Myodes gapperi - (Vigors, 1830)
Southern Red-backed Vole
Other English Common Names: Gapper's Red-backed Vole, southern red-backed vole
Synonym(s): Clethrionomys gapperi (Vigors, 1830)
Taxonomic Status: Accepted
Related ITIS Name(s): Clethrionomys gapperi (Vigors, 1830) (TSN 180294)
French Common Names: campagnol de Gapper, campagnol à dos roux de Gapper
Unique Identifier: ELEMENT_GLOBAL.2.105153
Element Code: AMAFF09020
Informal Taxonomy: Animals, Vertebrates - Mammals - Rodents
Kingdom Phylum Class Order Family Genus
Animalia Craniata Mammalia Rodentia Cricetidae Myodes
Check this box to expand all report sections:
Concept Reference
Concept Reference: Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at:
Concept Reference Code: B93WIL01NAUS
Name Used in Concept Reference: Clethrionomys gapperi
Taxonomic Comments: Includes subspecies occidentalis and caurinus, which formerly were included in the species now known as Myodes californicus. Some authors have suggested that rutilis and gapperi are conspecific, but this has not been accepted by most authorities (Jones et al. 1992; Musser and Carleton, in Wilson and Reeder 1993, 2005).

See Musser and Carleton (in Wilson and Reeder 2005) for an extensive discussion of the basis for correcting the generic name from Clethrionomys to Myodes.
Conservation Status

NatureServe Status

Global Status: G5
Global Status Last Reviewed: 04Apr2016
Global Status Last Changed: 12Nov1996
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G5 - Secure
Nation: United States
National Status: N5 (05Sep1996)
Nation: Canada
National Status: N5 (22Jan2016)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alaska (S4), Arizona (S3), Colorado (S5), Connecticut (S5), Georgia (S3S4), Idaho (S4), Iowa (S2), Kentucky (S3), Maine (S5), Maryland (S5), Massachusetts (S5), Michigan (S3S4), Minnesota (SNR), Montana (S4), New Hampshire (S5), New Jersey (S5), New Mexico (S3), New York (S5), North Carolina (S5), North Dakota (SNR), Ohio (SH), Oregon (S4?), Pennsylvania (S5), Rhode Island (S4), South Carolina (S2S3), South Dakota (S4), Tennessee (S4), Utah (S2S3), Vermont (S5), Virginia (S5), Washington (S5), West Virginia (S4), Wisconsin (S5), Wyoming (S5)
Canada Alberta (S5), British Columbia (S5), Labrador (S5), Manitoba (S5), New Brunswick (S5), Newfoundland Island (SNA), Northwest Territories (S5), Nova Scotia (S5), Ontario (S5), Prince Edward Island (S5), Quebec (S5), Saskatchewan (S5), Yukon Territory (S2S3)

Other Statuses

IUCN Red List Category: LC - Least concern

NatureServe Global Conservation Status Factors

Range Extent Comments: Most of forested Canada (northern British Columbia to Labrador) south through the Rocky Mountains to central New Mexico and east-central Arizona, northern Great Plains (to Iowa), northern Great Lakes, New England and Appalachian Mountains (to northern Georgia).

Other NatureServe Conservation Status Information

Global Range: Most of forested Canada (northern British Columbia to Labrador) south through the Rocky Mountains to central New Mexico and east-central Arizona, northern Great Plains (to Iowa), northern Great Lakes, New England and Appalachian Mountains (to northern Georgia).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AK, AZ, CO, CT, GA, IA, ID, KY, MA, MD, ME, MI, MN, MT, NC, ND, NH, NJ, NM, NY, OH, OR, PA, RI, SC, SD, TN, UT, VA, VT, WA, WI, WV, WY
Canada AB, BC, LB, MB, NB, NFexotic, NS, NT, ON, PE, QC, SK, YT

Range Map
Note: Range depicted for New World only. The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at

Range Map Compilers: Sechrest, 2002

U.S. Distribution by County Help
State County Name (FIPS Code)
AK Ketchikan Gateway (02130), Prince of Wales-Outer Ketchikan (CA) (02201), Wrangell-Petersburg (CA) (02280)
AZ Apache (04001), Greenlee (04011)*
GA Rabun (13241), Towns (13281), Union (13291)
IA Cerro Gordo (19033)*, Hancock (19081), Winnebago (19189), Worth (19195)*
KY Bell (21013)*, Harlan (21095), Letcher (21133)
OH Jefferson (39081)*
PA Berks (42011)*, Lehigh (42077)*, Northampton (42095)*, Schuylkill (42107)*
SC Oconee (45073)
SD Custer (46033), Day (46037)*, Lawrence (46081), Marshall (46091), Meade (46093), Pennington (46103), Roberts (46109)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
02 Middle Delaware-Musconetcong (02040105)+*, Lehigh (02040106)+*, Schuylkill (02040203)+*, Lower Susquehanna-Penns (02050301)+*, Lower Susquehanna-Swatara (02050305)+*
03 Seneca (03060101)+, Tugaloo (03060102)+
05 Upper Ohio (05030101)+*, North Fork Kentucky (05100201)+, Middle Fork Kentucky (05100202)+, Upper Cumberland (05130101)+
06 Upper Little Tennessee (06010202)+, Powell (06010206)+*, Hiwassee (06020002)+
07 Upper Minnesota (07020001)+, Shell Rock (07080202)+*, Winnebago (07080203)+
09 Western Wild Rice (09020105)+*
10 Beaver (10120107)+, Middle Cheyenne-Spring (10120109)+, Rapid (10120110)+, Middle Cheyenne-Elk (10120111)+, Lower Cheyenne (10120112)+, Lower Belle Fourche (10120202)+, Redwater (10120203)+, Upper James (10160003)+
15 Little Colorado headwaters (15020001)+, Upper Little Colorado (15020002)+*, Silver (15020005)+*, San Francisco (15040004)+*, Black (15060101)+, White (15060102)+
19 Southeast Mainland (19010101)+, Ketchikan (19010102)+, Mainland (19010201)+, Kuiu-Kupreanof-Mitkof-Etolin-Zarembo-Wrangell Isla (19010202)+, Icy Strait-Chatham Strait (19010500)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
Reproduction Comments: Breeds mid-January to late November; peak activity February-October. Gestation lasts 17-19 days. Litters size is 1-9 (average 5.6 in Alberta, 6.5 in Colorado). Litters/year: 1-4 for young, 1-6 for older females in Alberta; 2/year in Colorado (young of year breed).
Ecology Comments: Disperses viable spores of mycorrhizal fungi and nitrogen-fixing bacteria (see Maser and Maser 1988).

Home range varies from 0.25 to 3.5 acres (Merritt and Merritt 1978). Experimentation by Gillis and Nams (1998) suggests that populations separated by an inter-patch distance of 60-70 m likely would be isolated from one another. Mature females are territorial. Populations noncyclic.

Non-Migrant: Y
Locally Migrant: N
Long Distance Migrant: N
Palustrine Habitat(s): Bog/fen, FORESTED WETLAND
Terrestrial Habitat(s): Forest - Conifer, Forest - Hardwood, Forest - Mixed, Shrubland/chaparral
Special Habitat Factors: Burrowing in or using soil, Fallen log/debris
Habitat Comments: Prefers cool, mesic deciduous, coniferous, or mixed forests, especially areas with large amount of ground cover. Regarded as an ecological indicator of old-growth conditions in the Rocky Mountains. Also uses second-growth areas. Mossy logs and tree roots in coniferous forests are optimal. In the northern part of its range also found in muskegs, sedge marshes, shrubby habitats, and treed peatlands (Merritt, in Wilson and Ruff 1999). Often on rock outcrops in some areas (e.g., Virginia). Often associated with abandoned stone walls (fences) in the northeastern U.S. In Pennsylvania, abundance increased with forest fragmentation (Yahner 1992). Nests under logs, stumps and roots. Unlike MICROTUS, doesn't dig tunnels, but uses the burrows of moles and other small mammals.
Adult Food Habits: Herbivore
Immature Food Habits: Herbivore
Food Comments: Feeds chiefly on vegetation, seeds, nuts, fungi, some insects; summer diet in Colorado (and much of western U.S.) consists almost entirely of fungi.
Adult Phenology: Crepuscular, Nocturnal
Immature Phenology: Crepuscular, Nocturnal
Phenology Comments: Mainly nocturnal, active year-long.
Length: 16 centimeters
Weight: 42 grams
Economic Attributes Not yet assessed
Management Summary Not yet assessed
Population/Occurrence Delineation
Group Name: Small Murid Rodents

Use Class: Not applicable
Minimum Criteria for an Occurrence: Evidence of historical presence, or current and likely recurring presence, at a given location. Such evidence minimally includes collection or reliable observation and documentation of one or more individuals in appropriate habitat where the species is presumed to be established and breeding.
Mapping Guidance: Separate sites separated by less than 1000 meters should be mapped as separate polygons.
Separation Barriers: Barriers include: wide highways with heavy traffic (subjective determination) and highways with continuous solid barriers that prevent rodent passage; major water bodies, arbitrarily set at those greater than 50 meters across in ice-free areas and those greater than 200 meters wide if frozen regularly.
Separation Distance for Unsuitable Habitat: 2 km
Separation Distance for Suitable Habitat: 5 km
Separation Justification: Home ranges may be quite small, but at least some species exhibit good dispersal ability that may take them several kilometers from their natal area (Maier 2002). Peromyscus that have been displaced up to 3 km may return home within a few days (see Maier 2002). Displaced Neotoma fuscipes dispersed up to at least 1.6 km from their release point in five nights (Smith 1965). A male Dicrostonyx richardsoni moved more than 3 kilometers per day several times (Engstrom, in Wilson and Ruff 1999). Some species can traverse significant distances of unsuitable habitat. For example, Peromyscus leucopus may move between wooded areas separated by a deforested agricultural gap of up to at least 2 km (Krohne and Hoch 1999). In New Brunswick, a tagged subadult male Peromyscus maniculatus was captured at locations 1.77 km apart after a period of 2 weeks in September, suggesting that dispersal may extend at least this far (Bowman et al. 1999). In Kansas, individual Peromyscus maniculatus were captured at trap sites up to 1.32 km apart (Rehmeier et al. 2004). Dispersal can play a key role in the population dynamics of murid rodents.

Patterns of genetic (DNA) variation indicate that gene flow can be low among subpopulations of Neotoma magister and that effective dispersal is limited among subpopulations separated by as little as 3 km (Castleberry et al. 2002).

Separation distance for suitable habitat is a compromise between the typical small home range sizes of these mammals and their sometimes considerable dispersal ability and the likely low probability that two occupied locations separated by less than several kilometers of suitable habitat would represent independent populations.

Roads, especially divided highways, are major barriers to dispersal in small mammals (Oxley et al. 1974, Wilkins 1982, Garland and Bradley 1984).

Date: 08Mar2005
Author: Hammerson, G., and S. Cannings
Notes: Group contains most members of the family Muridae: mice, voles, lemmings, woodrats, etc.
Population/Occurrence Viability
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
Element Ecology & Life History Edition Date: 07Dec1993
Element Ecology & Life History Author(s): Hammerson, G.

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