cinereus shrew

The cinereus shrew (Sorex cinereus), also known as the masked shrew, is a small insectivorous mammal in the family Soricidae, native to North America. It has one of the widest distributions of any North American shrew, ranging from Alaska and Canada south through the northern United States, with isolated populations in the Appalachian Mountains and Rocky Mountains. It inhabits a broad range of habitats including moist forest, meadows, bogs, marshes, and brushy areas, where it hunts continuously for insects, earthworms, small vertebrates, fungi, and carrion to fuel its extremely rapid metabolism. Like all shrews, the cinereus shrew has a very high metabolic rate and must consume almost its own body weight in food daily. It is tiny—typically 3–5 grams—with dense gray-brown fur. The species is classified as Least Concern by the IUCN, with abundant and widespread populations across the boreal and northern temperate zones. It is a major component of small mammal communities in northern forests and plays an important role in food webs as prey for owls, hawks, and weasels. The species reproduces rapidly, with multiple litters per year, helping sustain populations despite high predation pressure. It is entirely North American and does not occur in Europe.