Microtus californicus
| California Vole
(Microtus californicus) | |
|---|---|
| Range | |
 | |
| Taxonomic classification | |
| Order: | Rodentia |
| Suborder: | Supramyomorpha |
| Infraorder: | Myomorphi |
| Superfamily: | Muroidea |
| Family: | Cricetidae |
| Subfamily: | Arvicolinae |
| Tribe: | Microtini |
| Genus: | Microtus |
| Subgenus: | Pitymys |
| Binomial details | |
| Microtus californicus (Peale, 1849) | |
| Other resources | |
| Full taxonomic details at MDD | |
Description
From Jameson & Peeters (2004): "A medium-sized vole with a faintly bicolored tail more than twice the length of the hind foot. It has six plantar tubercles."
From Cudworth & Koprowski (2010): "Microtus californicus is a medium-sized vole with light gray vibrissae, gray feet, and white near the anus (Verts and Carraway 1998). Dorsum is cinnamon-brown to tawny olive with dark brown to black hairs; venter fur is medium gray, occasionally washed with buff. Tail is bicolored, with black above and gray below (Verts and Carraway 1998). Subspecies inhabiting marsh lands (M. c. aestuarinus, M. c. vallicola, and M. c. scirpensis) tend to have a blackish dorsum; subspecies inhabiting the higher foothills (M. c. huperuthrus, M. c. sanctidiegi, and M. c. mariposae) are reddish (Kellogg 1918). M. c. constrictus is noticeably smaller (Kellogg 1918)."
External measurements
Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.
| Part of range | Reference | Total length | Tail length | Hindfoot length | Ear length | Mass |
|---|---|---|---|---|---|---|
| California | Jameson & Peeters (2004) | 157–211 | 39–68 | 20–25 | 13–16 | 35–72 |
Skull
From Cudworth & Koprowski (2010): "Incisive foramina are rounded at both ends, widest in the middle, and not constricted posteriorly (Hall 1981). M. californicus displays 3 closed triangles and 1 open triangle on M2, 3 closed triangles on M3, 5 closed triangles on m1, 4 closed triangles on m2, and 3 transverse loops on m3 (Carleton 1985). Common variants are 4 closed, triangles on M2, and 2 transverse loops and 2 open triangles on m3 (Carleton 1985)."
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Lateral view of the skull of Microtus californicus. -
Dorsal view of the skull of Microtus californicus. -
Ventral view of the skull of Microtus californicus. -
Upper incisors of Microtus californicus. -
Upper molars of the skull of Microtus californicus. -
Left lower molars of the skull of Microtus californicus,
Similar species
From Cudworth & Koprowski (2010): "Microtus californicus may be sympatric with 6 other species of Microtus (Hall 1981). Six plantar tubules and side glands on hips of males distinguish M. californicus from the North American water vole (M. richardsoni) and the creeping vole (M. oregoni), each with 5 plantar tubules and side glands on flanks or inconspicuous side glands, respectively (Hall 1981). M. californicus can be distinguished from Townsend's vole (M. townsendii), the gray-tailed vole (M. canicaudus), and the montane vole (M. montanus) by the lack of abrupt constriction of the incisive foramen, which is narrower posteriorly than anteriorly. The long-tailed vole (M. longicaudus) has a longer tail measuring greater than one-third the body length (Hall 1981). M. montanus and M. townsendii tend to occupy different ranges, further separating these species (Ingles 1965)."
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Ventral view of the skull of the Microtus californicus. The incisive foramina are broad and rounded. -
Ventral view of the skull of Microtus montanus. The incisive foramina are narrow and constrict abruptly.
References
Carleton MD. 1985. Macroanatomy. Pp. 116-175 in Biology of New World Microtus (R. H. Tamarin, ed.), Special Publication 8, The American Society of Mammalogists.
Cudworth NL, Koprowski JL. 2010. Microtus californicus (Rodentia: Cricetidae). Mammalian Species 42(868):230-243.
Hall ER. 1981. The mammals of North America. 2 vols. John Wiley and Sons, New York.
Ingles LG. 1965. Mammals of the Pacific states. Palo Alto (CA, USA): Stanford University Press.
Jameson EW, Peeters HJ. 2004. Mammals of California (No. 66). Berkeley (CA, USA): University of California Press.
Kellogg R. 1918. A revision of the Microtus californicus group of meadow mice. University of California Publications in Zoology 21:1-42.
Peale TR. 1848. Mammalia and ornithology. Reprint edition 1978. Arno Press Inc., New York.
Verts BJ, Carraway LN. 1998. Land mammals of Oregon. Berkeley (CA, USA): University of California Press.