Clethrionomys gapperi

Southern Red-backed Vole
(*Clethrionomys gapperi*)
Southern Red-backed Vole (Clethrionomys gapperi)
Range
Taxonomic classification
Order:	Rodentia
Suborder:	Supramyomorpha
Infraorder:	Myomorphi
Superfamily:	Muroidea
Family:	Cricetidae
Subfamily:	Arvicolinae
Tribe:	Clethrionomyini
Genus:	Clethrionomys
Binomial details
	Clethrionomys gapperi (Vigors in Gapper, 1830)
Other resources
	Full taxonomic details at MDD

The Southern Red-backed Vole (Clethrionomys gapperi) is a reddish vole found in a wide range of forest habitats, peat bogs, sedge marshes, shrub communities, rocky ridges, mesic prairie, and tundra (Merritt, 1981).

Description

From Naughton (2012): "Most Southern Red-backed Voles have a silvery underside, greyish-brown sides that have an ocherous or yellowish wash, and a broad band of chestnut-coloured fur along their back from forehead to tail. Their thinly furred tail is weakly bicoloured, dark above and silvery-grey, buff, or slate grey below, usually with a black tip. Ears and eyes are noticeable. A second colour phase is possible in any population; this dark form (melanistic) is sooty black on their back, and their sides are greyish brown. Individuals with the dark pattern are more common in northern and eastern populations."

From Armstrong et al. (2010): "the red-backed vole has a broad, reddish mid-dorsal stripe extending from forehead to tail. The background color is grayish brown. The belly is grayish with the bases of the hairs black. The bicolored tail is relatively long for an arvicoline but does not approach that of the long-tailed vole [Microtus longicaudus]. The ears are short and partly hidden by the body fur."

External measurements

Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.

Part of range	Reference	Total length	Tail length	Hindfoot length	Ear length	Mass
Arizona (White Mtns.)	Hoffmeister (1986)	127–162 (n=18)	34–47 (n=18)	18–21 (n=18)
Carolinas, Virginia, Maryland	Webster et al. (1985)	140–155	38–50			20–42
Colorado	Armstrong et al. (2010)	125–152	33–44	17–19	12–16	20–38
Minnesota	Hazard (1982)	114–150	30–45	17–19.2	11.5–17	14.8–34.3
North Dakota	Seabloom et al. (2020)	134	37	18	14	24

Color variation

This section shows some of the color variation present in Clethrionomys gapperi. The location is provided for reference only. The individual shown does not necessarily represent the only color variant within the local population.

NEON01IPP. Clethrionomys gapperi. Adult female. Rocky Mountain National Park, Boulder County, Colorado, Boulder County
NEON054FT. Clethrionomys gapperi. Adult male. Harvard Forest & Quabbin Watershed, Worcester County, Massachusetts.
NEON05G5Z. Clethrionomys gapperi. Adult female. Mountain Lake Biological Station, Giles County, Virginia.
NEON0A6OI. Clethrionomys gapperi. Adult male. Wind River Experimental Forest, Skamania County, Washington.
NEON08I3T. Clethrionomys gapperi. Adult male. Lincoln County, Wisconsin.

Skull

From Armstrong et al. (2010): "The skull resembles that of Microtus, with a blocky shape and prismatic cheekteeth, although the cheekteeth are different in that they are rooted (this showing distinct patterns of wear), not rootless (hence ever-growing) as molars are in voles of the genus Microtus. The lower molars have inner and outer reentrant angles of about the same depth. The angles are generally opposite one another so that they nearly meet in the middle of the tooth. In Microtus and Phenacomys, by contrast, inner and outer reentrant angles of lower molars are notably offset from each other. The palate ends at the level of M3 in a simple transverse shelf with no posterior projection."

NEON01IC0. Clethrionomys gapperi. Adult male. Bartlett Experimental Forest, Carroll County, New Hampshire. Collected 11 September 2018. Dorsal view of the skull.
NEON01IC0. Clethrionomys gapperi. Adult male. Bartlett Experimental Forest, Carroll County, New Hampshire. Collected 11 September 2018. Lateral view of the skull. Long scale bar is 1 cm; short scale bar is 1 mm.
NEON01IC0. Clethrionomys gapperi. Adult male. Bartlett Experimental Forest, Carroll County, New Hampshire. Collected 11 September 2018. Ventral view of the skull. Long scale bar is 1 cm; short scale bar is 1 mm.
NEON01IC0. Clethrionomys gapperi. Adult male. Bartlett Experimental Forest, Carroll County, New Hampshire. Collected 11 September 2018. Dorsal view of the lower jaw. Long scale bar is 1 cm; short scale bar is 1 mm.
Holotype: USNM 109945. Clethrionomys gapperi athabascae. Adult female. Fort Smith, near the Athabaska (Alberta)-Mackenzie line, Mackenzie District, Northwest Territories, Canada. Collected 27 June 1901.
NEON01IC0. Clethrionomys gapperi. Adult male. Upper molars.
NEON01IC0. Clethrionomys gapperi. Adult male. Lower molars.

Footprint

NEON06NZY. Clethrionomys gapperi. Right front footprint.
NEON0A5HI. Clethrionomys gapperi. Right hind footprint.

Similar species

Southern Red-backed Vole (Clethrionomys gapperi) are easily distinguished from other sympatric voles by the broad, reddish mid-dorsal stripe extending from forehead to tail. However, Merritt (1981) provides the following when comparing with congeners: "Species of Clethrionomys are difficult to distinguish morphologically; no single character is sufficient to distinguish C. gapperi from other species of Clethrionomys. C. gapperi differs from C. rutilus as follows: tail more slender, and with sparser and less bristly hairs (Hall and Cockrum, 1953); dorsum brighter red; post palatal bridge generally a solid, truncated shelf (C. rutilus has an incomplete palatal shelf or a central notch. Bailey, 1897; Burt, 1946; Hall and Cockrum, 1953; Hall, in press).

Dorsal view of the Southern Red-backed Vole (Clethrionomys gapperi) showing the broad, reddish mid-dorsal stripe extending from forehead to tail.
Dorsal view of Northern Red-backed Vole (Clethrionomys rutilus) showing the broad, reddish mid-dorsal stripe extending from forehead to tail.
Dorsal view of the Western Meadow Vole (Microtus drummondii), as an example of a sympatric vole species that lacks the broad, reddish mid-dorsal stripe.

References

Armstrong DM, Fitzgerald JP, Meaney CA. 2010. Mammals of Colorado, Second Edition. Denver (CO, USA): University Press of Colorado.

Hazard EB. 1982. The mammals of Minnesota. Minneapolis (MN, USA): University of Minnesota Press.

Hoffmeister DF. 1986. Mammals of Arizona. Tucson (AZ, USA): University of Arizona Press.

Merritt JF. 1981. Clethrionomys gapperi. Mammalian Species (146): 1–9. https://doi.org/10.2307/3503900

Naughton D. 2012. The natural history of Canadian mammals. Toronto (ON, CA): University of Toronto Press.

Seabloom R, Hoganson JW, Jensen WF. 2020. The mammals of North Dakota. Fargo (ND, USA): North Dakota State University Press.

Webster WD, Parnell JF, Biggs WC. 1985. Mammals of the Carolinas, Virginia, and Maryland. Chapel Hill (NC, USA): University of North Carolina Press.