The water shrew was first discovered in the park in 1950 along the West Prong of the Little Pigeon River. Mostly aquatic, this shrew lives beneath the overhanging banks, and in rock crevices along the edges of swiftly flowing mountain streams. It can swim, dive, float, and run along the bottom of a streams. The water shrew has even been observed running upon the surface of the water for some distance. They feed primarily on small aquatic organisms that they capture while swimming. The water shrew is the largest shrew in the park.

Species Measurements:
- Adult Total Length: 135-165 mm (5-6 in.)
- Tail: 60-75 mm (2-3 in.)
- Hind Foot: 18-21 mm (1 in.)
- Weight: 9-14 g (⅓ oz.)

Physical Characteristics:
The water shrew is the largest shrew in the park. It is blackish -gray dorsally, and pale to dark gray below. The feet are whitish, and the tail is indistinctly bicolored. A conspicuous fringe of stiff hairs is present along the sides of the feet and toes. The third and fourth hind toes are joined by a thin web for slightly more than half of their length. Shrews possess long tapering snouts and tiny eyes and ears. Hearing and smelling are acute. The tips of the incisor teeth are dark chestnut in color. Shrews have five toes on each foot.

Habitat:
Mostly aquatic, the water shrew lives beneath the overhanging banks, and in rock crevices along the edges of swiftly flowing mountain streams. Rhododendron and yellow birch are usually the dominant vegetation in these areas.

Reproduction:
Females produce two to three litters of three to ten young in the spring and summer. Gestation is estimated at about 3 weeks (Harris, 1999). Nests are usually constructed in tunnels, and in or under hollow logs. These nests are about 6 to 8 inches in diameter, with a 2 to 4 inch inside diameter. They are composed of finely shredded grasses and leaves. Young are weaned, and independent, at 4 weeks of age.

Longevity:
The maximum life span of a water shrew is approximately 18 months (Harris, 1999).

Terrestrial Ecology:
This shrew readily takes to the water. The large, hair-fringed feet and toes together with the dense fur make the water shrew well adapted to swimming. It can swim, dive, float, and run along the bottom of a stream. The water shrew has even been observed running upon the surface of the water for some distance. This later activity is made possible by air bubbles clinging to the fringes of hair on either side of the feet. These shrews are primarily nocturnal, and are active during all seasons.

They feed primarily on small aquatic organisms that they capture while swimming. Both Conaway (1952) and Linzey and Linzey (1973) recorded aquatic organisms in 49% of water shrew stomachs analyzed from the park. Conaway and Pfitzer (1952) recorded caddis flies, stoneflies, and mayflies as the most frequent food items.

The home range of shrews probably covers an area of ? to 1 acre.

Predators and Defense:
Predators include trout, snakes, owls, hawks, and carnivorous mammals such as opossums, foxes, bobcats, weasels, and skunks.

Parasites:
None recorded from the park.

The range of the water shrew extends across Canada from Labrador and Nova Scotia to southeastern Alaska. The range extends south through the Appalachian Mountains to Tennessee and North Carolina, through the Rocky Mountains to Utah and New Mexico, and through the Sierra Nevadas to California.

The water shrew was first discovered in the park in 1950 along the West Prong of the Little Pigeon River (Conaway and Pfitzer, 1952). They have since been found living along Walker Prong, and other tributaries of the Little Pigeon River, from 3,700 feet to 4,700 feet elevation. They have also been recorded by Linzey in 1980 along a tributary of the Middle Prong of the Little Pigeon River in Greenbrier, at an elevation of between 1,925 and 2,000 feet, the lowest elevation ever recorded for this species in the Appalachian Mountains (Linzey, 1984). The only North Carolina record of this shrew from the park was obtained by Linzey from Beech Flats Prong (4,000 feet) in Swain County in 1980 (Linzey, 1984) . This represents the only record for the Deep Creek watershed.

References:

Beneski, Jr., J.T. and D.W. Stinson. 1987. Sorex palustris. Mammalian Species No. 296: 1-6.

Conaway, C.H. 1952. Life History of the Water Shrew (Sorex palustris navigator). American Midland Naturalist 48(1): 219-248.

Conaway, C.H. and D.W. Pfitzer. 1952. Sorex palustris and Sorex dispar from the Great Smoky Mountains National Park. Journal of Mammalogy 33 (1): 106-108.

Harris, A.H. 1999. Water Shrew. Pages 38-39. In: Wilson, D.E. and S. Ruff (editors). The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washington, D.C.

Komarek, E. V. and R. Komarek. 1938. Mammals of the Great Smoky Mountains. Bulletin of the Chicago Academy of Science 5(6): 137-162.

Linzey, D. W. 1984. Distribution and Status of the Northern Flying Squirrel and the Northern Water Shrew in the Southern Appalachians. Pages 193-200. In: The Southern Appalachian Spruce-Fir Ecosystem: Its Biology and Threats. National Park Service Re

Linzey, D. W. 1995a. Mammals of Great Smoky Mountains National Park. The McDonald & Woodward Publishing Company, Inc., Blacksburg, Virginia.

Linzey, D. W. 1995b. Mammals of Great Smoky Mountains National Park-1995 Update. Journal of the Elisha Mitchell Scientific Society 111(1): 1-81.

Linzey, D. W. and A.V. Linzey. 1973. Notes on Food of Small Mammals from Great Smoky Mountains National Park, Tennessee-North Carolina. Journal of the Elisha Mitchell Scientific Society 89(1 and 2): 6-14.