The Arctic fox (Vulpes lagopus), also called the polar fox, white fox, or snow fox, is a small fox endemic to the Arctic regions of the Nothern Hemisphere.
It is also found throughout the Arctic tundra biome. The Arctic fox is well-adapted to living in cold environments and is known to be stealthy, as its thick, warm fur enables it to camouflage.
The Arctic fox is listed on the IUCN Red List as Least Concern.
Scientific classification
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Mammalia |
| Order | Carnivora |
| Family | Canidae |
| Genus | Vulpes |
| Species | Vulpes lagopus |
Subspecies
- Bering Islands Arctic fox (V. l. beringensis)
- Greenland Arctic fox (V. l. foragoapusis)
- Iceland Arctic fox (V. l. fuliginosus)
- Pribilof Islands Arctic fox (V. l. pribilofensis)
Characteristics
The average length (head and body) of the male is 22 in (55 cm), with a range of 18 – 27 in (46 – 68 cm), while the female averages 20 in (52 cm), with a range of 16 – 22 in (41 – 55 cm).
In some regions, there is little or no difference in size between both sexes. The tail is about 12 in (30 cm) long in both males and females. The height at the shoulder is 9.8 – 11.8 in (25 – 30 cm).
On average, males weigh 7.7 lb (3.5 kg), with a range of 7.1 – 20.7 lb (3.2 – 9.4 kg), while females average 6.4 lb (2.9 kg), with a range of 3.1 – 7.1 lb (1.4 – 7.1 lb).
Behavior
Arctic foxes endure a temperature difference of about 160 to 180 °F (90 to 100 °C) between their internal core temperature and the external environment.
The Arctic fox prevents heat loss by tightly tucking its head and legs under its body and behind its furry tail.
They also stay warm by getting out of the wind and staying in their dens. Arctic foxes do not hibernate, as they are active throughout the year.
Reproduction
In the spring, Arctic foxes begin to prepare for the mating season. They build a home for their potential offspring. They are known to live in large dens, which are frost-free and are in the slightly raised ground.
These are complex systems of tunnels covering as much as 1,200 sq yd (1,000 m2). Arctic foxes prefer dens with easily accessible entrances clear from ice and snow, making it easier to burrow in.
Arctic foxes choose and build dens that face southward, facing the sun, making the den warm.
They build a different den for pregnant females, and these dens are usually large and maze-like for a quick and easy escape from predators. These Natal dens are usually found in rugged terrain (to provide more protection for the pups).
In the tundra region, the main prey of the Arctic fox is lemmings, which is why it is often called the “lemmings fox”.
Arctic foxes mate and produce 18 pups when lemmings are available and do not mate when food becomes scarce.
So, the population density of Arctic foxes depends on the availability of food sources. The more abundant the food source, the more dense the population is, and vice versa.
Mating occurs between April – May, and the gestation period lasts 52 days. Arctic foxes are known to produce one of the largest litters in the order Carnivora. They produce litters that contain as many as 25 young.
The offspring begin to leave the den by 3 – 4 weeks old and are weaned at 9 weeks. Arctic foxes are mainly monogamous, with both parents caring for the offspring.
When prey and predators are abundant, Arctic foxes tend to be promiscuous (exhibited in both sexes). They are known to live for 3 to 6 years in the wild.
Diet
Arctic foxes primarily eat any small animal, including voles, lemmings, hares, fish, eggs, birds, and carrion. Arctic foxes also scavenge on carcasses left behind by larger predators such as polar bears and wolves.
Lemmings are the most common prey for Arctic foxes, as a family of foxes eats dozens of lemmings daily. They also feed on seaweed and berries, and with this, they may be classified as omnivores.
Arctic foxes survive food scarcity and harsh winters by storing body fat or hoarding food.
Fat is deposited viscerally and subcutaneously in Arctic foxes. At the beginning of winter, the Arctic fox begins to amass fat as a form of energy storage, providing it with an estimated 14740 kJ of energy.
Using the lowest MBR value ever recorded in Arctic foxes, an average-sized fox weighing 7.7 lb (3.5 kg) would need at least 471 kJ/day during the winter to survive.
Arctic foxes steal goose eggs (mostly greater snow geese) at a rate of 2.7 to 7.3 eggs/h, and they store 80 to 97% of them.
Habitat
Arctic foxes have a circumpolar distribution in Arctic tundra habitats in northern Asia, northern Europe, and North America.
Its range includes Iceland, Greenland, Svalbard, Fennoscandia, northern Russia, Alaska, islands in the Barents Sea, islands in the Bering Sea, and Canada. Arctic foxes were once hunted to extinction in Jan Mayen.
The Arctic fox mostly inhabits packs of ice and tundra. Still, he is also present in the Kenai Peninsula in Alaska and Canadian boreal forests (northern Saskatchewan, northeastern Alberta, Northern Ontario, northern Manitoba, Northern Quebec, and Newfoundland & Labrador).
They are found at altitudes up to 9,800 ft (3,000 m) above sea level and have been spotted on sea ice close to the North Pole.
The Arctic fox is the only known land mammal endemic to Iceland. The color of its coat depends on the region or location where it is found.
The white-colored fox mainly lives inland and blends with the snowy tundra, while the blue-colored fox lives on the coasts because of its dark color, which blends with the rocks and cliffs.
