Wildlife

Lemmings, Pikas, Mice, Voles, Shrews

Brown lemmings feed on grasses, sedges, seeds, willow bark and insects. They prefer tundra and alpine meadows. Lemmings remain active year-round and wear tiny trails beneath the snow moving to and from their nests in the winter. Their populations fluctuate dramatically which gives them a reputation for suicidal migrations that is more fiction than fact. Lemmings do not migrate, but in times of stress, individuals may move to the edges of their habitat which could explain their presence on sea ice and other “inappropriate” places.

Northern Bog Lemming (Synaptomy borealis)
The northern bog lemming has brownish grey upperparts with a grayish belly. Their ears are nearly concealed with a tail less than 1 inch. Northern bog lemmings inhabit wet alpine and subalpine meadows, muskegs, and sedges. They normally will build a winter nest above ground, and nest below the surface in the summer.

Collared Pika (Ochotona collaris)
Pikas are small, rat-sized animals related to hares and rabbits, grayish to buffy or brownish, with short, broad, rounded ears and no visible tail. They range from 6 to 8 ½ inches in length and weigh 4 to 6 ½ ounces. Pikas are found only in rockslides and near timberline in high mountains.

Pikas are active by day, feeding on grasses and herbs. They store their food in small piles of “hay” beneath boulders and do not hibernate.

Meadow Jumping Mouse (Zapus hudsonius)
The coat of this Zapus is dark above, yellow on the sides and white underneath. This is a medium sized mouse that has short forelegs, lengthened hind legs, and a long tapering tail. Meadow jumping mice average around 8 inches long including a five-inch tail. Jumping mice are reported to be capable of jumping more than 3 feet in a single bound.

Jumping mice feed on vegetation, seeds, nuts, grains, fungus, berries, fruit and insects. They occupy forests and moist plains where they prefer brush and shrub lined streams. Summer nests are made in shallow burrows but hibernating nests may be 3 feet or more below the ground.

Northern Red-Backed Vole (Clethrionomys rutilus)
Red-backed voles usually have a broad reddish stripe down their back and buffy-red sides. These small to medium-sized voles have small eyes, and small ears reaching just above their fur. Their average total length is 5 ½ inches including their 1-½ inch tail. They can be distinguished from meadow mice by their conspicuous reddish back.

This species is omnivorous but eats mainly greens, berries, seeds, lichens, fungi and insects. Red-backed voles are found in cool, damp locations and are partial to forests; however, they are sometimes found on the tundra. Northern red-backed voles are active year-round and do not hibernate.

Tundra Vole (Microtus oeconomus)
Tundra voles average 8 inches long including a two-inch tail. They have a fairly uniform back color; this uniformness and their large size distinguish them from most other small rodents in Alaska.

Tundra voles prefer moist to wet tundra. They make runways through the tundra vegetation and nest in shallow burrows. Tundra voles feed on grasses, sedges, seeds, grain, bark and insects.

Meadow Vole (Microtus pennsylvanicus)
The meadow vole varies from a gray washed with brown to dark brown. The belly is silvery or dark gray and the tail is bicolored. Meadow voles average around 7 inches including a two-inch tail.

Meadow voles prefer low moist areas or high grasslands. They feed on grasses, sedges, seeds, grain, bark and insects. Meadow vole nests can be found either above or below ground.

Yellow-cheeked Vole (Microtus xanthognathus)
Yellow-cheeked voles are large, have yellow cheeks, and a dull brown body. They inhabit spruce forests and bordering tundra. Yellow-cheeked voles may be active day or night, but are mainly crepuscular (active at dusk and dawn.) They construct dirt mounds two to ten feet in diameter and up to two feet high.

Long-tailed Vole (Microtus longicaudus)
The long-tailed vole is a large vole with a long tail. Their fur is a dark gray washed with brown or black. The tail is bicolored and their feet are white. Long-tailed voles occupy streambanks and mountain meadows, and can be found in brushy areas during the winter. They feed on grasses, bulbs and the bark of small twigs.

Singing (Alaska)Vole (Microtus miurus)
This vole may be distinguished by its small size and short tail. They occupy high, well-drained slopes, tundra benches, and scattered dwarf willows. Singing voles are active day or night, and dig their own burrows or may inhabit those created by ground squirrels. In the autumn, singing voles construct forage piles between 1 quart and 8 gallons in volume.

Common (Masked) Shrew (Sorex cinereus)
All shrews have short legs, a long, pointed snout and long whiskers. The common shrew has a grayish brown body, a bicolored tail and pale underparts. They average 2 inches in length with an additional two-inch tail.

Masked shrews prefer moist habitats in forests, open country, and brushlands. To meet their high-energy requirements, they must eat more than their own weight each day. Masked shrews mostly feed on insects but will also prey upon other small animals.

Dusky Shrew (Sorex monticous)
The dusky shrew has a dull brown upperbody and whitish underbelly with a bicolored tail. This shrew can be difficult to distinguish from other species occurring in the same area.

Dusky shrews are active day and night. They nest in stumps, logs, and beneath debris found in marshes, coniferous forests, and on dry hillsides.

Northern Water Shrew (Sorex palustris)
This is a large, blackish-grey shrew. Northern water shrews have stiff hairs along the sides of their hind feet that distinguish them from other shrew species. They live along cold small streams that have cover along the banks, and in bogs. Northern water shrews are adapted for swimming and readily take to the water; they are sometimes caught in fish traps.

Pygmy Shrew (Sorex hoyi)
Pygmy shrews are slightly smaller than common shrews, but can only be definitively distinguished by their teeth. By weight, the pygmy shrew is the smallest living mammal weighing about the same as a dime. They average 2 inches in length and have an additional one-inch long tail.

Pygmy shrews occupy wooded and open areas, either wet or dry. They prey on the same items as other shrews, mostly insects.

Arctic (Tundra) Shrew (Sorex arcticus tundrensis)
This is the most brilliantly colored of the shrews. Their back, sides and belly all contrast. In winter they are tricolored with a nearly black back and in summer their coat is a dull brown. Tundra shrews average 3 inches long and have and additional one-inch tail.

Tundra shrews prefer tamarack and spruce swamps; chiefly preying on insects and other invertebrates.

Alaska Tiny Shrew (Sorex yukonicus)
A new species first described in 1997, there are only 10 known specimens of the Alaska Tiny shrew to date. They appear to be widespread, although uncommon, across Alaska. Their fur is slightly tricolored gray and the tail is bicolored with white on the sides. Alaska Tiny shrews average about 2 inches with an additional 1 inch long tail.

Little else is known about this rare species, however, seven of the ten specimens were collected in riparian (stream corridor) habitats. Visit the University of Alaska’s museum collection and learn more.

Last updated: July 23, 2008

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