Rock voles were first discovered and named by Komarek (1932). The first specimens were taken in the Great Smoky Mountains National Park. They are fairly common above 3,000 feet elevation and often occur in association with the southern red-backed vole (Microtus chrotorrhinus). In the park, rock voles are found primarily among mossy rocks and logs or in cool, moist talus areas. The rock vole has been designated as a species of "State Concern" in North Carolina.

Species Measurements:
- Adult Total Length: 140-175 mm (5?-7 in.)
- Tail: 35-51 mm (1⅜-2 in.)
- Hind Foot: 20-24 mm (?-1 in.)
- Weight: 25-57 g (1-2 oz.)

Physical Characteristics:
Rock voles are medium-sized voles, brownish above and grayish-white below. The area between the nostrils and the eyes usually ranges from yellowish to deep orange-rufous, a condition that may be obvious in some specimens, but inconspicuous or lacking in others.

Habitat:
In the park, rock voles are found primarily among mossy rocks and logs or in cool, moist talus areas. They utilize a network of runways beneath and between the rocks and boulders.

Reproduction:
Breeding in the park extends from early spring into fall. Nursing females or females with embryos have been taken on the following dates: March 3, 3 (near birth); March 31 (nursing); April 13, 3 ("medium embryos") and April 29, 4 (3, 1; CR= 10 mm; nursing). Males in breeding condition have been noted in March (2), July, and August. Immature individuals have been found in July (1), August (1), September (1), and October (2), ( Linzey, 1995b).

Several litters, each consisting of an average of three young, are produced annually following a gestation period of 19-21 days (Linzey, 1995a; Kirkland, 1999).

Longevity:
N/A Terrestrial Ecology:
Rock voles may be active any time during the day or night and during all seasons.

Feeding Behavior:
Forage consists primarily of green vegetation, roots, and berries. Komarek and Komarek (1938) recorded blackberry seeds from the stomach of one individual. Stomach analyses of three rock voles taken in September from Indian Camp Creek and in December from Walker Prong and Kanati Fork were virtually identical. Vegetation comprised 99.7% of the volume (frequency - 100%) with the fungus Endogone comprising 0.3% (frequency -33.3%); hair, trace (frequency-66.7%); and pebbles, trace (frequency-33.3%) (Linzey and Linzey, 1973a).

Predators and Defense:
Rock voles have been recorded in the stomachs of eight timber rattlesnakes (Crotalus horridus) and one copperhead (Agkistrodon contortrix) in the park (Savage, 1967). A bobcat (Lynx rufus) killed by a car in August, 1952, along the Newfound Gap Road (Tennessee: 3,700 feet) contained five of these voles (Linzey, 1995b).

Parasites:
Approximately 65% of the voles collected by Komarek and Komarek (1938) were infested with warbles (Cuterebra sp.). One individual had several ticks (Ixodes sp.) attached about its nose. Mites (Laelaps microti and Neoschongastia signator) were also collected. Nematodes (Cheirapteranema sp.) were found in the intestines and cecae. Linzey and Linzey (1973b) recorded a flea (Ctenophthalmus pseudagyrtes) and a mite (Laelaps kochi) from one vole taken at Kanati Fork in December.

The rock vole ranges from Labrador west to northeastern Minnesota and south at higher elevations through New York and northeastern Pennsylvania. Disjunct populations occur in the southern Appalachian Mountains.

Rock voles were first discovered and named by Komarek (1932). The first specimens were taken in the Great Smoky Mountains National Park. They are fairly common above 3,000 feet elevation and often occur in association with the Southern red-backed vole (Clethrionomys gapperi).

References:

Kirkland, G.L., Jr. 1999. Rock Vole. Pages 629-630. In: D.E. Wilson, and S. Ruff (eds.). The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washington, D.C.

Kirkland, G.L., Jr. and F.J. Jannett, Jr. 1982. Microtus chrotorrhinus. Mammalian Species No. 180: 1-5. American Society of Mammalogists.

Komarek, E. V. 1932. Distribution of Microtus chrotorrhinus, with Description of a New Subspecies. Journal of Mammalogy 13(2): 155-158.

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

Linzey, A.V. and D.W. Linzey. 1973a. 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.

Linzey, A.V. and D.W. Linzey. 1973b. 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):15.

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. 1998. The Mammals of Virginia. The McDonald & Woodward Publishing Company, Inc., Blacksburg, Virginia.

Savage, T. 1967. The Diet of Rattlesnakes and Copperheads in the Great Smoky Mountains National Park. Copeia 1967 (1): 226-227.