Arctic Fox

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The arctic fox (Alopex lagopus) is a member of the canid family, which includes wolves, dogs and other foxes. Its scientific name translates as "hare-footed fox", referring to the dense fur on its feet which is similar to the fur on the foot of a hare. This extra fur provides increased insulation against the cold. Other adaptations to its arctic environment are short legs, ears and nose, and a thick, winter coat.

The arctic fox is a small animal, normally weighing between 2.5 and 5.0 kg. Its average body length is 65 to 85 cm. The female, or vixen, is slightly smaller than the male fox.

The arctic fox is the only canid that changes the colour of its coat in the summer. The back, tail, legs and head are brown, and the sides and belly are blond. This two-tone brown pelage lasts only for July and August and enables the fox to blend into the summer tundra. This coat is much shorter than the winter coat.

There are two winter colour phases of the arctic fox: white and blue. The blue coat varies from grey to dark blue-black. The different colour phases may occur within the same litter and the proportion of each colour phase varies geographically. In the Northwest Territories, the white phase is much more prevalent. The blue phase occurs in approximately 1 per cent of inland populations and comprises from 1 to 5 per cent of foxes on coastal areas and the arctic islands. However, in the Aleutian and Pribilof Islands of Alaska, the blue phase predominates. In southern Greenland, the proportion of the white and blue colours is equal. The winter coat of the arctic fox makes it appear much larger than it really is. The dense underfur and long guard hairs provide ample protection against the most bitter winter weather.

Distribution

The arctic fox is circumpolar in distribution. It inhabits northern Europe, Asia, North America and Greenland. It is widely distributed throughout the arctic tundra of the NWT, including the arctic islands. The natural southern limit of its distribution is the treeline, but some foxes venture into the boreal forest, especially when their food decreases on the tundra. They also move extensively over the polar ice cap.

Arctic foxes inhabit both inland and coastal terrain. Each fox has its own home range, which varies in size from 3 to 25 km2. However, arctic foxes are very mobile and can travel great distances over land or sea ice. Movement by individuals of over 2,000 km has been recorded. 

Grey shaded area - Distribution of Arctic Fox

Reproduction

In late winter, arctic foxes seek dens in which to raise their young. The dens are usually dug in gently sloping, sandy soil near rivers or lakes or on elevated areas free of permafrost. They have complex underground tunnels with numerous entrances and several metres of interconnecting tunnels. Good den sites are not common so they are occupied in successive years, becoming more complex with use. Wolves may move into old fox dens to raise their own young, and grizzly bears can cause extensive damage by digging in search of arctic ground squirrels.

Arctic foxes are sexually mature by 10 months of age. They breed in March or April. If the preceding winter was severe and the foxes are malnourished, they may breed later than usual or not at all. One litter is produced each season after a gestation period of about 51 days. On average, six pups are born between mid-May and mid-June. Litter sizes vary widely, but are generally between 3 and 9 pups, fluctuating with food availability and geographic location. Foxes inhabiting coastal areas have smaller litters than foxes that occupy inland tundra. The newborn pups are tiny and helpless. They are born blind, deaf and toothless with a soft dark-brown undercoat that grows rapidly and turns paler after a few weeks.

The young foxes emerge from the den after three or four weeks and are weaned at about six weeks. They are high-spirited and playful at this age and may boldly continue their antics in the presence of humans. By mid-August, they are independent and are abandoned first by the male fox and then by the vixen. The foxes then disperse for the winter.

Generally, the arctic fox does not live for much longer than four years. It has few natural predators. Wolves are its most serious threat, and it keeps its distance from polar bears. When threatened, a fox usually runs, but in a desperate situation, it will turn and fight, hissing and screaming. 

Rabies is the most common disease that affects foxes. Encephalitis and distemper are also fatal diseases, which are more prevalent during years with high numbers of foxes Most foxes are infected with a variety of internal and external parasites.

Diet

Arctic foxes live primarily on lemmings and voles. In winter, the lemmings must first be located in their tunnels under the snow. Most hunting is done in darkness, so the fox relies heavily on its acute sense of smell and hearing to detect its prey. It quietly traces the lemmings' movements under the snow and then pounces and digs rapidly down to the tunnel or nest. In summer, lemmings are caught mainly when they are scurrying across the tundra. The fox employs stalking manoeuvres and then dashes for its prey.

Winter in the Far North is harsh and limited food resources can have a profound effect on arctic fox numbers. Brown and collared lemmings undergo population peaks every three to five years followed by crashes caused by overcrowding and other factors, such as insufficient snow insulation in winter. The arctic fox population closely follows the rise and fall of the lemming population. After a crash in the lemming population, the number of surviving fox pups declines drastically in the fall. Large numbers of foxes starve the following winter and many do not breed the next spring.

In addition to lemmings, the winter food of arctic foxes consists of arctic hares, ptarmigan and carrion. They will trail wolves to obtain scraps from abandoned carcasses, and follow polar bears across frozen seas to scavenge from leftover seals. They may also kill ringed seal pups in their birth dens. In areas of human development, arctic foxes may scrounge food handouts or garbage.

During the summer, arctic foxes supplement their lemming diet with ground squirrels, hares, eggs, and fish. They also feed on flightless geese and waterfowl and clamber about seabird colonies stealing eggs and pulling young from the nest. During times of plenty, foxes will cache food for periods of want.

Harvest Levels

Many European traders were first lured to the Far North by the valuable white pelt of the arctic fox. The arctic fox industry was once the backbone of the economy of many northern communities. A reduction in fox numbers or a drop in the market value for the pelts had a drastic effect on these communities.

The arctic fox is classified as a furbearer in the NWT. Trapping seasons vary among areas, but generally run from November 1 to early April.

Year	Harvest	Average price per pelt	Total Value
1991/1992	2,291	$15.22	$34,859.80
1992/1993	851	$25.13	$21,384.00
1993/1994	518	$23.14	$11,985.00
1994/1995	37	$30.27	$1,120.00
1995/1996	366	$37.84	$13,851.00
1996/1997	241	$29.54	$7,120.00
1997/1998	663	$29.93	$19,841.00
1998/1999	663	$29.93	$19,841.00
1999/2000	406	$22.21	$9,017.34
2000/2001	1221	$23.73	$28,968.44
2001/2002	1435	$27.16	$38,978.44
2002/2003	845	$25.84	$21,837.67

Arctic foxes in the NWT are harvested in compliance with the Agreement on International Humane Trap Standards. The NWT has committed to implementing these standards and enforcing the use of certified humane traps.

For more information on the types of humane traps used in the NWT, visit the Humane Trap Research and Development website.