Clethrionomys
gapperi
(Southern Red-backed
Vole)
Description:
This small, mouse-type mammal
has dark brown hair on its back with a
reddish, rusty colored band from its head to its tail. Its is grayish
to whitish underneath. Its short tail is somewhat bicolored. Total length is
about 5 to 6.8 inches (124-170 mm), tail length is 1.4 to 1.8 inches (34-45
mm), and they weigh 0.6 to 0.7 ounces (18-22 g).
Range:
Most
of forested Canada, south through Rockies, northern Great Plains, northern Great
Lakes, New England, and Appalachian Mountains.
Habitat:
Prefers cool, moist, deciduous
, coniferous or mixed forests, especially
areas with large amounts of ground cover. Will also use second-growth areas.
Mossy logs and tree roots in coniferous forests are optimal. Idaho study found
species prefers mature grand fir stands over younger stands.
Diet:
The red-backed vole might be best described as an opportunistic feeder;
feeding on fungi (mushrooms) during summer and fall, but shifting to seeds,
some roots and bark during the winter. They are also known to eat insects.
Ecology:
They are active year-round,
and they appear to be mainly nocturnal. Like deer mice, they
travel under thj snow all winter and range over an area of about 1.3 acres (0.5
ha). They build round nests about 4 inches across, composed of grasses and other
fine materials. The nests are on the ground and usually tucked under logs or
stumps. They appear to have a large water requirement for their size (compared
to other similar-sized mice) which probably accounts for their moist habitat
requirements. They are know to be important dispersers of viable spores of mycorrhizal fungi and nitrogen-fixing bacteria.
Mature females are thought to be territorial. Their populations are do not cycle
like other “voles”. In Idaho, population density peaks in late summer to early
fall and density up to 26 per acre (65 per ha) have been recorded. This species
does not colonize area that have been recently burned, and clearcut logging
may reduce their populations. This species is preyed upon by mustelids, canids
and raptors. The red-backed vole is often the most common small mammal in coniferous
forests.
Reproduction:
They breed in mid-January
to late November, but peak breeding activity occurs February to October. Gestation
lasts 17 to 19 days, and litter size varies from 1 to
9 young (average 5.6 in Alberta, 6.5 in Colorado). In Alberta, young females
produce 1 to 4 litters per year, older females produce 1 to 6; in Colorado,
females produce 2 litters per year, and young-of-year breed as well.
Conservation:
 Status: |
 Unprotected
nongame species |
|
Global Rank: |
|
|
State Rank: |
S5 |
Important State References:
Scrivner, J.H. and H.D. Smith. 1984.
Relative abundance of small mammals in four successional stages of spruce-fir
in Idaho. Northwest Science 58:171-176.