Least Weasel
Overview
The least weasel is the smallest member of the Mustelidae
Mustelidae
Mustelidae , commonly referred to as the weasel family, are a family of carnivorous mammals. Mustelids are diverse and the largest family in the order Carnivora, at least partly because in the past it has been a catch-all category for many early or poorly differentiated taxa...

 (as well as the smallest of the Carnivora
Carnivora
The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...

), native to Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

, 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...

 and North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

, though it has been introduced elsewhere. It is classed as Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...

 by the IUCN, due to its wide distribution and presumably large population. Despite its small size, the least weasel is a fierce hunter, capable of killing a rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...

 5-10 times its own weight.
Within the genus Mustela, the least weasel is a relatively unspecialised form, as evidenced by its pedomorphic skull, which occurs even in large subspecies.
Encyclopedia
The least weasel is the smallest member of the Mustelidae
Mustelidae
Mustelidae , commonly referred to as the weasel family, are a family of carnivorous mammals. Mustelids are diverse and the largest family in the order Carnivora, at least partly because in the past it has been a catch-all category for many early or poorly differentiated taxa...

 (as well as the smallest of the Carnivora
Carnivora
The diverse order Carnivora |Latin]] carō "flesh", + vorāre "to devour") includes over 260 species of placental mammals. Its members are formally referred to as carnivorans, while the word "carnivore" can refer to any meat-eating animal...

), native to Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

, 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...

 and North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

, though it has been introduced elsewhere. It is classed as Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...

 by the IUCN, due to its wide distribution and presumably large population. Despite its small size, the least weasel is a fierce hunter, capable of killing a rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...

 5-10 times its own weight.

Evolution

Within the genus Mustela, the least weasel is a relatively unspecialised form, as evidenced by its pedomorphic skull, which occurs even in large subspecies. Its direct ancestor was Mustela praenivalis, which lived in Europe during the Middle Pleistocene
Middle 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....

 and Villafranchian. M. praenivalis itself was probably preceded by M. pliocaenica of the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...

. The modern species probably arose during the Late Pleistocene
Late Pleistocene
The Late Pleistocene is a stage of the Pleistocene Epoch. The beginning of the stage is defined by the base of the Eemian interglacial phase before the final glacial episode of the Pleistocene 126,000 ± 5,000 years ago. The end of the stage is defined exactly at 10,000 Carbon-14 years BP...

. The least weasel is the product of a process begun 5-7 million years ago, when northern forests were replaced by open grassland, thus prompting an explosive evolution of small, burrowing rodents. The weasel's ancestors were larger than the current form, and underwent a reduction in size to exploit the new food source. The least weasel thrived 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...

, as its small size and long body allowed it to easily operate beneath snow, as well as hunt in burrows. It probably crossed to North America through the Bering land bridge
Bering land bridge
The Bering land bridge was a land bridge roughly 1,000 miles wide at its greatest extent, which joined present-day Alaska and eastern Siberia at various times during the Pleistocene ice ages. Like most of Siberia and all of Manchuria, Beringia was not glaciated because snowfall was extremely light...

 200,000 years ago.

Subspecies

The least weasel has a high geographic variation, a fact which has historically led to numerous disagreements among biologists studying its systematics. Least weasel subspecies are divided into 3 categories:
  • The pygmaea-rixosa group (small weasels): Tiny weasels with short tails and pedomorphic skulls, which turn pure white in winter. They inhabit northern European Russia
    European Russia
    European Russia refers to the western areas of Russia that lie within Europe, comprising roughly 3,960,000 square kilometres , larger in area than India, and spanning across 40% of Europe. Its eastern border is defined by the Ural Mountains and in the south it is defined by the border with...

    , Siberia
    Siberia
    Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

    , the Russian Far East
    Russian Far East
    Russian Far East is a term that refers to the Russian part of the Far East, i.e., extreme east parts of Russia, between Lake Baikal in Eastern Siberia and the Pacific Ocean...

    , Finland
    Finland
    Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

    , northern Scandinavian Peninsula
    Scandinavian Peninsula
    The Scandinavian Peninsula is a peninsula in Northern Europe, which today covers Norway, Sweden, and most of northern Finland. Prior to the 17th and 18th centuries, large parts of the southern peninsula—including the core region of Scania from which the peninsula takes its name—were part of...

    , Mongolia
    Mongolia
    Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...

    , northeastern China
    China
    Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

    , Japan
    Japan
    Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

     and 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...

    .
  • The boccamela group (large weasels): Very large weasels with large skulls, relatively long tails and lighter coloured pelts. Locally, they either do not turn white or only partially in winter. They inhabit Transcaucasia, from western Kazakhstan
    Kazakhstan
    Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...

     to Semirechye and in the flat deserts of Middle Asia
    Middle Asia
    Middle Asia is a region of Asia from the Caspian Sea in the west, to Mongolia in the east, Afghanistan in the south, and Russia in the north. The geographical term has appeared sometime prior to the 20th century in the Russian Empire and was closely associated with the Russian Turkestan and the...

    .
  • The nivalis group (average weasels): Medium-sized weasels, with tails of moderate length, representing a transitional form between the former two groups. They inhabit the middle and southern regions of European Russia, Crimea
    Crimea
    Crimea , or the Autonomous Republic of Crimea , is a sub-national unit, an autonomous republic, of Ukraine. It is located on the northern coast of the Black Sea, occupying a peninsula of the same name...

    , Ciscaucasus, western Kazakhstan, southern and middle Urals and montane parts of Middle Asia, save for Koppet Dag.


, 18 subspecies are recognised.

Physical description

The least weasel has a thin, greatly elongated and extremely flexible body with a small, yet elongated, blunt muzzled head which is no thicker than the neck. The eyes are large, bulging and dark coloured. The legs and tail are relatively short, the latter constituting less than half its body length. The feet are armed with sharp, dark claws, and the sole
Sole
Sole may refer to:* Sole , the bottom of the foot* Sole , the bottom supporting member of the shoe-Business:* Sole proprietorship, a business which legally has no separate existence from its owner...

s are heavily haired. The skull, especially that of the small rixosa group, has an infantile appearance when compared with that of other members of the genus Mustela (in particular, the stoat and kolonok
Siberian Weasel
The Siberian weasel , also known as the Kolonok, is a medium-sized species of weasel native to Asia. It is classed as Least Concern for extinction by the IUCN, due to its wide distribution and presumably large numbers....

). This is expressed in the relatively large size of the cranium and shortened facial region. The skull is, overall, similar to that of the stoat, but smaller, though the skulls of large male weasels tend to overlap in size with those of small female stoats. It usually has 4 pairs of nipples, but these are only visible in females. The 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:...

 is short (16–20 mm), with a thick, straight shaft. Fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...

 is deposited along the spine, kidneys, gut mesentries and around the limbs. The least weasel has muscular anal glands under the tail, which measure 7 x 5 mm, and contain sulphurous volatiles, including thietane
Thietane
Thietane is a heterocyclic compound containing a saturated four-membered ring with three carbon atoms and one sulfur atom....

s and dithiacyclopentanes. The smell and chemical composition of these chemicals are distinct from those of the stoat. The least weasel moves by jumping, the distance between the tracks of the fore and hind limbs being 18–35 cm.

Dimensions vary geographically, to an extent rarely found among other mammals. Least weasels of the vulgaris group, for example, may outweigh the smaller races by almost four times. In some large subspecies, the male may be 1.5 times longer than the female. Variations in tail length are also variable, constituting from 13-30% of the length of the body. Average body length in males is 130–260 mm, while females average 114–204 mm. The tail measures 12–87 mm in males and 17–60 mm in females. Males weigh 36-250 gram
Gram
The gram is a metric system unit of mass....

s, while females weigh 29.5-117 grams.

The winter fur is dense, but short and closely fitting. In northern subspecies, the fur is soft and silky, but coarse in southern forms. The summer fur is very short, sparser and rougher. The upper parts in the summer fur are dark, but vary geographically from dark-tawny or dark-chocolate to light pale tawny or sandy. The lower parts, including the lower jaw and inner sides of the legs are white. The dividing line between the dark upper and light lower parts is straight, but sometimes forms an irregular line. In winter, the fur is pure white, and only exhibits black hairs in rare circumstances.

Reproduction and development

The least weasel mates in April–July, with a 34-37 day gestation period
Gestation period
For mammals the gestation period is the time in which a fetus develops, beginning with fertilization and ending at birth. The duration of this period varies between species.-Duration:...

. In the northern hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

, the average litter size consists of 6 kits, which reach sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...

 in 3–4 months. Males may mate during their first year of life, though this is usually unsuccessful. They are fecund in February–October, though the early stages of spermatogenesis
Spermatogenesis
Spermatogenesis is the process by which male primary germ cells undergo division, and produce a number of cells termed spermatogonia, from which the primary spermatocytes are derived. Each primary spermatocyte divides into two secondary spermatocytes, and each secondary spermatocyte into two...

 do occur throughout the winter months. Anestrus in females lasts from September-February.

The female raises its kits alone, which are 1.5-4.5 grams in weight when born. Newborn kits are born pink, naked, blind and deaf, but gain a white coat of downy fur at the age of 4 days. At 10 days, the margin between the dark upper parts and light under parts becomes visible. The milk teeth erupt at 2–3 weeks of age, at which point 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...

, though lactation can last 12 weeks. The eyes and ears open at 3–4 weeks of age, and by 8 weeks, killing behaviour is developed. The family breaks up after 9–12 weeks.

Territorial and social behaviours

The least weasel has a typical Mustelid territorial pattern, consisting of exclusive male ranges encompassing multiple female ranges. The population density of each territory depends greatly on food supply and reproductive success, thus the social structure and population density of any given territory is unstable and flexible. Like the stoat, the male least weasel extends its range during spring or during food shortages. Its scent marking behaviour is similar to the stoat's; it uses faeces, urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...

 and anal and dermal gland secretions, the latter two of which are deposited by anal dragging and body rubbing. The least weasel does not dig its own dens, but nest in the abandoned burrows of other species such as moles and rats. The burrow entrance measures about 2.5 cm across and leads to the nest chamber located up to 15 cm below-ground. The nest chamber (which is used for sleeping, rearing kits and storing food) measures 10 cm in diametre, and is lined with straw and the skins of the weasel's prey.

The least weasel has four basic vocalisations; a guttural hiss emitted when alarmed, which is interspersed with short screaming barks and shrieks when provoked. When defensive, it emits a shrill wail or squeal. During encounters between males and females or between a mother and kits, the least weasel emits a high-pitched trilling. The species' way of expressing aggression is similar to that of the stoat. Dominant weasels exhibit lunges and shrieks during aggressive encounters, while subdominant weasels will emit submissive squeals.

Diet

The least weasel feeds predominantly on mouse
Mouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...

-like rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

s, including mice, hamster
Hamster
Hamsters are rodents belonging to the subfamily Cricetinae. The subfamily contains about 25 species, classified in six or seven genera....

s, gerbil
Gerbil
A gerbil is a small mammal of the order Rodentia. Once known simply as "desert rats", the gerbil subfamily includes about 110 species of African, Indian, and Asian rodents, including sand rats and jirds, all of which are adapted to arid habitats...

s and others. It usually does not attack adult hamsters and rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...

s. Frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...

s, fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, small bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

s and bird eggs are rarely eaten. It can deal with adult pika
Pika
The pika is a small mammal, with short limbs, rounded ears, and short tail. The name pika is used for any member of the Ochotonidae, a family within the order of lagomorphs, which also includes the Leporidae . One genus, Ochotona, is recognised within the family, and it includes 30 species...

s and gerbils, but usually cannot overcome brown rat
Brown Rat
The brown rat, common rat, sewer rat, Hanover rat, Norway rat, Brown Norway rat, Norwegian rat, or wharf rat is one of the best known and most common rats....

s and sousliks. Exceptional cases are known of least weasels killing prey far larger than themselves, such as capercaillie
Capercaillie
The Western Capercaillie , also known as the Wood Grouse, Heather Cock or Capercaillie , is the largest member of the grouse family, reaching over 100 cm in length and 6.7 kg in weight. The largest one ever recorded in captivity had a weight of 7.2 kg....

, hazel hen
Hazel Grouse
The Hazel Grouse or Hazel Hen is one of the smaller members of the grouse family of birds. It is a sedentary species, breeding across northern Eurasia and central and eastern Europe in dense, damp, mixed coniferous woodland, preferably with some spruce.The nest is on the ground, and 3–6 eggs is...

 and hare
Hare
Hares and jackrabbits are leporids belonging to the genus Lepus. Hares less than one year old are called leverets. Four species commonly known as types of hare are classified outside of Lepus: the hispid hare , and three species known as red rock hares .Hares are very fast-moving...

s. Rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...

s are commonly taken, but are usually young specimens. Rabbits become an important food source during the spring, when small rodents are scarce and rabbit kits plentiful. Male least weasels take a higher proportion of rabbits than females, as well as an overall greater variety of prey. This is linked to the fact that being larger, and having vaster territorial ranges than females, males have more opportunities to hunt a greater diversity of prey. The least weasel forages undercover, to avoid foxes and birds of prey. It is adapted for pursuing its prey down tunnels, though it may also bolt prey from their burrows and kill it in the open. It kills small prey, such as vole
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...

s, with a bite to the occipital
Occiput
The occiput is the anatomical term for the posterior portion of the head, in insects the posterior part of those head capsule.-Clinical significance:Trauma to the occiput can cause a basilar skull fracture....

 region of the skull or the neck, dislocating the cervical vertebrae
Cervical vertebrae
In vertebrates, cervical vertebrae are those vertebrae immediately inferior to the skull.Thoracic vertebrae in all mammalian species are defined as those vertebrae that also carry a pair of ribs, and lie caudal to the cervical vertebrae. Further caudally follow the lumbar vertebrae, which also...

. Large prey typically dies of blood loss or shock
Acute stress reaction
Acute stress reaction is a psychological condition arising in response to a terrifying or traumatic event...

. When food is abundant, only a small portion of the prey is eaten, usually the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

. The average daily food intake is 35 grams, which is equivalent to 30-35% of its body weight.

Range

The least weasel has a circumboreal, Holarctic
Holarctic
The Holarctic ecozone refers to the habitats found throughout the northern continents of the world as a whole. This region is divided into the Palearctic, consisting of Northern Africa and all of Eurasia, with the exception of Southeast Asia and the Indian subcontinent, and the Nearctic,...

 distribution, encompassing much of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

, Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 and northern 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...

, though it has been introduced in New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, Malta
Malta
Malta , officially known as the Republic of Malta , is a Southern European country consisting of an archipelago situated in the centre of the Mediterranean, south of Sicily, east of Tunisia and north of Libya, with Gibraltar to the west and Alexandria to the east.Malta covers just over in...

, Crete
Crete
Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...

, the Azore Islands and also Sao Tome
São Tomé
-Transport:São Tomé is served by São Tomé International Airport with regular flights to Europe and other African Countries.-Climate:São Tomé features a tropical wet and dry climate with a relatively lengthy wet season and a short dry season. The wet season runs from October through May while the...

 off west Africa. It is found throughout Europe and on many islands, including the Azores, Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 (but not Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

), and all major Mediterranean islands. It also occurs on Honshu
Honshu
is the largest island of Japan. The nation's main island, it is south of Hokkaido across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyushu across the Kanmon Strait...

 and Hokkaido
Hokkaido
, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...

 islands in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 and on Kunashir, Iturup
Iturup
Iturup is the largest island of the South Kuril Islands. It is the northernmost island in the southern Kuril/Chishima islands, and though it is presently controlled by Russia, Japan also claims this island...

, and Sakhalin
Sakhalin
Sakhalin or Saghalien, is a large island in the North Pacific, lying between 45°50' and 54°24' N.It is part of Russia, and is Russia's largest island, and is administered as part of Sakhalin Oblast...

 Islands in Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

.

Predators and competitors

The least weasel is small enough to be preyed upon by a range of other predators. Least weasel remains have been found in the excrement of red fox
Red Fox
The red fox is the largest of the true foxes, as well as being the most geographically spread member of the Carnivora, being distributed across the entire northern hemisphere from the Arctic Circle to North Africa, Central America, and the steppes of Asia...

es, sable
Sable
The sable is a species of marten which inhabits forest environments, primarily in Russia from the Ural Mountains throughout Siberia, in northern Mongolia and China and on Hokkaidō in Japan. Its range in the wild originally extended through European Russia to Poland and Scandinavia...

s, steppe
Steppe polecat
The steppe polecat , also known as the white or masked polecat, is a species of Mustelid native to Central and Eastern Europe and Central Asia...

 and forest polecat
European polecat
The European polecat , also known as the black or forest polecat , is a species of Mustelid native to western Eurasia and North Africa, which is classed by the IUCN as Least Concern due to its wide range and large numbers. It is of a generally dark brown colour, with a pale underbelly and a dark...

, 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, eagle owls and buzzard
Buzzard
A buzzard is one of several large birds, but there are a number of meanings as detailed below.-Old World:In the Old World Buzzard can mean:* One of several medium-sized, wide-ranging raptors with a robust body and broad wings....

s. The owls
OWLS
OWLS is a mnemonic used by general aviation airplane pilots to assess an unprepared surface for a precautionary landing.Like all mnemonics this check has become part of aviation culture and folklore.OWLS:* Obstacles* Wind direction...

 most efficient at capturing least weasels are barn
Barn Owl
The Barn Owl is the most widely distributed species of owl, and one of the most widespread of all birds. It is also referred to as Common Barn Owl, to distinguish it from other species in the barn-owl family Tytonidae. These form one of two main lineages of living owls, the other being the typical...

, barred
Barred Owl
The Barred Owl is a large typical owl. It goes by many other names, including eight hooter, rain owl, wood owl, and striped owl, but is probably best known as the hoot owl.-Description:...

 and great horned owl
Great Horned Owl
The Great Horned Owl, , also known as the Tiger Owl, is a large owl native to the Americas. It is an adaptable bird with a vast range and is the most widely distributed true owl in the Americas.-Description:...

s. Other birds of prey threatening to the least weasel include broad-winged
Broad-winged Hawk
The Broad-winged Hawk is a small hawk of the genus Buteo. During the summer some subspecies are distributed over eastern North America, as far west as British Columbia and Texas; they then migrate south to winter in the neotropics from Mexico down to southern Brazil. Other subspecies are all-year...

 and rough-legged buzzard
Rough-legged Buzzard
The Rough-legged Buzzard , called the Rough-legged Hawk in North America, is a medium-large bird of prey. It is found in Arctic and Subarctic regions of North America and Eurasia during the breeding season and migrates south for the winter.The species exhibits a wide variety of plumage patterns...

s. Some snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

 species may prey on the least weasel, including the black rat snake
Black Rat Snake
The Western ratsnake — also called black rat snake, pilot black snake, or simply black snake — is a nonvenomous colubrid species found in North America. No subspecies are currently recognized....

 and copperhead
Agkistrodon contortrix
Agkistrodon contortrix is a species of venomous snake found in North America, a member of the Crotalinae subfamily. The more common name for the species is "copperhead". The behavior of Agkistrodon contortrix may lead to accidental encounters with humans...

. Aside from its smaller size, the least weasel is more vulnerable to predation than the stoat because it lacks a black predator deflection mark on the tail.

In areas where the least weasel is sympatric with the stoat, the two species compete with each other for rodent prey. The weasel manages to avoid overly competing with the stoat by living in more upland areas, and preying on smaller prey and being capable of entering smaller holes. The least weasel actively avoids encounters with stoats, though female weasels are less likely to stop foraging in the presence of stoats, likely because their smaller size allows them to quickly escape in holes.

Diseases and parasites

Ectoparasites known to infest weasels include the louse
Louse
Lice is the common name for over 3,000 species of wingless insects of the order Phthiraptera; three of which are classified as human disease agents...

 Trichodectes mustelae and the mite
Mite
Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology.-Diversity and systematics:...

s Demodex and Psoregates mustela. The species may catch flea
Flea
Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...

s from the nests and burrows of its prey. Flea species known to infest weasels include Ctenophthalmus bisoctodentatus and Palaeopsylla m. minor, which they get from moles, P. s. soricis, which they get from shrews, Nosopsyllus fasciatus, which they get from rodents and Dasypsyllus gallinulae which they get from birds.

Helminths known to infest weasels include the trematode Alaria
Alaria
Alaria is a genus of brown alga comprising approximately 17 species. Members of the genus are dried and eaten as a food in Western Europe, China, Korea, Japan , and South America 17:56, 1 August 2010...

, the nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...

s Capillaria
Capillaria (genus)
Capillaria is a genus of nematodes in the family Trichinellidae. Some species formerly placed in this genus are now classified in Aonchotheca.-Species:Species in the genus Capillaria include:* Capillaria aerophila*Capillaria gastrica...

, Filaroides and Trichinella
Trichinella
Trichinella is the genus of parasitic roundworms of the phylum Nematoda that cause trichinosis . Members of this genus are often called trichinella or trichina worms...

 and the cestode Taenia
Taenia
Taenia can refer to:* Taenia of Doric columnsIn medicine and anatomy* Taenia coli of the large intestine* Taenia thalami of the mammal brain* Taenia of fourth ventricle of the mammal brain...

. Least weasels are commonly infected with Skrjabingylus nasicola, which burrows into their skulls and causes fits.

In folklore and mythology

The Ancient Macedonians
Ancient Macedonians
The Macedonians originated from inhabitants of the northeastern part of the Greek peninsula, in the alluvial plain around the rivers Haliacmon and lower Axios...

 believed that to see a weasel was a good omen. In some districts of Macedon
Macedon
Macedonia or Macedon was an ancient kingdom, centered in the northeastern part of the Greek peninsula, bordered by Epirus to the west, Paeonia to the north, the region of Thrace to the east and Thessaly to the south....

, women who suffered from headaches after having washed their heads in water drawn overnight would set the problem down to the fact that a weasel had previously used the water as a mirror, but they would refrain from mentioning the animal's name, for fear that it would destroy their clothes. Similarly, a popular superstition in southern Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

 had it that the weasel had previously been a bride
Bride
A bride is a woman about to be married or newlywed.The word may come from the Proto-Germanic verb root *brū-, meaning 'to cook, brew, or make a broth' which was the role of the daughter-in-law in primitive families...

, who was transformed into a bitter animal which would destroy the wedding dresses of other brides out of jealousy. According to Pliny the Elder
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

, the weasel is the only animal capable of killing the basilisk
Basilisk
In European bestiaries and legends, a basilisk is a legendary reptile reputed to be king of serpents and said to have the power to cause death with a single glance...

;

To this dreadful monster the effluvium of the weasel is fatal, a thing that has been tried with success, for kings have often desired to see its body when killed; so true is it that it has pleased Nature that there should be nothing without its antidote. The animal is thrown into the hole of the basilisk, which is easily known from the soil around it being infected. The weasel destroys the basilisk by its odour, but dies itself in this struggle of nature against its own self.


The Chippewa believed that the weasel could kill the dreaded wendigo
Wendigo
The Wendigo is a mythical creature appearing in the mythology of the Algonquian people. It is a malevolent cannibalistic spirit into which humans could transform, or which could possess humans...

 giant by rushing up its anus. In Inuit mythology
Inuit mythology
Inuit mythology has many similarities to the religions of other polar regions. Inuit traditional religious practices could be very briefly summarised as a form of shamanism based on animist principles....

, the weasel is credited with both great wisdom and courage, and whenever a mythical Inuit
Inuit
The Inuit are a group of culturally similar indigenous peoples inhabiting the Arctic regions of Canada , Denmark , Russia and the United States . Inuit means “the people” in the Inuktitut language...

 hero wished to accomplish a valorous task, he would generally change himself into a weasel. According to Matthew Hopkins
Matthew Hopkins
Matthew Hopkins was an English witchhunter whose career flourished during the time of the English Civil War. He claimed to hold the office of Witchfinder General, although that title was never bestowed by Parliament...

, a witch hunter general during the English Civil War
English Civil War
The English Civil War was a series of armed conflicts and political machinations between Parliamentarians and Royalists...

, weasels were the familiars of witches.

External links

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