Tuesday, March 24, 2009

Polar Bears, Rulers of the Arctic North

Polar Bears, Rulers of the Arctic North
By Clint Leung

The polar bears (Thalarctos maritimus) live in the Arctic regions of the north near open water where they can find their main source of food which are seals. These bears are huge with adults at 7 to 8 ½ feet tall and up to 1,600 pounds. Polar bears are white to creamy white all year round which gives them excellent camouflage against the Arctic snow when hunting. Along with the Arctic fox, the polar bear is the most northerly located land mammal on earth.

Unlike other species of bears, polar bears have longer necks and smaller heads making them appear more streamlined. Despite their large sizes, they are incredibly fast being able to run up to 25 miles per hour. At speeds like this, a polar bear can outrun a reindeer. They are also excellent swimmers being able to swim at about 3 miles per hour but for considerable distances.

During winters, they spend most of their time on the ice floes hunting seals. Polar bears have rough, leathery pads on the bottoms of their feet to maintain footholds on slippery ice surfaces. Their adaptation to the cold Arctic waters is even more impressive. Their thick coats of fur traps a deep layer of insulating air around their bodies. An inner layer of fur is so compact that it is almost impossible to wet it. An outer layer of long guard hairs mat together in the water which forms another layer over the inner layer. After a polar bear leaves the water, it simply shakes its body which results in most of the water being thrown right off leaving the bear almost dry. These protective layers of fur ensure that the polar bear’s skin is kept dry most of the time, even while in the Arctic waters.

Polar bears hunt seals by waiting for seals to come through holes in the ice to breathe. They also stalk their prey utilizing their white camouflage abilities against the mounds of ice. Sometimes polar bears have been known to crawl on their bellies until they are close enough to rush their prey, particularly if no cover is available. Besides seals, polar bears will eat Arctic foxes, birds, baby walruses and even man if they are extremely hungry.

Males and females stay apart for most of the year except during the summer mating season. Females tend to breed only every other year and when they do, usually 1 to 4 cubs are born during March to April. The polar bear cubs stay with their mothers for 1 to 2 years. The life span of polar bears can be up to 34 years.

The Inuit hunt polar bears for their fat, tendons and fur. Scientists say that climate changes have been reducing the ice floes in the Arctic which has disrupted the polar bear’s feeding grounds and migration patterns. There are estimates of about 22,000 to 25,000 polar bears left in the world with 60 percent of them in the Canadian Arctic region. Their populations are thought to be stable for now but some speculate that the species is at risk. Some think that if climate changes continue at its present rate and if worldwide hunting is not adequately controlled, polar bears could face extinction in about 100 years. There is presently much debate on adjusting annual hunting quotas of polar bears, even for Inuit hunters, to further help protect these great bears.

Polar bears have become the most popular symbol of the Arctic north with representations used in everything from soft drink commercials to corporate logos of northern based companies including Canadian North airlines. Nunavut even has their license plates cut in the shape of a polar bear. Tourists can see polar bears in the wild through unique tours on specially designed tundra buggies in Churchill, Manitoba Canada. It’s also not surprising that polar bears are some of the most sought after Inuit art sculptures. Polar bears are definitely the rulers of the Arctic north.

Article Source: http://EzineArticles.com/?expert=Clint_Leung

Polar Bears Population And Habitat

Polar Bears Population And Habitat

The polar bear is found throughout the Arctic Ocean and adjacent seas. Due to the absence of human development in its remote habitat, it retains more of its original range than any other extant large carnivore. While they are rare north of 88°, there is evidence that they range all the way across the Arctic, and as far south as James Bay in Canada. They can occasionally drift widely with the sea ice, and there have been anecdotal sightings as far south as Berlevåg on the Norwegian mainland and the Kuril Islands in the Sea of Okhotsk. It is difficult to estimate a global population of polar bears as much of the range has been poorly studied, however biologists use a working estimate of about 20,000-25,000 polar bears worldwide.

There are 19 generally recognized discrete subpopulations. The subpopulations display seasonal fidelity to particular areas, but DNA studies show that they are not reproductively isolated. The thirteen North American subpopulations range from the Beaufort Sea south to Hudson Bay and east to Baffin Bay in western Greenland and account for about 70% of the global population. The Eurasian population is broken up into the eastern Greenland, Barents Sea, Kara Sea, Laptev Sea, and Chukchi Sea subpopulations, though there is considerable uncertainty about the structure of these populations due to limited mark and recapture data.

The range includes the territory of five nations: Denmark (Greenland), Norway (Svalbard), Russia, US (Alaska) and Canada. These five nations are the signatories of the 1973 International Agreement for the Conservation of Polar Bears which mandates cooperation on research and conservations efforts throughout the polar bear's range.

Modern methods of tracking polar bear populations have been implemented only since the mid-1980s, and are expensive to perform consistently over a large area.The most accurate counts require flying a helicopter in the Arctic climate to find polar bears, shooting a tranquilizer dart at the bear to sedate it, and then tagging the bear. In Nunavut, some Inuit have reported increases in bear sightings around human settlements in recent years, leading to a belief that populations are increasing.

Scientists have responded by noting that hungry bears may be congregating around human settlements, leading to the illusion that populations are higher than they actually are. The Polar Bear Specialist Group of the IUCN takes the position that "estimates of subpopulation size or sustainable harvest levels should not be made solely on the basis of traditional ecological knowledge without supporting scientific studies."

Of the 19 recognized polar bear subpopulations, 5 are declining, 5 are stable, 2 are increasing, and 7 have insufficient data.

he polar bear is often regarded as a marine mammal because it spends many months of the year at sea. Its preferred habitat is the annual sea ice covering the waters over the continental shelf and the Arctic inter-island archipelagos. These areas, known as the "Arctic ring of life", have high biological productivity in comparison to the deep waters of the high Arctic.The polar bear tends to frequent areas where sea ice meets water, such as polynyas and leads (temporary stretches of open water in Arctic ice), to hunt the seals that make up most of its diet. Polar bears are therefore found primarily along the perimeter of the polar ice pack, rather than in the Polar Basin close to the North Pole where the density of seals is low.

Annual ice contains areas of water that appear and disappear throughout the year as the weather changes. Seals migrate in response to these changes, and polar bears must follow their prey. In Hudson Bay, James Bay, and some other areas, the ice melts completely each summer (an event often referred to as "ice-floe breakup"), forcing polar bears to go onto land and wait through the months until the next freeze-up. In the Chukchi and Beaufort seas, polar bears retreat each summer to the ice further north that remains frozen year-round.

Endangered Polar Bear - The Battle To Protect The Arctic Goes On

Endangered Polar Bear - The Battle To Protect The Arctic Goes On

The polar bear world is disappearing. Whether from the consequences of global warming or from intrusion from humans and the hunt for resources such as oil, the endangered polar bear is becoming a target of our intensifying environmental and economic pressures.

As it has been projected that by the middle of this century we will no longer have year-round Arctic sea ice, the polar bear may vanish from the wilderness. Climate change and thinning ice has already lessened, by a few weeks, the time mother polar bears have to feed and collect the fat that sustains them and nourishes their young.

Many scientists feel that the rapid rate of climate change (global warming) underway in the Arctic will lead to resounding effects. In addition to suspected changes in ocean and atmospheric circulation patterns, effects on the endangered polar bear is likely to be faster and can already be observed in a thinning of the weight of polar bears and also in the birth and survival rate of the cubs.

Exceedingly susceptible to disturbances, oil exploration affects the endangered polar bear in a number of ways. For instance, when oil exploration equipment drives too close to the dens, it blasts shock waves through the ground as it searches for oil and gas reserves, making the polar bear mother abandon her den and her cubs, disturbing her hunting patterns. Since the cubs do not leave the den until they're 3 months old, when abandoned, they will die.

It is known that 1 bear has died from consuming a toxic substance, due to the constant release of contaminants from petroleum exploration, production and support activities in active oil fields on Alaska's North Slope. That's 1 bear too many!

Although most Americans concur that there is not adequate oil in the Arctic Refuge to compromise the loss of this place, its people and its wildlife, unfortunately the struggle to protect the Arctic carries on in this, the polar bear world.

As more people reside near these areas, they can't help but acquire garbage and, of course, a few polar bears will move in too near when hunting for food, and be killed. The polar bear habitat is shrinking. Extinction of these magnificent creatures, so unparalleled in our world, is almost a certainty.

The combination of pollution moving to the Far North from sources thousands of miles away, along with oil development and global warming, could affect not only the polar bear world but also the entire ecosystem. Thinning sea ice, greenhouse gas emissions, climate change--these components and more are impacting the future of this and many additional vulnerable arctic species. The endangered polar bear is potentially our generation's "canary in the coal mine." Its demise could forecast even larger environmental dangers to come. Polar bears are a national treasure, and their survival depends on us!

By: Frankie Kangas

Article Directory: http://www.articledashboard.com

Polar Bears In Trouble

Polar Bears In Trouble

Polar bears have long fascinated us. With their thick, white coats, they look incredibly cuddly, particularly the cubs. In truth, they are the biggest and most powerful bears on the planet. Alas, they may be added to the endangered species list.

Polar bears are an amazingly beautiful animal. Unfortunately, they are under a lot of pressure as a species due to climate change in the Arctic. Receding ice and pollution issues are leading to concerns polar bears may be facing extinction. To better understand polar bears, here’s an overview of this amazing animal.

While penguins are only found in Antarctica, polar bears are only found in the Arctic Circle. This, of course, means they are particularly susceptible to any environmental changes in the Arctic.

Polar bears are the largest bear species by over 400 pounds on average. They are primarily solitary creatures. For food, seal is always on the menu, but they will also scavenge if they come across something tasty. Interestingly, polar bears never drink water. They get it all from their meals.

Polar bears are known for their beautiful white coats. In truth, the coats are not white. The hairs are colorless, hollow tubes that absorb the light giving them the bears their white color. Polar bear skin is actually black like their noses. A common myth is the hollow tubes of polar bear skin can act like fiber optics for your phone. This myth has been disproved, but it gives you an idea of the nature of the hairs.

Female polar bears usually give birth in the last two months of the year. They almost always give birth to twins. When it is time to do so, the mothers will dig dens out of the snow and ice. They will remain in the den without food until the cubs are able to leave.

When born, polar bear cubs are absolutely tiny. They weigh less than one pound, which is pretty amazing considering an adult polar bear can weigh 1,100 pounds on average. After birth, the mother will stay with the cubs for two years and train them in all aspects of polar bear etiquette. After that she abandons them to their own fates. The fathers take no part in the raising of the cubs.

As with many animals, polar bears have some unique characteristics. They can walk up to 40 miles a day and swim up to 60. To catch seals, they stand over a breathing hole and wait for a seal to come up for air. They then swat the seal with their left paw, always their left paw for some unknown reason. After eating, they can go five days without swatting another seal.

As of the writing of this article, polar bear populations are under duress as the Arctic undergoes fundamental changes. Ice is melting and so is the territory of the polar bear. Latest estimates indicate only 25,000 polar bears remain.

By: Richard Monk

Article Directory: http://www.articledashboard.com

Polar Bears

The Polar Bears

The polar bear (Ursus maritimus) is a bear native to the Arctic Ocean and its surrounding seas. The world's largest carnivore found on land, a title it shares with the Kodiak Bear, an adult male weighs around 400–680 kg (880–1,500 lb), while an adult female is about half that size. Although it is closely related to the brown bear, it has evolved to occupy a narrow ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Although most polar bears are born on land, it spends most of its time at sea, hence its name meaning "maritime bear", and can hunt consistently only from sea ice, spending much of the year on the frozen sea.

The polar bear is classified as a vulnerable species, with 5 of the 19 polar bear subpopulations in decline. For decades, unrestricted hunting raised international concern for the future of the species; populations have rebounded after controls and quotas began to take effect. For thousands of years, the polar bear has been a key figure in the material, spiritual, and cultural life of Arctic indigenous peoples, and the hunting of polar bears remains important in their cultures.

The IUCN now lists global warming as the most significant threat to the polar bear, primarily because the melting of its sea ice habitat reduces its ability to find sufficient food. The IUCN states, "If climatic trends continue polar bears may become extirpated from most of their range within 100 years." On May 14, 2008, the United States Department of the Interior listed the polar bear as a threatened species under the Endangered Species Act.

source : http://en.wikipedia.org/wiki/Polar_bears