Microtus montanus
| Montane Vole
(Microtus montanus) | |
|---|---|
| Range | |
 | |
| Taxonomic classification | |
| Order: | Rodentia |
| Suborder: | Supramyomorpha |
| Infraorder: | Myomorphi |
| Superfamily: | Muroidea |
| Family: | Cricetidae |
| Subfamily: | Arvicolinae |
| Tribe: | Microtini |
| Genus: | Microtus |
| Subgenus: | Pitymys |
| Binomial details | |
| Microtus montanus (Peale, 1849) | |
Description
From Sera & Early (2003): "Upper body is some shade of brown, often with a buffy or gray wash, with a mixture of black-tipped hairs. Sides are paler and more buffy than upper body, and venter is white to gray, sometimes washed with buffy. Tail is bicolored, with blackish brown to black above and gray or white below (Hall 1981). Darker pelage is more pronounced in southwestern part of range and is more diluted with paler hair or other colors of hair (including red, gray, or brown) to north and east (Anderson 1959). Grayest individuals are generally in northern part of range. Female pelage color varies more than does that of males (Howell 1924)."
From Armstrong et al. (2010): "The montane vole is a medium-sized vole with a tail less than 40 percent of the length of the head and body. The dorsal color is grayish brown to brownish yellow. The venter is silver-gray with white-tipped, black hairs. The tail is indistinctly bicolored."
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 |
|---|---|---|---|---|---|---|
| Arizona (White Mountains) | Hoffmeister (1986) | 124–180 (n=58) | 34–48 (n=58) | 18.5–22 (n=58) | ||
| California | Jameson & Peeters (2004) | 169–189 | 39–54 | 20–27 | 11–14 | 30–65 |
| Colorado | Armstrong et al. (2010) | 140–182 | 34–62 | 17–22 | 11–18 | 35–60 |
Variation
This section shows some of the color variation present in Microtus montanus. The location is provided for reference only. The individual shown does not necessarily represent the only color variant within the local population.
-
California, Fresno County -
Wyoming, Park County
Skull
From Armstrong et al. (2010): "The skull is stout with a square braincase. The last upper molar has 5 dentine lakes, the second molar has 4, and the incisive foramina are narrow and constricted posteriorly. The posterior edge of the premaxillaries does not extend beyond the posterior margins of the nasals."
From Naughton (2012): "incisive foramina ≤ 5mm and constrict sharply to points posteriorly; upper incisors of adults protrude beyond the nasal bones when viewed from directly above; M3 has 3 closed triangles and a closed recurved posterior loop; m1 has 4 re-entrant angles on each side."
-
Dorsal view of the skull of Microtus montanus. -
Lateral view of the skull of Microtus montanus. -
Ventral view of the skull of Microtus montanus. -
Upper incisors of Microtus montanus. -
Lower jaw of Microtus montanus. -
Enamel pattern of Microtus montanus. The left pair are the upper molars (top to bottom are M1, M2, M3) and right pair are the lower molars (top to bottom are m1, m2, m3).
Similar species
From Sera & Early (2003): "M. montanus has 3 closed triangles on M3 and 8 mammae, whereas the potentially sympatric M. ochrogaster has only 2 closed triangles on M3 and 6 mammae. Upper body of sympatric M. townsendii has more dark brown or black with a heavier mixture of black-tipped guard hairs than M. montanus, which has a more buffy and grayish wash where these 2 species overlap (Hall 1981). M. montanus is distinguished from allopatric Microtus canicaudus (formerly considered a geographic race of M. montanus-Hall and Kelson 1951) by a distinctive karyotype (Hsu and Johnson 1970; Modi 1986) and different globulin- and hemoglobin-banding patterns (Johnson 1968). In addition, M. canicaudus has a more yellow upper body (Hall 1981)."
-
Microtus montanus -
Long-tailed Vole (Microtus longicaudus) -
Western Heather Vole (Phenacomys intermedius) -
Prairie Vole (Microtus ochrogaster) -
Gray-tailed Vole (Microtus canicaudus), image by David C. -
Western Meadow Vole (Microtus drummondii)
References
Anderson S. 1959. Distribution, variation, and relationships of the montane vole, Microtus montanus. University of Kansas Publications, Museum of Natural History 9:415-511.
Armstrong DM, Fitzgerald JP, Meaney CA. 2010. Mammals of Colorado, Second Edition. Denver (CO, USA): University Press of Colorado.
Hall ER. 1981. The mammals of North America. Second ed. John Wiley and Sons, New York, 2:601-1181 + 90.
Hall ER, Kelson KR. 1951. A new subspecies of Microtus montanus from Montana and comments on Microtus canicaudus Miller. University of Kansas publications, Museum of Natural History 5: 73-79.
Hoffmeister DF. 1986. Mammals of Arizona. Tucson (AZ, USA): University of Arizona Press.
Howell AB. 1924. Individual and age variation in Microtus montanus yosemite. Journal of Agricultural Research 28:977-1017.
Hsu TC, Johnson ML. 1970. Cytological distinction between Microtus montanus and Microtus canicaudus. Journal of Mammalogy 51:824-826.
Jameson EW, Peeters HJ. 2004. Mammals of California (No. 66). Berkeley (CA, USA): University of California Press.
Johnson ML. 1968. Application of blood protein electrophoretic studies to problems in mammalian taxonomy. Systematic Zoology 17:23-30.
Modi WS. 1986. Karyotypic differentiation among two sibling species pairs of new world microtine rodents. Journal of Mammalogy 67:159-165.
Naughton D. 2012. The natural history of Canadian mammals. Toronto (ON, CA): University of Toronto Press.
Peale TR. 1848. United States Exploring Expedition during the Years 1838, 1839, 1840, 1841, 1842 under the Command of Charles Wilkes, U.S.N. Volume 8, Mammalia and Ornithology. C. Sherman, Philadelphia, 44.
Sera WE, Early CN. 2003. Microtus montanus. Mammalian Species 2003(716): 1-10.