The vagrant shrew is very widely distributed in western North America, from Columbian Plateau, Snake River Plains, and northern Great Basin, west to the Pacific Ocean, and east to the Continental Divide. It has recently been found east of the Continental Divide in southwestern Alberta.
The vagrant shrew is medium sized; it appears reddish in summer, darker in the winter, and like some other shrews, its tail is bicolored. Total length is 3.7 to 4.8 inches (95 to 119 mm), tail length is 1.25 to 2 inches (34-51 mm), and it weighs 0.12 to 0.36 ounce (3-8.5 g).
It is found in a wide variety of habitats such as forests, meadows, and riparian situations, but it is often found in more arid areas including sagebrush steppe.
Feeds primarily on forest insects (eggs, larvae, pupae, and adults), slugs, and earthworms. It may feed occasionally on salamanders and other small vertebrates.
Like all shrews, it is active all year, and mostly at night. diurnal activity increases in the spring. In a southern British Columbia study, mean home range was estimated at 1039 m2 for nonbreeding, and 3258 m2 for breeding individuals. In an old field community in western Washington, annual crude density was estimated at 36.6 shrews per ha (2.5 ac).
Breeding may occur from March to September, but most activity occurs in the spring, between March and May. Litter size varies from 2 to 9 young (average 5.2). Gestation lasts approximately 20 days.
|Status:||Unprotected nongame species|
Important State References:
Rickard, W.H. 1960. The distribution of small mammals in relation to climax vegetation mosaic in eastern Washington and northern Idaho. Ecology 41: 99-106.