally is smaller than [less commonly equal to, or sometimes larger than in subspecies OHIOENSIS] the third, and both of these are smaller than the first and second; tips of teeth are dark chestnut; feet are delicate, with slender weak claws; condylobasal length of skull 14.6-16.9 mm; maxillary breadth less than 4.6 mm; posterior border of infraorbital foramen even with, or anterior to, plane of space between M1 and M2 (Armstrong 1987, Hall 1981, Godin 1977).
Global Reproduction Comments: Breeding season may last from March through September (there is evidence of mid-winter births in at least some years in Nova Scotia) (Stewart et al. 1989). Usually 2 litters, may be 3. Gestation lasts 18 days. Litter size is 2-10 (average around 7). Young are weaned in 3 weeks. Sexually mature in 20-26 weeks. Some young may breed in the year of their birth.
Global Ecology Comments: Large annual fluctuations in population size. Density estimates range from 1-12 shrews per acre (Buckner 1966). Home range about 0.10 acre. Usually in scattered, locally abundant populations. Rarely lives past second summer.
Migration Characteristics:
(Global / Provincial)		 
    Nonmigrant:
    Local Migrant:
    Distant Migrant:
    Within Borders Migrant: 		Y /
N /
N /
na /
Habitats:
(Type / Subtype / Dependence)
Global Habitat Comments: Occupies most terrestrial habitats excluding areas with very little or no vegetation. Thick leaf litter in damp forests may represent favored habitat, although appears adaptable to major successional disturbances. In Nova Scotia, diet indicated that much foraging was done among wrack on beaches (Stewart et al. 1989). Nest sites are typically in shallow burrows or above ground in logs and stumps.
Food Habits: Invertivore: Adult, Immature
Global Food Habits Comments: A generalist, opportunistic invertivore. Eats primarily insects and other invertebrates, carrion, small vertebrates, occasionally seeds. Echolocation may be used for detecting prey (Gould et al. 1964). Consumes daily its own weight in food.
Global Phenology: Circadian: Adult, Immature
Global Phenology Comments: Active throughout the day (and the year) to secure enough food to maintain high metabolic rate. Peak active period 0100-0200 (van Zyll de Jong 1983). Cloudy, rainy nights increase nocturnal activity.
Provincial Phenology:
(1st half of month/
2nd half of month)
Colonial Breeder: N
Length(cm)/width(cm)/Weight(g): 10/ / 5
Elevation (m) (min / max): Global: 
Provincial: 
   
 
Distribution
Endemic: N
Global Range Comment: Alaska to Labrador/Newfoundland, south to Washington, Utah, New Mexico, the Northern Great Plains, southern Indiana and Ohio, through the Appalachian Mountains to northern Georgia and western South Carolina, and on the east coast to New Jersey and northern Maryland (Laerm et al. 1995, Brimleyana 22:15-21; Whitaker 2004).
 
Authors / Contributors
Global Information Author:
Last Updated: Apr 08, 1996
Provincial Information Author:
Last Updated:
   
References and Related Literature
Armstrong, D. M. 1987. Rocky Mountain mammals. Revised edition. Colorado Associated Univ. Press, Boulder. x + 223 pp.
Baker, R. H. 1983. Michigan mammals. Michigan State University Press. 642 pp.
Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, Canada. 438 pp.
Bellocq, M. I., J. F. Bendell, and B. l. Cadogan. 1992. Effects of the insecticide Bacillus thuringiensis on Sorex cinereus (Masked Shrew) populations, diet, and prey selection in a jack pine plantation in northern Ontario. Can. J. Zool. 70:505-510.
Buckner, C.H. 1966. Populations and ecological relationships of shrews in tamarack bogs of southeastern Manitoba. Jour. Mamm. 47(2):181-194.
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.
Churchfield, S. 1992. The Natural History of Shrews. Cornell University Press, Ithaca, New York. 192 pp.
Forsyth, D.J. 1976. A field study of growth and development of nestling masked shrews (Sorex cinereus). J. Mammalogy, 57(4):708-721.
Frey, J. K. 1992. Response of a mammalian faunal element to climatic changes. J. Mamm. 73:43-50.
George, S. B. 1988. Systematics, historical biogeography, and evolution of the genus Sorex. J. Mammalogy 69:443-461.
Godin, A. J. 1977. Wild mammals of New England. Johns Hopkins University Press, Baltimore. 304 pp.
Gould, E., N.C. Negus, and A. Novick. 1964. Evidence for echolocation in shrews. J. Exp. Zool. 156:19-38.
Hall, E. R. 1981a. The Mammals of North America, second edition. Vols. I & II. John Wiley & Sons, New York, New York. 1181 pp.
Hamilton, W. J., Jr., and J. O. Whitaker, Jr. 1979. Mammals of the eastern United States. Cornell Univ. Press, Ithaca, New York. 346 pp.
Jackson, H.H. 1928. A taxonomic review of the North Americanlong tailed shrews (genera Sorex and Microsorex). N. Amer. Fauna. 51:1-238.
Nagorsen, D. and N. Panter. 2024. Shrews and Moles of British Columbia. Second Edition. Royal BC Museum Handbook. 239 pp.
Rausch, R. L., and V. R. Rausch. 1995. The taxonomic status of the shrew of St. Lawrence Island, Bering Sea (Mammalia: Soricidae). Proceedings of the Biological Society of Washington 108:717-728.
Schwartz, C. W., and E. R. Schwartz. 1981. The wild mammals of Missouri. University of Missouri Press, Columbia. 356 pp.
Stewart, D. T., A. J. Baker, and S. P. Hindocha. 1993. Genetic differentiation and population structure in Sorex haydeni and S. cinereus. J. Mamm. 74:21-32.
Stewart, D. T., and A. J. Baker. 1992. Genetic differentiation and biogeography of the masked shrew in Atlantic Canada. Can. J. Zool. 70:106-114.
Stewart, D. T., T. B. Herman, and T. Teferi. 1989. Littoral feeding in a high-density insular population of Sorex cinereus. Can. J. Zool. 67:2074-2077.
van Zyll de Jong, C. G., and G. L. Kirkland, Jr. 1989. A morphometric analysis of the Sorex cinereus group in central and eastern North America. J. Mamm. 70:110-122.
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.
Volobouev, V. T., and C. G. van Zyll de Jong. 1994. Chromosome banding analysis of two shrews of the cinereus group: Sorex haydeni and Sorex cinereus (Insectivora, Soricidae). Can. J. Zool. 72:958-964.
Wrigley, R.F., J.E. DuBois, and H.W. Copland. 1979. Habitat, abundance and distribution of six species of shrew in Manitoba. J. Mamm. 60:505-520.
 

Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.

Suggested Citation:

B.C. Conservation Data Centre. 1996. Species Summary: Sorex cinereus. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Aug 31, 2025).