Perception Channels: tactile ; chemical
Myodes californicus are adversely affected by habitat fragmentation (due to reduced sporocarp abundance in cleared fields). They are also known to avoid road verge habitats, prefering to remain towards the forest interior. Human development of land, therefore, can apply a significant and damaging effect on M. californicus abundance.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
M. californicus feed primarily on the ectomycorrhizal fungi symbionts of trees and probably help disperse the fungal spores. These symbiotic relationships are believed to be essential for the health and growth of trees
Ecosystem Impact: disperses seeds
Interestingly, M. californicus seems to rely heavily on fungal sprorocarps (75 to 90% of diet). These voles appear to have physiological and morphological adaptations of their digestive sytems which allow them to digest to fibrous materials of EMF (ectomycorrhizal fungi) sporocarps more efficiently than their body size would suggest. Myodes californicus is also known to eat some lichens, green vegetation (late winter), seeds, twigs, and insects (and occasionally insect larvae). Foraging is mostly terrestrial, but they occassionally climb into trees and shrubs in search of food. There is some evidence that they cache fungi for later consumption.
Animal Foods: insects
Plant Foods: leaves; seeds, grains, and nuts; lichens
Foraging Behavior: stores or caches food
Primary Diet: mycophage
Pacific coast of northern California and Oregon.
Biogeographic Regions: nearctic (Native )
Myodes californicus prefers forested riparian habitats and is often found at stream edges. Abundance is positively correlated to size of logs, depth of organic soil, diameter of standing trees and snag size. Overall, old-growth, naturally degenerate forests with moist soils, abundant ground cover and litter are the ideal habitat.
Range elevation: 0 to 1900 m.
Habitat Regions: temperate
Terrestrial Biomes: forest
Other Habitat Features: riparian
Dorsally, this species is chestnut brown, mixed with black. Its color gradually lightens on sides to buff-gray on belly. It has an indistinct reddish stripe along back. The tail is bicolored and roughly 1/2 the length of the head and body.
Range mass: 15 to 40 g.
Range length: 110 to 190 mm.
Other Physical Features: endothermic ; bilateral symmetry
Myodes californicus are an important prey base for the forest ecosystem. They are preyed upon by martens, weasels, skunks, owls (including Spotted Owls), and other carnivorous birds and mammals.
Known Predators:
Myodes californicus construct lichen nests under logs and forest floor debris. Mating occurs from February to October and young are born from April to November (Alexander, 1999).
Breeding season: February to November
Range number of offspring: 2 to 6.
Average number of offspring: 3.
Average gestation period: 18 days.
Key Reproductive Features: iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Parental Investment: altricial ; female parental care
The western red-backed vole (Clethrionomys californicus) is a species of vole in the family Cricetidae. It is found in California and Oregon in the United States and lives mainly in coniferous forest. The body color is chestnut brown, or brown mixed with a considerable quantity of black hair gradually lightening on the sides and grading into a buffy-gray belly, with an indistinct reddish stripe on the back and a bicolored tail about half as long as the head and body.
The western red-backed vole was initially described by C. Hart Merriam under its original scientific name Evotomys californicus.[3] The type specimen was obtained at near Eureka, California.[3] It was an adult male collected by Theodore Sherman Palmer on June 3, 1889.[4]
The length of the western red-backed vole ranges from 121–165 mm (4.8–6.5 in) overall, with a tail between 34–56 mm (1.3–2.2 in), hindfoot 17–21 mm (0.67–0.83 in), and ear 10–14 mm (0.39–0.55 in).[3] The height ranges between 18–21 mm (0.71–0.83 in).
The species is closely related to the southern red-backed vole (Clethrionomys gapperi), which lives to the north and east of the range of this species, and is redder, with a more sharply bicolored tail. They are differentiated based on a reddish stripe on the dorsum of the western red-backed vole.[3] The western red-backed vole also has characteristic differences in the anatomy of the hard palate.[3]
It is found in northern California and western Oregon in the United States. The northern limit is defined by the Columbia River, with the range extending south to around 100 km (62 mi) north of the San Francisco Bay.[3] The range extends from the summits of the Cascade Range in the east, to the Pacific Ocean.[1][3] They live mainly in mature coniferous forest but also inhabit mixed fir-oak forest. They live in the Transition and Canadian life zones, described by Vernon Orlando Bailey in The mammals and life zones of Oregon.[3]
The western red-backed vole lives largely underground in an extensive system of burrows.[5] It feeds primarily on fruiting bodies of hypogeous fungi.[5] These mycorrhizal fungi are the symbionts of the forest trees around it. Rhizopogon vinicolor is one such which is associated with the Douglas-fir (Pseudotsuga spp.). Fruiting of the fungus takes place in well decayed timber when the nutrients are becoming exhausted. Because the fruiting bodies are underground, the spores are not liberated into the air as in most fungal species. However, the spores are found in the vole's droppings and are deposited throughout its burrows, thus enabling the fungus to spread and form associations with uninfected trees. It has been found that in a clear-cut forest where all the dead wood and trimmings are removed, the mycorrhiza stops fruiting, the vole population dies out and newly planted trees fail to thrive. This is an example of a three way symbiosis, as the vole gains food from the fungus and spreads its spores, and the fungus gains photosynthetic products from the tree which benefits from the nutrients produced by the fungus.[6]
The western red-backed vole plays an important role as prey to a number of species, including martens, ermines, and long-tailed weasels.[3] The red tree vole, northern flying squirrel, and western red-backed vole may constitute more than 75% of the northern spotted owls diet.[5]
No fossil remains have been identified yet.[3]
The species breeds between February and November on the slopes of the Cascade Range in north Oregon, as well as all year to the west of the Cascade Range, with 2–7 young per litter and a gestation period of around 18 days.[3]
According to the IUCN, the species conservation status is of "least concern".[1]
In areas where vole populations live in close proximity to industrial areas, voles are used as a biological indicator to monitor environmental contamination, especially persistent organic pollutants such as PCBs which build up in the vole's fatty tissues.
The western red-backed vole (Clethrionomys californicus) is a species of vole in the family Cricetidae. It is found in California and Oregon in the United States and lives mainly in coniferous forest. The body color is chestnut brown, or brown mixed with a considerable quantity of black hair gradually lightening on the sides and grading into a buffy-gray belly, with an indistinct reddish stripe on the back and a bicolored tail about half as long as the head and body.
