Gray-tailed vole
Gray-tailed vole | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Cricetidae |
Subfamily: | Arvicolinae |
Genus: | Microtus |
Subgenus: | Pitymys |
Species: | M. canicaudus
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Binomial name | |
Microtus canicaudus Miller, 1897 | |
Distribution of the gray-tailed vole |
The gray-tailed vole (Microtus canicaudus) also known as the gray-tailed meadow vole or gray-tailed meadow mouse, is a rodent in the genus
Taxonomy
The
The gray-tailed vole is
Description
The gray-tailed vole is a small mammal in the middle of the size range for voles in general.[4] The fur on the back is yellowish-brown or yellowish-gray.[4] They have a short tail, black or brown above and grayish below.[4] The young have gray fur on the underside and a darker, "sooty" gray on the back.[8] The feet of the young are dusky, and they have a gray tail with a black stripe.[8] They are similar in size and overall appearance to the montane vole,[9] but with a more yellowish fur and a grayer tail.[9] The type specimen measured 135 mm (5.3 in) in total length.[10] The tail vertebrae measured 33 mm (1.3 in) and the hind foot measured 20 mm (0.79 in).[10] Typical adults average 141 mm (5.6 in) in total length, with a 35 mm (1.4 in) tail.[9] The feet measure 20 mm (0.79 in) and the ears 12 mm (0.47 in).[9] On each side they have an upper and lower incisor and three upper and lower molars, for a total of 16 teeth.[11]
Gray-tailed voles are
Distribution and habitat
The gray-tailed vole is endemic to the Willamette Valley, Oregon, and to Clark County, Washington.[4] Its range in Oregon extends from Scappoose and Gresham in the north, through the Willamette Valley to around Eugene.[4] Reports of the species east of the Cascades have been called into question.[4] Gray-tailed voles are prevalent in agricultural areas: they are found in and around pastures, hayfields, grain fields, and disturbed habitats.[4] They once inhabited grassy prairies of the valley.[12] These prairies were burned annually by Native Americans, with uncertain effects on vole populations.[5]
Vernon Orlando Bailey describes the Willamette Valley as part of the humid division of the Transition Zone.[13] Annual precipitation there is 40 in (100 cm), falling mostly in the winter.[13] The valley is warmer and drier than the surrounding hills, less heavily forested, and better suited to agricultural use.[13] In 1901, zoologist Edmund Heller visited McCoy, where the type specimen of the gray-tailed vole had been collected.[14] The account of his journey is relayed by Daniel Giraud Elliot, referring specifically to the terrain inhabited by the gray-tailed vole.[14]
Heller described the area around McCoy as "much the same kind of country as Beaverton, but more level and forested. The coast range is about fifteen miles distant. In some places, forests of Douglas fir occur, but the land is chiefly open and grassy. White oaks and a few yellow pine occur also, and the region I should judge was more Transition than that at Beaverton."
Mammals sharing the Transition Zone with the gray-tailed vole include:
Behavior
Gray-tailed voles are burrowing rodents that construct complex networks of tunnels and burrows.[15][1] They may also nest above ground, sheltered under wood, abandoned equipment, or other agricultural debris.[1] They are known to use the tunnel networks of the Camas pocket gopher.[15] The tunnels are built to provide shelter during wet periods, which are frequent throughout their range.[16] When the tunnels flood, the voles swim to dry areas or chambers in which air has been trapped.[16][15] If the networks flood completely, they will head for higher ground.[15] As many as 20–30 voles have been seen gathered on dry fence posts in flooded areas. When approached, they swam to safer ground nearby.[16] Where tunnels intersect, they sometimes establish middens 8–15 cm (3.1–5.9 in) long by 3–5 cm (1.2–2.0 in) wide by 8–10 cm (3.1–3.9 in) deep.[16]
Gray-tailed voles are difficult to capture live in the wild, as they are unlikely to enter enclosure type traps.[2] The most effective traps are laid inconspicuously along commonly used runways, so that the voles run directly into them.[2] Much of what is known about the voles has been obtained from observing them in captivity.[2]
Ecology
Male | Female | |||
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Age (weeks) | Weight | Length | Weight | Length |
1 | 6.0 g (0.21 oz) | 68.7 mm (2.70 in) | 5.5 g (0.19 oz) | 66 mm (2.6 in) |
2 | 11 g (0.39 oz) | 97.5 mm (3.84 in) | 10.3 g (0.36 oz) | 92.2 mm (3.63 in) |
3 | 16.5 g (0.58 oz) | 117 mm (4.6 in) | 15.2 g (0.54 oz) | 114.8 mm (4.52 in) |
4 | 21.0 g (0.74 oz) | 129.5 mm (5.10 in) | 19.3 g (0.68 oz) | 24 mm (0.94 in) |
5 | 24.6 g (0.87 oz) | 136.9 mm (5.39 in) | 21.3 g (0.75 oz) | 129 mm (5.1 in) |
6 | 26.1 g (0.92 oz) | 140.9 mm (5.55 in) | 22.2 g (0.78 oz) | 131.1 mm (5.16 in) |
7 | 27.6 g (0.97 oz) | 144.8 mm (5.70 in) | 22.1 g (0.78 oz) | 132.6 mm (5.22 in) |
8 | 28.8 g (1.02 oz) | 146.9 mm (5.78 in) | 22.8 g (0.80 oz) | 134.3 mm (5.29 in) |
Information about the reproductive habits of gray-tailed voles is based on studies of captive animals.
Gray-tailed voles recognize
Although gray-tailed voles are now described as common, Bailey reported them to be so scarce that few specimens were available.[12] He also claimed that they were present east of the Cascades,[12] but subsequent authorities have refuted this. Their population density fluctuates widely during the year.[18][4] There is not much data available to calculate population density in the field, but studies in more controlled settings yield estimates of around 600 animals per 1 hectare (2.5 acres).[18]
Human interactions
Gray-tailed voles have been used in laboratory research projects.[21] They have been used to study the effects of mineral deficiencies, such as selenium, which is lacking in Willamette Valley soils. They have also been used in studies on livestock feed modifications, including pretreatment of feeds by fermentation, sprouting the grains in the feeds, and clearance of radioactive isotopes from contaminated food.[21]
Gray-tailed voles can become so abundant within their range that humans may take measures to control populations.[5] Trapping them is challenging.[15]
Conservation status
The gray-tailed vole is listed as "
References
Footnotes:
- ^ a b c d e f IUCN Red List 2008.
- ^ a b c d e Verts & Carraway 1987, p. 4.
- ^ a b c d e Miller 1897, p. 67.
- ^ a b c d e f g h i j k l m n o p q r Verts & Carraway 1998, p. 317.
- ^ a b c d e Verts & Carraway 1998, p. 318.
- ^ a b Musser & Carleton 2005.
- ^ Verts & Carraway 1998, pp. 317–318.
- ^ a b Bailey 1900, p. 32.
- ^ a b c d Bailey 1936, pp. 205.
- ^ a b Miller 1897, p. 68.
- ^ Verts & Carraway 1987, p. 1.
- ^ a b c Bailey 1936, pp. 206.
- ^ a b c d e Bailey 1936, p. 21.
- ^ a b c d Elliot 1904, pp. 179–180.
- ^ a b c d e Verts & Carraway 1998, p. 319.
- ^ a b c d e Verts & Carraway 1987, p. 3.
- ^ a b c d e Verts & Carraway 1987, p. 2.
- ^ a b c d NatureServe 2014.
- ^ Boyd & Blaustein 1985.
- ^ Verts & Carraway 1998, pp. 318–319.
- ^ a b Verts & Carraway 1998, p. 1.
Sources:
- Bailey, Vernon (1900). Revision of American Voles of the Genus Microtus. U.S. Government Printing Office.
- Bailey, Vernon (1936). The Mammals and Life Zones of Oregon. U.S. Government Printing Office.
- Cassola, F. (2016). "Microtus canicaudus". . Retrieved 12 November 2021.
- Boyd, S. K.; Blaustein, A. R. (May 1985). "Familiarity and Inbreeding Avoidance in the Gray-Tailed Vole (Microtus canicaudus)". Journal of Mammalogy. 66 (2): 348–352. JSTOR 1381247.
- "Comprehensive Report Species – Microtus canicaudus". NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. 2014. Retrieved 4 December 2014.
- Elliot, Daniel Giraud (1904). "A List of Mammals obtained by Edmund Heller from the Coast Region of Northern California and Oregon". Field Columbian Museum Publication, Zoological Series. 3 (11): 175–197.
- Miller, Gerrit S. (1897). Proceedings of the Biological Society of Washington. Biological Society of Washington.
- OCLC 62265494.
- Verts, B. J.; Carraway, Leslie N. (27 February 1987). "Microtus canicaudus" (PDF). Mammalian Species (267): 1–4. JSTOR 3504014. Archived from the original(PDF) on 3 March 2016. Retrieved 27 November 2014.
- Verts, B.J.; Carraway, Leslie N (1998). Land Mammals of Oregon. Berkeley: University of California Press. ISBN 9780520211995. Retrieved 15 November 2014.
Further reading
- Wolff, J. O.; Schauber, E. M.; Edge, W. D. (August 1997). "Effects of Habitat Loss and Fragmentation on the Behavior and Demography of Gray-Tailed Voles". Conservation Biology. 11 (4): 945–956. S2CID 7815283.
External links
Data related to Microtus canicaudus at Wikispecies