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Species Description

• Adult total length: 5 1/2 - 7 in. (140 - 175 mm)

• Tail: 1 3/8 - 2 in. (35 - 51 mm)

• Hind foot: 3/4 - 1 in. (20 - 24 mm)

• Weight: 1 - 2 oz. (25 - 57 g)

• 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.

left lateral view of skull and mandible	dorsal view of skull	ventral view of skull

• Range Maps

  North America	Great Smokies

• Great Smoky Mountains National Park: 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).
  • Blount Co.: Spence Field (5,000 feet); Thunderhead (5,400 feet).

  • Cocke Co.: Indian Camp Creek Trail (2,650 feet).

  • Sevier Co.: Fort Harry Cliffs (3,200 feet); Newfound Gap Road (3,200 - 5,000 feet); Chapman Prong (3,200 feet); Lost Fork; Eagle Rocks Creek (3,500 - 4,000 feet); former Chimneys Campground; Ramsay Prong; Greenbrier Cove (3,500 - 4,700 feet); Grassy Patch (4,000 feet); Buck Fork (4,200 - 5,200 feet); Walker Prong (4,750 feet); Rocky Spring Gap; Indian Gap (5,200 feet); Sawtooth (5,500 feet); Silers Bald (5,620 feet).

  • State (Tenn. - N.C.) line: Newfound Gap (5,000 feet); Mt. Kephart (6,200 feet).

  • Swain Co.: Kanati Fork (2,800 feet); Bradley Fork (3,200 feet); Smokemont (3,000 - 3,200 feet); Newfound Gap Road (3,500 feet, 3,800 feet, 4,500 feet); Straight Fork of Raven Creek (3,600 feet); Mingus Mill Creek (4,000 feet); Forney Creek (4,700 feet); Pecks Corner Shelter (5,500 feet); Andrews Bald (5,700 feet, 5,800 feet); Clingmans Dome.

Index

Natural History

• 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
  No data.

• Terrestrial Ecology
  Rock voles may be active any time during the day or night and during all seasons.

  Food 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.

• University of Michigan, Museum of Zoology

Index

Acknowledgements

• Text
  • Dr. Donald W. Linzey, Wytheville Community College - wclinzd@wcc.vccs.edu
  • Christy Brecht, Wytheville Community College - wcbrecc@wcc.vccs.edu

• Photographs
  • Roger Barbour

• Map development
  • Richard Schulz, Great Smoky Mountains National Park - richard_schulz@nps.gov

• Web page design & coding
  • Denise Lim, University of Georgia, Athens
  • John Pickering, University of Georgia, Athens

• 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. Washington, D.C.: Smithsonian Institution Press.

• 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. Blacksburg, Virginia: The McDonald & Woodward Publishing Company, Inc.

• 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. Blacksburg, Virginia: The McDonald & Woodward Publishing Company, Inc.

• Savage, T. 1967. The diet of rattlesnakes and copperheads in the Great Smoky Mountains National Park. Copeia 1967 (1): 226-227.