Linneaus,
the 18th century botanist, bestowed the scientific name lagopus (rabbit
or hare-footed) on the arctic fox for its distinctive furred paws.
As its name implies, the arctic foxÕs range includes the circumpolar
northern Arctic regions of North America, Scandinavia, Siberia, Greenland
and Iceland.
Habitat
Arctic
foxes inhabit treeless arctic and alpine tundra. They live in both
coastal and inland areas of the mainland and on islands. Arctic foxes
travel extensively and possess large range
sizes from 2,100-15,000 acres (850-6,070 ha). Other than humans, the
arctic fox travels more extensively than any terrestrial animal. |
Physical Characteristics
Compared to the slender bodies and long legs of other foxes, arctic foxes have a stocky
body with short legs and torso. Arctic foxes also have a short muzzle and short, rounded
ears. The arctic fox has dense fur with an especially thick and fine undercoat that comprises
70% of its coat. Arctic foxes have extremely long and bushy tails that muffle the sounds made
by their bodies crossing terrain.
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Weight
Arctic foxes are medium-size foxes that weigh from 6-10 pounds (2.7-4.5
kg) and average 43 inches (109 cm) in length from head to tail. The
tail length averages 15 inches (38 cm). Females (vixens) are slightly
smaller than males. |
Life
Span
In the wild: Average
for those reaching adulthood is 3 years, although a few live as long
as 10 years
At the zoo: 6-10 years
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Diet
In the wild: Arctic foxes are opportunistic
and omnivorous feeders. Small mammals make up their preferred
summer diet. However, they also eat plants,
bird eggs, insects and fish. Winter diets include small marine
mammals, birds, small seals, invertebrates and carrion.
At
the zoo: Thawed frozen quail and mice, along with
eggs, fruits and vegetables.
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More
Physical Characteristics
Arctic foxes shed their coat twice a year. In springtime, they lose their long winter coats,
and in autumn they start acquiring a new winter pelt. A camouflaging change in coloration accompanies
these molts. Arctic foxes come in two distinct color "morphs" (also called "forms" or "phases"): the
white or polar and the blue morphs. The familiar pure white winter pelt is the white morph commonly
associated with arctic foxes. After the spring molt, the white morph has a short summer pelt that
appears gray to brown on the face, legs and upper body, while the under body fur is lighter colored.
In contrast, the blue morph spends summer with a dark brown, black, light gray or steel blue coat
that lightens during the winter. However, the blue morph never turns truly white in color. In the far
north, 99% of all arctic foxes are white morphs, while blue morphs make up 90% of those species living
on the Aleutian and Pribilof islands. Even though the white morph is genetically recessive, the amount
of snow cover in the northern regions probably accounts for its predominance there.
Reproduction and
Life Cycle
Arctic
foxes sexually mature at 9-10 months
of age and usually form lifetime monogamous bonds. A typical family unit
consists of a single adult male, an adult breeding female, one or more
other adult females and the current year's offspring. The non-breeding
females may be from the previous year's litter and serve as helpers
for the new litter. When digging den sites, arctic foxes select dry,
well-drained sandy soil or rocky areas usually with a southern exposure.
Dens have a central chamber and multiple entrances for use in emergencies.
Some dens have been in use by generations of foxes over the past few
centuries.
Mating occurs in mid-spring, and the young (also
called kits, pups, whelps or cubs) emerge in late spring or early
summer after an average gestation of 52 days. Litters range from
three to 12, with an average of seven. Short, dark, brown fur covers
all newborn pups, and a single litter may contain both color morphs.
By two months of age, the blue morph pups acquire their dark coloration,
while the white morph pups develop the contrasting pattern of darker
backs, heads and legs with lighter underbodies. Many pups do not
reach adulthood, as there are high mortality rates among the young.
The male guards the den and may lead intruders away from the den
site. He also brings back food for both the mother and her pups.
The pups begin eating meat at 1 month old and the mother weans them
around one and half months after birth. By 3 months old, the pups
begin to travel away from the den and participate in hunts. In autumn,
the family unit gradually dissolves and these foxes spend the winters
in solitary hunts for food.
Life in the Arctic - Brrrrr
Life in the Arctic is difficult, and the arctic fox is wonderfully
adapted to live in very cold climates. While many mammals hibernate
during the winter, the arctic fox does not. Its physical characteristics
of superb insulation with fur and fat, combined with its stocky
body shape enable the arctic fox to conserve body heat. Therefore,
it can continue to remain active throughout the frigid months.
During winters, their densely furred paws prevent heat loss through
their feet. They also have the ability to restrict blood flow to
the legs, which helps maintain core body heat. Lastly, the arctic
fox has a tremendous tolerance for cold. Its metabolic rate only
starts to increase at -58° Fahrenheit (-50° Celsius) and
it only starts to shiver when temperatures reach -94° Fahrenheit
( -70° Celsius).
Got Food?
In addition to its physical attributes, the arctic fox has many behaviors
that enable it to survive in the far north. They will eat virtually
anything edible. Besides their preferred summer diet of lemmings
and voles, coastal arctic foxes dine on nesting birds and their
eggs. They also eat berries and seaweed. These foxes eat continually
and thereby gain insulating fat during summer's plenty. For
later consumption, they stash eggs and other surplus food in their
dens or under rocks. When snow arrives, their sharp sense of hearing
enables them to locate lemmings in burrows deep under the snow.
Their excellent sense of smell helps detect white ptarmigans (a
species of bird) against a background of snow and also leads them
to carrion left behind by other predators. At times, arctic foxes
remain near hoofstock (such as musk ox or caribou) waiting for
one to die. They may even trail a polar bear in hopes of leftovers.
They have been observed scavenging the remains of seals out on
sea ice. When all else fails, they may consume feces of both humans
and animals.
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Fascinating
Facts
- Arctic foxes are noted for high fertility
rates. Their litters may produce up to 25 pups, and arctic
foxes have the largest litter sizes of all carnivores!
- These carnivores are found farther north
than any other land mammal and have been observed less than
38 miles (61 km) from the North Pole!
- The
four-year population cycles of lemmings affect arctic fox
populations in a repeating cycle. Abundant years for lemmings
result in large fox litters. In turn, large fox litters result
in smaller lemming populations. This leads to smaller fox
litters in the next year!
- Arctic foxes
often hide their food in rocky areas later covered with deep
snow. To find their cache sites, they spray them with a powerful,
skunk-like odor!
- Arctic foxes also affect the populations
of some migrating birds!
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The arctic
fox lives in the zoo's award-winning
Northern Trail. The zoo also has another species of fox, which is
the fennec fox in the Adaptations exhibit. Other animals that can
be seen at the Northern Trail are bald eagle, gray wolf, magpie,
mountain goat, porcupine, river otter, Roosevelt elk and snowy owl.

Arctic foxes are not listed as an endangered
species, and although arctic fox populations are abundant, at least
three other species of foxes are listed as endangered.** However,
arctic fox numbers have declined significantly in some of their native
ranges. For centuries, indigenous peoples in Arctic regions sought
the warm pelts of arctic foxes for their own use and for the fur
trade more recently. In the past two centuries, fur trade considerably
reduced numbers of arctic foxes in most of Scandinavia. The world
fur trade in arctic fox pelts reached peaks in Siberia, Russia, with
over 100,000 pelts taken in a single year. Currently in Alaska, this
is reduced to around 4,000 pelts annually. The most prized and expensive
pelts come from the rare black or steel blue color morphs. While
the fur trade has declined, trapping still continues, and humans
also farm captive foxes for their fur.
Other human activities affect arctic fox populations. In Iceland, farmers considered
arctic foxes as pests that threatened their sheep and ducks. Thus, they have
waged eradication campaigns since the 13th century. On Mednyi Island in the Commander
Islands of Russia, domestic dogs introduced mange, which has drastically reduced
arctic fox numbers. These foxes are also susceptible to rabies in some areas.
Arctic foxes may acclimate themselves close to human settlements, creating further
potential conflicts.
Arctic foxes
face dangers from other sources; these animals (and especially their
young) are prey to other predators. As the red fox's range
expands into that of the arctic fox, these two species compete for
food. The larger red fox also preys on the smaller arctic fox. Polar
bears and wolves also threaten the arctic fox in two ways. When larger
predators decline in numbers, they leave behind less carrion for
the scavenging arctic fox. Bears and wolves also prey upon the arctic
fox as a source of food. Despite all these hazards, arctic foxes
are remarkably successful in most areas of their range.
Sources and Suggested
Reading
Macdonald,
David. 1999. Foxes.” The
Encyclopedia of Mammals. Barnes & Noble Books, New York. pp.
68–-75.
Middlebrook,
C. 1999. Alopex lagopus” (On-line),
Animal Diversity Web. Accessed June 23, 2004 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Alopex_lagopus.html
Stephenson,
Bob. "Alaska
Arctic Fox" (On-line), Alaska Department of Fish and Game. Accessed
June 23, 2004 at http://www.ak.blm.gov/animals/arcfox1.html
Tannerfeldt,
Magnus. “The Arctic Fox Alopex
lagopus” (On-line), Accessed June 23, 2004 at http://www.zoologi.su.se/research/alopex/the_arctic_fox.htm
For Kids!
Ling, Mary. 1991. Amazing Wolves Dogs and Foxes. Alfred A
Knopf, NY, New York.
Matthews, Downs. 1995. Arctic Foxes.
Simon & Schuster
Books for Young Readers, NY, New York.
Other Sources:
Lioncrusher's Den: http://www.lioncrusher.com/animal.asp?animal=3
IUCN/SSC Canid Specialist Group: Arctic Fox: http://www.canids.org/SPPACCTS/arcticfx.htm
2003 IUCN Red List off Threatened Species: http://www.redlist.org/search/details.php?species=899
Natural Worlds: http://www.naturalworlds.org/wolf/canids/Alopex_lagopus.htm
* Taxonomic classification varies between
references. Classification information used in this fact sheet was
taken from Mammal Species of the World: A Taxonomic And Geographic
Reference, edited by Don E. Wilson and Dee Ann M. Reeder, Second
Edition, 1993.
**There are
several international and federal agencies that determine the endangered
status of species. WPZ designates a species as endangered if it is
listed as endangered on the IUCN (International Union for the Conservation
of Nature) Red List, the US Fish & Wildlife Service's Endangered
Species List, or on Appendix I of CITES (Convention on the International
Trade of Endangered Species of Flora and Fauna). |