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Sorex cinereus

Kerr, 1792

Cinereus Shrew

G5Secure Found in 19 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
Identity
Unique IDELEMENT_GLOBAL.2.101993
Element CodeAMABA01010
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
Masked Shrew (EN) masked shrew (EN) Musaraigne cendrée (FR)
Concept Reference
Hope, A. G., K. A. Speer, J. R. Demboski, S. L. Talbot, and J. A. Cook. 2012. A climate for speciation: rapid spatial diversification with the Sorex cinereus complex of shrew. Molecular Phylogenetics and Evolution 64:671-684.
Taxonomic Comments
Sorex fontinalis has had a complex taxonomic history. Here we follow Diersing (2025) in recognizing Sorex fontinalis as a distinct species separate from S. cinereus. The American Society of Mammalogists (ASM 2025) tentatively includes fontinalis in cinereus, although further studies using integrative taxonomic methods are needed (ASM 2025). According to Diersing (2025), based on molecular analyses by Hope et al. (2012), the current taxonomy of S. cinereus likely includes several species; however, because the distribution of these species is still largely unknown, it is uncertain how this impacts the current taxonomy within S. cinereus, i.e., some subspecies may be species, etc.

Based on evidence of bidirectional mtDNA introgression in Minnesota, Brunet et al. (2002) concluded that S. haydeni does not warrant specific status, but Demboski and Cook (2003) found that S. cinereus and S. haydeni do not appear to be sister species and regarded S. haydeni as a valid species (based on a mtDNA phylogeny). Baker et al. (2003), Wilson and Reeder (2005), and the American Society of Mammalogists (ASM 2025) maintain S. haydeni as a distinct species.

Rausch and Rausch (1995) examined karyotypic and morphological characteristics of shrews on St. Lawrence Island and the Alaskan mainland and found no significant differences; they concluded that S. jacksoni should be regarded as a subspecies of S. cinereus. However, van Zyll de Jong (in Wilson and Ruff 1999), Demboski and Cook (2003), Baker et al. (2003), Wilson and Reeder (2005) and the American Society of Mammalogists (ASM 2025) recognize S. jacksoni as a species.
Conservation Status
Rank MethodExpertise without calculation
Review Date2016-04-05
Change Date1996-11-01
Edition Date2005-02-28
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments
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).
Threat Impact Comments
This and other generalist insectivores are not likely to be impacted negatively by selective insecticides such as BACILLUS THURINGIENSIS (Bellocq et al. 1992).
Ecology & Habitat

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).

Diagnostic Characteristics

Generally paler and smaller than S. FUMEUS (95-129 mm total length) (Godin 1977). See Hall (1981) for a (somewhat outdated) key to North American species of SOREX. See Carraway (1995) for a key to western North American soricids based primarily on dentaries.

Habitat

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.

Ecology

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.

Reproduction

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.
Terrestrial Habitats
Forest - HardwoodForest - ConiferForest - MixedWoodland - HardwoodWoodland - ConiferWoodland - MixedShrubland/chaparralSavannaGrassland/herbaceousOld field
Palustrine Habitats
HERBACEOUS WETLANDFORESTED WETLANDBog/fenRiparian
Other Nations (2)
United StatesN5
ProvinceRankNative
UtahS3Yes
MinnesotaS5Yes
North CarolinaS4Yes
MaineS5Yes
OhioS5Yes
PennsylvaniaS5Yes
GeorgiaSUYes
MichiganS5Yes
New YorkS5Yes
MarylandS5Yes
New JerseyS5Yes
VermontS5Yes
MissouriSNRYes
MassachusettsS5Yes
New HampshireS5Yes
AlaskaS5Yes
IndianaS4Yes
MontanaS5Yes
New MexicoS2Yes
DelawareS5Yes
Rhode IslandS5Yes
WisconsinS5Yes
South DakotaS5Yes
WashingtonS4Yes
VirginiaS5Yes
KentuckyS3Yes
ColoradoS5Yes
IdahoS4Yes
WyomingS5Yes
IllinoisS5Yes
South CarolinaS2Yes
West VirginiaS4Yes
TennesseeS4Yes
IowaSNRYes
North DakotaSNRYes
ConnecticutS5Yes
CanadaN5
ProvinceRankNative
Prince Edward IslandS5Yes
British ColumbiaS5Yes
LabradorS5Yes
Nova ScotiaS5Yes
Yukon TerritoryS5Yes
AlbertaS5Yes
Island of NewfoundlandSNANo
SaskatchewanS4Yes
OntarioS5Yes
New BrunswickS5Yes
Northwest TerritoriesS5Yes
ManitobaS5Yes
NunavutSUYes
QuebecS5Yes
Roadless Areas (19)
Alaska (7)
AreaForestAcres
Douglas IslandTongass National Forest28,065
Freshwater BayTongass National Forest44,933
Game CreekTongass National Forest54,469
RhineTongass National Forest23,010
South KruzofTongass National Forest55,193
Taku-SnettishamTongass National Forest664,928
Tenakee RidgeTongass National Forest20,527
Colorado (1)
AreaForestAcres
Long ParkRoutt NF42,100
Minnesota (1)
AreaForestAcres
Brule Lake - Eagle MountainSuperior National Forest12,380
Montana (2)
AreaForestAcres
East PioneerBeaverhead-Deerlodge National Forest145,082
West PioneerBeaverhead-Deerlodge National Forest248,631
New Hampshire (1)
AreaForestAcres
Kinsman MountainWhite Mountain National Forest8,999
North Carolina (2)
AreaForestAcres
BearwallowPisgah National Forest4,113
Cheoah BaldNantahala National Forest7,795
Tennessee (3)
AreaForestAcres
Flint Mill GapCherokee National Forest9,494
Rogers RidgeCherokee National Forest4,738
Sampson Mountain AdditionCherokee National Forest3,064
Wisconsin (2)
AreaForestAcres
09162 - MooseChequamegon-Nicolet National Forest6,161
09166 - East TorchChequamegon-Nicolet National Forest4,647
References (46)
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