Arctic foxes (Vulpes lagopus) are typically brownish gray in the summer and frosty white in the winter. Weirdly, coastal populations in Alaska and Canada are slate gray and lighten only slightly during the winter. Some of these were introduced to the Aleutian Islands by fur trappers, who could charge more money for their unusually colored coats. Among the main predators of the Arctic fox is its cousin the red fox (V. vulpes). Though the overlap in range was historically rather thin, climate change has allowed the red fox to move farther into the Arctic fox’s icy domain, outcompeting it for food and sometimes eating it.
Username: Shopno Published on 2024-12-05 02:21:22 ID NUMBER: 125981
As temperatures drop and autumn gives way to the seemingly ceaseless snows of winter, some animals in northerly climes exchange their pelage or plumage of summer drab for the purest white. Unlike many white animals associated with the north, such as polar bears and snowy owls, which are white all year, these creatures shift their colors with the seasons. Why this happens is not entirely clear. While camouflage is one evolutionary factor that has selected for seasonally white fur, it is likely that the switch to winter whites confers other advantages as well. Scientists believe that if staying hidden were the only upside, many more snow dwellers would be white, but that is not the case. In fact, most Arctic animals do not change color with the seasons at all, even species closely related to those that do. One theory is that a pale coat may have better insulating properties—because melanin, the substance responsible for colored hair, is absent from white fur, leaving air spaces in the hair shaft.
Several species of hares—including the Arctic hare (Lepus arcticus), the mountain hare (L. timidus), and the snowshoe hare (L. americanus)—turn from brown or grayish to white in the winter. The color change is thought to be at least partially linked to photoperiod—that is, the amount of light received during the day. As the days shorten, receptors in the retina transmit that information to the hare’s brain, stimulating the replacement of brown hair to white, starting with the extremities. One study has shown that global warming may be a major threat to the survival of these animals. By reducing snow cover, the climatic phenomenon throws a wrench in the timing of the color change, leaving milk-colored animals to conceal themselves against earth-colored surroundings.
Three species of weasels swap their warm summer browns for icy whites: the least weasel (Mustela nivalis), the long-tailed weasel (M. frenata), and the short-tailed weasel, or stoat (M. erminea). The latter species is perhaps best known as the ermine, also the name of its winter fur, which is white except for the black tip of the tail. The uniquely patterned fur was once used to trim the robes of royalty and clergy. Weasels of the same species that live in more southerly climates usually don’t change color, though their more northerly relatives do. In transition zones, some weasels only partially change color, resulting in patchy white-and-brown fur. Interestingly, color-changing weasels have been shown to change color regardless of temperature or location, suggesting that they too rely on photoperiod to cue their molts.
A subspecies of caribou native to the High Arctic of Canada and Greenland, Peary caribou (Rangifer tarandus pearyi) exchange their silvery summer coats for white ones with the coming of winter. They are the only subspecies of caribou to undergo such a change. Other subspecies remain brown or gray year-round, though the shades may lighten slightly with the growth of their winter coats. Peary caribou are the smallest subspecies of caribou and, because of their morphological differences, were once considered a separate species.
Lemmings in the genus Dicrostonyx, which comprises an indeterminate number of species, turn from brown or gray in the warmer months to white when the snows come. (They belong to a different genus than true lemmings, which remain brown.) Strangely, they spend most of their time burrowing beneath the snow, which would seem to render camouflage unnecessary. They even grow special winter claws—really extensions of the toe pads—for digging through the drifts to create nests and reach the stems of the Arctic willows upon which they feed. Their skins were once used by Eskimo peoples as clothing embellishments.
All three species of ptarmigans—a genus of birds related to grouse, chickens, and pheasants—trade their scalloped brown plumage for white feathers. (They spend spring and fall in a mottled state, matching the patchy snow cover.) The white-tailed ptarmigan (Lagopus leucura) turns entirely white, while the willow ptarmigan (L. lagopus) and rock ptarmigan (L. muta) retain some black feathers in their tails. Ptarmigans even develop white boots to match; the downy foot covering also helps them to walk atop the snow. The air bubbles in their winter feathers—which may help with insulation—scatter light, making them appear more brightly white than other white birds.
This is probably the only animal on this list that you can actually keep as a pet. The Siberian hamster, or Dzhungarian hamster (Phodopus sungorus), often sold as the “winter white,” will change from a silvery chinchilla shade to mostly white if it is kept in a room that receives natural light. Temperature does not seem to affect the molt.
Arctic foxes (Vulpes lagopus) are typically brownish gray in the summer and frosty white in the winter. Weirdly, coastal populations in Alaska and Canada are slate gray and lighten only slightly during the winter. Some of these were introduced to the Aleutian Islands by fur trappers, who could charge more money for their unusually colored coats. Among the main predators of the Arctic fox is its cousin the red fox (V. vulpes). Though the overlap in range was historically rather thin, climate change has allowed the red fox to move farther into the Arctic fox’s icy domain, outcompeting it for food and sometimes eating it.
Arctic foxes (Vulpes lagopus) are typically brownish gray in the summer and frosty white in the winter. Weirdly, coastal populations in Alaska and Canada are slate gray and lighten only slightly during the winter. Some of these were introduced to the Aleutian Islands by fur trappers, who could charge more money for their unusually colored coats. Among the main predators of the Arctic fox is its cousin the red fox (V. vulpes). Though the overlap in range was historically rather thin, climate change has allowed the red fox to move farther into the Arctic fox’s icy domain, outcompeting it for food and sometimes eating it.
As omnivores, foxes in the Artic eat voles, mice, lemmings, rabbits and other small animals throughout the fall and winter. In the spring, they supplement their diet with nesting birds, and are often seen sneaking around the tundra attempting to steal Canada goose eggs. In summer, they add in insects and berries to their menu. They’ve also been known to catch young lake trout by jumping from the bank into a school of fish in shallow water. In short, they’re opportunists.
Foxes will also eat seal pups, beaver, reptiles, fruits and even garbage. (Hinterland Who’s Who, n.d.). Red foxes stock up, hiding their food in the dirt or snow and marking it with urine. I, for one, am glad we have a freezer and pantry instead.
Did you know that Arctic foxes are ecosystem engineers? A fascinating research project was published in 2016 demonstrating how effective they are at growing gardens around their dens. They may not set out with the intention of having wildflowers and vegetation marking the spot of their homes, but it’s a beautiful development of Nature’s cycle. The tundra maintains minimal and very low-lying vegetation, so you can visibly spot Arctic fox dens by the lushness of the vegetation surrounding them.
The researchers tested the soil throughout the seasons and found that the effects of a fox den increased the nutrients in the soil drastically. In June, extractable phosphorus – a major plant nutrient – was found to be nearly 1200% greater around dens. The natural garden growing is due to the defecation, the remains of foxes’ meals, and urination around the den (Gharajehdaghipour, 2016). The extra fauna helps attract herbivores, like the foxes’ main food source, the lemming.
More elusive in the summer, Arctic foxes come out in their full marshmallow-y glory in the fall. Their grey-brown coats turn a pristine white and they fluff up to the size of a large housecat, with their tail making up one third of their length. Changing colours throughout the year allows them to camouflage themselves, whether predator or prey.
People often wonder how something so small survives the sub-zero temperatures, but Arctic foxes have adapted to their environment surprisingly well. Their small ears, muzzle, and short legs reduce the surface area exposed to the cold. Research has shown it takes temperatures of -70°C or -94°F to even get Arctic foxes to shiver. Now that’s cold! And just in case you’re wondering, polar bears don’t shiver easily either. They normally have a harder time not overheating, thanks to two coats of fur and a thick layer of insulating fat.
The Arctic fox (Vulpes lagopus), also known as the white fox, polar fox, or snow fox, is a small species of fox native to the Arctic regions of the Northern Hemisphere and common throughout the Arctic tundra biome.[1][8][9][10] It is well adapted to living in cold environments, and is best known for its thick, warm fur that is also used as camouflage. It has a large and very fluffy tail. In the wild, most individuals do not live past their first year but some exceptional ones survive up to 11 years.[11] Its body length ranges from 46 to 68 cm (18 to 27 in), with a generally rounded body shape to minimize the escape of body heat.
Antarctica (/ænˈtɑːrktɪkə/ ⓘ)[note 1] is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of 14,200,000 km2 (5,500,000 sq mi). Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of 1.9 km (1.2 mi).
Arctic foxes (Vulpes lagopus) are typically brownish gray in the summer and frosty white in the winter. Weirdly, coastal populations in Alaska and Canada are slate gray and lighten only slightly during the winter. Some of these were introduced to the Aleutian Islands by fur trappers, who could charge more money for their unusually colored coats. Among the main predators of the Arctic fox is its cousin the red fox (V. vulpes). Though the overlap in range was historically rather thin, climate change has allowed the red fox to move farther into the Arctic fox’s icy domain, outcompeting it for food and sometimes eating it.
The Arctic tern (Sterna paradisaea) is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe (as far south as Brittany), Asia, and North America (as far south as Massachusetts). The species is strongly migratory, seeing two summers each year as it migrates along a convoluted route from its northern breeding grounds to the Antarctic coast for the southern summer and back again about six months later. Recent studies have shown average annual round-trip lengths of about 70,900 km (44,100 mi) for birds nesting in Iceland and Greenland and about 48,700 km (30,300 mi) for birds nesting in the Netherlands. These are by far the longest migrations known in the animal kingdom. The Arctic tern nests once every one to three years (depending on its mating cycle).
Our final destination is the ethereal peak known as “The Spectre,” situated in the icy wilderness of Antarctica. While not dominating in height, this striking rock pinnacle is surrounded by a seemingly endless expanse of snow and ice. It’s a destination only accessible to the most intrepid explorers, making it the world’s most remote mountain as well.