Singing Vole
Encyclopedia
The singing vole, Microtus miurus, is a medium-sized vole
found in northwestern North America
, including Alaska
and northwestern Canada
.
s, but these are so sparse that have little effect on the visible coloration of the animal. The fur is greyer in color during the winter. The paws have sharp, narrow claws, which are largely hidden by fur.
Adult singing voles range from 9 to 16 cm (3.5 to 6.3 in) in length, not counting the short, 1.5 to 4 cm (0.590551181102362 to 1.6 in), tail. They can weigh anything from 11 to 60 g (0.388013583156232 to 2.1 oz), depending on their exact age and recent diet. There is no significant difference in size or coloration between the two sexes. Male singing voles possess modified sebaceous gland
s on their flanks, which are used in scent marking; these glands have also been noted in some lactating
females. The penis is relatively long and narrow, with a complex baculum
.
Singing voles can be distinguished from other neighboring vole species by their shorter tails and the color of their underparts (other local voles have grey underparts).
, the central regions, and much of the northern coast. In the east, they reach as far as the Mackenzie Mountains
, being found throughout the Yukon
, aside from the northern coasts, and in border regions of the neighboring provinces.
Four subspecies are currently recognised:
Singing voles are found in tundra
regions above the tree line. They avoid the most extreme environments within these regions, preferring open, well-drained slopes and rock flats with abundant shrubs and sedges. They feed on arctic plants such as lupin
es, knotweed, sedge
s, horsetails, and willow
s. Their main predators include wolverine
s, Arctic fox
es, stoat
s, skua
s, hawk
s, and owl
s.
The burrows consist of a number of chambers, many of them used to store food for the winter, connected by very narrow passages. These passages, typically around 2.5 centimetre (0.984251968503937 in) wide, make it difficult for any animal larger than a vole to pass through, and thus help protect against predators such as weasel
s. The burrows run horizontally, no more than 20 centimetres (7.9 in) below ground level, and can extend for as far as 1 metres (3.3 ft) from the tunnel entrance.
Unusually among voles, in addition to storing food, such as roots and rhizome
s, underground, singing voles also often leave stacks of grasses out on rocks to dry. Often, these stacks are instead constructed on low-lying branches, or on exposed tree roots, helping to keep them dry. The stacks of grasses slowly dry out, producing hay
, and may include other food materials, such as horsetails or lupines. The voles begin to construct the stacks around August, and by the winter, they may have reached considerable size, with piles of up to 50 centimetres (19.7 in) in height having been reported. The piles are a source of nutritious food through the winter, although they are liable to be raided by other animals.
This species gets its common name from its warning call, a high-pitched trill, usually given from the entrance of its burrow.
The young weigh 2 to 2.8 g (0.0705479242102239 to 0.0987670938943135 oz) at birth, and grow rapidly during the first three weeks of life. They are weaned
at around four weeks, by which time the mother is often ready to produce a new litter. Although females generally do not reproduce until their second year, males may be sexually active within as little as a month of birth.
In the wild, many singing voles do not survive even their first winter. In captivity, they have been reported to live for up to 112 weeks, although the median lifespan is only 43 weeks.
, around 300,000 years ago, and were found near Fairbanks
. During the Ice Age
s of the late Pleistocene
, singing voles may have been much more widely distributed than today, and fossils have been reported from as far south as Iowa
, which was then probably similar in climate to present-day Alaska. The closest living relative of the Singing Vole today is the Insular Vole
, which is found only on two small islands off the west coast of Alaska, and probably diverged as those islands were cut off from the Beringia land bridge by rising sea levels.
Vole
A vole is a small rodent resembling a mouse but with a stouter body, a shorter hairy tail, a slightly rounder head, smaller ears and eyes, and differently formed molars . There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice in North America...
found in northwestern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, including Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
and northwestern Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
Physical characteristics
Singing voles have short ears, often concealed by their long fur, and a short tail. The fur is soft and dense, especially in winter. They vary in color from pale tawny to pale grey, with buff-colored patches running from the undersides of the ears along the flanks to the rump, and buff or ochre underparts. The fur is lightly ticked with black guard hairGuard hair
Guard hairs are the longest, coarsest hairs in a mammal's coat, forming the topcoat . They taper to a point and protect the undercoat from the elements. They are often water repellent and stick out above the rest of the coat...
s, but these are so sparse that have little effect on the visible coloration of the animal. The fur is greyer in color during the winter. The paws have sharp, narrow claws, which are largely hidden by fur.
Adult singing voles range from 9 to 16 cm (3.5 to 6.3 in) in length, not counting the short, 1.5 to 4 cm (0.590551181102362 to 1.6 in), tail. They can weigh anything from 11 to 60 g (0.388013583156232 to 2.1 oz), depending on their exact age and recent diet. There is no significant difference in size or coloration between the two sexes. Male singing voles possess modified sebaceous gland
Sebaceous gland
The sebaceous glands are microscopic glands in the skin that secrete an oily/waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals...
s on their flanks, which are used in scent marking; these glands have also been noted in some lactating
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...
females. The penis is relatively long and narrow, with a complex baculum
Baculum
The baculum is a bone found in the penis of most mammals. It is absent in humans, but present in other primates, such as the gorilla and chimpanzee.The bone aids in sexual intercourse.-Purpose:...
.
Singing voles can be distinguished from other neighboring vole species by their shorter tails and the color of their underparts (other local voles have grey underparts).
Distribution and habitat
Singing voles are native to Alaska and north-western Canada. They are found from the western coasts, across southern and northern Alaska, but avoid the Alaska PeninsulaAlaska Peninsula
The Alaska Peninsula is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The peninsula separates the Pacific Ocean from Bristol Bay, an arm of the Bering Sea....
, the central regions, and much of the northern coast. In the east, they reach as far as the Mackenzie Mountains
Mackenzie Mountains
The Mackenzie Mountains are a mountain range forming part of the Yukon-Northwest Territories boundary between the Liard and Peel rivers. The range is named in honour of Canada's second Prime Minister Alexander Mackenzie. Nahanni National Park Reserve is in the Mackenzie Mountains.The Mackenzie...
, being found throughout the Yukon
Yukon
Yukon is the westernmost and smallest of Canada's three federal territories. It was named after the Yukon River. The word Yukon means "Great River" in Gwich’in....
, aside from the northern coasts, and in border regions of the neighboring provinces.
Four subspecies are currently recognised:
- Microtus miurus miurus - Kenai PeninsulaKenai PeninsulaThe Kenai Peninsula is a large peninsula jutting from the southern coast of Alaska in the United States. The name Kenai is probably derived from Kenayskaya, the Russian name for Cook Inlet, which borders the peninsula to the west.-Geography:...
- Microtus miurus cantator - south-eastern Alaska and southern Yukon
- Microtus miurus miuriei - south-western Alaska
- Microtus miurus oreas - northern Alaska and Yukon
Singing voles are found in tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
regions above the tree line. They avoid the most extreme environments within these regions, preferring open, well-drained slopes and rock flats with abundant shrubs and sedges. They feed on arctic plants such as lupin
Lupin
Lupinus, commonly known as Lupins or lupines , is a genus in the legume family . The genus comprises about 280 species , with major centers of diversity in South and western North America , and the Andes and secondary centers in the Mediterranean region and Africa Lupinus, commonly known as Lupins...
es, knotweed, sedge
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
s, horsetails, and willow
Willow
Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...
s. Their main predators include wolverine
Wolverine
The wolverine, pronounced , Gulo gulo , also referred to as glutton, carcajou, skunk bear, or quickhatch, is the largest land-dwelling species of the family Mustelidae . It is a stocky and muscular carnivore, more closely resembling a small bear than other mustelids...
s, Arctic fox
Arctic fox
The arctic fox , also known as the white fox, polar fox or snow fox, is a small fox native to Arctic regions of the Northern Hemisphere and is common throughout the Arctic tundra biome. The Greek word alopex, means a fox and Vulpes is the Latin version...
es, stoat
Stoat
The stoat , also known as the ermine or short-tailed weasel, is a species of Mustelid native to Eurasia and North America, distinguished from the least weasel by its larger size and longer tail with a prominent black tip...
s, skua
Skua
The skuas are a group of seabirds with about seven species forming the family Stercorariidae and the genus Stercorarius. The three smaller skuas are called jaegers in North America....
s, hawk
Hawk
The term hawk can be used in several ways:* In strict usage in Australia and Africa, to mean any of the species in the subfamily Accipitrinae, which comprises the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter genus includes goshawks,...
s, and owl
Owl
Owls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
s.
Behavior
Singing voles are at least semi-colonial animals, sharing burrows between family groups. They are active throughout the day, with no clear preference for sunlight or night time. They make runways through the surface growth, connecting feeding grounds to burrow entrances, although these are not as clear as those made by some other vole species. They also sometimes forage in low bushes.The burrows consist of a number of chambers, many of them used to store food for the winter, connected by very narrow passages. These passages, typically around 2.5 centimetre (0.984251968503937 in) wide, make it difficult for any animal larger than a vole to pass through, and thus help protect against predators such as weasel
Weasel
Weasels are mammals forming the genus Mustela of the Mustelidae family. They are small, active predators, long and slender with short legs....
s. The burrows run horizontally, no more than 20 centimetres (7.9 in) below ground level, and can extend for as far as 1 metres (3.3 ft) from the tunnel entrance.
Unusually among voles, in addition to storing food, such as roots and rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
s, underground, singing voles also often leave stacks of grasses out on rocks to dry. Often, these stacks are instead constructed on low-lying branches, or on exposed tree roots, helping to keep them dry. The stacks of grasses slowly dry out, producing hay
Hay
Hay is grass, legumes or other herbaceous plants that have been cut, dried, and stored for use as animal fodder, particularly for grazing livestock such as cattle, horses, goats, and sheep. Hay is also fed to pets such as rabbits and guinea pigs...
, and may include other food materials, such as horsetails or lupines. The voles begin to construct the stacks around August, and by the winter, they may have reached considerable size, with piles of up to 50 centimetres (19.7 in) in height having been reported. The piles are a source of nutritious food through the winter, although they are liable to be raided by other animals.
This species gets its common name from its warning call, a high-pitched trill, usually given from the entrance of its burrow.
Reproduction
Singing voles breed from May to September, and each female can give birth to up to three litters in a breeding season. Gestation lasts 21 days, and typically results in the birth of eight young, although litters of between 6 and 14 young have been reported. Since, like other voles, the female has only eight teats, litters of more than eight young are unlikely to survive.The young weigh 2 to 2.8 g (0.0705479242102239 to 0.0987670938943135 oz) at birth, and grow rapidly during the first three weeks of life. They are weaned
Weaning
Weaning is the process of gradually introducing a mammal infant, either human or animal, to what will be its adult diet and withdrawing the supply of its mother's milk.The process takes place only in mammals, as only mammals produce milk...
at around four weeks, by which time the mother is often ready to produce a new litter. Although females generally do not reproduce until their second year, males may be sexually active within as little as a month of birth.
In the wild, many singing voles do not survive even their first winter. In captivity, they have been reported to live for up to 112 weeks, although the median lifespan is only 43 weeks.
Evolution
The oldest known fossils of singing voles date from the IonianMiddle Pleistocene
The Middle Pleistocene, more specifically referred to as the Ionian stage, is a period of geologic time from ca. 781 to 126 thousand years ago....
, around 300,000 years ago, and were found near Fairbanks
Fairbanks
Fairbanks may refer to:Places in the United States*Fairbanks, Alaska, city*Fairbanks, California, unincorporated community in El Dorado County*Fairbanks, Mendocino County, California, former settlement*Fairbanks, Indiana, unincorporated community...
. During the Ice Age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
s of the late Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
, singing voles may have been much more widely distributed than today, and fossils have been reported from as far south as Iowa
Iowa
Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...
, which was then probably similar in climate to present-day Alaska. The closest living relative of the Singing Vole today is the Insular Vole
Insular Vole
The Insular Vole or St. Matthew Island Vole is a species of rodent in the family Cricetidae. It occurs only on St. Matthew Island and the adjacent Hall Island, in Alaska. On these Bering Sea islands, Insular Voles live in damp lowland areas, on the lower slopes of mountains, and on rye...
, which is found only on two small islands off the west coast of Alaska, and probably diverged as those islands were cut off from the Beringia land bridge by rising sea levels.