The Cinereus Shrew (Sorex cinereus), also known as the masked shrew, is a small shrew found in Alaska. It is also found in Canada, the northern United States, and northeastern Siberia. This is the most widely distributed shrew in North America where it is also known as the common shrew.
It is grey-brown in color with a light grey underside. It has a long tail that is brown on top and pale underneath with a dark tip. Its body is about 3.54 in (9 cm) long including a 1.57 in (4 cm) long tail. It weighs about .18 oz (5 g).
This animal is found in humid areas and damp northern forests. Its range extends further south along the Rocky Mountains in the west and the Appalachians in the east. This species was introduced into Newfoundland in the late 1950s.
Prey and predation
It eats insects, worms, snails, small mammals, salamanders and seeds. It has a voracious appetite, and can eat its own body weight in a day. Predators include larger shrews, hawks, owls, shrikes, snakes, herons, and foxes.
This animal is active day and night year-round. It digs tunnels but also uses tunnels created by other small mammals. It mates between spring and fall. Three to six young are born, in a nest, under a log, or in a stump. In the north, females have only one litter per year. This animal usually lives less than 18 months.