Preble's shrew (Sorex preblei)

A black and white illustration of a Preble's shrew. The shrew is dark on top with a white underside.
Illustration of Preble's shrew.  (Summers Scholl (2000) - Wyoming Natural Diversity Database)
View of a tiny dark Preble's shrew in a hand, held by its tail by another hand
The tiny size of this Preble's shrew is notable.  (USDA Deschutes National Forest - Oregon)
Category: Mammals
Ecosystems: Riparian areas
Vulnerability to climate change (More details)

Moderate

If you see this species, please share your observation using the WDFW wildlife reporting tool or email us at  wildlife.data@dfw.wa.gov. Be sure to include a photo of the species for verification and location (latitude/longitude coordinates) of your observation. 

Preble’s shrew is a poorly known species that appears to be extremely rare in Washington; additional sampling is needed to understand distribution, habitat needs, and factors that affect populations.

Description and Range

Physical description

Oregon Department of Fish and Wildlife describes Preble’s shrew as follows: …{A]dults commonly weigh less than a dime. The pelage (fur) is medium dark-brown to very dark-gray on the dorsum (topside) and silvery gray on the ventral (underside). The tail is bicolored, medium dark-brown on the dorsal surface, which on the ventral surface and darkening toward the tip.

Ecology and life history

Preble’s shrews are most often associated with sagebrush and grasses but have been collected in a wide variety of habitats, including subalpine shrubland, whitebark pine, and wetlands. In Washington, Preble’s shrews have been captured in dense lodgepole pine, dense subalpine fir/lodgepole, and grand fir/Engelmann spruce forest at 5,000 to 6,000 feet in the Blue Mountains, which is rather atypical habitat for the species. It was also captured in a U.S. Department of Agriculture - Conservation Reserve Program grassland.

Preble’s shrew is an insectivore; mandible morphology suggests a diet of soft-bodied invertebrates, such as spiders and grubs.

Litter size is estimated to be three to six young.

Shrews are active throughout the year and forage under the snow in colder regions. Life expectancy is less than 1½ years.

Shrews are not rodents.

Geographic range

As currently recognized, the range of Preble’s shrew includes southern British Columbia, south to northeastern California, northern Nevada and Utah and east to western Wyoming and Colorado, and south to New Mexico and north to include much of Montana. However, a future taxonomic revision may split the species, restricting the name Sorex preblei to populations in Washington, Oregon, British Columbia, California and Nevada. 

In Washington, the only records of Preble’s shrew were from the Blue Mountains in 1956 to 1958, until 2004 when a single specimen was captured in Douglas County. There are no density estimates or data on population numbers in Washington or elsewhere. Preble’s shrews seem to be very rare, though this may partly be an artifact of inadequate sampling. Population trends can only be hypothesized from the reduction in steppe habitats; less than 50 percent of the historical shrubsteppe in Washington remains and much of the remainder is fragmented and degraded.

For a map of worldwide distribution of Preble’s shrew and other species' information, check out NatureServe Explorer.

Climate vulnerability

Sensitivity to climate change

Moderate

Limited information is available regarding the biology and ecology of Preble's shrews and their potential response to climate change. This species is most often associated with shrub-steppe and grasslands, but also occupies a variety of other habitats such as forest, subalpine shrubland, and wetlands. In Washington, shrub-steppe and grasslands are expected to be stressed in the future by drier conditions, drought, and increased occurrence of wildfire, which may reduce habitat suitability and possibly prey availability (e.g., insects) for Preble's shrew. Further expansion of cheatgrass resulting from increased fires could also be detrimental to this species.

Confidence: Low

Exposure to climate change

Moderate

  • Changes in precipitation
  • Altered fire regimes
  • Drought
  • Increased invasive plants
Confidence: Moderate

Conservation

This species is identified as a Species of Greatest Conservation Need (SGCN) under the State Wildlife Action Plan (SWAP). SGCN-classified species include both those with and without legal protection status under the Federal or State Endangered Species programs, as well as game species with low populations. The WDFW SWAP is part of a nationwide effort by all 50 states and five U.S. territories to develop conservation action plans for fish, wildlife and their natural habitats—identifying opportunities for species' recovery before they are imperiled and more limited.
This species is identified as a Priority Species under WDFW's Priority Habitat and Species Program. Priority species require protective measures for their survival due to their population status, sensitivity to habitat alteration, and/or recreational, commercial, or tribal importance. The PHS program is the agency's main means of sharing fish and wildlife information with local governments, landowners, and others who use it to protect priority habitats for land use planning.

Conservation Threats and Actions Needed

  • Resource information collection needs  
    • Threat: Lack of data on current distribution and population status.
    • Action Needed: Determine distribution and population status.
    • Threat: Lack of adequate information on threats.
    • Action Needed: As better population distribution information is obtained, assess threats that may exist.

See the Climate vulnerability section for information about the threats posed by climate change to this species.

Resources