Wolverine

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The wolverine, pronounced /  ˈ   w   ʊ   l   v   ə   r   iː   n   /, Gulo gulo (Gulo is  Latin  for "glutton"), also referred to as glutton, carcajou, skunk bear, or quickhatch, is the largest land-dwelling  species  of the family  Mustelidae  (weasels). It is a stocky and muscular carnivore, more closely resembling a small bear  than other mustelids. The wolverine has a reputation for ferocity and strength out of proportion to its size, with the documented ability to kill prey many times its size.

The wolverine can be found primarily in remote reaches of the Northern and  subarctic  and  alpine tundra  of the  Northern hemisphere, with the greatest numbers in the  U.S.  state of  Alaska ,  northern Canada , the  Nordic countries  of  Europe , and throughout  western Russia  and  Siberia. Their populations have experienced a steady decline since the 19th century in the face of trapping, range reduction and  habitat fragmentation , such that they are essentially absent in the southern end of their European range. It is, however, estimated that large populations remain in North America  and northern  Asia. Wolverines are solitary animals.| [2]

Taxonomy

Genetic evidence suggests that the wolverine is most closely related to thetayraandmartens(scientific names Eira  and  Martes  respectively), all of which shared a Eurasian ancestor.|[3]

Within the Gulo genus, there is a clear separation between twosubspecies: theOld Worldform Gulo gulo gulo and theNew Worldform G. g. luscus. Some authors had described as many as four additional North American subspecies, including ones limited toVancouver Island(G. g. vancouverensis) and theKenai Peninsulain Alaska (G. g. katschemakensis). However, the most currently accepted taxonomy recognizes either the two continentalsubspeciesor recognize G. gulo as a singleHolarctictaxon.|[4]

Recently compiled genetic evidence suggests that most of North America's wolverines are descended from a single source, likely originating fromBeringiaduring the last glaciation and rapidly expanding thereafter, though there is considerable uncertainty to this conclusion due to the difficulty of collecting samples in the extremely depleted southern extent of the range.|[4]

[edit]Physical characteristics
|undefinedundefinedWolverine dentitionAnatomically, the wolverine is a stocky and muscular animal. With short legs, broad and rounded head, and small eyes with short rounded ears, it resembles a bear more than other mustelids.Though its legs are short, its large five-toed paws andplantigrade posturefacilitate movement through deep snow.|[5]

The adult wolverine is about the size of a medium dog, with a length usually ranging from 65–107 cm (26–42 in), a tail of 17–26 cm (6.7–10 in), and a weight of 9–25 kg (20–55 lb), though exceptionally large males can weigh up to 32 kg (71 lb).[6][7][8]The males are as much as 30% larger than the females and can be twice the female's weight. Shoulder height is reported from 30 to 45 cm (12 to 18 in).[9]It is the largest of terrestrial mustelids; only the marine-dwellingsea otterandgiant otterof the Amazon basin are larger.

Wolverines have thick, dark, oily fur which is highlyhydrophobic, making it resistant to frost. This has led to its traditional popularity among hunters and trappers as a lining in jackets andparkasin Arctic conditions. A light silvery facial mask is distinct in some individuals, and a pale buff stripe runs laterally from the shoulders along the side and crossing the rump just above a 25–35 cm (9.8–14 in) bushy tail. Some individuals display prominent white hair patches on the throat or chest.[5]

Like many other mustelids, it has potentanal scent glandsused for marking territory and sexual signaling. The pungent odor has given rise to the nicknames "skunk bear" and "nasty cat." Wolverines, like othermustelids, possess a special upper molar in the back of the mouth that is rotated 90 degrees, towards the inside of the mouth. This special characteristic allows wolverines to tear off meat from prey or carrion that has been frozen solid.[10][11]

[edit]Behavior
undefinedundefinedWolverine pelts from Siberia (left) and Alaska (right)The wolverine is a powerful and versatile predator and scavenger. Prey mainly consists of small to large-sized mammals and the wolverine has been recorded killing prey such as adult deer that are many times larger than itself. Prey species includeporcupine,squirrel,beaver,marmot,rabbit,vole,mice,shrew,lemming,caribou,roe deer,white-tailed deer,mule deer,sheep,moose, andelk.[12]Smaller predators are occasionally preyed on, includingmartens,mink,foxes,canada lynx,weasels,Eurasian lynx,[13]andcoyoteandwolfpups. Wolverines often pursue live prey that is relatively easy to obtain, including animals caught in traps, newborn mammals and deer (including adult moose and elk) when they're weakened by winter or immobilized by heavy snow. The diet is sometimes supplemented by bird's eggs,birds(especiallygeese),roots,seeds,insectlarvae andberries. A majority of the wolverine's sustenance is derived from carrion, which they depend on almost exclusively in winter and early spring. Wolverines may find carrion themselves, feed on it after the predator is done feeding (especially wolf packs) or simply take it from another predator. Whether eating live prey or carrion, the wolverine's feeding style appears voracious, leading to the nickname of "glutton" (also the basis of the scientific name). However, this feeding style is believed to be an adaptation to food that is scarcely encountered, especially in the winter.[14]

Armed with powerful jaws, sharp claws, and a thick hide,[15]wolverines, like most mustelids, are remarkably strong for their size. They may defend kills against larger or more numerouspredators. There is at least one published account of a 12 pounds (5.4 kg) wolverine's apparent attempt to steal a kill from ablack bear(adult males weigh 400 to 500 pounds (180 to 230 kg). Unfortunately for the mustelid, the bear won what was ultimately a fatal contest.[16]Another account placed apolar bearof unknown age and weight together with a similar wolverine where the smaller, tenacious predator came out the victor.[17][18]Interestingly, while wolverines have dominated wolves in competitions over a carcass, some wolves become habituated to predating wolverines and, in such cases, wolves may lead to a complete absence of wolverines in a given area.[8]

Wolverines inhabiting theOld World(specifically,Fennoscandia) are more active hunters than theirNorth Americancousins.[19]This may be because competing predator populations in Eurasia are not as dense, making it more practical for the wolverine to hunt for itself than to wait for another animal to make a kill and then try to snatch it. They often feed oncarrionleft bywolves, so changes in the population of wolves may affect the population of wolverines.[20]Wolverines are also known on occasion to eat plant material.[21]

Successful males will form lifetime relationships with 2–3 females which they will visit occasionally, while other males are left without a mate.[22]Mating season is in the summer, but the actual implantation of the embryo (blastocyst) in theuterusisstayeduntil early winter, delaying the development of thefetus. Females will often not produce young if food is scarce. The wolverine gestation period is 30–50 days. Litters of typically two or three young ("kits") are born in the spring. Kits develop rapidly, reaching adult size within the first year of a lifespan that may reach anywhere from five to (in exceptional individuals) thirteen years.[ citation needed ] Fathers make visits to their offspring until they are weaned at 10 weeks of age; also, once the young are about 6 months old, some reconnect with their fathers and travel together for a time.[22]

[edit]Range
undefinedundefinedWolverine on rocky terrainWolverines live primarily in isolated northern areas, for example thearcticandalpineregions ofAlaska, northernCanada,Siberia, andScandinavia; they are also native toRussia, theBalticcountries, and NorthernChinaandMongolia. In 2008 and 2009, wolverines were sighted as far south as theSierra Nevada, nearLake Tahoe, for the first time since 1922.[23][24][25]They are also found in low numbers in theRocky Mountainsand northernCascadesof the United States, and have been sighted as far south and east as Michigan.[26]However, most New World wolverines live in Canada.[21]

The world's total wolverine population is unknown. The animal exhibits a low population density and requires a very large home range.[20]The range of a male wolverine can be more than 620 km2 (240 sq mi), encompassing the ranges of several females which have smaller home ranges of roughly 130–260 km2 (50–100 sq mi). Adult wolverines try for the most part to keep non-overlapping ranges with adults of the same sex.[11]Radio tracking suggests an animal can range hundreds of miles in a few months.

Female wolverines burrow into snow in February to create a den, which is used until weaning in mid-May. Areas inhabited nonseasonally by wolverines are thus restricted to zones with late-springsnowmelts. This fact has led to concern thatglobal warmingwill shrink the ranges of wolverine populations.[22]

TheWildlife Conservation Societyreported in June 2009 that a wolverine researchers had been tracking for almost three months had crossed into northernColorado. Society officials had tagged the young male wolverine inWyomingnearGrand Teton National Parkand it had traveled southward for approximately 500 miles. It was the first wolverine seen in Colorado since 1919, and its appearance was also confirmed by theColorado Division of Wildlife.[21] This requirement for large territories brings wolverines into conflict with human development, and hunting and trapping further reduce their numbers, causing them to disappear from large parts of their former range; attempts to have them declared an endangered species have met with little success.[20]

[edit]In captivity
undefinedundefinedCaptive at the Kristiansand Zoo, NorwayAround a hundred wolverines are held in zoos across North America and Europe, and they have been successfully bred in captivity, but only with difficulty and high infant mortality.[32]

[edit]Name
The wolverine's questionable reputation as an insatiable glutton (reflected in the Latin genus name Gulo) may be in part due to afalse etymology. The animal's name inOld Swedish, fjellfräs, meaning "mountain cat", worked its way intoGermanas Vielfraß, which means roughly "devours much". Its name in other West Germanic languages is similar (e.g.Dutch: veelvraat).

TheFinnishname is ahma, derived from ahmatti, which is translated as "glutton". Similarly, theEstonianname is ahm, with the equivalent meaning to the Finnish name. InLithuanianis ernis, inLatvian—tinis or āmrija.

TheEastern Slavicросомаха (rosomakha) and thePolishandCzechname rosomak seem to be borrowed from the Finnish rasva-maha (fat belly). Similarly, theHungarianname is rozsomák or torkosborz which means "gluttonous badger".

InFrench-speaking parts of Canada, the wolverine is referred to as carcajou, borrowed from theInnu-aimunorMontagnaiskuàkuàtsheu.[33]However inFrance, the wolverine's name is Glouton (glutton).

Purported gluttony is reflected neither inEnglishnor inNorth Germanic languages. The English word wolverine (alteration of the earlier form wolvering of uncertain origin) probably implies "a little wolf". The name inProto-Norse, erafaz  andOld Norse, jarfr, lives on in the regularIcelandicname jarfi, regularNorwegianname jerv, regularSwedishname järv and regularDanishname jærv.

[edit]In culture
undefinedundefinedTheWolverine pendant of Les Eyzies, about 10,500 BC, when wolverines were still found in southern FranceMany cities, teams, and organizations use the wolverine as a mascot. For example, theU.S. stateofMichiganis, by tradition, known as "The Wolverine State", and theUniversity of Michigantakes the wolverine as its mascot. The association is well and long established: for example, manyDetroitersvolunteered to fight during theAmerican Civil WarandGeorge Armstrong Custer, who led the Michigan Brigade, called them the "Wolverines". The origins of this association are obscure; it may derive from a busy trade in wolverine furs inSault Ste. Mariein the 18th century or may recall a disparagement intended to compare early settlers in Michigan with the vicious mammal. Wolverines are, however, extremely rare in Michigan. A sighting in February 2004 nearUblywas the first confirmed sighting in Michigan in 200 years.[34]The animal was found dead in 2010.[35]

The wolverine figures prominently in the mythology of theInnupeople of easternQuébecandLabrador. In at least one Innu myth, it is the creator of the world.[36]

Wolverineis the name of a popular fictional character byMarvel Comics—named for his highly individualistic and aggressive behavior, as well his great ferocity despite his small stature.

[edit]Film
The 91-minute 1994 motion picture Running Free (also known as One Paw) is about a young boy and his friendship with an Alaskan wolverine. The wolverines seen in the film were born in captivity and directed by U.S.D.A.-licensed filmmaker, Steve Kroschel. Many of the wolverine scenes are documentary footage of trained wolverines that are being filmed in their natural habitat. The movie was screened on October 5, 1994. The American Humane Society was involved before the start of filming and during some of the filming.[37]

The first full length nature documentary about wild wolverines Wolverines - Hyenas of the North was produced 2006 by German wildlife film company Gulo Film Productions for German Television (NDR) and has been broadcasted in many countries - also under the titles Wolverine X or Wolverine Revealed[38](in the U.S. by Animal Planet as an episode of Mutual of Ohama's Wild Kingdom): The film by German director Oliver Goetzl shows many different social behaviour aspects of wild wolverines at the Finnish / Russian border area - some of them previously unknown - and has won more than 30 international festival awards and nominations, incl. at Jackson Hole Wildlife Film Festival, Wildscreen Film Festival, IWFF Missoula, Animal Behavior Society Film Festival and Banff World Television Awards.

The PBS series "Nature" released a documentary, "Wolverine: Chasing the Phantom" as episode #166 on 14 November 2010.[39]This 53 minute documentary[40]focuses on the efforts of a number of naturalists in the United States to track wolverines, collect genetic data, and learn more about wolverine populations, individual behavior and social behavior. It also tracks the raising of two male wolverines in captivity at an Alaska nature reserve from birth to maturity, and profiles the naturalists making these efforts.

The guerrilla force in the 1984 filmRed Dawnwas named the Wolverines, after a high school athletic team.