Red Fox | |
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Conservation status | |
Least Concern (IUCN 3.1)[1] |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Subphylum: | Vertebrata |
Class: | Mammalia |
Order: | Carnivora |
Suborder: | Caniformia |
Family: | Canidae |
Subfamily: | Caninae |
Tribe: | Vulpini |
Genus: | Vulpes |
Species: | V. vulpes |
Binomial name | |
Vulpes vulpes Linnaeus, 1758 |
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Subspecies | |
45 ssp., see text |
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Distribution of the red fox. Native distribution in blue, introduced in red. | |
Synonyms | |
Vulpes fulva, Vulpes fulvus |
The Red Fox (Vulpes vulpes) is a small canid native to much of Eurasia and North America, as well as northern Africa. It is the most recognizable species of fox and in many areas it is referred to simply as "the fox". As its name suggests, its fur is predominantly reddish-brown, but there is a naturally occurring grey morph known as the “silver” fox; a strain of domesticated silver fox has been produced from these animals by systematic domestication.
The red fox is by far the most widespread and abundant species of fox and canines, found in almost every single habitat in the Northern Hemisphere, from the coastal marshes of United States, to the alpine tundras of Tibetan Plateau. It was introduced into Australia in the 19th century.[2] It is capable of co-existing with more specialized species of foxes, such as Arctic fox, in the same habitat. The red fox can withstand and sometimes thrive in areas with heavy human disturbance.
The red fox is frequently featured in stories of many cultures, and is often portrayed as a sly animal.
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Today, the red fox has a range spanning most of Eurasia and North America, southern Australia, and with several populations in North Africa. In Australia the red fox is an introduced species and a conservation problem.[3] Introduction occurred about 1850, for recreational fox hunting,[4] In North America the red fox is native in boreal regions, introduced in temperate regions.[5][6] There is a recent fossil record of red foxes in boreal North America, and one subspecies of these native boreal foxes extends south in the Rocky Mountains.[7] In temperate North America, red foxes are derived from European red foxes, which were introduced into the Southeastern United States around 1650-1750[8][9] for fox hunting,[10], and from there to California for the fur trade. The first introduction is attributed to Robert Brooke, Sr., who is said to have imported 24 red foxes from England.[11]. The introduced European red fox may have interbred with the scarce indigenous population to produce a hybrid population.[12] Three subspecies of red fox are found in India: Vulpes vulpes montana (the Tibetan red fox), found in Ladakh and the Himalayas, Vulpes vulpes griffithi (the Kashmir Fox) found in Jammu and Kashmir less the Ladakh sector, and Vulpes vulpes pusilla (the Desert Fox) found in the Thar Desert of Rajasthan and in Kutch, Gujarat. A subspecies, the Japanese red fox (Vulpes vulpes japonica) migrated from India to China and eventually to Japan.
The largest species within the genus Vulpes and the largest of the true foxes, adult red foxes range in weight from 3.6 to 7.6 kg (7.9 to 17 lb) depending on region, with those living in higher latitudes being larger – foxes living in Canada and Alaska tend to be larger than foxes in the United Kingdom, which are in turn larger than those inhabiting the Southern United States.[13][14] Very large red foxes can weigh up to 14 kg (31 lb).[15] Head and body length is 46 to 90 cm (18 to 35 in), with a tail of 30 to 55 cm (12 to 22 in)[15][16] Size can be estimated from tracks. Red fox footprints are normally about 4.4 cm (1.7 in) wide and 5.7 cm (2.2 in) long. A normal red fox's trotting stride is about 33 to 38 cm (13 to 15 in).[17] Sexual dimorphism is noticeable and males are typically 15% heavier than females.[18]
The red fox is most commonly a rusty red, with white underbelly, black ear tips and legs, and a bushy tail usually with a distinctive white tip. The "red" tone can vary from dark chestnut to golden, and in fact can be "agouti", with bands of red, brown, black and white on each individual hair. In North America, the red fox's pelt has long, soft hair, whereas the fur of European red foxes is flatter and less silky.[19]. In the wild, two other colour phases are also seen. The first is silver or black, comprising 10% of the wild population. Approximately 30% of wild individuals have additional dark patterning, which usually manifests as bold markings on the face, with a stripe across the shoulders and down the centre of the back. The stripes form a "cross" over the shoulders, and these foxes are therefore often called cross foxes. Various phases can interbreed and offspring of different phases can occur within one litter. Farmed stock are mostly silver, but may be almost any colour including spotted or blotched with white.
Fox eyes are gold to yellow and have distinctive vertical-slit pupils, similar to those of domestic cats. Their eyesight, despite having cat-like eyes, has been described by fox expert J. David Henry as "poor" and "near-sighted".[20] Their behavior, and eye-slits, combined with their extreme agility for a canid, warrants the red fox to be referred to as the "cat-like canine". Its strong legs allow it to reach speeds of approximately 72 km/h (45 mph), a great benefit to catching prey or evading predators.[20]
The red fox's prominent bushy tail is another one of its iconic features. It accounts for about one third of the body length, and is used for insulation and a soft pillow for sleeping, as well as a tool for communication. It also provides balance for large jumps and complex movements. The distinctive white tip, or "tag", is used as a field mark for distinguishing the red fox from other canids.[21]
In general, the spacing between the canine teeth is approximately 18 to 25 mm (0.7 to 1.0 in) apart. Foxes lack the facial muscles necessary to bare their teeth, unlike most other canids.[14]
During the autumn and winter, the red fox will grow more fur. This so-called "winter fur" keeps the animal warm in the colder environment. The fox sheds this fur at the onset of spring, reverting back to the short fur for the duration of the summer.
The red fox is found in a variety of biomes, from prairies and scrubland to forest settings. It is most suited to lower latitudes but does venture considerably far north, competing directly with the Arctic Fox on the tundra. The red fox has also become a familiar sight in suburban and even urban environments both in Europe and in North America.
Although classified as a carnivore, red foxes are omnivorous and are highly opportunistic. Prey can range in size from 0.5 cm insects to 150 cm red-crowned cranes. The majority of their diet consists of invertebrates, such as insects, mollusks, earthworms and crayfish. They also eat plant material, especially blackberries, apples, plums, sunflower seeds, and other fruit. Common vertebrate prey includes rodents (such as mice and voles), rabbits, birds, eggs, amphibians, small reptiles and fish.[22] Foxes have been known to kill deer fawns. In Scandinavia, predation by red fox is the most important mortality cause for neonatal Roe deer.[23] They will scavenge carrion and other edible material they find, and in urban areas, they will scavenge on human refuse, even eating from pet food bowls left outside. Analysis of country and urban fox diets show that urban foxes have a higher proportion of scavenged food than country foxes.[24] They typically eat 0.5 to 1 kg (1 to 2 lb) of food a day.
They usually hunt alone. With their acute sense of hearing, they can locate small mammals in thick grass, and they jump high in the air to pounce on the prey. They also stalk prey such as rabbits and other small mammals, keeping hidden until close enough to catch them in a short dash. Foxes tend to be extremely possessive of their food and will not share it with others. Exceptions to this rule include dog foxes feeding vixens during courtship and vixens feeding cubs.[14]
Red foxes have disproportionately small stomachs for their size and can only eat half as much food in relation to their body weight as wolves and dogs can (about 10% compared with 20%). In periods of abundance, foxes will cache excess food against starvation at other times. They typically store the food in shallow holes (5 to 10 cm (2 to 4 in) deep). Foxes tend to make many small caches, scattering them across their territories rather than storing their food in a single central location. This is thought to prevent the loss of the fox's entire food supply in the event that another animal finds the store.[25]
Along with the gray fox, the red fox is the most common species of fox in North America. The two species prefer different habitats. The red fox prefers sparsely-settled, hill areas with wooded tracts, marshes and streams. The gray fox is found in brushy areas, swamplands and rugged, mountainous terrain. Where their ranges overlap, the smaller gray foxes tend to be the dominant species due to higher levels of aggression.[26] Red foxes tend to be dominant in areas where they co-exist with Arctic Foxes. The larger, more aggressive red fox can dominate Arctic foxes in direct competition for den sites and other limited resources.[27] Red foxes in the San Joaquin Valley of California compete with the smaller endangered San Joaquin Kit Fox.[28]
In areas in North America where red fox and coyote populations are sympatric, fox territories tend to be located outside of coyote territories. The principal cause of this separation is believed to be active avoidance of coyotes by the foxes. Interactions between the two species vary in nature, ranging from active antagonism, to indifference. The majority of aggressive encounters are initiated by coyotes, and there are few reports of red foxes acting aggressively toward coyotes except when attacked or when their pups were approached. Foxes and coyotes have sometimes been seen feeding together.[29]
In Israel, the red fox shares its habitat with the golden jackal. Where their ranges meet, the two canids compete due to near identical diets. Foxes ignore jackal scents or tracks in their territories, and avoid close physical proximity with jackals themselves. Studies show that in areas where jackals became very abundant, the population of foxes decreases significantly, apparently because of competitive exclusion.[30]
Red foxes sometimes compete with Eurasian badgers for earthworms, eggs, fruits and den sites. Badgers have been known to kill and eat fox kits. However, violence between the two animals is thought to be uncommon, and most encounters amount to little more than mutual indifference.[31] Foxes have on occasion shared dens with Eurasian Badgers.[32]
Eurasian lynxes tend to depress fox populations in areas where the two species are sympatric. The killing of red foxes by Eurasian Lynxes is uncommon but occurs during winter and spring, the main period when foxes establish new territories.[33] Beyond coyotes, badgers and lynxes, red foxes are known to be preyed on by golden eagles, gray wolves, cougars and bears.[15]
Living as it does in a wide variety of habitats, the red fox displays a wide variety of behaviours. In Biology and Conservation of Wild Canids,[34] MacDonald and Sillero-Zubiri state that two populations of the red fox may be behaviourally as different as two species.
The red fox is primarily crepuscular with a tendency to becoming nocturnal in areas of great human interference (and artificial lighting); that is to say, it is most active at night and at twilight. It is generally a solitary hunter. If a fox catches more food than it can eat, it will bury the extra food (cache) to store it for later.
In general, each fox claims its own territory; it pairs up only in winter, foraging alone in the summer. Territories may be as large as 50 km² (19 square miles); ranges are much smaller (less than 12 km², 4.6 sq mi) in habitats with abundant food sources, however. Several dens are utilized within these territories; dens may be claimed from previous residents such as marmots, or dug anew. A larger main den is used for winter living, birthing and rearing of young; smaller dens are dispersed throughout the territory for emergency and food storage purposes. A series of tunnels often connects them with the main den. One fox may only need a square kilometre of land marked by recognition posts that are special smells that come from a scent gland located just above a fox's tail.
The scent from this gland is composed of or very closely related to the thiols and thioacetate derivatives used by skunks (most notably Mephitis mephitis) as a defensive weapon. This gives the red fox a skunk-like scent detectable by humans at close proximity (about 2 to 3 meters or less) but which is not easily transferred to other animals or inanimate objects; so the concentrations secreted and/or produced by the gland must be very much less than that of the skunk. The red fox cannot spray the thiolates like the skunks and does not appear to use the secretion as a defense.
The red fox primarily forms monogamous pairs each winter, who cooperate to raise a litter of 4–6 kits (also called pups) each year. Young foxes disperse promptly on maturity (approx. 8–10 months).
Though usually monogamous, evidence for polygamy (polygyny and polyandry) exists, including males’ extraterritorial movements during breeding season (possibly searching for additional mates) and males’ home ranges overlapping two or more females’ home ranges. Such variability is thought to be linked to variation in the spatial availability of key resources such as food.[1]
The reason for this "group living" behaviour is not well understood; some researchers believe the non-breeders boost the survival rate of the litters while others believe there is no significant difference, and such arrangements are made spontaneously due to a resource surplus.
Socially, the fox communicates with body language and a variety of vocalizations. Its vocal range is quite large and its noises vary from a distinctive three-yip "lost call" to a shriek reminiscent of a human scream. It also communicates with scent, marking food and territorial boundary lines with urine and faeces.
John James Audubon noted that cross foxes tended to be shyer than their fully red counterparts. He conjectured that the reason was due to the greater commercial value its fur, thus forcing it to adopt a warier behaviour to evade hunters.[35]
The red fox breeding period varies widely due to its broad distribution; southern populations breed from December to January, central populations from January to February and northern populations from February to April. Females have an annual estrous period of between 1 and 6 days; ovulation is spontaneous. Although a female may mate with several males (who fight amongst each other for the right), she will eventually settle with only one. Gestations lasts between 49 and 56 days, but is most typically from 51 to 53 days.
Males will supply food to females up to and after birthing, otherwise leaving the female alone with her kits (also called cubs or pups) in a "maternity den". An average litter size is five kits, but may be as large as 13. Kits are born blind and may weigh as much as 150 grams (5.3 oz). Their eyes are open by two weeks and the kits have taken their first exploratory steps out of the den by five weeks; by ten weeks they are fully weaned.
In autumn of the same year, the young foxes will disperse and claim their own territories. The red fox reaches sexual maturity by ten months of age, and may live for 12 years in captivity but will usually only live three years in the wild.
The red fox has both positive and negative standing with humans, often being loved or hated. This has been most visible in the United Kingdom where fox hunting with dogs was a traditional sport and an occasional localised means of culling, until this was made illegal in Scotland in August, 2002, and in England and Wales in February, 2005. The fox features in much folklore (see Reynard), usually as a wily villain, though sometimes also as the underdog who triumphs over human efforts to control or destroy it.
Like other wild animals, foxes are considered vectors of disease. The red fox helps farmers by preying on animals that damage crops but is considered to be a pest by farmers involved in poultry farming. In some places, the red fox is used as a food animal.[36]
In June 2010, an urban fox was reported to have entered a family home in London and attacked twin baby girls, who were sleeping in their cots. However, there was no independent confirmation. A similar attack was alleged in the UK in 2002.[37][38]
Greater visibility in nature documentaries and sympathetic portrayals in fiction have improved the red fox's reputation and appeal in recent years.
In Hong Kong, it is a protected species under Wild Animals Protection Ordinance Cap 170.
In Japan, foxes, known as kitsune, are considered as messengers of Inari, the god of farming, possibly because they prey on rodents that destroy harvests.[39]
The red fox is of some importance in the fur industry. The fur of a silver fox was once considered by the natives of New England to be worth over 40 beaver skins. A chieftain accepting a gift of silver fox fur was seen as an act of reconciliation.[36] Silver foxes were first commercially bred on Prince Edward Island, Canada in 1878. Red foxes are among the most commonly bred animals in fur farms, along with American Minks.[40] Today, silver fox is traditionally used for collars and cuffs, wraps and stoles, while common Red fox fur is used for trimming and for full fur garments.[19]
Red foxes are generally considered to be the most serious predator of free range poultry. The safest option known in poultry protection is to keep the flock and the fox physically separated, usually with fencing. A fence needs to be at least 2 metres (6 ft 7 in) high to keep out most foxes, though on some rare occasions, a determined fox might succeed in climbing over.[41] Surplus killing will often occur in enclosed spaces such as huts, with discarded feathers and headless bodies usually being the main indicators of fox predation.
Although poultry is the most commonly-taken domesticated prey, red foxes will on some occasions kill young or small animals, particularly lambs and kids. In exceptional circumstances, they may attack sub-adult and adult sheep and goats and sometimes small calves.[17] Foxes will usually kill lambs or kids by repeatedly biting the neck and back, which is usually the result from young animals being caught while lying down. Other than with poultry, fox predation on livestock can be distinguished from dog or coyote predation by the fact that foxes rarely cause severe bone damage when feeding.[17] Red foxes also are noted for carrying small carcasses back to their dens to feed their young which may account for some poultry, lambs and kids that disappear and are never found.[17] Scientific studies in Britain found that between 0.5 % and 3 % of otherwise viable lambs may be taken by foxes, described as a small amount when compared to the mortality caused by exposure, starvation and disease.[42]
The emblematic red fox is a frequent player in the stories of many cultures. A trickster character, the word Sly is almost invariably associated with foxes in English, and the connotation of a sneaking intelligence (or even magic powers of stealth) are seen in traditional tales of Europe, Japan, China, and North America (though in North America the Coyote usually plays this role).
In the European fable tradition, running from Aesop's Fables, to Jean de La Fontaine's Fabliaux and the Reynard tales, the fox ranges from immoral villain (as the Fox in the hen house), to sly operator (either foolish or crafty), to wise observer (as a mouthpiece for the moral in some Aesop tales) to clever underdog (exemplified by the Reynard tradition). Some historians argue that the fox came to symbolize the survival strategies of European peasantry from the Medieval period to the French Revolution. Peasants admired guile and wit needed to outmaneuver the powers of aristocracy, state and church, just as they saw the fox use these same qualities to raid their livestock under cover of darkness.[43]
Japan, hosting two subspecies of red fox, also uses foxes in much of its mythology. The Japanese believed foxes (which are called kitsune) to possess mystical powers, which advance as they age. As in Europe, the kitsune were portrayed in numerous ways, from being mischievous troublemakers to noble guardians, and even taking human form and becoming wives. The Japanese Kitsune have cultural similarities in both China, called Huli jing and Korea, called Kumiho.
Feral foxes in Australia pose a serious conservation problem. The red fox was introduced to Australia for hunting in 1843 near Melbourne, but has since become widespread, and is considered responsible for the decline in a number of species of native animals in the "critical weight range".
In Australia, foxes are usually controlled with baits or the animals shot with the aid of spotlighting. The eyeshine signature (from the tapetum lucidum in the eye) of foxes, and body shape and silhouette are used to identify them. Success has also been found with the reintroduction of the native "Australian Dog", the dingo, which has been shown to control the number of wild foxes, and a consequential increase in native fauna.[44]
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