The silver mountain vole (''Alticola argentatus'') is a species of
rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...
in the family
Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and h ...
. They are distinguished by their silver-grey
pelage
Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an insulating blanket ...
, long
vibrissae
Vibrissae (; singular: vibrissa; ), more generally called Whiskers, are a type of stiff, functional hair used by mammals to sense their environment. These hairs are finely specialised for this purpose, whereas other types of hair are coarser ...
, rootless
hypsodont
Hypsodont is a pattern of dentition with high-crowned teeth and enamel extending past the gum line, providing extra material for wear and tear. Some examples of animals with hypsodont dentition are cows and horses; all animals that feed on gritt ...
molars and angular skull shape. Like many mammals of the
Eurasian Steppe eco-region, they are well adapted to life in high altitudes, and can be found in mountain areas of Central Asia from
Saur Mountains in the north-east to
Kugitang Range in the west, and to
Tibet
Tibet (; ''Böd''; ) is a region in East Asia, covering much of the Tibetan Plateau and spanning about . It is the traditional homeland of the Tibetan people. Also resident on the plateau are some other ethnic groups such as Monpa, Taman ...
and the
Himalayas
The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 10 ...
in the south.
[Adam Nadachowski and Jim I. Mead]
"Alticola argentatus"
''Oxford University Press'', December 1999. Retrieved March 2015.
Taxonomy
Evolutionary History
The phylogeny and life history of the Central Asian voles within the genus ''
Alticola
''Alticola'' is a genus of rodent in the family Cricetidae.
Species
*Subgenus ''Alticola''
** White-tailed mountain vole (''Alticola albicauda'')
** Silver mountain vole (''Alticola argentatus'')
** Gobi Altai mountain vole (''Alticola ba ...
'' are not well understood. There are three subgenera of ''Alticola''; ''Alticola'' s.str. containing the silver mountain vole,
Aschizomys and
Platycranius. Through a genetic analysis of the
cytochrome b
Cytochrome b within both molecular and cell biology, is a protein found in the mitochondria of eukaryotic cells. It functions as part of the electron transport chain and is the main subunit of transmembrane cytochrome bc1 and b6f complexes.
F ...
gene, subgenera Alticolas str. and Platycranius have been found to form in a monophyletic clade, and have genetic differences with the Asian vole subgenera Aschisomys, with splitting of these subgenera occurring in the
late Pleistocene.
[Vladimir S. Lebedev, Anna A. Bannikova, Alexey S. Tesakov andNatalia I. Abramson]
"Molecular phylogeny of the genus Alticola (Cricetidae, Rodentia) as inferred from the sequence of the cytochrome b gene"
''Zoologica Scripta'', November 2007. Retrieved March 2015.
Description
The silvery mountain vole displays a broad spectrum of color variation, from a bright yellow to a dark brown. Color differences are thought to be correlated with a dryness gradient throughout the region and not altitude. This species' tail length varies considerably in individuals, from 32 to 51% of its body mass, and is almost hairless. The tail of this species is white in light-colored specimens and distinctly bicolored in dark animals. These voles are observed to be darkest in the fur on their back and the top of their head. Young animals start molting when they reach a body mass of 18-21g. Molting starts in March or April, and the autumn molt takes place in September or October.
[ A. N. Formozov]
"Adaptive Modifications of Behavior in Mammals of the Eurasian Steppes"
''Journal of Mammalogy'', May, 1966. Retrieved March 2015.
Skull morphology has been found to vary in animals separated by space in this broad region. Skull length has been found to vary independently from body length. From comparative analysis in morphology, two sub populations have been found to exist; one being centered in the
Tien-Shan
The Tian Shan,, , otk, 𐰴𐰣 𐱅𐰭𐰼𐰃, , tr, Tanrı Dağı, mn, Тэнгэр уул, , ug, تەڭرىتاغ, , , kk, Тәңіртауы / Алатау, , , ky, Теңир-Тоо / Ала-Тоо, , , uz, Tyan-Shan / Tangritog‘ ...
region and a southern population being found in the
Pamir Pamir may refer to:
Geographical features
* Pamir Mountains, a mountain range in Central Asia
** Pamir-Alay, a mountain system in Tajikistan, Kyrgyzstan and Uzbekistan, part of the Pamir Mountains
*A pamir (valley) is a high plateau or valley surro ...
-
Hindu Kush
The Hindu Kush is an mountain range in Central and South Asia to the west of the Himalayas. It stretches from central and western Afghanistan, Quote: "The Hindu Kush mountains run along the Afghan border with the North-West Frontier Province ...
mountain system.
Like many rodents, the silvery mountain vole possesses
hypsodont
Hypsodont is a pattern of dentition with high-crowned teeth and enamel extending past the gum line, providing extra material for wear and tear. Some examples of animals with hypsodont dentition are cows and horses; all animals that feed on gritt ...
molars that are ever growing, and are adapted for feeding on fibrous material.
[
]
Distribution and habitat
This vole is common in the Tien Shan
The Tian Shan,, , otk, 𐰴𐰣 𐱅𐰭𐰼𐰃, , tr, Tanrı Dağı, mn, Тэнгэр уул, , ug, تەڭرىتاغ, , , kk, Тәңіртауы / Алатау, , , ky, Теңир-Тоо / Ала-Тоо, , , uz, Tyan-Shan / Tangritog‘ ...
and Pamir Mountains of Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
, Kyrgyzstan
Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the south, and the People's Republic of China to the ea ...
, Tajikistan
Tajikistan (, ; tg, Тоҷикистон, Tojikiston; russian: Таджикистан, Tadzhikistan), officially the Republic of Tajikistan ( tg, Ҷумҳурии Тоҷикистон, Jumhurii Tojikiston), is a landlocked country in Centr ...
, Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
, China, and Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
. The northernmost part of its geographic range is in the Saur Mountains, and southernmost being the Gilgit region of Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
. The only fossil remains of this species come from Sel’-Ugnur in Kyrgyzstan
Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the south, and the People's Republic of China to the ea ...
, and are dated to the late Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...
.
The eco-region inhabited by the silver mountain vole is the Eurasian Steppe, and is characterized by a grass cover with a predominance of low perennial grasses. These grasses are able to resist droughts and are usually low and fibrous. These botanical features has caused many small mammal species to live partially in burrows, or to find shelter within rock pilings, as in the case of the Silvery Mountain Vole.[January Weiner, Andrzej Górecki]
"Standard metabolic rate and thermoregulation of five species of Mongolian small mammals"
''Journal of Comparative Physiology'', January 1981. Retrieved March 2015.
They reside often in high mountains, in the sub-alpine
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...
and alpine
Alpine may refer to any mountainous region. It may also refer to:
Places Europe
* Alps, a European mountain range
** Alpine states, which overlap with the European range
Australia
* Alpine, New South Wales, a Northern Village
* Alpine National Pa ...
biome
A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...
. They also are found in low foothills and forested regions, but to a much smaller extent. They build nesting burrows in the rocks of talus slopes, and rock covered scree. They often fill in rock fissures with excrement mixed with plant debris to form an insulated wall. Nests are built as a soft sphere of plant debris, and are functionally divided into brooding nests with separate areas for rest. The silver mountain vole has been seen being active in the day and at night, and movements of the vole under winter snow have been recorded.[
]
Behavior
Diet
In winter and early spring, the silver mountain vole feeds mainly on roots of plants and on seeds, these food materials form 87-92% of their stomach composition from November to February. In March, they begin to feed on green plant vegetation, and these fresh greens form 90-99% of their stomach composition from April to September. In autumn, these animals forage for a stock of food for winter. The mass of these food reserves are not large, and range from 2-5g to 35-42g.[
]
Breeding
The breeding season for this species varies by altitude; in forest and subalpine zones it lasts from March to October, and there is a shortened breeding season of May to September for animals in the alpine zone. On the southern slopes of the foothills, at an altitude from 900 to 1,300 m the vole has been observed to breed in the winter.
The young individuals appear in May in the forest and subalpine zones, and are fertile by the summer months. Normally 3 litters are born each year. Sexual maturity is attained at a relatively young age.[
]
Disease
Alticola argentatus is effected by the plague, a bacterial infection caused by ''Yersinia pestis
''Yersinia pestis'' (''Y. pestis''; formerly '' Pasteurella pestis'') is a gram-negative, non-motile, coccobacillus bacterium without spores that is related to both ''Yersinia pseudotuberculosis'' and ''Yersinia enterocolitica''. It is a facult ...
''. It is enzootic in wild rodent populations over large rural areas of Mongolia, and has the most active natural plague foci in the westernmost regions. The marmot flea '' Oropsylla silantiewi'' is considered the primary vector for the plague. Human cases of plague have been recorded in Mongolia since 1897.[Bolormaa Galdan, Undraa Baatar, Baigalmaa Molotov, and Otgonbaatar Dashdavaa]
"Plague in Mongolia"
''Vector-Borne and Zoonotic Diseases'', January 2010. Retrieved March 2015.
References
{{Taxonbar, from=Q303524
Alticola
Mammals described in 1879
Taxonomy articles created by Polbot