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Snowy Owls

Facts About Snowy Owlsw460

Snowy owls are large owls notable for their striking white plumage and their extreme northerly range which includes tundra habitat throughout Alaska, Canada and Eurasia. In this article, you’ll find a collection of snowy owl facts that will help you gain a deeper understanding of this intriguing owl species.

FACT: Snowy owls are known by numerous common names.

Snowy owls have a large assortment of common names that includes Arctic owls, great white owls, white owls, harangues, American snowy owls, snow owls, ghost owls, tundra ghosts, ookpiks, ermine owls, Scandinavian night birds and highland tundra owls.

FACT: Snowy owls are relatively quiet birds.

Outside the breeding season, snowy owls make very few vocalizations. During the breeding season, snowy owls are a bit more vocal. Males make a barking kre or krek-krek call. Females produce a loud whistling or mewling pyee-pyee or prek-prek sound. Snowy owls also produce a low-pitched hoot that carries through the air for long distances and can be heard as much as 10 kilometers away. Other sounds snowy owls make include hissing, bill snapping and a clapping sound believed to be created by clicking the tongue.

FACT: Snowy owls prefer tundra habitat.

Snowy owls are primarily tundra birds although they sometimes also inhabit grasslands. They venture into forests only on very rare occasions, if ever. During the winter, snowy owls often move southward. During their migration, they are sometimes seen along coastlines and lake shores. They sometimes stop at airports, possibly because they offer them the wide-open habitat they prefer. During the breeding season, which snowy owls spend in the Arctic, they nest on small rises in the tundra where the female carves out a scrape or shallow depression in the ground in which to lay her eggs.

FACT: Snowy owls are not entirely white.

The plumage of an adult male snowy owl is mostly white with few dark markings. Females and young owls have a sprinkling of darker feathers that form spots or bars over their wings, breast, upper parts and the back of their head. This speckling offers superb camouflage and enables juveniles and females to blend well with the summertime colors and textures of the tundra’s vegetation. During the nesting season, females are often are heavily soiled on their underside from sitting on the next. Snowy owls have bright yellow eyes and a black bill.

FACT: Snowy owls are diurnal.

Unlike most owls, snowy owls are primarily diurnal birds. This means snowy owls are usually active during the day, from dawn to dusk. Sometimes snowy owls do hunt at night. It is important to remember that within their Arctic range, snowy owls experience long summer days and hunting at night simply isn’t an option as there are few or no hours of darkness. The opposite is true in winter when day length shortens and hunting during daylight hours is reduced or eliminated as the sun remains below the horizon for long stretches of time.

FACT: In years when prey is abundant, snowy owls lay more eggs.

Normally, snowy owls lay between 5 and 8 eggs per clutch. But in good years when prey such as lemmings are abundant, they lay as many as 14 eggs per clutch. Female snowy owls lay their eggs at 2-day intervals so that the young emerge from the egg at different times. The hatchlings in the same nest are therefore of differing ages, with some having hatched as much as 2 weeks apart.

FACT: Snowy owls are nomadic birds.

Snowy owls rely on prey populations that fluctuate significantly over time. As a result, snowy owls are nomadic birds and go wherever there is ample food resources at any particular time. During normal years, snowy owls remain in the northernmost parts of Alaska, Canada and Eurasia. But in seasons when prey is not abundant in the northern stretches of their range, snowy owls move further southward.

FACT: Snowy owl populations occasionally shift far southwards.

Occasionally, snowy owls move to regions that are farther south than their normal range. For example, during the years of 1945 through 1946, snow owls made a widespread, coast-to-coast incursion into the southern stretches of Canada and the northern parts of the United States. Then in 1966 and 1967, snowy owls moved deeply into the Pacific Northwest region. These incursions have been coincided with cyclic declines in the lemming population.

FACT: Snowy owls belong to the genus Bubo.

Until recently, snowy owls were the only member of the genus Nyctea but recent molecular studies showed snowy owls to be close relatives of the horned owls. As a result, taxonomists have moved snowy owls to the genus Bubo. Other members of the genus Bubo include the American horned owls and the Old World eagle-owls. Like other horned owls, snowy owls have ear tufts but they are small and usually kept tucked away.

FACT: Snowy owls feed primarily on lemmings and voles.

During the breeding season, snowy owls survive on a diet that consists of lemmings and voles. In parts of their range where lemmings and voles are absent, such as the Shetland Islands, snowy owls feed on rabbits or chicks of wading birds.

The Arctic Fox

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The arctic fox (Vulpes lagopus), also known as the white fox, polar fox, or snow fox, is a small fox native to the Arctic regions of the Northern Hemisphere and is common throughout the Arctic tundra biome.[1][3] It is well adapted to living in cold environments. It has a deep thick fur which is brown in summer and white in winter. It averages in size at about 85.3 cm (33.6 in) in body length, with a generally rounded body shape to minimize the escape of body heat.

They prey on any small animals they can find, including lemmings, voles, ringed seal pups, fish, and seabirds. They will also eat carrion, berries, and seaweed. They form monogamous pairs during the breeding season and usually stay together in family groups of multiple generations in complex underground dens.

The arctic fox lives in some of the most frigid extremes on the planet. Among its adaptations for cold survival is its deep, thick fur,[4] a system of countercurrent heat exchange in the circulation of paws to retain core temperature, and a good supply of body fat. The fox has a low surface area to volume ratio, as evidenced by its generally rounded body shape, short muzzle and legs, and short, thick ears. Since less of its surface area is exposed to the arctic cold, less heat escapes the body. Its furry paws allow it to walk on ice in search of food. The arctic fox has such keen hearing that it can precisely locate the position of prey under the snow. When it finds prey, it pounces and punches through the snow to catch its victim. Its fur changes color with the seasons: in the winter it is white to blend in with snow, while in the summer in turns darker.

The arctic fox tends to be active from early September to early May. The gestation period is 52 days. Litters tend to average 5–8 kits but may be as many as 25[6](the largest in the order Carnivora[7]). Both the mother and the father help to raise their young. The females leave the family and form their own groups and the males stay with the family.
Foxes tend to form monogamous pairs in the breeding season. Litters are born in the early summer and the parents raise the young in a large den. Dens can be complex underground networks, housing many generations of foxes. Young from a previous year’s litter may stay with the parents to help rear younger siblings.[6] The kits are initially brownish; as they become older they turn white. Their coat of fur also changes color when summer arrives, but in winter it is white.

The arctic fox will generally eat any small animal it can find: lemmings, voles, hares, owls, eggs, and carrion, etc. Lemmings are the most common prey. A family of foxes can eat dozens of lemmings each day. During April and May the arctic fox also preys on ringed seal pups when the young animals are confined to a snow den and are relatively helpless. Fish beneath the ice are also part of its diet. They also consume berries and seaweed and may thus be considered omnivores.[8] It is a significant bird egg predator, excepting those of the largest tundra bird species.[9] If there is an overabundance of food hunted, the arctic fox will bury what the family cannot eat. When its normal prey is scarce, the arctic fox scavenges the leftovers and even feces of larger predators, such as the polar bear, even though the bear’s prey includes the arctic fox itself.

Polar Bears

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New evidence suggests that the polar bear, Ursus maritimus, or the sea bear, started to evolve about five million years ago from brown bear ancestors. Unlike their land-based cousins, polar bears are superbly adapted for survival in the Far North on a sea ice habitat. Polar bears live in the Arctic in areas where they hunt seals at openings in sea ice called leads. Five nations have polar bear populations: the United States (Alaska), Canada, Russia, Greenland, and Norway.

Polar bears top the food chain in the Arctic, where they prey primarily on ringed seals. They reach these seals from a platform of sea ice.

Adult male polar bears weigh from 775 to 1,200 pounds. A few weigh more than 1,200 pounds, but these individuals would be exceptional. Females normally weigh 330 to 650 pounds. It’s not uncommon for female polar bears preparing to enter maternity dens in the fall to weigh over 600 pounds.
Females usually bear two cubs. Single cubs and triplets also occur depending on the health and condition of the mother. Cubs stay with their moms for up to 2-1/2 years, learning how to hunt and survive in the harsh arctic environment.

Polar bears live in the circumpolar north in areas where they can hunt seals at openings in the sea ice called leads. They are found in Canada (home to roughly 60% of the world’s polar bears), the U.S. (Alaska), Greenland, Russia, and Norway (the Svalbard archipelago). Scientists have identified 19 populations of polar bears living in four different ice regions in the Arctic.

Although popular art and children’s books often show polar bears and penguins together, the two live at opposite poles. Polar bears live in the Arctic. Penguins live in Antarctica.

Fur. Polar bears’ fur consists of a dense, insulating undercoat topped by guard hairs of various lengths. It is not actually white—it just looks that way. Each hair shaft is pigment-free and transparent with a hollow core that scatters and reflects visible light, much like what happens with ice and snow. Polar bears look whitest when they are clean and in sunlight, especially just after the molt period, which usually begins in spring and is complete by late summer. Before molting, oils from the seals they eat can make them look yellow.
In zoos, polar bears have been known to turn green due to colonies of algae growing in their hollow hair shafts. This happened at the San Diego Zoo in 1979. No harm came to the bears, and zoo veterinarian Phillip Robinson restored the bears to white by killing the algae with a salt solution.

Skin. Polar bears have black skin under which there is a layer of fat that can measure 4.5 inches (11.5 centimeters) thick.

On land (or on top of the sea ice) the polar bear’s thick fur coat—not its fat—prevents nearly any heat loss. In fact, adult males quickly overheat when they run.

In the water, polar bears rely on their fat layer to keep warm: wet fur is a poor insulator. This is why mother bears are so reluctant to swim with young cubs in the spring: the cubs don’t have enough fat. As long as they don’t have to go into water, dry fur keeps little cubs warm at very cold spring temperatures, including -30°F.

Scientific Finding. Scientists used to think that polar bears’ hollow hairs acted like fiber optic tubes and conducted light to their black skin. In 1988, Daniel W. Koon, a physicist at St. Lawrence University in Canton, New York, and graduate assistant, Reid Hutchins, proved this false.

Their experiments showed that a one-fifth inch strand of polar bear hair conducted less than a thousandth of a percent of applied ultraviolet light. So, the black skin absorbs very little ultraviolet light. Instead, Koon believes keratin, a basic component of the hair, absorbs the ultraviolet light.

Reindeer

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In most populations both sexes grow antlers and it is the only cervid species in which females grow them as well as males. In the Scandinavian populations, old males’ antlers fall off in December, young males’ fall off in the early spring, and females’ fall off in the summer. The antlers typically have two separate groups of points, a lower and upper. There is considerable sub-specific variation in the size of the antlers (e.g., rather small and spindly in the northernmost subspecies), but, on average, the bull reindeer’s antlers are the second largest of any extant deer, after the moose. In the largest races, the antlers of big males can range up to 100 cm (39 in)in width and 135 cm (53 in) in beam length. They have the largest antlers relative to body size among living deer species.

The color of the fur varies considerably, both individually and depending on season and subspecies. Northern populations, which usually are relatively small, are whiter, while southern populations, which typically are relatively large, are darker. This can be seen well in North America, where the northernmost subspecies, the Peary caribou, is the whitest and smallest subspecies of the continent, while the southernmost subspecies, the Woodland Caribou, is the darkest and largest.] The coat has two layers of fur: a dense woolly undercoat and longer-haired overcoat consisting of hollow, air-filled hairs.

Like moose, reindeer have specialized noses featuring nasal turbinate bones that dramatically increase the surface area within the nostrils. Incoming cold air is warmed by the animal’s body heat before entering the lungs, and water is condensed from the expired air and captured before the deer’s breath is exhaled, used to moisten dry incoming air and possibly absorbed into the blood through the mucous membranes.

Reindeer hooves adapt to the season: in the summer, when the tundra is soft and wet, the footpads become sponge-like and provide extra traction. In the winter, the pads shrink and tighten, exposing the rim of the hoof, which cuts into the ice and crusted snow to keep it from slipping. This also enables them to dig down (an activity known as “cratering”) through the snow to their favorite food, lichen known as reindeer food.