The vagrant shrew (Sorex vagrans), also known as the wandering shrew, is a medium-sized North American shrew. At one time, the montane shrew and the Orizaba long-tailed shrew were considered to belong to the same species.
Range and habitat
This animal inhabits open and wooded areas in western Canada and the United States west of the Continental Divide. In Canada, it is found in southern British Columbia, including Vancouver Island, and as far east as extreme south-western Alberta. In the United States, it is found throughout most of Washington, Oregon, and Idaho, as far south as central California, in northern and central Nevada, northern Utah, and western Montana and Wyoming. One subspecies is found only in salt marshes.
There are three recognised subspecies:
Description
Vagrant shrews are generally red brown in color with white or grey underparts, although coastal populations can be much darker, being almost black on the upper parts of the body. They have a long tail which is sometimes paler in color underneath, especially in juveniles. Although similar in appearance to other shrews found in the same area, it can be distinguished from the montane shrew by its smaller size and shorter tail, and by having a smaller number of friction pads on the hind feet. It can most readily be distinguished from Trowbridge's shrew by examining fine details of the shape of the skull, although the latter species also tends to have a more distinctly pale underside to the tail in adults.
During winter, its fur is dark brown. with no evidence of torpor in winter.
Behavior
Vagrant shrews feed mainly on earthworms, spiders, insects, and other small invertebrates, but also eat some plant material. Because of their high metabolic rate, they have been reported to consume over 160% of their own body weight in food each day. Their primary predators include owls, and even bobcats.
It often uses runways created by voles.
Reproduction
Vagrant shrews primarily breed between April and June, although births may occur as early as February, or as late as September. Gestation lasts twenty days, and results in the birth of a litter of two to eight young.