Geographic Range
Pacific coast of northern California and Oregon.
Habitat
Clethrionomys 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.
- Habitat Regions
- temperate
- Terrestrial Biomes
- forest
- Other Habitat Features
- riparian
Physical Description
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.
- Other Physical Features
- endothermic
- bilateral symmetry
Reproduction
Clethrionomys 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).
- Key Reproductive Features
- iteroparous
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
- Parental Investment
- altricial
- female parental care
Behavior
Although they are sometimes active during the day, M. californicus are primarily nocturnal. They are active year round (do not hibernate). They spend most of their time moving amongst forest floor litter and underground in search of sporocarps. They are often found around and under downed trees, and appear to use log overhangs as travel corridors.
Communication and Perception
Food Habits
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.
- Primary Diet
- mycophage
- Animal Foods
- insects
- Plant Foods
- leaves
- seeds, grains, and nuts
- lichens
- Foraging Behavior
- stores or caches food
Predation
Clethrionomys 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.
Ecosystem Roles
- Ecosystem Impact
- disperses seeds
Economic Importance for Humans: Positive
C. 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
Conservation Status
Clethrionomys 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 C. californicus abundance.
Additional Links
Contributors
Mike Watson (author), University of Michigan-Ann Arbor, Bret Weinstein (editor), University of Michigan-Ann Arbor.
- 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.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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).
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- riparian
-
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
- 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.
- 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.
- 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).
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- 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.
- female parental care
-
parental care is carried out by females
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- solitary
-
lives alone
- stores or caches food
-
places a food item in a special place to be eaten later. Also called "hoarding"
- mycophage
-
an animal that mainly eats fungus
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
References
Alexander, L. 1999. Western red-backed vole. Pp. 612-613 in The Smithsonian Book of North American Mammals . Washington DC: Smithsonian Institution Press.
Brylski, P. "M129" (On-line). Accessed November 17, 2001 at http://www.dfg.ca.gov/whdab/cwhr/M129.html .
Carey, A., M. Johnson. 1995. Small Mammals in Managed, Naturally Young, and Old-Growth Forests. Ecol. Appl. , 5(2): 336-352.
Claridge, A., J. Trappe, S. Cork, D. Claridge. 1999. Mycophagy by small mammals in the coniferous forests of North America: nutritional value of the sprocarps of the Rhizopogon vinicolor, a common hypogeous fungi. J. Comp. Phys. B, Biochem, Syst., and Env. Phys. , 169 (3): 172-178.
Cotter, S. "Scientific Papers" (On-line). Accessed November 17, 2001 at http://www.geocities.com/scott_cotter/smallmammal.htm .
Ford, S. May 30, 2001. "Strategic Policy" (On-line). Accessed November 17, 2001 at http://www.for.gov.bc.ca/hfp/policy/cwdlib.htm .
Randgaard, D. "Roads: A Big Impact on Small Mammals" (On-line). Accessed November 17, 2001 at http://www.wildlandscpr.org/notes/biblionotes/roads-sm-mammals.html .
Whitaker, J. 1996. National Audobon Society Field Guide to North American Mammals . N.Y.: Alfred A. Knopf, Inc..
Wilson, D., D. Reeder. 1993. Mammal Species of the World . Smithsonian Institution Press.
"End of the Road - Chapter 1" (On-line). Accessed November 17, 2001 at http://www.nrdc.org/land/forests/roads/chap1.asp .
"Thumbnail Photographs of Ectomycorrhiza Types" (On-line). Accessed November 17, 2001 at http://www.fsl.orst.edu/mycology/typelist.html .