Shrews are small, highly active mammals, often mistaken for mice but more closely related to moles and hedgehogs (family Soricidae). Known for their high metabolic rates, shrews must consume food almost constantly, often eating their own body weight daily. They cannot survive more than a few hours without sustenance, which drives their behavior and habitat preferences.
General Shrew Habitats
Shrews prefer environments with ample ground cover, predator protection, and consistent food. They often inhabit areas with dense vegetation, such as grasslands, forests, and shrublands. Moist soil and abundant leaf litter are particularly favorable. These conditions provide ideal foraging locations, as shrews primarily consume insects, worms, spiders, and other small invertebrates found in soil and decaying organic matter.
Moisture is a factor in shrew habitat suitability. Many species thrive in damp brushy woodlands, bogs, marshes, and near water sources like streams and lakeshores. This preference helps meet their physiological needs, as their high metabolic rate leads to high evaporative water loss. While most shrews prefer moist environments, some species adapt to drier upland regions if sufficient vegetation and water are present.
Shrew Distribution Across US Regions
Shrews are widely distributed across the United States. They are found throughout the northern contiguous United States, extending from Alaska and Canada southward. Their distribution spans diverse terrestrial habitats, including montane, boreal, and even arid areas.
In the Northeast and Mid-Atlantic, shrews are common in forests, fields, and wetlands, with species like the Northern Short-tailed and Masked Shrews prevalent. The Southeast hosts various shrews, particularly in moist hardwood forests, pine stands with deep organic matter, and along forest meadow borders, reaching as far south as Florida and eastern Texas. In the Midwest, shrews are found in various habitats, including open grasslands, brush, and fallow fields, often using tunnels created by other animals.
The Pacific Northwest and areas west of the Continental Divide, including the Rocky Mountains, are home to shrews in open and wooded areas, wet grasslands, and meadows. These regions offer diverse elevations, from alpine tundra to swampland, supporting different shrew species.
Notable US Shrew Species and Their Ranges
Several prominent shrew species inhabit the United States, each with distinct features and geographical distributions.
Northern Short-tailed Shrew
The Northern Short-tailed Shrew (Blarina brevicauda) is one of North America’s largest shrews, measuring 3.7 to 5.5 inches. It is found throughout central and eastern North America, from southern Saskatchewan to Atlantic Canada, extending south to northern Arkansas and Georgia. It prefers moist habitats with leaf litter or thick plant cover, including deciduous and coniferous forests, marshy areas, and gardens.
Masked Shrew
The Masked Shrew (Sorex cinereus) is the most widely distributed shrew across North America. It is found throughout Alaska, Canada, and the northern United States, with its range extending south along the Rocky Mountains and Appalachians. They inhabit various environments, including forests, meadows, and riverbanks, with higher densities in moist areas. It typically measures about 3.5 inches in body length with a 1.6-inch tail.
Least Shrew
The Least Shrew (Cryptotis parva) is among the smallest mammals in North America, measuring around 3 inches. Unlike many shrews, it often prefers open fields with tall grasses, brush, and dry fallow fields, though it can also be found in marshy areas. Its range primarily covers the eastern and central United States, extending from Florida north to New York and west to Texas and South Dakota.
Vagrant Shrew
The Vagrant Shrew (Sorex vagrans) is found in western North America, primarily west of the Continental Divide. Its range includes Washington, Oregon, Idaho, central California, Nevada, Utah, and western Montana and Wyoming. It prefers wet grasslands and meadows, often near water sources, and can inhabit both open and wooded areas. It is a small shrew, typically less than three inches long.
American Pygmy Shrew
The American Pygmy Shrew (Sorex hoyi) is the smallest mammal native to North America, with a 2-inch body and 0.8-inch tail, weighing only 0.07 to 0.16 ounces. It is distributed across Alaska, Canada, and the northern contiguous United States, with populations extending south along the Appalachian Mountains and into the Colorado and Wyoming Rockies. It primarily inhabits northern coniferous and deciduous forests, preferring moist forest floors with decaying leaf litter and debris.