Myodes gapperisouthern red-backed vole

Geographic Range

Red-backed voles, Myodes gapperi, range from British Columbia to mainland Newfoundland and throughout the northern United States from the Rocky Mountains to the Appalachians.

Habitat

Red-backed voles inhabit cool, mossy and rocky boreal forests in both dry and moist areas. They also inhabit tundra and bogs. Coniferous forests are preferred habitat, although deciduous or mixed coniferous/deciduous woods are also accepted. Nests are generally constructed under the roots of stumps, logs, or brush piles, but may be located in holes or branches of trees high above the ground.

Physical Description

The head and body length of red-backed voles varies between 70 and 112 mm. The tail is 25 to 60 mm long. Weights between 6 and 42 g have been recorded.

Red-backed voles have dense, long, soft fur in winter but this changes to shorter, coarser fur in summer. The general coloration above is dark gray with a pronounced chestnut brown stripe running along the back from head to tail. Face and sides appear yellowish brown and the underparts are dark slate gray to almost white. Males and females are similar in size and color, and young animals tend to be darker than adults.

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    6 to 42 g
    0.21 to 1.48 oz
  • Average mass
    20.57 g
    0.72 oz
  • Range length
    70 to 112 mm
    2.76 to 4.41 in

Reproduction

The mating system of these animals has not been described.

Breeding may begin as early as late winter and continue to late fall, so that females are generally able to rear 2 or 3 litters each year. Gestation is 17 to 19 days, and litter size is from 1 to 11 young, although the average is 3 to 7, depending on environmental conditions.

Offspring are born naked and blind. They are able to stand when 4 days old, have fur by day 8, open their eyes by 15 days and are weaned at 17 to 21 days. Sexual maturity occurs at approximately 3 months. Average life span in the wild is 10 to 12 months, with a maximum reported longevity of 20 months.

  • Breeding interval
    Breeding occurs every 1.5 months during warm weather.
  • Breeding season
    Breeding season extends from March through November.
  • Range number of offspring
    1 to 11
  • Average number of offspring
    3-7
  • Range gestation period
    17 to 19 days
  • Range weaning age
    17 to 21 days
  • Average age at sexual or reproductive maturity (female)
    3 months
  • Average age at sexual or reproductive maturity (male)
    3 months

The parental behavior of these animals has not been described. However, because they are mammals, we know that the mother provides some care for the young. Mothers nurse their offspring for 17 to 21 days after birth, and provide the young with a protective nest in which to live. It is not known whether males help to care for the young.

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Red-backed voles can live in the wild to be 20 months. However, most voles only live as long as 12 to 18 months

  • Range lifespan
    Status: wild
    20 (high) months
  • Typical lifespan
    Status: wild
    12 to 18 months

Behavior

Red-backed voles are active night and day (more often at night) year round, staying close to fallen logs or rocks and frequently traveling though underground passages when they forage. They usually hop rather than run and are agile jumpers and climbers. They do not generally make runways of their own, but they often use those of other small mammals such as shrews or moles. Red-backed voles construct spherical nests of grasses, mosses, lichens, or shredded leaves. During the winter, these are sometimes placed directly on the ground under the snow, with tunnels radiating from the nest under the snow. Home ranges may be as large as 1.4 ha in the summer (0.5 ha is most common) and as small as 0.14 ha in the winter, when foraging is restricted by a blanket of snow.

When disturbed, red-backed voles utter a chirplike bark that can be heard 1 to 2 m away. They may flee or freeze in position, depending on their preceding activity. They also gnash or chatter their teeth.

Red-backed voles are quite territorial, excluding other red-backed voles from their homes and showing aggression toward other species as well. No communal living or pair bonds have been observed, with the only amicable interactions among individuals occuring at mating time and between a mother and her offspring.

  • Range territory size
    1,400 to 14,000 m^2

Home Range

Home ranges range in size from 0.14 ha in the winter to 1.4 ha in the summer (0.5 ha is most common) and as small as 0.14 ha in the winter.

Communication and Perception

Communication in these animals has not been thoroughly described. Some vocalizations are used. When disturbed, red-backed voles utter a chirplike bark that can be heard 1 to 2 m away. They also gnash or chatter their teeth.

In addition, visual cues such as body posture may be of some importance in interactions with members of the same species.

The role of chemical signals in these animals remains unknown, although it is likley that some information is transmitted through scents.

Tactile communication is important in aggression, as well as in the relationship between a mother and her offspring.

Food Habits

Red-backed voles are opportunistic feeders and change their diet as the seasons progress. They eat leaf petioles and young shoots in the spring, add fruits and berries to their diet in the summer, and then switch to nuts and seeds in the autumn. They also consume some bark, roots, lichens, fungi, and insects. They sometimes store food in their nests for use in the winter when it becomes difficult to forage, although they continue to forage for seeds, tree roots, and bark under the snow.

  • Animal Foods
  • insects
  • Plant Foods
  • leaves
  • roots and tubers
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit
  • flowers
  • Other Foods
  • fungus

Predation

Red-backed voles are almost certainly eaten by a number of predatory species. Owls, hawks, mustelids, black bears, Canada lynx, bobcats, coyotes, foxes, and wolves are all likely predators of these small rodents.

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

These animals are likely to play some role in local food webs. As a prey item, these voles provide food for many other species. As predators, they may have a great impact on some insect populations. In addition, they help to disperse seeds.

Economic Importance for Humans: Positive

Red-backed voles destroy harmful insect larvae and are also a major source of food for fur-bearing animals. They have been found to be important in some areas as agents in transporting and burying seeds, although some seeds are obviously eaten.

Economic Importance for Humans: Negative

Red-backed voles may damage or kill tree seedlings, and they also eat a large number of seeds. This has been of little economic importance to humans, however.

Conservation Status

Populations of Myodes gapperi often fluctuate widely from year to year but with no apparent periodicity. Numbers are fairly low in most of the species range, however, with an average of approximately 2 to 3 voles per acre in favorable habitat.

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Liz Ballenger (author), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

taiga

Coniferous or boreal forest, located in a band across northern North America, Europe, and Asia. This terrestrial biome also occurs at high elevations. Long, cold winters and short, wet summers. Few species of trees are present; these are primarily conifers that grow in dense stands with little undergrowth. Some deciduous trees also may be present.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tundra

A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Jackson, H.H.T. 1961. Mammals of Wisconsin. The University of Wisconsin Press, Madison, Wisconsin.

Kurta, A. 1995. Mammals of the Great Lakes Region. The University of Michigan Press, Ann Arbor, Michigan.

Nowak, R.M. and J.L Paradiso. 1983. Walker's Mammals of the World. 4th edition. John Hopkins University Press, Baltimore, Maryland.