Fox

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Foxes
Rød ræv (Vulpes vulpes).jpg
Red fox (Vulpes vulpes)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Genera

Foxes are small-to-medium-sized, omnivorous mammals belonging to several genera of the Canidae family. Foxes are slightly smaller than a medium-size domestic dog, with a flattened skull, upright triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or brush).

Twelve species belong to the monophyletic group of Vulpes genus of "true foxes". Approximately another 25 current or extinct species are always or sometimes called foxes; these foxes are either part of the paraphyletic group of the South American foxes and the outlying group, which consists of Bat-eared fox, Gray fox, and Island fox.[1] Foxes are found on every continent except Antarctica. By far the most common and widespread species of fox is the red fox (Vulpes vulpes) with about 47 recognized sub-species.[2] The global distribution of foxes, together with their widespread reputation for cunning, has contributed to their prominence in popular culture and folklore in many societies around the world. The hunting of foxes with packs of hounds, long an established pursuit in Europe, especially in the British Isles, was exported by European settlers to various parts of the New World.

Etymology[edit]

The word fox comes from Old English, which derived from Proto-Germanic *fuhsaz.[nb 1] This in turn derives from Proto-Indo-European *puḱ- ‘thick-haired; tail’.[nb 2] Male foxes are known as dogs, tods or reynards, females as vixens, and young as cubs, pups, or kits. A group of foxes is referred to as a skulk, leash, or earth.[3]

Biology[edit]

Drawing of a fox skeleton.

General morphology[edit]

Foxes are generally smaller than other members of the family Canidae such as wolves, jackals, and domestic dogs. For example, in the largest species, the red fox, males weigh on average between 4.1 and 8.7 kg (9.0 and 19.2 lb),[4] while the smallest species, the fennec fox, weighs just 0.7 to 1.6 kg (1.5 to 3.5 lb).[5] Fox-like features typically include a triangular face, pointed ears, an elongated rostrum, and a bushy tail. Foxes are digitigrade, and thus, walk on their toes. Their claws are not retractable and therefore compared to a feline's, relatively dull.[6] Fox vibrissae, or whiskers, are black. The whiskers on the muzzle, mystaciae vibrissae, average 100-110mm long, which the whiskers everywhere else on the head average to be shorter in length. Whiskers (carpal vibrissae) are also found on the forelimbs and average to be 40mm long, pointing downward and backward.[2] Other physical characteristics vary according to habitat and its adaptive significance.

Pelage[edit]

Fox species differ in fur color, length, and density. Coat colors range from pearly white to black and white to black flecked with white or grey on the underside. Fennec foxes, for example, (and other species of fox adapted to life in the desert, such as kit foxes) have large ears and short fur to aid in keeping the body cool.[2][6] Arctic foxes, on the other hand, have tiny ears and short limbs as well as thick, insulating fur, which aid in keeping the body warm.[7] Red foxes, by contrast, have a typical auburn pelt, the tail normally ending with white marking.[8] A fox's coat color and texture may vary due to the change in seasons; fox pelts are richer and denser in the colder months and lighter in the warmer months. To get rid of the dense winter coat, foxes moult once a year around April; the process begins from the feet, up the legs, and then along the back.[6] Coat color may also change as the individual ages.[2]

Dentition[edit]

A fox's dentition, like all other Canids, are I 3/3, C 1/1, PM 4/4, M 3/2 = 42 (Bat-eared foxes have six extra molars, totaling in 48 teeth). Foxes also have pronounced carnassial pairs which are characteristic of a carnivore. These pairs consist of the upper premolar and the lower first molar and are work together to shear tough material like flesh. Their canines are also pronounced, another characteristic of a carnivore, which are excellent in gripping onto their target prey.[9]

Arctic fox curled up in snow

Behavior[edit]

In the wild, the typical lifespan of a fox is one to three years, although individuals may live up to ten years. Unlike many canids, foxes are not always pack animals. Typically, they live in small family groups, but some (arctic foxes) are known to be solitary.[2][6] Foxes are omnivores.[10][11] The diet of foxes is largely made up of invertebrates such as insects, and small vertebrates such as reptiles and birds, and also can include eggs and plants. Many species are generalist predators, but some (such as the crab-eating fox) have more specialized diets. Most species of fox consume around 1 kg (2.2 lb) of food every day. Foxes cache excess food, burying it for later consumption, usually under leaves, snow, or soil.[6][12] Foxes tend to use a pouncing technique where they crouch down to camouflage themselves in the terrain, then using their hind legs, leap up with great force to land on top of their targeted prey.[2] Using their pronounced canine teeth, foxes grip on to their prey's neck and either shake until the prey is dead, or until the animal can be disemboweled.[2] The gray fox is one of only two canine species known to climb trees; the other is the raccoon dog.

Sexual characteristics[edit]

The vixen, a female fox, has four pairs of teats. Each teat has 8 to 20 lactiferous ducts, which connects the mammary gland to the nipple, allowing for milk to be carried to the nipple in a lactating vixen. The male fox's scrotum is held close to the body with the testis inside even after they descend. Like other canines, the male fox has a baculum, or penile bone.[2] The testes of red foxes are smaller than those of Arctic foxes.[13] Sperm formation in red foxes begins in August–September, with the testicles attaining their greatest weight in December–February.[14]

Vixens are in heat for one to six days, making their reproductive cycle twelve months long. Like other canines, the ova are shed during estrus without the need for the stimulation of copulating. Once the egg is fertilized, the vixen enters a period of gestation that can last from 52 to 53 days. Foxes tend to have an average litter size of four to five with an 80 percent success rate in becoming pregnant.[2][15] Litter sizes can vary greatly according to species and environment – the arctic fox, for example, can have up to eleven cubs.[16]

Vocalization[edit]

The fox's vocal repertoire is vast:

  • Whine- Made shortly after birth. Occurs at a high rate when cubs are hungry and when their body temperatures are low. Whining stimulates the mother to care for her young; it also has been known to stimulate the male fox into caring for his mate and cubs.
  • Yelp- Made about 19 days later. The cubs' whining turns into infantile barks, yelps, which occur heavily during play.
  • Explosive call- At about a month old, the cubs can emit an explosive call which is intended to be threatening to intruders or other cubs; a high pitch howl.
  • Combative call- In adults, the explosive call becomes an open-mouthed combative call during any conflict; a sharper bark.
  • Growl- An adult fox's indication to their cubs to feed or head to the adult's location.
  • Bark- Adult foxes warn against intruders and in defense by barking.[2][17]

In the case of domesticated foxes, the whining seems to remain in adult individuals as a sign of excitement and submission in the presence of their owners.[2]

Classification[edit]

Canids commonly known as foxes include the following genera and species:[2]

Genus Species Picture
Canis Ethiopian wolf, sometimes called the Simien fox or Simien jackal
Ethiopian wolf, native to the Ethiopian highlands
Cerdocyon Crab-eating fox
Crab-eating fox, a South American species
Dusicyon Extinct genus, including the Falkland Islands wolf, sometimes known as the Falklands Islands fox
Falkland Islands wolf Illustration by John Gerrard Keulemans (1842–1912)
Lycalopex
A South American gray fox in Pan de Azúcar National Park in the coast of Atacama Desert
Otocyon Bat-eared fox
Urocyon
Island fox (Urocyon littoralis), in the Channel Islands, California, US
Vulpes
The fennec fox is the smallest species of fox
Red fox at Ystad, Swedener

Conservation[edit]

Several fox species are endangered in their native environments. Pressures placed on foxes include habitat loss and being hunted for pelts, other trade, or control.[18] Due in part to their opportunistic hunting style and industriousness, foxes are commonly resented as nuisance animals.[19] On the other hand, foxes, while often considered pests themselves, have been successfully employed to control pests on fruit farms while leaving the fruit intact.[20]

Island fox (Urocyon littoralis)[edit]

The island fox, though considered a near-threatened species throughout the world, is becoming increasingly endangered in its endemic environment of the California Channel Islands.[21] A population on an island is smaller than those on the mainland because of limited resources like space, food and shelter.[22] Island populations, therefore, are highly susceptible to external threats ranging from introduced predatory species and humans to extreme weather.[22] On the California Channel Islands, it was found that the population of the island fox was so low due to an outbreak of canine distemper virus from 1999 to 2000[23] as well as predation by non-native golden eagles.[24] Since 1993, the eagles have caused the population to decline by as much as 95%.[23] Because of the low number of foxes, the population went through an Allee effect; this is where at low enough densities, an individual's fitness decreases.[21] Conservationists, therefore, had to take healthy breeding pairs out of the wild population to breed them in captivity until they had enough foxes to release back into the wild.[23] Nonnative grazers were also removed so that native plants would be able to grow back to their natural height, thereby providing adequate cover and protection for the foxes against golden eagles.[24]

Darwin's fox (Pseudalopex fulvipes)[edit]

Darwin's fox is considered critically endangered because of their small known population of 250 mature individuals as well as their restricted distribution.[25] On the Chilean mainland, the population is limited to Nahuelbuta National Park and the surrounding Valdivian rainforest.[25] Similarly on Chiloé Island, their population is limited to the forests that extend from the southernmost to the northwestern most part of the island.[25] Though the Nahuelbuta National Park is protected, 90% of the species live on Chiloé Island.[26] A major problem the species faces, therefore, is their dwindling, limited habitat due to the cutting and burning of the unprotected forests.[25] Because of deforestation, the Darwin's fox habitat is shrinking, allowing for their competitor's (chilla fox) preferred habitat of open space, to increase; the Darwin's fox, subsequently, is being outcompeted.[27] Another problem they face is their inability to fight off diseases transmitted by the increasing number of pet dogs.[25] To conserve these animals, researchers suggest the need for the forests that link the Nahuelbuta National Park to the coast of Chile and in turn Chiloé Island and its forests, to be protected.[27] They also suggest that other forests around Chile be examined to determine whether Darwin's foxes have previously existed there or can live there in the future, should the need to reintroduce the species to those areas arise.[27] And finally, the researchers advise for the creation of a captive breeding program, in Chile, because of the limited number of mature individuals in the wild.[27]

Relationships with humans[edit]

A red fox on the porch of an Evergreen, Colorado home.

Foxes are often considered pests or nuisance creatures for their opportunistic attacks on poultry and other small livestock. Fox attacks on humans are not common but have increased in frequency.[28] Many foxes adapt well to human environments, with several species classified as "resident urban carnivores" for their ability to sustain populations entirely within urban boundaries.[29] Foxes in urban areas can live longer and can have smaller litter sizes than foxes in non-urban areas.[29] Urban foxes are ubiquitous in Europe, where they show altered behaviors compared to non-urban foxes, including increased population density, smaller territory, and pack foraging.[30]

Foxes have been introduced in numerous locations, with varying effects on indigenous flora and fauna.[31]

Fox hunting[edit]

Main article: Fox hunting

Fox hunting originated in the United Kingdom in the 16th century. Hunting with dogs is now banned in the United Kingdom,[32][33][34][35] though hunting without dogs is still permitted. Red foxes were introduced into Australia in the early 19th century for sport, and have since become widespread through much of the country. Their impact on native vegetation and animals is subject to much speculation.[31] It is practiced as recreation in several other countries including Canada, France, Ireland, Italy, Russia and the United States.

Domestication[edit]

There are many records of domesticated red foxes and others, but rarely of sustained domestication. A recent and notable case is the Russian silver fox,[36] which resulted in visible and behavioral changes, and is a case study of an animal population modeling according to human domestication needs. The current group of domesticated silver foxes are the result of nearly fifty years of experiments in the Soviet Union and Russia to domesticate the silver morph of the red fox. This selective breeding resulted in physical and behavioral traits appearing that are frequently seen in domestic cats, dogs, and other animals, such as pigmentation changes, floppy ears, and curly tails.[37] Notably, the new foxes became more tame, allowing themselves to be petted, whimpering to get attention and sniffing and licking their caretakers.[38]

Urban foxes[edit]

Foxes, particularly red foxes, have been inhabiting and breeding in human-populated areas since the twentieth century. They have adapted well to these environments, taking advantage of man-made features such as houses and gardens to create dens. For sustenance, they take advantage of food thrown away by humans. In some cases, human residents will feed foxes that frequent their local area. In this sense, a benign relationship has been established in which foxes have become comfortable and amiable toward the humans who, while becoming their providers, do not much mind the presence of the foxes. However for some, urban foxes have proven to be a nuisance due to their intrusion and destruction of private property. Urban fox control methods and laws vary regionally.[39]

In culture[edit]

Main article: Foxes in culture

The fox appears in many cultures, usually in folklore. However, there are slight variations in their depictions in folklore. In Western folklore, foxes are depicted as a symbol of cunning and trickery. This is usually represented as a character possessing these traits. These traits are used on a wide variety of characters, either making them a nuisance to the story, a misunderstood hero, or a devious villain.

In Asian folklore, foxes are depicted as a familiar spirit possessed of magic powers. Similar towards Western folklore, foxes are depicted as mischievous, usually tricking other people, with the ability to disguise as an attractive female human. However, there are other depictions of foxes as a mystical, sacred creature, that can either bring wonder or ruin.[40]

Foxes in Western media[edit]

Foxes in Asian media[edit]

  • Kitsune (Japanese for fox) appears in Japanese folklore with the ability to transform into a human. They have various depictions such as cunning, mischivious creatures, or a faithful guardian.
  • The Nine-Tailed Fox appears in many Asian folklore, in which, depending on the folklore can be a good or a bad omen. A distinct example is Ninetales from Pokémon, represented as a mystical animal. Zorua and Zoroark, also from Pokémon, are represented as mischievous tricksters.
  • Foxes appear in many forms of Manga, usually combining the Japanese connotation of foxes in culture. Examples include Kurama from Naruto, and Shippo from Inuyasha.

The constellation Vulpecula represents a fox.[41]

In some countries, foxes are major predators of rabbits and hens. Population oscillations of these two species were the first nonlinear oscillation studied, and led to the now-famous Lotka-Volterra equation.[42][43]

Notes[edit]

  1. ^ Cf. West Frisian foks, Dutch vos, and German Fuchs.
  2. ^ Cf. Hindi pū̃ch ‘tail’, Tocharian B päkā ‘tail; chowrie’, and Lithuanian paustìs ‘fur’. The bushy tail also forms the basis for the fox's Welsh name, llwynog, literally ‘bushy’, from llwyn ‘bush’. Likewise, Portuguese: raposa from rabo ‘tail’, Lithuanian uodẽgis from uodegà ‘tail’, and Ojibwa waagosh from waa, which refers to the up and down "bounce" or flickering of an animal or its tail.

References[edit]

  1. ^ Macdonald, edited by David W.; Sillero-Zubiri, Claudio (2004). The biology and conservation of wild canids (Nachdr. d. Ausg. 2004. ed.). Oxford: Oxford University Press. p. 49. ISBN 0198515561. 
  2. ^ a b c d e f g h i j k l Lloyd, H.G. (1981). The red fox (2. impr. ed.). London: Batsford. p. 21. ISBN 0 7134 11902. 
  3. ^ Fellows, Dave. "Animal Congregations, or What Do You Call a Group of.....?". Northern Prairie Wildlife Research Center. USGS. Retrieved 9 October 2014. 
  4. ^ Larivière, S. & Pasitschniak-Arts, M. (1996). "Vulpes vulpes". Mammalian Species: No. 537, pp. 1–11. doi:10.2307/3504236. 
  5. ^ Nobleman, Marc Tyler (2007). Foxes. Benchmark Books (NY). pp. 35–36. ISBN 978-0-7614-2237-2. 
  6. ^ a b c d e Burrows, Roger (1968). Wild fox. Newton Abbot: David & Charles. ISBN 9780715342176. 
  7. ^ "Arctic fox (Vulpes lagopus)". ARKive. Retrieved 2 October 2014. 
  8. ^ Fox, David. "Vulpes vulpes, red fox". Animal Diversity Web. Retrieved 2 October 2014. 
  9. ^ "Canidae". The University of Edinburgh. Retrieved 23 September 2014. 
  10. ^ Fedriani, J.M.; T. K. Fuller; R. M. Sauvajot; E. C. York (2000-07-05). "Competition and intraguild predation among three sympatric carnivores". Oecologia 125 (2): 258–270. doi:10.1007/s004420000448. 
  11. ^ Fox, David L. (2007). "Vulpes vulpes (red fox)". Animal Diversity Web. University of Michigan Museum of Zoology. 
  12. ^ Macdonald, David W. (26 April 2010). "Food Caching by Red Foxes and Some Other Carnivores". Zeitschrift für Tierpsychologie 42 (2): 170–185. doi:10.1111/j.1439-0310.1976.tb00963.x. 
  13. ^ Heptner & Naumov 1998, p. 341
  14. ^ Heptner & Naumov 1998, p. 537
  15. ^ Parkes, I. W. Rowlands and A. S. (21 August 2009). "The Reproductive Processes of certain Mammals.-VIII. Reproduction in Foxes (Vulpes spp.).". Proceedings of the Zoological Society of London 105 (4): 823–841. doi:10.1111/j.1469-7998.1935.tb06267.x. 
  16. ^ Hildebrand, Milton (1952). "The Integument in Canidae". Journal of Mammalogy 33 (4): 419–428. doi:10.2307/1376014. JSTOR 1376014. 
  17. ^ Tembrock, Günter. "Canid vocalizations". Behavioural Processes 1 (1): 57–75. doi:10.1016/0376-6357(76)90007-3. 
  18. ^ Ginsburg, Joshua Ross and David Whyte MacDonald. Foxes, Wolves, Jackals, and Dogs. p.58.
  19. ^ Bathgate, Michael. The Fox's Craft in Japanese Religion and Culture. 2004. p.18.
  20. ^ McCandless, Linda Foxes are Beneficial on Fruit Farms. nysaes.cornell.edu (1997-04-24)
  21. ^ a b ANGULO, ELENA; ROEMER, GARY W.; BEREC, LUDĚK; GASCOIGNE, JOANNA; COURCHAMP, FRANCK (29 May 2007). "Double Allee Effects and Extinction in the Island Fox". Conservation Biology 21 (4): 1082–1091. doi:10.1111/j.1523-1739.2007.00721.x. 
  22. ^ a b Primack, Richard B. (2014). Essentials of conservation biology (Sixth edition. ed.). Sinauer Associates. pp. 143–146. ISBN 9781605352893. 
  23. ^ a b c Kohlmann, Stephan G.; Schmidt, Gregory A.; Garcelon, David K. (10 April 2005). "A population viability analysis for the Island Fox on Santa Catalina Island, California". Ecological Modelling 183 (1): 77–94. doi:10.1016/j.ecolmodel.2004.07.022. 
  24. ^ a b "Channel Islands: The Restoration of the Island Fox". National Park Service. Retrieved 25 September 2014. 
  25. ^ a b c d e Jiménez, J. E. (2006). "Ecology of a coastal population of the critically endangered Darwin's fox (Pseudalopex fulvipes) on Chiloé Island, southern Chile". Journal of Zoology 271 (1): 63–77. doi:10.1111/j.1469-7998.2006.00218.x. Retrieved 30 September 2014. 
  26. ^ Jiménez, J.E., Lucherini, M. & Novaro, A.J. (2008). "Pseudalopex fulvipes". IUCN Red List of Threatened Species. Version 2014.1. International Union for Conservation of Nature. Retrieved 30 September 2014. 
  27. ^ a b c d Yahnke, Christopher J.; Johnson, Warren E.; Geffen, Eli; Smith, Deborah; Hertel, Fritz; Roy, Michael S.; Bonacic, Cristian F.; Fuller, Todd K.; Van Valkenburgh, Blaire; Wayne, Robert K. (1996). "Darwin's Fox: A Distinct Endangered Species in a Vanishing Habitat". Conservation Biology 10 (2): 366–375. doi:10.1046/j.1523-1739.1996.10020366.x. 
  28. ^ Barratt, Sarah and Martin Barratt. Practical Quail-keeping. 2013.
  29. ^ a b Iossa, G. et al. A Taxonomic Analysis of Urban Carnivore Ecology, from Urban Carnivores. Stanley Gehrt et al. eds. 2010. p.174.
  30. ^ Francis, Robert and Michael Chadwick. Urban Ecosystems 2013. p.126.
  31. ^ a b See generally Long, John. Introduced Mammals of the World. 2013.
  32. ^ "Hunt campaigners lose legal bid". BBC News Online. 2006-06-23. 
  33. ^ Singh, Anita (2009-09-18). "David Cameron 'to vote against fox hunting ban'". The Daily Telegraph. London. Retrieved 2010-05-02. [dead link]
  34. ^ Fox Hunting. North West League Against Cruel Sports Support Group. nwlacs.co.uk
  35. ^ "Fox Hunting: For and Against". 
  36. ^ "The most affectionate foxes are bred in Novosibirsk". Redhotrussia.com. Retrieved 2014-04-08. 
  37. ^ Trut, Lyudmila N. (1999). "Early Canid Domestication: The Fox Farm Experiment". American Scientist 87. 
  38. ^ Kenneth Mason, Jonathan Losos, Susan Singer, Peter Raven, George Johnson(2011)Biology Ninth Edition, p. 423. McGraw-Hill, New York.ISBN 978-0-07-353222-6.
  39. ^ Harris, Stephen (1986). Urban Foxes. 18 Anley Road, London W14 OBY: Whittet Books Ltd. ISBN 0905483472. 
  40. ^ Uther, Hans-Jörg (2006). "The Fox in World Literature: Reflections on a "Fictional Animal"". Asian Folklore Studies 65 (2): 133–160. Retrieved 2 October 2014. 
  41. ^ "Constellation Names". Constellation Guide. Retrieved 1 October 2014. 
  42. ^ Sprott, Julien. Elegant Chaos 2010. p.89.
  43. ^ Komarova, Natalia. Axiomatic Modeling in Life Sciences, from Mathematics and Life Sciences. Alexandra Antoniouk and Roderick Melnik, eds. pp.113-114.

External links[edit]