Mink

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For other uses, see Mink (disambiguation).
Mink
European Mink (Mustela lutreola)
European Mink (Mustela lutreola)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Neovison and Mustela
Species

Neovison vison
Neovison macrodon
Mustela lutreola

Mink is the common name for semiaquatic carnivorous mammals of the two extant Mustelidae species Mustela lutreola (European mink) and Neovison vison (American mink; synonym Mustela vison) and one recently extinct species, Neovison macrodon (sea mink; synonym Mustela macrodon). Minks are characterized by a slender body, arched back, long neck, short ears, pointed snout, short limbs, bushy tail, and webbed feet. Minks have been valued historically for their thick and shiny fur, which remains a luxury good to this day.


The American Mink's fur has been highly prized for its use in clothing, with hunting giving way to large-scale mink farming. Its treatment has also been a focus of animal welfare activism.

American Mink have found their way into the wild in Europe (including Great Britain) and South America, after being released from mink farms by animal rights activists. American Mink are believed by some to have contributed to the decline of the less hardy European mink through competition. Trapping is used to control and eliminate any feral American Mink.

Overview

Minks are members of the Mustelidae family of the mammalian order Carnivora. The Mustelidae family includes 55 species of weasels, badgers, and otters), placed in 24 genera. This "weasel family" is a diverse family and the largest in the order Carnivora, at least partly because it has in the past been a catch-all category for many early or poorly differentiated taxa. Within a large range of variation, the mustelids exhibit some common characteristics. They are typically small animals with short legs, short round ears, and thick fur.

The common name "mink" is applied to three species within Mustelidae:

  • European Mink Mustela lutreola
  • American Mink Neovison vison (synonym Mustela vison)
  • Sea Mink Neovison macrodon (extinct) (synonym Mustela macrodon)

There are two living species of mink, the European mink and the larger American mink. The extinct sea mink is related to the American mink, but is much larger. All three species of mink are dark-colored, semi-aquatic, carnivorous mammals. It is sometimes possible to distinguish the European and American species based on the fact that the American mink usually lacks a large white patch on its upper lip, while the European mink always possesses one. Any mink without such a patch can be identified with certainty as an American mink, but an individual with such a patch, if encountered in continental Europe, cannot be certainly identified without looking at the skeleton. The European mink always and the American mink usually has a white spot on the lower lip, which continues in broken or unbroken fashion to form ventral markings. Since each is a different shape, it is possible to recognize individuals based on these ventral patterns.

Taxonomies often place all three species as part of the Mustela genus, a taxonomic group that is known collectively as weasels, and includes about 17 species of animals known commonly as ermines, ferrets, minks, polecats, and weasels (ITIS 2006e). However, according to cytogenetic and biochemical data, there are significant differences between the American mink and other species listed in Mustela—differences greater than that among Mustela species—and thus recent taxonomies separate the American mink into its own genus as Neovison vison (ITIS 2006a). The sea mink (Neovison macrodon), which is now extinct, likewise is often listed as Mustela macrodon, and is listed as extinct by IUCN as M. macrodon, but is similar to Neovison vision, and indeed is considered by some to be conspecific with N. vison (ITIS 2006b).

Mink first entered Europe from America at the end of the Pleistocene Ice Age. The two extant species are believed to have diverged only in the last ten thousand years, and therefore remain remarkably similar in a number of ways (Birks 1984).

European mink

Drawing of a European Mink

The European mink, Mustela lutreola, is a European member of the Mustelidae family found in some regions of Spain, France, Romania, Ukraine, Estonia, and the greater part of Russia, though not found east of the Ural Mountains. Formerly it extended across all Europe, reaching Finland in the north, but it is now extinct in the major part of its ancient range. It is similar in appearance to the American mink.

European Mink have slender, flexible bodies, bushy tails, and webbed paws. They have a sleek summer coat, and a darker, denser, winter coat, better suited to low temperatures. Their eyesight is generally poor, so that they rely heavily on their superior sense of smell while hunting (Birks 1984).


Fur also grows white over a scar and older mink tend to have more such patches, although absolute age is difficult to quantify without studying the animal from birth. In fur farms, mink are generally slaughtered after eight months, but can live several years in the wild (although mortality is high, especially among dispersing juveniles).

Male European Mink are from 28-43 cm in body length, and weight about 900 grams, while the females are only slightly smaller at 30-40 cm long and 600 grams in weight. These figures are somewhat smaller than those for the American Mink. [1]

Habits and reproduction

European Mink are solitary animals, and live in dens close to fresh water. They range over an area of shoreline or riverbank up to four kilometres in length, and defend the territory with a combination of scent marking and physical aggression. They are carnivores, and prey on a wide range of waterside animals, including fish, voles, rabbits, and waterfowl.

Between February to March, males leave their dens and travel considerable distances in search of a mate. Both males and females mate with several different individuals over the course of the season. The female gives birth to four to six naked, blind, kits after a mean gestation period of 49.66 days to 51.7 days.[2] This process may appear longer due to delayed implantation.[3] The young kits are weaned at eight to ten weeks, and leave to establish their own dens at three to four months. They are sexually mature in time for the breeding season the following year.[1]

Conservation

A trend in recent years has been the release of farmed minks into the wild by animal rights activists.[citation needed] The result of the introduction of the American Mink into the wild in Europe has been disastrous for the European Mink, who occupies almost the same ecological niche but is outcompeted by the larger and better-swimming American species. Attempts are now underway to introduce the European Mink to islands too far from the continent for American Mink to swim to, in an attempt to prevent the species from becoming extinct.

The endangered populations of European Mink Mustela lutreola have shown a large decline over 80% of their natural range and the species may be regarded as one of the most endangered mammals in the world. Although natural hybridization events between two native species is regarded as an exceptional event, Thierry Lodé found some hybrids, emphasizing that European Mink and European Polecats are able to hybridize and their hybrids were fertile. [4].

The European mink is one of the most endangered mammals in the world. The endangered western population of European mink Mustela lutreola has shown a large decline over its natural range. The species has been extinct in central Europe since the beginning of the century and the mink's range is actually fragmented into two population units: an eastern population unit ranging from the Urals and Estonia to the Black sea, a population which is already subdivided into small units, and a western population. Inhabiting mainly forest brooks, the European mink occupies an intermediate semi-aquatic niche between the European polecat Mustela putorius and the otter Lutra lutra. Polecats and European mink are able to hybridize achieving natural hybridization events between two native species (as found by Lodé Thierry).

American mink

A wild American Mink, Lower Saranac Lake.

The American Mink, Neovison vison, is a North American member of the Mustelidae family found in Alaska, Canada and most of the United States. They are related to weasels, otters, European Mink, wolverines, and fishers. They were once grouped with skunks although new genetic evidence suggests skunks should be classified in a separate family Mephitidae. A domestic form of American Mink has also been raised in fur farms for their lustrous fur, which is highly esteemed. Breeders have developed a range of colors from deep black to white. A related marine species, Neovison macrodon, was hunted to extinction in the 19th century.

Mink-mustella-vison.jpg

Their long slim body is covered in glossy, thick dark brown fur with a white patch under the chin. They have short legs with partially webbed feet, which make them excellent swimmers. They can be found in wooded areas and fields near streams and lakes. They do not dig burrows, but instead take over dens abandoned by other animals.

Mink are semi aquatic predators able to hunt both aquatic and terrestrial prey. They can dive under water like an otter to capture fish, crayfish, and frogs. They can also capture terrestrial prey like birds, snakes, mice, voles, and rabbits. Mink are generalist predators focusing on what ever prey is most available and easily captured. These animals are mainly active at night and do not hibernate. Their predators include coyotes, Great Horned Owl, and wolves. They are also trapped for their fur. Their numbers have been reduced due to loss of habitat, the effects of pollution on their aquatic food supply, and the mixing of domestic mink genes into the wild mink gene pool.[5]

MustelaVison001.JPG

They are usually solitary animals. Mating occurs from early February through early April; males and females may have more than one partner. Females give birth to 4–5 kits per litter once a year. While mortality is extremely high in the early months of the life of the American Mink, animals that do survive the first year can live as long as three years in the wild.[citation needed] In captivity, mink can live 10–12 years.[citation needed] The mink is found in places which suit its habits throughout almost all North America, from Florida to the Arctic. An endangered subspecies, the Everglades Mink (Mustela vison evergladensis), is endemic to the Florida Everglades.


Fur Farms

Mink farm in Wisconsin


There is debate about the subject of fur farming. Many people argue that fur farming is cruel and should be eliminated completely. Others argue that fur farming is a necessary evil, because it allegedly protects wild fur bearers from over harvest. Before fur farming was developed many animals, like the sea mink, were driven to extinction due to over harvesting them for their fur. Many other animals like the fur seal, sea otter, river otter, and beaver had their populations drastically reduced from over harvesting. If fur farming were eliminated, the price of fur might increase. Wild fur bearing animals might again be in danger of over harvest.

A 2006 study in Denmark concluded that, due to frequent escapes from existing mink farms, “Closing mink farms may result in a crash of the free-ranging population, or alternatively it may result in the establishment of a better-adapted, truly feral population that may ultimately outnumber the population that was present before farm closures.” The study reported that more information would be necessary to determine the outcome.[6] Another Danish study reported that a significant majority of the “wild” mink were mink which had escaped from fur farms. 47% had escaped within two months, 31% had escaped prior to 2 months, and 21% “may or may not have been born in nature.”[7]

In recent years, animal rights activists have also released several thousand domestic mink causing negative environmental consequences. Domestic mink, which are bred in fur farms, are different from wild mink. Domestic mink are found to have 19.6% smaller brains, 8.1% smaller hearts, and 28.2% smaller spleens than wild mink do.[8][9] Because of these physical differences, domestic mink may not be suited for life in the wild. A University of Copenhagen study found that most domestic mink that escape from fur farms die in less than two months.[10]

This data is contested by M. Hammershøj and M.C. Forchhammer, who studied the survival rate of escaped mink in Denmark, then compared that data to similar studies in the US and Sweden. The authors concluded that the survival rate for recently released mink is lower than for wild mink, but if mink survive at least two months, their survival rate is the same as for wild mink. The authors suggest that this is due to the rapid behavioural adaptation of the animals.[11] A biologist with the Washington State Department of Fish and Wildlife commenting on a mik farm release concurs, stating that "These things will survive and reproduce as long as they have something to survive on."[12]

Mink that escaped from a fur farm in Cox’s Cove, Newfoundland, Canada

Domestic mink are larger than wild mink which may cause problems with the ecosystem when they escape. Mink are solitary, territorial animals and are intolerant of other mink. In times of overpopulation, mink control their own numbers by either killing each other through direct conflict or by causing weaker mink to be driven from territory until starvation sets in.[13] When hundreds or thousands of released domestic mink flood an ecosystem, it causes a great disturbance for the wild mink. This disturbance causes the deaths of the majority of the released mink and many of the wild mink. Most of the released and wild mink in the area die slow deaths, due to starvation, or from injuries from the unnaturally high number of mink fighting for a territory.[14] When a domestic mink survives long enough to reproduce, it may cause problems for the wild mink populations.[15] The adding of weaker domestic mink genes into wild mink populations, is believed by some, to have contributed to the decline of mink populations in Canada.[16]

Feral Mink

Some American Mink have established themselves in the wild in Newfoundland, Europe and South America due to escapes or intentional release by animal rights activists from fur farms. In parts of Europe, tens of thousand were intentionally introduced by the Soviet Union over a period of several decades, to provide a new game animal for trappers, with disastrous population declines of the European Mink as result.[citation needed]

The larger American male will mate with European Mink females earlier in the spring than the males of the same species; no offspring are born, but the females do not then breed again that season.[citation needed] This is believed by some, to have contributed to the decline of the European Mink. American Mink have also been implicated in the decline of the Water Vole in the United Kingdom and linked to the decline of water fowl across their range in Europe. They are now considered vermin in much of Europe and are hunted for the purpose of wildlife management.[citation needed]

Mink intelligence

Like their cousins, the otters, mink are very playful. They are very inquisitive, highly intelligent animals. A study was performed that compared the learning ability of mink to ferrets, skunks, and house cats.[17] The animals were tested on their ability to remember different shapes. The order of ability of remembering these different shapes were from best to worst; mink, ferrets, skunks and cats. Mink were in fact found to be more intelligent than certain groups of primates. After considerable training, mink were also found to learn after only one trial. This is a phenomenon usually only observed in higher primates.

Mink as pets

Snappemat.gif

Despite the fact that they are inquisitive, playful and cute, mink do not make good pets for the average person because they have strong jaws, very sharp teeth, can be highly aggressive, and are very active. Most people do not have the knowledge, or the patience to properly care for a pet mink.

Even though domestic mink have been bred in captivity for around a hundred years, they have not been bred to be tame. Domestic mink have been bred for size, fur quality, and color. However, the Fur Commission of the US claims that "mink are truly domesticated animals" based on the number of years they have been kept on fur farms.[18]

The belief that mink are completely untameable is not true ether. Mink can be tamed and kept as pets, but it is a difficult process. Individuals with lots of time, patience, and experience with wild animals, have successfully kept mink as pets.[citation needed]

Sea mink

The sea mink, Neovison macrodon, is an extinct North American member of the Mustelidae family. It is the only mustelid, and one of two mammalian carnivore species to have gone extinct in historic times, along with the Falkland Island Fox. It was significantly longer than the closely related American Mink (N. vison), and also larger and fatter, leading to a pelt that was around twice the size. The longest specimen recorded was said to be 82.6cm (32.5 in). The fur of the Sea Mink was said to be coarser and redder than the American Mink's, and give off a distinctive odour.[19]

It was found along the rocky coasts of New England and Atlantic Canada, as far north as Nova Scotia. It was not a truly marine species, being confined to coastal waters. The Labrador Duck, with which it co-existed, may have been a prey item; the extinction of the duck may have in turn contributed to the mink's.[citation needed]

Due to its highly-prized fur, it was hunted to extinction. The animal's remains are often found in Native American shell-heaps on the coasts of the islands of Maine, but while indigenous hunting may have had some contribution to the Sea Mink's decline, it was the competitive European fur trade that led to its extinction.[19]

The last known member of the species was said to have been captured in New Brunswick, New Jersey in 1894, although there is some debate if this was a specimen of N. macrodon or N. vison. The last substantiated report has led to an estimated extinction date of around 1860,[20] although a specimen was reported as sold to a fur-buyer in Maine in 1880.[19]

Although well known to fur hunters, it became extinct before being scientifically described, and therefore little is known about its habits. Existing data suggests it was nocturnal and solitary.[20]

The Sea Mink is sometimes considered to have been a subspecies of the American Mink, in which case the name Neovison vison macrodon is used.


References
ISBN links support NWE through referral fees

. [1]

Taxonomic Serial No.: 621951. Retrieved June 19, 2008.

Taxonomic Serial No.: 180552. Retrieved June 19, 2008.

  1. 1.0 1.1 1.2 Birks, J. (1984). in Macdonald, D.: The Encyclopedia of Mammals. New York: Facts on File, 116-117. ISBN 0-87196-871-1. 
  2. The Gestation Period of Mink
  3. Animal Info - European Mink
  4. Lodé T., Guiral G. & Peltier D. (2005). European mink-polecat hybridization events: hazards from natural process. Journal of Heredity 96 (2): 1-8.
  5. Bowman, J., Kidd, A., Gorman, R., Schulte-Hostedde, A. 2007. "Assessing the potential for impacts by feral mink on wild mink in Canada," Biological Conservation 139: 12-18.
  6. Incorporating evolutionary processes into a spatially-explicit model: exploring the consequences of mink-farm closures in Denmark by Hammershøj, Mette; Travis, Justin M. J.; Stephenson, Catriona M.
  7. Danish free-ranging mink populations consist mainly of farm animals: evidence from microsatellite and stable isotope analyses by Mette Hammershøj1, Cino Pertoldi, Tommy Asferg, Thomas Bach Møller & Niels Bastian Kristensen
  8. Kruska, D. and Schreiber, A. 1999. "Compatative morphpmetrical and biochemical-geneic investigations in wild and ranch mink," Acta Theriologica 44, 4: 382. .
  9. Kruska, D. 1996 "The effect of domestication on brain size and composition on the mink," J.Zoo.,Lond 239: 655.
  10. Hammershøj, M. 2004. "Population ecology of free-ranging American mink Mustela vison in Denmark," Thesis. University of Copenhagen.
  11. Survival rates of free-ranging farm mink suggest quick behavioural adaptation to natural conditions
  12. Freed mink attack Sultan farms
  13. Dunstone, N. 1993. "The Mink," London.
  14. Dunstone, N. 1993. "The Mink," London.
  15. Bowman, J., Kidd, A., Gorman, R., Schulte-Hostedde, A. 2007. "Assessing the potential for impacts by feral mink on wild mink in Canada," Biological Conservation 139: 12-18.
  16. Bowman, J., Kidd, A., Gorman, R., Schulte-Hostedde, A. 2007. "Assessing the potential for impacts by feral mink on wild mink in Canada," Biological Conservation 139: 12-18.
  17. Barbara A. Doty, C. Neal Jones and Larry A. Doty "Learning-Set Formation by Mink, Ferrets, Skunks,and Cats".
  18. Mink Farming in the United States
  19. 19.0 19.1 19.2 Day, David (1981). The Encyclopedia of Vanished Species. London: Universal Books Ltd, p220. ISBN 0-947889-30-2. 
  20. 20.0 20.1 Maas, Peter (2007). Sea Mink. The Extinction Website. Retrieved 2007-10-14.
  • Mustelid Specialist Group 1996. [1]. 2006 IUCN Red List of Threatened Species., World Conservation Union. Retrieved on 11 May 2006. Listed as Endangered (EN A1ace v2.3)
  • De Jongh A.W.J.J., Tokar G.A., Matvyeyev A.S., De Jong Tj. & E.V. de Jongh-Nesterko (in press). European mink (Mustela lutreola) still surviving in Ukrainian delta’s of Danube and Dniester. Lutra.
  • Mustelid Specialist Group 1996. [2]. 2006 IUCN Red List of Threatened Species., World Conservation Union. Retrieved on 12 May 2006.
  • P. Hellsetde, E. Kallio & I. Hanski. "Survival rate of captive-born released Least weasels in Southern Finland." Mammal Review, 2000, 30:3/4
  • Kruska, D. and Schreiber, A. (1999) "Compatative morphpmetrical and biochemical-geneic investigations in wild and ranch mink." Acta Theriologica 44 (4): 382.
  • Kruska, D. (1996) "The effect of domestication on brain size and composition on the mink." J.Zoo.,Lond 239: 655.
  • Hammershøj, M. (2004) "Population ecology of free-ranging American mink Mustela vison in Denmark." Thesis. University of Copenhagen
  • Dunstone, N. (1993) The Mink. London.
  • Bowman, J., Kidd, A., Gorman, R., Schulte-Hostedde, A. (2007) "Assessing the potential for impacts by feral mink on wild mink in Canada." Biological Conservation 139: 12-18.
  • Mustelid, Viverrid & Procyonid Specialist Group 2002. [3]. 2006 IUCN Red List of Threatened Species., World Conservation Union. Retrieved on 11 May 2006. Database entry includes justification for why this species is listed as extinct

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