Northern red-backed voles are common prey to many carnivores and raptors. Cryptic coloration and crepuscular behavior are both antipredatory adaptations.
Known Predators:
Anti-predator Adaptations: cryptic
Northern red-backed voles are medium mouse-sized, reaching an average total length of 130 to 158 mm and usually weighing about 30 g. The tail is 30 to 40 mm long, hind foot is 18.5 to 21.0 mm long and ears are 10 to 14 mm long. Pelage is light gray with the dorsal surface exhibiting rusty-to-reddish color. Color intensity varies with season (darkest in winter), geographic distribution, and subspecies. The tail is dark gray dorsally, yellow ventrally, and densely covered with hair. Terminal hairs on the tail are often long and dark.
At least 10 subspecies have been described, but researchers differ on the species composition and subspecies validity. Juvenile pelage is similar to adults. There are 8 mammae. The dental formula is I1/1 C0/0 P0/0 M3/3 = 16. Basal metabolic rate is not reported, but average respiratory frequency in normoxic atmosphere is 120 breaths per minute.
Myodes rutilus may sometimes be confused with Myodes gapperi along the southern boundary of the species range. The two species can be distinguished, however, because M. rutilus has brighter reddish coloration than does M. gapperi. Also, the tail of M. rutilus is shorter and thicker than that of M. gapperi.
Range mass: 20 to 40 g.
Range length: 130 to 158 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
Northern red-backed voles normally survive less than 2 years in the wild; however, average lifespan information varies among publications and is probably affected by locally and temporally varying factors, such as food availability, predation, population density, seasonal weather patterns, etc. Adult mortality is highest in winter and is directly proportional to weather severity. Based on published information, it is unclear whether mortality results mostly from predation, starvation, aging, or other causes.
Range lifespan
Status: wild: 2 (high) years.
Range lifespan
Status: captivity: 728 (high) days.
Typical lifespan
Status: wild: 12 (high) months.
Average lifespan
Status: wild: 6 months.
Average lifespan
Status: captivity: 203 days.
Northern red-backed voles are found in a wide range of terrestrial habitats. They are commonly found in tundra, taiga, and shrub forests. Greatest population densities were recorded in overgrown talus slopes and in stands of dwarf willow, alder, and dwarf birch.
Range elevation: 1800 (high) m.
Habitat Regions: temperate ; polar ; terrestrial
Terrestrial Biomes: tundra ; taiga ; forest ; scrub forest
Wetlands: marsh ; swamp ; bog
Other Habitat Features: suburban ; agricultural ; riparian
Myodes rutilus is a Holarctic species first described from Siberia. It occurs in northern Europe, Asia, Alaska, and Canada.
Biogeographic Regions: nearctic ; palearctic
Other Geographic Terms: holarctic
Diet varies and includes berries, leaves, shoots, buds, and seeds of various plants, epigeous and hypogeous fungi, and lichens. Their diet includes a large variety of plant materials in the summer when plants are abundant. Voles gather and store food in their nests and the stored food comprises most of their diet during the winter months. Small invertebrates may occasionally be included in the diet and animal foods (e.g. eggs, cat/dog food) are sometimes fed in captivity.
Animal Foods: eggs; carrion ; insects; terrestrial non-insect arthropods; mollusks; terrestrial worms
Plant Foods: leaves; roots and tubers; wood, bark, or stems; seeds, grains, and nuts; fruit; nectar; pollen; flowers; sap or other plant fluids; bryophytes; lichens
Other Foods: fungus
Foraging Behavior: stores or caches food
Primary Diet: herbivore (Folivore )
Northern red-backed voles act as plant and fungi dispersers (by caching seeds, breaking and relocating parts of vegetation, and ingestion and excretion of spores). They also play an important role as prey to many carnivorous predators, because they are active all winter long when other prey becomes less abundant.
Ecosystem Impact: disperses seeds
Species Used as Host:
Northern red-backed voles have been used as laboratory animals, but require more care and skill in handling than mice.
Positive Impacts: research and education
Northern red-backed voles readily invade human structures and dwellings. In high densities they can cause damage to farm crops. Interstitial pneumonia and interstitial nephritis were documented in northern red-backed voles, but involvement of viral agents was only suggested. No published information is available on viral or bacterial health threats.
Negative Impacts: injures humans (bites or stings); crop pest; household pest
Northern red-backed voles are usually common and not protected throughout their range.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Communication and perception are underrepresented in literature. High-pitch vocalization may be produced in high stress situations, such as hostile contacts with potential predators. As in most mammals, it is likely that these voles use some forms of tactile communication during reproduction. Visual cues may also be used.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; infrared/heat ; tactile ; acoustic ; vibrations ; chemical
Species-specific information on the mating system is not available for wild populations. However, captive colonies in laboratory settings were reported to be promiscuous.
Mating System: polygynandrous (promiscuous)
Northern red-backed voles breed from May until September, usually beginning breeding when the snow melts. They can be prolific, producing as many as 5 litters during this time. Postpartum estrus in females helps to increase the rate of reproduction. Winter breeding has been reported to be infrequent.
Pregnancy lasts from 17 to 19 days. Litters of M. rutilus range from 1 to 9, although litters are commonly of 6 to 8 young. The young develop rapidly, and are weaned by about 18 days of age. The young voles become independent at the time of weaning. Reproductive maturity is reached at a minimum age of 2 months. The percentage of sexually mature juveniles varies inversely with population density.
Breeding interval: Northern red-backed voles can breed up to 5 times in a year. Breeding mostly occurs in the warmer months. One study reported it takes a minimum of 20.5 days between litters.
Breeding season: Breeding season generally occurs May to September, but may be longer or shorter depending on climate and weather conditions. One study suggests that the onset of breeding season is related to timing of snow ablation.
Range number of offspring: 1 to 9.
Average number of offspring: 5.4.
Range gestation period: 17 to 19 days.
Average weaning age: 18 days.
Average time to independence: 18 days.
Range age at sexual or reproductive maturity (female): 2 (low) months.
Range age at sexual or reproductive maturity (male): 2 (low) months.
Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous ; post-partum estrous
Males participate in copulation only and do not take any part in parental care. Captive females are reported to enlarge and improve nests prior to giving birth by collecting and modifying soft materials. Both males and females occasionally cannibalize young. It is difficult to estimate average litter sizes and numbers of weaned offspring in the wild, because weaning periods are short and weaned offspring tend to migrate as soon as they leave the nest. As a result, population recruitment rates include immigration, which makes it difficult to estimate reproduction. Captive females that produced average litters of 4.9 offspring weaned only 3.6 young per litter.
Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
The northern red-backed vole (Clethrionomys rutilus) is a small slender vole found in Alaska, northern Canada, Scandinavia and northern Russia.[2]
They have short slender bodies with a rust-colored back, light brown sides and underparts and a short thick tail. Their short ears are visible through their fur. They are 14 cm long with a 3.5 cm tail and weigh about 30 to 40 g. Their dental formula is 1/1, 0/0, 0/0, 3/3.[3] They are active year-round, usually at night. They can cause damage to fruit trees and stored grains.
Northern red-backed voles live in a variety of northern forest and shrubland habitats.[2][4] They occur in every major forest type in central Alaska.[5] Plant species commonly found in areas occupied by northern red-backed voles include black spruce (Picea mariana), white spruce (Picea glauca), quaking aspen (Populus tremuloides), paper birch (Betula papyrifera), alder (Alnus spp.), willow (Salix spp.), mountain cranberry (Vaccinium vitis-idaea), blueberry and bilberry (Vaccinium spp.), bunchberry (Cornus canadensis), and a variety of grasses and forbs. Important fungi, mosses and lichens include truffle (Endogone fascilulata), Schreber's moss (Pleurozium schreberi), mountain fern moss (Hylocomium splendens), sphagnum (Sphagnum spp.), and lichens (Cladonia and Peltigera spp.).[5][6]
The breeding season of northern red-backed voles generally extends from May to August. Females are polyestrous and produce two or three litters during the breeding season. The first litter is produced in late May or early June.[2]
Litter size ranges from four to nine. The average litter size is 5.93.[2] Young northern red-backed voles are unable to regulate their temperature successfully until about 18 days. At this time they are weaned and leave the nest. Young grow little during the winter because of low food supplies. Age of sexual maturity depends to some extent on time of birth. About 20% of females from the first litter breed during the summer of birth. The remaining 80%, and later litters, breed the following May.[2] Martell and Fuller [7] found that the onset of summer breeding was related to the time of snowmelt. A late spring was followed by a low rate of maturation of young-of-the-year females.[7]
In dense populations of northern red-backed voles, sexual maturation of young females may be delayed, or they may migrate to a vacant breeding space.[8]
Northern red-backed voles are mainly nocturnal and crepuscular, but remain active whenever necessary during the prolonged arctic daylight season.[2]
Northern red-backed voles are commonly found in northern shrub vegetation or open taiga forests. They also inhabit tundra.[2][5][7] Northern red-backed voles are abundant on early successional sites as well as in mature forests.[5] They occasionally inhabit rock fields and talus slopes.[2]
Northern red-backed voles use surface runways through the vegetation as travel corridors. Nests are built in short burrows or under some protective object such as a rock or root.[2] Northern red-backed voles are active all winter and construct long tunnels under the snow. Winter nests typically are placed on the ground among thick moss.[2][5] Northern red-backed voles frequently invade houses during the winter.[2]
Northern red-backed voles inhabit areas that contain dense ground cover for protection from weather and predation.[5][9] On the Kenai National Wildlife Refuge in south-central Alaska, the presence of northern red-backed voles was positively correlated with protective cover.[6] During the winter, northern red-backed voles use layers of thick moss or matted vegetation as thermal cover.[5][10] During the mid-winter months in a spruce forest of central Alaska, all northern red-backed voles on a control area aggregated in a small area of thick moss cover, despite abundant food resources elsewhere on the trapping grid.[5]
Northern red-backed voles eat the leaves, buds, twigs and berries of numerous shrubs; they also eat forbs, fungi, mosses, lichens, and occasionally insects.[2][5][6] Berries are generally the major food item in the diet of northern red-backed voles and are eaten whenever available. In central Alaska, West [5] found that northern red-backed voles relied heavily upon the fruits of several berry-producing plants during all seasons. These included bog blueberry (Vaccinium uliginosum), mountain cranberry, black crowberry (Empetrum nigrum), comandra (Comandra livida), and bunchberry. Northern red-backed voles primarily ate berries during the fall and winter. Lichens were consumed only during the winter and spring. In early summer, when berries are not available, mosses were eaten. The mid- to late summer diet of northern red-backed voles also included a large proportion of mosses, although berries were still the primary food.[5]
Northern red-backed voles on the Kenai National Wildlife Refuge fed during the summer on berries of species such as mountain cranberry and bunchberry. They also ate fungi, succulent green plants, and insects. As fungi became plentiful late in the summer, they made up a large percentage of the diet. Mountain cranberry consumption declined as the summer progressed even though berry abundance increased. This suggests that fungi were preferred over mountain cranberries. The amount of truffle in the diet remained constant throughout the summer.[6]
Some predators of northern red-backed voles include American marten (Martes americana), Arctic fox (Alopex lagopus), red fox (Vulpes vulpes), raccoon (Procyon lotor), stoat (Mustela erminea), snowy owl (Bubo scandiacus), coyote (Canis latrans),[9][11][12] and probably most other predators of small mammals that occur within the range of northern red-backed voles. In Alaska, northern red-backed voles and voles (Microtus spp.) comprised 74% of the diet of American martens in the summer and 68% of the diet during the winter.[12]
This article incorporates public domain material from Myodes rutilus. United States Department of Agriculture.
The northern red-backed vole (Clethrionomys rutilus) is a small slender vole found in Alaska, northern Canada, Scandinavia and northern Russia.
