Arctic fox

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Arctic fox
Polarfuchs 1 2004-11-17.jpg
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Genus: Vulpes
Species: V. lagopus
Binomial name
Vulpes lagopus
(Linnaeus, 1758)[2]
Cypron-Range Vulpes lagopus.svg
Arctic fox range
Synonyms
  • Alopex lagopus (Linnaeus, 1758)
  • Canis lagopus Linnaeus, 1758
  • Canis fuliginosus Bechstein, 1799
  • Canis groenlandicus Bechstein, 1799
  • Vulpes arctica Oken, 1816
  • Vulpes hallensis Merriam, 1900
  • Vulpes pribilofensis Merriam, 1903
  • Vulpes beringensis Merriam, 1903

The arctic fox (Vulpes lagopus), also known as the white fox, polar fox, or snow fox, is a small fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome.[1][3] It is well adapted to living in cold environments. It has a deep thick fur which is brown in summer and white in winter. Its body length ranges from 46 to 68 cm (18 to 27 in), with a generally rounded body shape to minimize the escape of body heat.

They prey on any small animals they can find, including lemmings, voles, ringed seal pups, fish, and seabirds. They will also eat carrion, berries, and seaweed. They form monogamous pairs during the breeding season and usually stay together in family groups of multiple generations in complex underground dens.

Adaptations[edit]

Arctic fox sleeping with its tail wrapped as a blanket.

The arctic fox lives in some of the most frigid extremes on the planet. Among its adaptations for cold survival is its deep, thick white fur,[4] a system of countercurrent heat exchange in the circulation within the paws to retain core temperature, and a good supply of body fat. The fox has a low surface area to volume ratio, as evidenced by its generally rounded body shape, short muzzle and legs, and short, thick ears. Since less of its surface area is exposed to the arctic cold, less heat escapes the body. Its furry paws allow it to walk on ice in search of food. The arctic fox has such keen hearing that it can precisely locate the position of prey under the snow. When it finds prey, it pounces and punches through the snow to catch its victim. Its fur changes color with the seasons: in the winter it is white to blend in with snow, while in the summer it is brown.[5]

Reproduction[edit]

The arctic fox tends to be active from early September to early May. The gestation period is 52 days. Litters tend to average 5–8 kits but may be as many as 25[6] (the largest in the order Carnivora).[7] Both the mother and the father help to raise their young. The females leave the family and form their own groups and the males stay with the family.

Foxes tend to form monogamous pairs in the breeding season. Litters are born in the early summer and the parents raise the young in a large den. Dens can be complex underground networks, housing many generations of foxes. Young from a previous year's litter may stay with the parents to help rear younger siblings.[6] The kits are initially brownish; as they become older they turn white. Their coat of fur also changes color when summer arrives, but in winter it is white.

Diet[edit]

The arctic fox will generally eat any small animal it can find: lemmings, voles, hares, owls, eggs, and carrion, etc. Lemmings are the most common prey. A family of foxes can eat dozens of lemmings each day. During April and May, the arctic fox also preys on ringed seal pups when the young animals are confined to a snow den and are relatively helpless. Fish beneath the ice are also part of its diet. They also consume berries and seaweed and may thus be considered omnivores.[8] It is a significant bird egg predator, excepting those of the largest tundra bird species.[9] If there is an overabundance of food, the arctic fox will bury the surplus as a reserve. When its normal prey is scarce, the arctic fox scavenges the leftovers and even feces of larger predators, such as the polar bear, even though the bear's prey includes the arctic fox itself.

Size[edit]

The average length is 55 cm (22 in), with a range of 46 to 68 cm (18 to 27 in), in the male.[10][11] The tail is 31 cm (12.2 in) long in the male and 30 cm (11.8 in) long in the female. It is 25–30 cm (9.8–11.8 in) high at the shoulder.[12] On average males weigh 3.5 kg (7.7 lb), with a range of 3.2 to 9.4 kg (7.1 to 20.7 lb), while females average 2.9 kg (6.4 lb), with a range of 1.4 to 3.2 kg (3.1 to 7.1 lb).[11]

Taxonomy[edit]

Vulpes lagopus is a 'true fox' belonging to the genus Vulpes of the fox tribe Vulpini. It is classified under the subfamily Caninae of the canid family Canidae. Although it has previously been assigned to its own monotypic genus Alopex, recent genetic evidence now places it in the genus Vulpes along with the majority of other foxes.[3][13]










Arctic fox[14](Fig. 10)



Kit fox




Swift fox[15]





Corsac fox




Rüppell's fox



Red fox






Cape fox





Blanford's fox



Fennec fox





Raccoon dog





Bat-eared fox





It was originally described by Carl Linnaeus in the 10th edition of Systema Naturae in 1758 as Canis lagopus. The type specimen was recovered from Lapland, Sweden. The generic name vulpes is Latin for "fox".[16] The specific name lagopus is derived from Ancient Greek λαγως (lagos, "hare") and πους (pous, "foot"), referring to the hair on its feet similar to those found in cold-climate species of hares.[15]

Subspecies[edit]

Besides the nominate subspecies, Vulpes lagopus lagopus, there are four other subspecies of this fox:

  • Bering Islands arctic fox, Vulpes lagopus beringensis
  • Iceland Arctic fox, Vulpes lagopus fuliginosus
  • Pribilof Islands arctic fox, Vulpes lagopus pribilofensis
  • Greenland arctic fox, Vulpes lagopus foragorapusis
Arctic fox at Svalbard, Norway.
The arctic fox's seasonal furs, summer (top), "blue" (middle) and winter (bottom)

Population and distribution[edit]

Arctic fox skull

The arctic fox has a circumpolar range, meaning that it is found throughout the entire Arctic, including the outer edges of Greenland, Russia, Canada, Alaska, and Svalbard, as well as in Subarctic and alpine areas, such as Iceland and mainland alpine Scandinavia. The conservation status of the species is good, except for the Scandinavian mainland population. It is acutely endangered there, despite decades of legal protection from hunting and persecution. The estimate of the adult population in all of Norway, Sweden and Finland is a mere 120 individuals.

The arctic fox is the only land mammal native to Iceland.[17] It came to the isolated North Atlantic island at the end of the last ice age, walking over the frozen sea. The Arctic Fox Center in Súðavík contains an exhibition on the arctic fox and conducts studies on the influence of tourism on the population.[18]

The abundance of the arctic fox tends to fluctuate in a cycle along with the population of lemmings and voles (a 3-to-4-year cycle).[9] The populations are especially vulnerable during the years when the prey population crashes, and uncontrolled trapping has almost eradicated two subpopulations.

The pelts of arctic foxes with a slate blue coloration—an expression of a recessive gene—were especially valuable. They were transported to various previously fox-free Aleutian Islands during the 1920s. The program was successful in terms of increasing the population of blue foxes, but their predation of Aleutian Canadian geese conflicted with the goal of preserving that species.[19]

The arctic fox is losing ground to the larger red fox. This has been attributed to climate change—the camouflage value of its lighter coat decreases with less snow cover.[20] Red foxes dominate where their ranges begin to overlap by killing arctic foxes and their kits.[21] An alternate explanation of the red fox's gains involves the gray wolf: Historically, it has kept red fox numbers down, but as the wolf has been hunted to near extinction in much of its former range, the red fox population has grown larger, and it has taken over the niche of top predator.[citation needed] In areas of northern Europe, there are programs in place that allow the hunting of red foxes in the arctic fox's previous range.

As with many other game species, the best sources of historical and large scale population data are hunting bag records and questionnaires. There are several potential sources of error in such data collections.[22] In addition, numbers vary widely between years due to the large population fluctuations. However, the total population of the arctic fox must be in the order of several hundred thousand animals.[23]

The world population is thus not endangered, but two arctic fox subpopulations are. One is on Medny Island (Commander Islands, Russia), which was reduced by some 85–90%, to around 90 animals, as a result of mange caused by an ear tick introduced by dogs in the 1970s.[24] The population is currently under treatment with antiparasitic drugs, but the result is still uncertain.

The other threatened population is the one in Fennoscandia (Norway, Sweden, Finland and Kola Peninsula). This population decreased drastically around the start of the 20th century as a result of extreme fur prices, which caused severe hunting also during population lows.[25] The population has remained at a low density for more than 90 years, with additional reductions during the last decade.[26] The total population estimate for 1997 is around 60 adults in Sweden, 11 adults in Finland and 50 in Norway. From Kola, there are indications of a similar situation, suggesting a population of around 20 adults. The Fennoscandian population thus numbers around 140 breeding adults. Even after local lemming peaks, the arctic fox population tends to collapse back to levels dangerously close to non-viability.[23]

The arctic fox is classed as a "prohibited new organism" under New Zealand's Hazardous Substances and New Organisms Act 1996 preventing it from being imported into the country.[27]

See also[edit]

References[edit]

  1. ^ a b Angerbjörn, A., Hersteinsson, P. & Tannerfeldt, M. (2008). Alopex lagopus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 11 February 2009.
  2. ^ Linnæus, Carl (1758). Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I (in Latin) (10 ed.). Holmiæ (Stockholm): Laurentius Salvius. p. 40. Retrieved 23 November 2012. 
  3. ^ a b Wozencraft, W. C. (2005). "Order Carnivora". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. pp. 532–628. ISBN 978-0-8018-8221-0. OCLC 62265494. 
  4. ^ Claudio Sillero-Zubiri, Michael Hoffmann and David W. Macdonald (eds.) (2004). Canids: Foxes, Wolves, Jackals and Dogs. IUCN/SSC Canid Specialist Group.
  5. ^ Arctic Fox Alopex lagopus. Department of Environment and Conservation, Government of Newfoundland and Labrador
  6. ^ a b Dewey, T. and Middlebrook, C. (2007). "Vulpes lagopus". Retrieved 16 May 2009 at Animal Diversity Web
  7. ^ MacDonald, David W. (2004). Biology and Conservation of Wild Canids. Oxford University Press. ISBN 0-19-851556-1. 
  8. ^ Bockstoce, John R. (2009). Furs and frontiers in the far north: the contest among native and foreign nations for the Bering Strait fur trade. Yale University Press. p. 41. ISBN 978-0-300-14921-0. 
  9. ^ a b Truett, Joe Clyde and Johnson, Stephen R. (2000). The natural history of an Arctic oil field: development and the biota. Academic Press. pp. 160–163. ISBN 978-0-12-701235-3. 
  10. ^ http://animals.nationalgeographic.com/animals/mammals/arctic-fox/?source=A-to-Z
  11. ^ a b Alopex lagopus at the Smithsonian
  12. ^ Boitani, Luigi (1984). Simon & Schuster's Guide to Mammals. Simon & Schuster/Touchstone Books, ISBN 978-0-671-42805-1
  13. ^ Bininda-Emonds, ORP; JL Gittleman; A Purvis (1999). "Building large trees by combining phylogenetic information: a complete phylogeny of the extant Carnivora (Mammalia)". Biol. Rev. 74 (2): 143–175. doi:10.1017/S0006323199005307. PMID 10396181. Retrieved 30 July 2008. 
  14. ^ Lindblad-Toh; Wade, CM; Mikkelsen, TS; Karlsson, EK; Jaffe, DB; Kamal, M; Clamp, M; Chang, JL; Kulbokas, EJ, III et al. (2005). "Genome sequence, comparative analysis and haplotype structure of the domestic dog". Nature 438 (7069): 803–819. doi:10.1038/nature04338. PMID 16341006. 
  15. ^ a b Audet, Alexander M.; Robbins, C. Brian and Larivière, Serge (2002). "Alopex lagopus". Mammalian Species 713 (713): 1–10. doi:10.1644/1545-1410(2002)713<0001:AL>2.0.CO;2. 
  16. ^ Larivière, Serge (2002). "Vulpes zerda". Mammalian Species 714 (714): 1–5. doi:10.1644/1545-1410(2002)714<0001:VZ>2.0.CO;2. 
  17. ^ "Wildlife". Iceland Worldwide. iww.is. 2000. Archived from the original on 14 April 2010. Retrieved 22 April 2010. 
  18. ^ "The Arctic Fox Center". Retrieved 19 May 2011. 
  19. ^ Bolen, Eric G. (1998). Ecology of North America. John Wiley and Sons. p. 42. ISBN 978-0-471-13156-4. 
  20. ^ Hannah, Lee (2010). Climate Change Biology. Academic Press. p. 63. ISBN 978-0-12-374182-0. 
  21. ^ Macdonald, David Whyte and Sillero-Zubiri, Claudio (2004). The biology and conservation of wild canids. Oxford University Press. p. 10. ISBN 978-0-19-851556-2. 
  22. ^ Garrott, R. A. and Eberhardt, L. E. (1987). "Arctic fox". In Novak, M. et al. (eds.). Wild furbearer management and conservation in North America. pp. 395–406. ISBN 0774393653. 
  23. ^ a b Tannerfeldt, M. (1997). Population fluctuations and life history consequences in the Arctic fox. Stockholm, Sweden: Dissertation, Stockholm University. 
  24. ^ Goltsman, M.; Kruchenkova, E. P.; MacDonald, D. W. (1996). "The Mednyi Arctic foxes: treating a population imperilled by disease". Oryx 30 (4): 251–258. doi:10.1017/S0030605300021748. 
  25. ^ Lönnberg, E. (1927). Fjällrävsstammen i Sverige 1926. Uppsala, Sweden: Royal Swedish Academy of Sciences. 
  26. ^ Angerbjörn, A. et al. (1995). "Dynamics of the Arctic fox population in Sweden". Annales Zoologici Fennici 32: 55–68. 
  27. ^ Hazardous Substances and New Organisms Act 2003 – Schedule 2 Prohibited new organisms. New Zealand Government. Retrieved 26 January 2012. 

Further reading[edit]

  • Nowak, Ronald M. (2005). Walker's Carnivores of the World. Baltimore: Johns Hopkins Press. ISBN 0-8018-8032-7

External links[edit]