Polar Bear

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Polar bear From Wikipedia, the free encyclopedia Jump to: navigation, search This article is about the animal. For other uses, see Polar bear (disambiguation ). This is a good article. Click here for more information. Page semi-protected Polar bear Conservation status Vulnerable (IUCN 3.1)[1] Scientific classification Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Carnivora Family: Ursidae Genus: Ursus Species: U. maritimus Binomial name Ursus maritimus Phipps, 1774[2] Polar bear range Synonyms Ursus eogroenlandicus Ursus groenlandicus Ursus jenaensis Ursus labradorensis Ursus marinus Ursus polaris Ursus spitzbergensis Ursus ungavensis Thalarctos maritimus The polar bear (Ursus maritimus) is a bear native largely within the Arctic Circ le encompassing the Arctic Ocean, its surrounding seas and surrounding land mass es. It is the world's largest land carnivore and also the largest bear, together with the omnivorous Kodiak Bear, which is approximately the same size.[3] A boa r (adult male) weighs around 350 700 kg (770 1,500 lb),[4] while a sow (adult female ) is about half that size. Although it is closely related to the brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristic s adapted for cold temperatures, for moving across snow, ice, and open water, an d for hunting the seals which make up most of its diet.[5] Although most polar b ears are born on land, they spend most of their time at sea. Their scientific na me means "maritime bear", and derives from this fact. Polar bears can hunt their preferred food of seals from the edge of sea ice, often living off fat reserves when no sea ice is present. The polar bear is classified as a vulnerable species, with eight of the nineteen polar bear subpopulations in decline.[6] For decades, large scale hunting raise d international concern for the future of the species but populations rebounded after controls and quotas began to take effect.[citation needed] For thousands o f years, the polar bear has been a key figure in the material, spiritual, and cu ltural life of Arctic indigenous peoples, and polar bears remain important in th eir cultures. Contents 1 Naming and etymology 2 Taxonomy and evolution

3 Population and distribution 4 Habitat 5 Biology and behavior 5.1 Physical characteristics 5.2 Hunting and diet 5.3 Behavior 5.4 Reproduction and lifecycle 5.4.1 Maternity denning and early life 5.4.2 Later life 5.4.3 Life expectancy 5.5 Ecological role 5.6 Long distance swimmer 6 Hunting 6.1 Indigenous people 6.2 History of commercial harvest 6.3 Contemporary regulations 6.3.1 Russia 6.3.2 Greenland 6.3.3 Canada 6.3.4 United States 7 Conservation status, efforts and controversies 7.1 Climate change 7.2 Pollution 7.3 Oil and gas development 7.4 Predictions 7.5 Controversy over species protection 7.6 U.S. endangered species legislation 7.7 Canadian endangered species legislation 8 In culture 8.1 Indigenous folklore 8.2 Symbols and mascots 8.3 Literature 9 See also 10 Notes 11 References 12 External links Naming and etymology Constantine John Phipps was the first to describe the polar bear as a distinct s pecies in 1774.[7] He chose the scientific name Ursus maritimus, the Latin for ' maritime bear',[8] due to the animal's native habitat. The Inuit refer to the an imal as nanook[9] (transliterated as nanuq in the Inupiat language).[10] The Yup ik also refer to the bear as nanuuk in Siberian Yupik.[11] The bear is umka in t he Chukchi language. In Russian, it is usually called ?????? ???????? (bélyj medvédj , the white bear), though an older word still in use is ?????? (Oshkúj, which come s from the Komi oski, "bear").[12] In French, the polar bear is referred to as o urs blanc ("white bear") or ours polaire ("polar bear").[13] In the Norwegian-ad ministered Svalbard archipelago, the polar bear is referred to as Isbjørn ("ice be ar"). The polar bear was previously considered to be in its own genus, Thalarctos.[14] However, evidence of hybrids between polar bears and brown bears, and of the re cent evolutionary divergence of the two species, does not support the establishm ent of this separate genus, and the accepted scientific name is now therefore Ur sus maritimus, as Phipps originally proposed.[15] Taxonomy and evolution Polar bears have evolved unique features for Arctic life. Large furry feet and s hort, sharp, stocky claws giving it good traction on ice are evolutionary adapta tions to this environment.

The bear family, Ursidae, is believed to have split off from other carnivorans a bout 38 million years ago. The Ursinae subfamily originated approximately 4.2 mi llion years ago. The oldest known polar bear fossil is a 130,000 to 110,000-year -old jaw bone, found on Prince Charles Foreland in 2004.[16] Fossils show that b etween ten to twenty thousand years ago, the polar bear's molar teeth changed si gnificantly from those of the brown bear. Polar bears are thought to have diverg ed from a population of brown bears that became isolated during a period of glac iation in the Pleistocene.[17] The evidence from DNA analysis is more complex. The mitochondrial DNA (mtDNA) of the polar bear diverged from the brown bear, Ursus arctos, roughly 150,000 year s ago.[16] Further, some clades of brown bear, as assessed by their mtDNA, are m ore closely related to polar bears than to other brown bears,[18] meaning that t he polar bear would not be a true species according to some species concepts.[19 ] The mtDNA of Irish brown bears is particularly close to polar bears.[20] A com parison of the nuclear genome of polar bears with that of brown bears revealed a different pattern, the two forming genetically distinct clades that diverged ap proximately 603,000 years ago,[21] although the latest research is based on anal ysis of the complete genomes (rather than just the mitochondria or partial nucle ar genomes) of polar, brown and black bears, and establishes the divergence of p olar and brown bears at 4-5 million years ago.[22] However, the two species have mated intermittently for all that time, most likel y coming into contact with each other during warming periods, when polar bears w ere driven onto land and brown bears migrated northward. Most brown bears have a bout 2 percent genetic material from polar bears, but one population residing in the Alexander Archipelago has between 5 percent and 10 percent polar bear genes , indicating more frequent and recent mating.[23] Polar bears can breed with bro wn bears to produce fertile grizzly polar bear hybrids,[17][24] rather than indica ting that they have only recently diverged, the new evidence suggests more frequ ent mating has continued over a longer period of time, and thus the two bears re main genetically similar.[23] However, because neither species can survive long in the other's ecological niche, and because they have different morphology, met abolism, social and feeding behaviors, and other phenotypic characteristics, the two bears are generally classified as separate species.[25] When the polar bear was originally documented, two subspecies were identified: U rsus maritimus maritimus by Constantine J. Phipps in 1774, and Ursus maritimus m arinus by Peter Simon Pallas in 1776.[26] This distinction has since been invali dated. One fossil subspecies has been identified. Ursus maritimus tyrannus desce nded from Ursus arctos became extinct during the Pleistocene. U.m. tyrannus was significantly larger than the living subspecies.[17] Population and distribution Polar bears investigate the submarine USS Honolulu 450 kilometres (280 mi) from the North Pole. The polar bear is found in the Arctic Circle and adjacent land masses as far sou th as Newfoundland Island. Due to the absence of human development in its remote habitat, it retains more of its original range than any other extant carnivore. [27] While they are rare north of 88°, there is evidence that they range all the w ay across the Arctic, and as far south as James Bay in Canada. They can occasion ally drift widely with the sea ice, and there have been anecdotal sightings as f ar 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 estimat e of about 20,000 to 25,000 polar bears worldwide.[1][28] There are 19 generally recognized, discrete subpopulations.[28][29] The subpopul ations display seasonal fidelity to particular areas, but DNA studies show that

they are not reproductively isolated.[30] The thirteen North American subpopulat ions range from the Beaufort Sea south to Hudson Bay and east to Baffin Bay in w estern Greenland and account for about 70% of the global population. The Eurasia n population is broken up into the eastern Greenland, Barents Sea, Kara Sea, Lap tev Sea, and Chukchi Sea subpopulations, though there is considerable uncertaint y about the structure of these populations due to limited mark and recapture dat a. Polar bears play-fighting The range includes the territory of five nations: Denmark (Greenland), Norway (S valbard), Russia, the United States (Alaska) and Canada. These five nations are the signatories of the International Agreement on the Conservation of Polar Bear s, which mandates cooperation on research and conservations efforts throughout t he polar bear's range. Modern methods of tracking polar bear populations have been implemented only sin ce the mid-1980s, and are expensive to perform consistently over a large area.[3 1] 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 th en tagging the bear.[31] In Nunavut, some Inuit have reported increases in bear sightings around human settlements in recent years, leading to a belief that pop ulations are increasing. Scientists have responded by noting that hungry bears m ay be congregating around human settlements, leading to the illusion that popula tions are higher than they actually are.[31] 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."[32] Of the 19 recognized polar bear subpopulations, eight are declining, three are s table, one is increasing, and seven have insufficient data, as of 2009.[6][28] Habitat A polar bear in a synthetic arctic zoo environment The polar bear is often regarded as a marine mammal because it spends many month s of the year at sea.[33] Its preferred habitat is the annual sea ice covering t he waters over the continental shelf and the Arctic inter-island archipelagos. T hese areas, known as the "Arctic ring of life", have high biological productivit y in comparison to the deep waters of the high Arctic.[27][34] The polar bear te nds to frequent areas where sea ice meets water, such as polynyas and leads (tem porary stretches of open water in Arctic ice), to hunt the seals that make up mo st of its diet.[35] Polar bears are therefore found primarily along the perimete r of the polar ice pack, rather than in the Polar Basin close to the North Pole where the density of seals is low.[36] 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 b ears must follow their prey.[34] In Hudson Bay, James Bay, and some other areas, the ice melts completely each summer (an event often referred to as "ice-floe b reakup"), forcing polar bears to go onto land and wait through the months until the next freeze-up.[34] In the Chukchi and Beaufort seas, polar bears retreat ea ch summer to the ice further north that remains frozen year-round. Biology and behavior Physical characteristics Polar bear skeleton The polar bear is the largest terrestrial carnivore, being more than twice as la rge as the Siberian tiger.[37] It shares this title with the Kodiak Bear.[38] Ad ult males weigh 350 700 kg (770 1,500 lb) and measure 2.4 3 m (8 10 ft) in length.[39] T he Guinness Book of World Records listed the average male as having a body mass of 386 to 408 kg (850 to 900 lb) and a shoulder height of 133 cm (4.36 ft).[40]

Adult females are roughly half the size of males and normally weigh 150 250 kg (33 0 550 lb), measuring 1.8 2.4 metres (6 8 ft) in length. When pregnant, however, they c an weigh as much as 500 kg (1,100 lb).[39] The polar bear is among the most sexu ally dimorphic of mammals, surpassed only by the pinnipeds.[41] The largest pola r bear on record, reportedly weighing 1,002 kg (2,210 lb), was a male shot at Ko tzebue Sound in northwestern Alaska in 1960.[40] This specimen, when mounted, st ood 3.39 m (11 ft 1 in) tall.[40] The shoulder height of an adult polar bear is 122 to 160 cm (48 to 63 in).[40][42] Compared with its closest relative, the brown bear, the polar bear has a more el ongated body build and a longer skull and nose.[25] As predicted by Allen's rule for a northerly animal, the legs are stocky and the ears and tail are small.[25 ] However, the feet are very large to distribute load when walking on snow or th in ice and to provide propulsion when swimming; they may measure 30 cm (12 in) a cross in an adult.[43] The pads of the paws are covered with small, soft papilla e (dermal bumps) which provide traction on the ice.[25] The polar bear's claws a re short and stocky compared to those of the brown bear, perhaps to serve the fo rmer's need to grip heavy prey and ice.[25] The claws are deeply scooped on the underside to assist in digging in the ice of the natural habitat. Research of in jury patterns in polar bear forelimbs found injuries to the right forelimb to be more frequent than those to the left, suggesting, perhaps, right-handedness.[44 ] Unlike the brown bear, polar bears in captivity are rarely overweight or parti cularly large, possibly as a reaction to the warm conditions of most zoos. The 42 teeth of a polar bear reflect its highly carnivorous diet.[25] The cheek teeth are smaller and more jagged than in the brown bear, and the canines are la rger and sharper.[25] The dental formula is Upper: 3.1.4.2, lower: 3.1.4.3[25] Polar bear swimming. Polar bears are superbly insulated by up to 10 cm (4 in) of blubber,[43] their h ide and their fur; they overheat at temperatures above 10 °C (50 °F), and are nearly invisible under infrared photography.[45] Polar bear fur consists of a layer of dense underfur and an outer layer of guard hairs, which appear white to tan but are actually transparent.[43] The guard hair is 5 15 cm (2 6 in) over most of the b ody.[46] Polar bears gradually moult from May to August,[47] but, unlike other A rctic mammals, they do not shed their coat for a darker shade to camouflage them selves in the summer conditions. The hollow guard hairs of a polar bear coat wer e once thought to act as fiber-optic tubes to conduct light to its black skin, w here it could be absorbed; however, this theory was disproven by recent studies. [48] The white coat usually yellows with age. When kept in captivity in warm, humid c onditions, the fur may turn a pale shade of green due to algae growing inside th e guard hairs.[49] Males have significantly longer hairs on their forelegs, that increase in length until the bear reaches 14 years of age. The male's ornamenta l foreleg hair is thought to attract females, serving a similar function to the lion's mane.[50] The polar bear has an extremely well developed sense of smell, being able to det ect seals nearly 1.6 km (1 mi) away and buried under 1 m (3 ft) of snow.[51] Its hearing is about as acute as that of a human, and its vision is also good at lo ng distances.[51] The polar bear is an excellent swimmer and individuals have been seen in open Ar ctic waters as far as 300 km (200 mi) from land. With its body fat providing buo yancy, it swims in a dog paddle fashion using its large forepaws for propulsion. [52] Polar bears can swim 10 km/h (6 mph). When walking, the polar bear tends to have a lumbering gait and maintains an average speed of around 5.6 km/h (3.5 mp h).[52] When sprinting, they can reach up to 40 km/h (25 mph).[53] Hunting and diet

The long muzzle and neck of the polar bear help it to search in deep holes for s eals, while powerful hindquarters enable it to drag massive prey.[54] The polar bear is the most carnivorous member of the bear family, and most of it s diet consists of ringed and bearded seals.[55] The Arctic is home to millions of seals, which become prey when they surface in holes in the ice in order to br eathe, or when they haul out on the ice to rest.[54] Polar bears hunt primarily at the interface between ice, water, and air; they only rarely catch seals on la nd or in open water.[56] The polar bear's most common hunting method is called still-hunting:[57] The bea r uses its excellent sense of smell to locate a seal breathing hole, and crouche s nearby in silence for a seal to appear. When the seal exhales, the bear smells its breath, reaches into the hole with a forepaw, and drags it out onto the ice . The polar bear kills the seal by biting its head to crush its skull. The polar bear also hunts by stalking seals resting on the ice: Upon spotting a seal, it walks to within 90 m (100 yd), and then crouches. If the seal does not notice, t he bear creeps to within 9 to 12 m (30 to 40 ft) of the seal and then suddenly r ushes forth to attack.[54] A third hunting method is to raid the birth lairs tha t female seals create in the snow.[57] A widespread legend tells that polar bears cover their black noses with their pa ws when hunting. This behavior, if it happens, is rare although the story exists in native oral history and in accounts by early Arctic explorers, there is no r ecord of an eyewitness account of the behavior in recent decades.[52] Polar bear at a whale carcass Mature bears tend to eat only the calorie-rich skin and blubber of the seal, whe reas younger bears consume the protein-rich red meat.[54] Studies have also phot ographed polar bears scaling near-vertical cliffs, to eat birds' chicks and eggs .[58] For subadult bears which are independent of their mother but have not yet gained enough experience and body size to successfully hunt seals, scavenging th e carcasses from other bears' kills is an important source of nutrition. Subadul ts may also be forced to accept a half-eaten carcass if they kill a seal but can not defend it from larger polar bears. After feeding, polar bears wash themselve s with water or snow.[52] The polar bear is an enormously powerful predator. It can kill an adult walrus, although this is rarely attempted. A walrus can be more than twice the bear's we ight,[59] and has up to 1-metre (3 ft)-long ivory tusks that can be used as form idable weapons. Most attacks on walruses occur when the bear charges a group and either targets the slower moving walruses, usually either young or infirm ones, or a walrus that is injured in the rush of walruses trying to escape. They will also attack adult walruses when their diving holes have frozen over or intercep t them before they can get back to the diving hole in the ice. Since an attack o n a walrus tends to be an extremely protracted and exhausting venture, bears hav e been known to abandon the hunt after making the initial injury.[60] Polar bear s have also been seen to prey on beluga whales, by swiping at them at breathing holes. The whales are of similar size to the walrus and nearly as difficult for the bear to subdue. Polar bears very seldom attack full-grown adult whales. Most terrestrial animals in the Arctic can outrun the polar bear on land as polar be ars overheat quickly, and most marine animals the bear encounters can outswim it . In some areas, the polar bear's diet is supplemented by walrus calves and by t he carcasses of dead adult walruses or whales, whose blubber is readily devoured even when rotten.[61] Some characteristic postures: 1. - at rest; 2. - at an estimated reaction; 3. - when feeding

With the exception of pregnant females, polar bears are active year-round,[62] a lthough they have a vestigial hibernation induction trigger in their blood. Unli ke brown and black bears, polar bears are capable of fasting for up to several m onths during late summer and early fall, when they cannot hunt for seals because the sea is unfrozen.[62] When sea ice is unavailable during summer and early au tumn, some populations live off fat reserves for months at a time.[45] Polar bea rs have also been observed to eat a wide variety of other wild foods, including muskox, reindeer, birds, eggs, rodents, shellfish, crabs, and other polar bears. They may also eat plants, including berries, roots, and kelp, however none of t hese are a significant part of their diet.[59] The polar bear's biology is speci alized to require large amounts of fat from marine mammals, and it cannot derive sufficient caloric intake from terrestrial food.[63][64] Being both curious animals and scavengers,[59][65] polar bears investigate and c onsume garbage where they come into contact with humans.[59] Polar bears may att empt to consume almost anything they can find, including hazardous substances su ch as styrofoam, plastic, car batteries, ethylene glycol, hydraulic fluid, and m otor oil.[59][65] The dump in Churchill, Manitoba was closed in 2006 to protect bears, and waste is now recycled or transported to Thompson, Manitoba.[66][67] Behavior Polar bear males frequently play-fight. During the mating season, actual fightin g is intense and often leaves scars or broken teeth. Unlike grizzly bears, polar bears are not territorial. Although stereotyped as b eing voraciously aggressive, they are normally cautious in confrontations, and o ften choose to escape rather than fight.[68] Satiated polar bears rarely attack humans unless severely provoked, whereas hungry polar bears are extremely unpred ictable and are known to kill and sometimes eat humans.[61] Polar bears are stea lth hunters, and the victim is often unaware of the bear's presence until the at tack is underway.[69] Whereas brown bears often maul a person and then leave, po lar bear attacks are more likely to be predatory and are almost always fatal.[69 ] However, due to the very small human population around the Arctic, such attack s are rare. In general, adult polar bears live solitary lives. Yet, they have often been see n playing together for hours at a time and even sleeping in an embrace,[61] and polar bear zoologist Nikita Ovsianikov has described adult males as having "well -developed friendships."[68] Cubs are especially playful as well. Among young ma les in particular, play-fighting may be a means of practicing for serious compet ition during mating seasons later in life.[70] Polar bears have a wide range of vocalisations, including bellows, roars, growls, chuffs and purrs.[71] In 1992, a photographer near Churchill took a now widely circulated set of photo graphs of a polar bear playing with a Canadian Eskimo Dog a tenth of its size.[7 2][73] The pair wrestled harmlessly together each afternoon for ten days in a ro w for no apparent reason, although the bear may have been trying to demonstrate its friendliness in the hope of sharing the kennel's food.[72] This kind of soci al interaction is uncommon; it is far more typical for polar bears to behave agg ressively towards dogs.[72] Reproduction and lifecycle Cubs are born helpless, and typically nurse for two and a half years. Courtship and mating take place on the sea ice in April and May, when polar bear s congregate in the best seal hunting areas.[74] A male may follow the tracks of a breeding female for 100 km (60 mi) or more, and after finding her engage in i ntense fighting with other males over mating rights, fights which often result i n scars and broken teeth.[74] Polar bears have a generally polygynous mating sys tem; recent genetic testing of mothers and cubs, however, has uncovered cases of litters in which cubs have different fathers.[75] Partners stay together and ma te repeatedly for an entire week; the mating ritual induces ovulation in the fem

ale.[76] After mating, the fertilized egg remains in a suspended state until August or Se ptember. During these four months, the pregnant female eats prodigious amounts o f food, gaining at least 200 kg (440 lb) and often more than doubling her body w eight.[74] Maternity denning and early life A female emerging from her maternity den When the ice floes break up in the fall, ending the possibility of hunting, each pregnant female digs a maternity den consisting of a narrow entrance tunnel lea ding to one to three chambers.[74] Most maternity dens are in snowdrifts, but ma y also be made underground in permafrost if it is not sufficiently cold yet for snow.[74] In most subpopulations, maternity dens are situated on land a few kilo meters from the coast, and the individuals in a subpopulation tend to reuse the same denning areas each year.[27] The polar bears that do not den on land make t heir dens on the sea ice. In the den, she enters a dormant state similar to hibe rnation. This hibernation-like state does not consist of continuous sleeping; ho wever, the bear's heart rate slows from 46 to 27 beats per minute.[77] Her body temperature does not decrease during this period as it would for a typical mamma l in hibernation.[45][78] Between November and February, cubs are born blind, covered with a light down fu r, and weighing less than 0.9 kg (2.0 lb),[76] but in captivity they might be de livered in the earlier months. The earliest recorded birth of polar bears in cap tivity was on 11 October 2011 in the Toronto Zoo.[79] On average, each litter ha s two cubs.[74] The family remains in the den until mid-February to mid-April, w ith the mother maintaining her fast while nursing her cubs on a fat-rich milk.[7 4] By the time the mother breaks open the entrance to the den, her cubs weigh ab out 10 to 15 kilograms (22 to 33 lb).[74] For about 12 to 15 days, the family sp ends time outside the den while remaining in its vicinity, the mother grazing on vegetation while the cubs become used to walking and playing.[74] Then they beg in the long walk from the denning area to the sea ice, where the mother can once again catch seals.[74] Depending on the timing of ice-floe breakup in the fall, she may have fasted for up to eight months.[74] A cub nursing Cubs may fall prey to wolves or to starvation. Female polar bears are noted for both their affection towards their offspring[citation needed], and their valianc e in protecting them[citation needed]. One case of adoption of a wild cub has be en confirmed by genetic testing.[75] Adult male bears occasionally kill and eat polar bear cubs,[80] for reasons that are unclear.[81] As of 2006, in Alaska, 42 % of cubs now reach 12 months of age, down from 65% 15 years ago.[82] In most ar eas, cubs are weaned at two and a half years of age,[74] when the mother chases them away or abandons them. The western coast of Hudson Bay is unusual in that i ts female polar bears sometimes wean their cubs at only one and a half years.[74 ] This was the case for 40% of cubs there in the early 1980s; however by the 199 0s, fewer than 20% of cubs were weaned this young.[83] After the mother leaves, sibling cubs sometimes travel and share food together for weeks or months.[61] Later life Females begin to breed at the age of four years in most areas, and five years in the Beaufort Sea area.[74] Males usually reach sexual maturity at six years; ho wever, as competition for females is fierce, many do not breed until the age of eight or ten.[74] A study in Hudson Bay indicated that both the reproductive suc cess and the maternal weight of females peaked in their mid-teens.[84] Polar bears appear to be less affected by infectious diseases and parasites than most terrestrial mammals.[81] Polar bears are especially susceptible to Trichin ella, a parasitic roundworm they contract through cannibalism,[85] although infe

ctions are usually not fatal.[81] Only one case of a polar bear with rabies has been documented, even though polar bears frequently interact with Arctic foxes, which often carry rabies.[81] Bacterial Leptospirosis and Morbillivirus have bee n recorded. Polar bears sometimes have problems with various skin diseases which may be caused by mites or other parasites. Life expectancy Polar bears rarely live beyond 25 years.[86] The oldest wild bears on record die d at age 32, whereas the oldest captive was a female who died in 1991, age 43.[8 7] The causes of death in wild adult polar bears are poorly understood, as carca sses are rarely found in the species's frigid habitat.[81] In the wild, old pola r bears eventually become too weak to catch food, and gradually starve to death. Polar bears injured in fights or accidents may either die from their injuries o r become unable to hunt effectively, leading to starvation.[81] Ecological role The polar bear is the apex predator within its range. Several animal species, pa rticularly Arctic Foxes and Glaucous Gulls, routinely scavenge polar bear kills. [52] The relationship between ringed seals and polar bears is so close that the abund ance of ringed seals in some areas appears to regulate the density of polar bear s, while polar bear predation in turn regulates density and reproductive success of ringed seals.[56] The evolutionary pressure of polar bear predation on seals probably accounts for some significant differences between Arctic and Antarctic seals. Compared to the Antarctic, where there is no major surface predator, Arc tic seals use more breathing holes per individual, appear more restless when hau led out on the ice, and rarely defecate on the ice.[52] The baby fur of most Arc tic seal species is white, presumably to provide camouflage from predators, wher eas Antarctic seals all have dark fur at birth.[52] Polar bears rarely enter conflict with other predators, though recent brown bear encroachments into polar bear territories have led to antagonistic encounters. Brown bears tend to dominate polar bears in disputes over carcasses,[88] and dea d polar bear cubs have been found in brown bear dens.[89] Wolves are rarely enco untered by polar bears, though there are two records of wolf packs killing polar bear cubs.[90] Polar bears are sometimes the host of arctic mites such as Alask ozetes antarcticus.[52] Long distance swimmer The Canadian Journal of Zoology tracked 52 sows in the southern Beaufort Sea off Alaska with GPS system collars; no boars were involved in the study due to male s' necks being too thick for the GPS-equipped collars. Fifty long-distance swims were recorded; the longest at 354 kilometres (220 mi), with an average of 155 k ilometres (96 mi). The length of these swims ranged from most of a day to ten da ys. Ten of the sows had a cub swim with them and after a year six cubs survived. The study did not determine if the others lost their cubs before, during, or so me time after their long swims. Researchers do not know whether or not this is a new behavior; Before polar ice shrinkage, they opined that there was probably n either the need nor opportunity to swim such long distances.[91] Hunting Indigenous people Skins of hunted polar bears in Ittoqqortoormiit, Greenland Polar bears have long provided important raw materials for Arctic peoples, inclu ding the Inuit, Yupik, Chukchi, Nenets, Russian Pomors and others. Hunters commo nly used teams of dogs to distract the bear, allowing the hunter to spear the be ar or shoot it with arrows at closer range.[92] Almost all parts of captured ani mals had a use.[93] The fur was used in particular to sew trousers and, by the N enets, to make galoshes-like outer footwear called tobok; the meat is edible, de

spite some risk of trichinosis; the fat was used in food and as a fuel for light ing homes, alongside seal and whale blubber; sinews were used as thread for sewi ng clothes; the gallbladder and sometimes heart were dried and powdered for medi cinal purposes; the large canine teeth were highly valued as talismans.[94] Only the liver was not used, as its high concentration of vitamin A is poisonous.[95 ] Hunters make sure to either toss the liver into the sea or bury it in order to spare their dogs from potential poisoning.[94] Traditional subsistence hunting was on a small enough scale to not significantly affect polar bear populations, mostly because of the sparseness of the human population in polar bear habitat.[ 96] History of commercial harvest In Russia, polar bear furs were already being commercially traded in the 14th ce ntury, though it was of low value compared to Arctic Fox or even reindeer fur.[9 4] The growth of the human population in the Eurasian Arctic in the 16th and 17t h century, together with the advent of firearms and increasing trade, dramatical ly increased the harvest of polar bears.[45][97] However, since polar bear fur h as always played a marginal commercial role, data on the historical harvest is f ragmentary. It is known, for example, that already in the winter of 1784/1785 Ru ssian Pomors on Spitsbergen harvested 150 polar bears in Magdalenefjorden.[94] I n the early 20th century, Norwegian hunters were harvesting 300 bears a year at the same location. Estimates of total historical harvest suggest that from the b eginning of the 18th century, roughly 400 to 500 animals were being harvested an nually in northern Eurasia, reaching a peak of 1,300 to 1,500 animals in the ear ly 20th century, and falling off as the numbers began dwindling.[94] In the first half of the 20th century, mechanized and overpoweringly efficient m ethods of hunting and trapping came into use in North America as well.[98] Polar bears were chased from snowmobiles, icebreakers, and airplanes, the latter prac tice described in a 1965 New York Times editorial as being "about as sporting as machine gunning a cow."[98] The numbers taken grew rapidly in the 1960s, peakin g around 1968 with a global total of 1,250 bears that year.[99] Contemporary regulations A road sign on Svalbard, warning about the presence of polar bears. Concerns over the future survival of the species led to the development of natio nal regulations on polar bear hunting, beginning in the mid-1950s. The Soviet Un ion banned all hunting in 1956. Canada began imposing hunting quotas in 1968. No rway passed a series of increasingly strict regulations from 1965 to 1973, and h as completely banned hunting since then. The United States began regulating hunt ing in 1971 and adopted the Marine Mammal Protection Act in 1972. In 1973, the I nternational Agreement on the Conservation of Polar Bears was signed by all five nations whose territory is inhabited by polar bears: Canada, Denmark, Norway, t he Soviet Union, and the United States. Member countries agreed to place restric tions on recreational and commercial hunting, ban hunting from aircraft and iceb reakers, and conduct further research.[100] The treaty allows hunting "by local people using traditional methods". Norway is the only country of the five in whi ch all harvest of polar bears is banned. The agreement was a rare case of intern ational cooperation during the Cold War. Biologist Ian Stirling commented, "For many years, the conservation of polar bears was the only subject in the entire A rctic that nations from both sides of the Iron Curtain could agree upon sufficie ntly to sign an agreement. Such was the intensity of human fascination with this magnificent predator, the only marine bear."[101] Agreements have been made between countries to co-manage their shared polar bear subpopulations. After several years of negotiations, Russia and the United Stat es signed an agreement in October 2000 to jointly set quotas for indigenous subs istence hunting in Alaska and Chukotka.[102] The treaty was ratified in October 2007.[103] Russia

The Soviet Union banned the harvest of polar bears in 1956, however poaching con tinued and is believed to pose a serious threat to the polar bear population.[29 ] In recent years, polar bears have approached coastal villages in Chukotka more frequently due to the shrinking of the sea ice, endangering humans and raising concerns that illegal hunting would become even more prevalent.[104] In 2007, th e Russian government made subsistence hunting legal for Chukotka natives only, a move supported by Russia's most prominent bear researchers and the World Wide F und for Nature as a means to curb poaching.[104] Greenland In Greenland, hunting restrictions were first introduced in 1994 and expanded by executive order in 2005.[29] Until 2005 Greenland placed no limit on hunting by indigenous people. However, in 2006 it imposed a limit of 150, while also allow ed recreational hunting for the first time.[105] Other provisions included yearround protection of cubs and mothers, restrictions on weapons used, and various administrative requirements to catalogue kills.[29] Canada Dogsleds are used for recreational hunting of polar bears in Canada. Use of moto rized vehicles is forbidden. About 500 bears are killed per year by humans across Canada,[106] a rate believe d by scientists to be unsustainable for some areas, notably Baffin Bay.[28] Cana da has allowed sport hunters accompanied by local guides and dog-sled teams sinc e 1970,[107] but the practice was not common until the 1980s.[108] The guiding o f sport hunters provides meaningful employment and an important source of income for native communities in which economic opportunities are few.[31] Sport hunti ng can bring CDN$20,000 to $35,000 per bear into northern communities, which unt il recently has been mostly from American hunters.[109] The territory of Nunavut accounts for the location 80% of annual kills in Canada .[106] In 2005, the government of Nunavut increased the quota from 400 to 518 be ars,[109] despite protests from some scientific groups.[110] In two areas where harvest levels have been increased based on increased sightings, science-based s tudies have indicated declining populations, and a third area is considered data -deficient.[111] While most of that quota is hunted by the indigenous Inuit peop le, a growing share is sold to recreational hunters. (0.8% in the 1970s, 7.1% in the 1980s, and 14.6% in the 1990s)[108] Nunavut polar bear biologist, Mitchell Taylor, who was formerly responsible for polar bear conservation in the territor y, insists that bear numbers are being sustained under current hunting limits.[1 12] In 2010, the 2005 increase was partially reversed. Government of Nunavut off icials announced that the polar bear quota for the Baffin Bay region would be gr adually reduced from 105 per year to 65 by the year 2013.[113] The Government of the Northwest Territories maintain their own quota of 72 to 103 bears within th e Inuvialuit communities of which some are set aside for sports hunters.[citatio n needed] Environment Canada also banned the export from Canada of fur, claws, s kulls and other products from polar bears harvested in Baffin Bay as of 1 Januar y 2010.[113] Because of the way polar bear hunting quotas are managed in Canada, attempts to discourage sport hunting would actually increase the number of bears killed in t he short term.[31] Canada allocates a certain number of permits each year to spo rt and subsistence hunting, and those that are not used for sport hunting are re -allocated to Native subsistence hunting. Whereas Native communities kill all th e polar bears they are permitted to take each year, only half of sport hunters w ith permits actually manage to kill a polar bear. If a sport hunter does not kil l a polar bear before his or her permit expires, the permit cannot be transferre d to another hunter.[31] United States

The Marine Mammal Protection Act of 1972 afforded polar bears some protection in the United States. It banned hunting (except by indigenous substinence hunters) , banned importing of poar bear parts (except polar bear pelts taken legally in Canada), and banned the harassment of polar bears. On 15 May 2008, the United St ates department of Interior listed the polar bear as a threatened species under the Endangered Species Act and banned all importing of polar bear trophies. Impo rting products made from polar bears had been prohibited from 1972 to 1994 under the Marine Mammal Protection Act, and restricted between 1994 and 2008. Under t hose restrictions, permits from the United States Fish and Wildlife Service (FWS ) were required to import sport-hunted polar bear trophies taken in hunting expe ditions in Canada. The permit process required that the bear be taken from an ar ea with quotas based on sound management principles.[114] Since 1994, more than 800 sport-hunted polar bear trophies have been imported into the U.S.[115] Conservation status, efforts and controversies This map from the U.S. Geological Survey shows projected changes in polar bear h abitat from 2001 to 2010 and 2041 to 2050. Red areas indicate loss of optimal po lar bear habitat; blue areas indicate gain. As of 2008, the World Conservation Union (IUCN) reports that the global populati on of polar bears is 20,000 to 25,000, and is declining.[1] In 2006, the IUCN up graded the polar bear from a species of least concern to a vulnerable species.[1 16] It cited a "suspected population reduction of >30% within three generations (45 years)", due primarily to climate change.[7] Other risks to the polar bear i nclude pollution in the form of toxic contaminants, conflicts with shipping, str esses from recreational polar-bear watching, and oil and gas exploration and dev elopment.[7] The IUCN also cited a "potential risk of over-harvest" through lega l and illegal hunting.[7] According to the World Wildlife Fund, the polar bear is important as an indicato r of arctic ecosystem health. Polar bears are studied to gain understanding of w hat is happening throughout the Arctic, because at-risk polar bears are often a sign of something wrong with the arctic marine ecosystem.[117] Climate change The IUCN, Arctic Climate Impact Assessment, United States Geological Survey and many leading polar bear biologists have expressed grave concerns about the impac t of climate change, including the belief that the current warming trend imperil s the survival of the species.[27][118][119][120][121][122] The key danger posed by climate change is malnutrition or starvation due to habi tat loss. Polar bears hunt seals from a platform of sea ice. Rising temperatures cause the sea ice to melt earlier in the year, driving the bears to shore befor e they have built sufficient fat reserves to survive the period of scarce food i n the late summer and early fall.[83] Reduction in sea-ice cover also forces bea rs to swim longer distances, which further depletes their energy stores and occa sionally leads to drowning.[123] Thinner sea ice tends to deform more easily, wh ich appears to make it more difficult for polar bears to access seals.[56] Insuf ficient nourishment leads to lower reproductive rates in adult females and lower survival rates in cubs and juvenile bears, in addition to poorer body condition in bears of all ages.[27] Mothers and cubs have high nutritional requirements, which are not met if the se al-hunting season is too short. In addition to creating nutritional stress, a warming climate is expected to aff ect various other aspects of polar bear life: Changes in sea ice affect the abil ity of pregnant females to build suitable maternity dens.[24] As the distance in creases between the pack ice and the coast, females must swim longer distances t o reach favored denning areas on land.[27] Thawing of permafrost would affect th e bears who traditionally den underground, and warm winters could result in den roofs collapsing or having reduced insulative value.[27] For the polar bears tha

t currently den on multi-year ice, increased ice mobility may result in longer d istances for mothers and young cubs to walk when they return to seal-hunting are as in the spring.[27] Disease-causing bacteria and parasites would flourish more readily in a warmer climate.[56] Problematic interactions between polar bears and humans, such as foraging by bea rs in garbage dumps, have historically been more prevalent in years when ice-flo e breakup occurred early and local polar bears were relatively thin.[118] Increa sed human-bear interactions, including fatal attacks on humans, are likely to in crease as the sea ice shrinks and hungry bears try to find food on land.[118][12 4] A polar bear swimming The effects of climate change are most profound in the southern part of the pola r bear's range, and this is indeed where significant degradation of local popula tions has been observed.[122] The Western Hudson Bay subpopulation, in a souther n part of the range, also happens to be one of the best-studied polar bear subpo pulations. This subpopulation feeds heavily on ringed seals in late spring, when newly weaned and easily hunted seal pups are abundant.[111] The late spring hun ting season ends for polar bears when the ice begins to melt and break up, and t hey fast or eat little during the summer until the sea freezes again.[111] Due to warming air temperatures, ice-floe breakup in western Hudson Bay is curre ntly occurring three weeks earlier than it did 30 years ago, reducing the durati on of the polar bear feeding season.[111] The body condition of polar bears has declined during this period; the average weight of lone (and likely pregnant) fe male polar bears was approximately 290 kg (640 lb) in 1980 and 230 kg (510 lb) i n 2004.[111] Between 1987 and 2004, the Western Hudson Bay population declined b y 22%.[125] In Alaska, the effects of sea ice shrinkage have contributed to higher mortality rates in polar bear cubs, and have led to changes in the denning locations of p regnant females.[82][126] In recent years, polar bears in the Arctic have undert aken longer than usual swims to find prey, resulting in four recorded drownings in the unusually large ice pack regression of 2005.[123] Pollution Polar bears accumulate high levels of persistent organic pollutants such as poly chlorinated biphenyl (PCBs) and chlorinated pesticides. Due to their position at the top of the food pyramid, with a diet heavy in blubber in which halocarbons concentrate, their bodies are among the most contaminated of Arctic mammals.[127 ] Halocarbons are known to be toxic to other animals, because they mimic hormone chemistry, and biomarkers such as immunoglobulin G and retinol suggest similar effects on polar bears. PCBs have received the most study, and they have been as sociated with birth defects and immune system deficiency.[128] The most notorious of these chemicals, such as PCBs and DDT, have been internati onally banned. Their concentrations in polar bear tissues continued to rise for decades after the ban as these chemicals spread through the food chain. But the trend seems to have abated, with tissue concentrations of PCBs declining between studies performed from 1989 to 1993 and studies performed from 1996 to 2002.[12 9] Oil and gas development German stamp depicting Knut and the slogan "Preserve nature worldwide" Oil and gas development in polar bear habitat can affect the bears in a variety of ways. An oil spill in the Arctic would most likely concentrate in the areas w here polar bears and their prey are also concentrated, such as sea ice leads.[7] Because polar bears rely partly on their fur for insulation and soiling of the fur by oil reduces its insulative value, oil spills put bears at risk of dying f

rom hypothermia.[62] Polar bears exposed to oil spill conditions have been obser ved to lick the oil from their fur, leading to fatal kidney failure.[62] Materni ty dens, used by pregnant females and by females with infants, can also be distu rbed by nearby oil exploration and development. Disturbance of these sensitive s ites may trigger the mother to abandon her den prematurely, or abandon her litte r altogether.[7] Predictions The U.S. Geological Survey predicts two-thirds of the world's polar bears will d isappear by 2050, based on moderate projections for the shrinking of summer sea ice caused by climate change.[56] The bears would disappear from Europe, Asia, a nd Alaska, and be depleted from the Arctic archipelago of Canada and areas off t he northern Greenland coast. By 2080, they would disappear from Greenland entire ly and from the northern Canadian coast, leaving only dwindling numbers in the i nterior Arctic archipelago.[56] Predictions vary on the extent to which polar bears could adapt to climate chang e by switching to terrestrial food sources. Mitchell Taylor, who was director of Wildlife Research for the Government of Nunavut, wrote to the U.S. Fish and Wil dlife Service arguing that local studies are insufficient evidence for global pr otection at this time. The letter stated, "At present, the polar bear is one of the best managed of the large Arctic mammals. If all Arctic nations continue to abide by the terms and intent of the Polar Bear Agreement, the future of polar b ears is secure ... Clearly polar bears can adapt to climate change. They have ev olved and persisted for thousands of years in a period characterized by fluctuat ing climate."[112] Ken Taylor, deputy commissioner for the Alaska Department of Fish and Game, has said, "I wouldn't be surprised if polar bears learned to feed on spawning salmon like grizzly bears."[31] However, many scientists consider these theories to be naive;[31] it is noted th at black and brown bears at high latitudes are smaller than elsewhere, because o f the scarcity of terrestrial food resources.[111] An additional risk to the spe cies is that if individuals spend more time on land, they will hybridize with br own or grizzly bears.[122] The IUCN wrote: Polar bears exhibit low reproductive rates with long generational spans. The se factors make facultative adaptation by polar bears to significantly reduced i ce coverage scenarios unlikely. Polar bears did adapt to warmer climate periods of the past. Due to their long generation time and the current greater speed of climate change, it seems unlikely that polar bear will be able to adapt to the c urrent warming trend in the Arctic. If climatic trends continue polar bears may become extirpated from most of their range within 100 years.[7] Controversy over species protection Polar bear at Central Park Zoo, New York City, USA Warnings about the future of the polar bear are often contrasted with the fact t hat worldwide population estimates have increased over the past 50 years and are relatively stable today.[130][131] Some estimates of the global population are around 5,000 to 10,000 in the early 1970s;[132] other estimates were 20,000 to 4 0,000 during the 1980s.[34][45] Current estimates put the global population at b etween 20,000 and 25,000.[29] There are several reasons for the apparent discordance between past and projecte d population trends: Estimates from the 1950s and 1960s were based on stories fr om explorers and hunters rather than on scientific surveys.[133][134] Second, co ntrols of harvesting were introduced that allowed this previously overhunted spe cies to recover.[133] Third, the recent effects of climate change have affected sea ice abundance in different areas to varying degrees.[133] Finally, the predi ction methods used to predict the decline in the future population of bear bears

excluded key forecasting principles and included unquestionable assumptions.[13 5] Debate over the listing of the polar bear under endangered species legislation h as put conservation groups and Canada's Inuit at opposing positions;[31] the Nun avut government and many northern residents have condemned the U.S. initiative t o list the polar bear under the Endangered Species Act.[136][137] Many Inuit bel ieve the polar bear population is increasing, and restrictions on sport-hunting are likely to lead to a loss of income to their communities.[31][138] U.S. endangered species legislation On 14 May 2008 the U.S. Department of the Interior listed the polar bear as a th reatened species under the Endangered Species Act, citing the melting of Arctic sea ice as the primary threat to the polar bear.[139] While listing the polar be ar as a threatened species, the Interior Department added a seldom-used stipulat ion to allow oil and gas exploration and development to proceed in areas inhabit ed by polar bears, provided companies continue to comply with the existing restr ictions of the Marine Mammal Protection Act. The main new protection for polar b ears under the terms of the listing is that hunters will no longer be able to im port trophies from the hunting of polar bears in Canada.[140] The ruling followed several years of controversy. On 17 February 2005 the Center for Biological Diversity filed a petition asking that the polar bear be listed under the Endangered Species Act. An agreement was reached and filed in Federal district court on 5 June 2006. On 9 January 2007, the United States Fish and Wil dlife Service proposed to list the polar bear as a threatened species. A final d ecision was required by law by 9 January 2008, at which time the agency said it needed another month. On 7 March 2008, the inspector general of the U.S. Departm ent of the Interior began a preliminary investigation into why the decision had been delayed for nearly two months. The investigation is in response to a letter signed by six environmental groups that United States Fish and Wildlife Directo r Dale Hall violated the agency's scientific code of conduct by delaying the dec ision unnecessarily, allowing the government to proceed with an auction for oil and gas leases in the Alaska's Chukchi Sea, an area of key habitat for polar bea rs. The auction took place in early February 2008.[141] An editorial in The New York Times said that "these two moves are almost certainly, and cynically, relat ed."[31][142] Hall denied any political interference in the decision and said th at the delay was needed to make sure the decision was in a form easily understoo d.[141] On 28 April 2008, a Federal court ruled that a decision on the listing m ust be made by 15 May 2008;[143] the decision came on 14 May to make the polar b ear a protected species.[140] On 18 July 2011, Charles Monnett, whose work was cited by the United States Fish and Wildlife Service in its decision to list the polar bear as threatened under the Endangered Species Act, was suspended from his work at the Bureau of Ocean Energy Management, Regulation and Enforcement.[144] Investigators are reviewing Monnett's research methods as well as the significance he attached to his discov ery in 2004 of polar bear carcasses in the Arctic, but supporters argue that the investigation is essentially "a smear campaign" against Monnett.[145] Upon listing the polar bear under the Endangered species act, the Department of the Interior immediately issued a statement that the listing could not be used t o regulate greenhouse gas emissions,[139] although some policy analysts believe that the Endangered Species Act can be used to restrict the issuing of federal p ermits for projects that would threaten the polar bear by increasing greenhouse gas emissions.[139] Environmental groups have pledged to go to court to have the Endangered Species Act interpreted in such a way.[139] On 8 May 2009, the new a dministration of Barack Obama announced that it would continue the policy.[146] The polar bear is only the third species, after the elkhorn coral and the stagho rn coral protected under the Endangered Species Act due to climate change.[citat

ion needed] On 4 August 2008, the state of Alaska sued U.S. Interior Secretary D irk Kempthorne, seeking to reverse the listing of the polar bear as a threatened species out of concern that the listing would adversely affect oil and gas deve lopment in the state. Alaska Governor Sarah Palin said that the listing was not based on the best scientific and commercial data available, a view rejected by p olar bear experts.[147]. In March 2013, a United States Appeals Court ruling uph eld the "threatened" status of the polar bear against a challenge led by the Sta te of Alaska.[148] Canadian endangered species legislation In Canada, the Committee on the Status of Endangered Wildlife in Canada recommen ded in April 2008 that the polar bear be assessed as a species of special concer n under the federal Species at Risk Act (SARA). A listing would mandate that a m anagement plan be written within five years, a timeline criticized by the World Wide Fund for Nature as being too long to prevent significant habitat loss from climate change.[149] In culture This engraving, made by Chukchi carvers in the 1940s on a walrus tusk, depicts p olar bears hunting walrus. Indigenous folklore For the indigenous peoples of the Arctic, polar bears have long played an import ant cultural and material role.[93][94] Polar bear remains have been found at hu nting sites dating to 2,500 to 3,000 years ago[96] and 1,500 year old cave paint ings of polar bears have been found in the Chukchi Peninsula.[94] Indeed, it has been suggested that Arctic peoples' skills in seal hunting and igloo constructi on has been in part acquired from the polar bears themselves.[94] The Inuit and Eskimos have many folk tales featuring the bears including legends in which bears are humans when inside their own houses and put on bear hides wh en going outside, and stories of how the constellation which is said to resemble a great bear surrounded by dogs came into being.[92] These legends reveal a dee p respect for the polar bear, which is portrayed as both spiritually powerful an d closely akin to humans.[92] The human-like posture of bears when standing and sitting, and the resemblance of a skinned bear carcass to the human body, have p robably contributed to the belief that the spirits of humans and bears were inte rchangeable.[92] Eskimo legends tell of humans learning to hunt from the polar b ear. For the Inuit of Labrador, the polar bear is a form of the Great Spirit, Tu urngasuk.[150] Among the Chukchi and Yupik of eastern Siberia, there was a longstanding shamani stic ritual of "thanksgiving" to the hunted polar bear. After killing the animal , its head and skin were removed and cleaned and brought into the home, a feast was held in the hunting camp in its honor. In order to appease the spirit of the bear, there were traditional song and drum music and the skull would be ceremon ially fed and offered a pipe.[151] Only once the spirit was appeased would the s kull be separated from the skin, taken beyond the bounds of the homestead, and p laced in the ground, facing north.[94] Many of these traditions have faded somew hat in time, especially in light of the total hunting ban in the Soviet Union (a nd now Russia) since 1955. The Nenets of north-central Siberia placed particular value on the talismanic po wer of the prominent canine teeth. They were traded in the villages of the lower Yenisei and Khatanga rivers to the forest-dwelling peoples further south, who w ould sew them into their hats as protection against brown bears. It was believed that the "little nephew" (the brown bear) would not dare to attack a man wearin g the tooth of its powerful "big uncle" (the polar bear).[94] The skulls of kill ed polar bears were buried at specific sacred sites and altars, called sedyangi, were constructed out of the skulls. Several such sites have been preserved on t he Yamal Peninsula.[94]

Symbols and mascots Coat of arms of the Chukotka Autonomous Okrug in the Russian Federation. Coat of arms of the Greenlandic Self-Rule government (Kalaallit Nunaat). Their distinctive appearance and their association with the Arctic have made pol ar bears popular icons, especially in those areas where they are native. The Can adian Toonie (two-dollar coin) features the image of a polar bear and both the N orthwest Territories and Nunavut license plates in Canada are in the shape of a polar bear. The polar bear is the mascot of Bowdoin College in Maine and the Uni versity of Alaska Fairbanks (see also Alaska Nanooks) and was chosen as mascot f or the 1988 Winter Olympics held in Calgary. Companies such as Coca-Cola, Polar Beverages, Nelvana, Bundaberg Rum or Good Hum or-Breyers have used images of the polar bear in advertising,[152] while Fox's G lacier Mints have featured a polar bear named Peppy as the brand mascot since 19 22. Literature Polar bears are also popular in fiction, particularly in books aimed at children or young adults. For example, The Polar Bear Son is adapted from a traditional Inuit tale.[153] Polar bears feature prominently in East (also released as North Child) by Edith Pattou, The Bear by Raymond Briggs, and Chris d'Lacey's The Fir e Within series. The panserbjørne of Philip Pullman's fantasy trilogy His Dark Mat erials are sapient, dignified polar bears who exhibit anthropomorphic qualities, and feature prominently in the 2007 film adaptation of The Golden Compass. See also Portal icon Animals portal Portal icon Arctic portal Polar Bears International Arctic National Wildlife Refuge List of solitary animals Notes ^ a b c Schliebe et al. (2008). Ursus maritimus. IUCN Red List of Threatened Species. Retrieved 5 January 2010. ^ Phipps, pg. 185 ^ "Polar bear, (Ursus maritimus)" (PDF). United States Fish and Wildlife ser vice. Retrieved 9 September 2009. "Appearance. The polar bear is the largest mem ber of the bear family, with the exception of Alaska's Kodiak brown bears, which equal polar bears in size." (Overview page) ^ Kindersley, Dorling (2001, 2005). Animal. New York City: DK Publishing. IS BN 0-7894-7764-5. ^ Gunderson, Aren (2007). "Ursus Maritimus". Animal Diversity Web. Universit y of Michigan Museum of Zoology. Retrieved 27 October 2007. ^ a b IUCN Polar Bear Specialist Group, 2009.15th meeting of PBSG in Copenha gen, Denmark 2009: Press Release. Retrieved 10 January 2010. ^ a b c d e f g IUCN SSC Polar Bear Specialist Group (2008). "Ursus maritimu s". IUCN Red List of Threatened Species. Version 2010.3. International Union for Conservation of Nature. Retrieved 25 August 2010. Database entry includes a len gthy justification of why this species is listed as vulnerable. ^ Kidd, D.A. (1973). Collins Latin Gem Dictionary. London: Collins. ISBN 0-0 0-458641-7. ^ The Marine Mammal Center ^ The Arctic Sounder[dead link] ^ The fourth world: the heritage of the Arctic and its destruction, Sam Hall , Vintage Books, 1988, pp. 29, 232. ^ "??????????????? ??????? Piotr Czerwinski Oshkuy". Nicomant.fils.us.edu.pl

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lar Bears International Newsletter. Polar Bears International. Archived from the original on 26 June 2008. Retrieved 9 June 2008. ^ Dough O'Harra Polar bears, grizzlies increasingly gather on North Slope. A nchorage Daily News. 24 April 2005 ^ "ABC News: Grizzlies Encroaching on Polar Bear Country". ABC News. Retriev ed 10 October 2009. ^ "Wolf (Canis lupus) Predation of a Polar Bear (Ursus maritimus) Cub on the Sea Ice off Northwestern Banks Island, Northwest Territories, Canada. ARCTIC Vo l. 59, No. 3 (September 2006) p. 322 324" (PDF). Retrieved 20 March 2011. ^ Rosen, Yereth (1 May 2012). "Polar bears can swim vast distances, study fi nds". Reuters. Retrieved 8 May 2012. ^ a b c d Stirling, Ian (1988). "The Original Polar Bear Watchers". Polar Be ars. Ann Arbor: University of Michigan Press. ISBN 0-472-10100-5. ^ a b Lockwood, pp. 6 9 ^ a b c d e f g h i j k Uspensky, Savva Mikhailovich (1977). ????? ??????? ( tr: Belyi Medved') (in Russian). Moscow: Nauka. ^ As a carnivore which feeds largely upon fish-eating carnivores, the polar bear ingests large amounts of vitamin A, which is stored in their livers. The re sulting high concentrations cause Hypervitaminosis A, Rodahl, K.; Moore, T. (194 3). "The vitamin A content and toxicity of bear and seal liver". The Biochemical Journal 37 (2): 166 168. PMC 1257872. PMID 16747610. ^ a b Lockwood, pp. 31 36 ^ "Polar Bear Management". Government of the Northwest Territories. Archived from the original on 4 May 2008. Retrieved 14 March 2008. ^ a b Bruemmer, pp. 93 111 ^ "Proceedings of the 2nd Working Meeting of Polar Bear Specialists". Polar Bears. Morges, Switzerland: IUCN. February 1970. Archived from the original on 4 May 2008. Retrieved 24 October 2007. ^ International Agreement on the Conservation of Polar Bears, 15 November 19 73, Oslo ^ Stirling, Ian Foreword in Rosing, Norbert (1996). The World of the Polar B ear. Willowdale, ON: Firefly Books Ltd.. ISBN 1-55209-068-X. ^ "U.S. and Russia Sign Pact To Protect the Polar Bear". The New York Times. 17 October 2000. Retrieved 12 April 2008. ^ "US-Russia Polar Bear Treaty Ratified". ScienceDaily. 18 October 2007. Ret rieved 12 April 2008. ^ a b Steven Lee Myers (16 April 2007). "Russia Tries to Save Polar Bears Wi th Legal Hunt". The New York Times. Retrieved 12 April 2008. ^ Naomi A. Rose Hitting Polar Bears When They Are Down. The Humane Society o f the United States. 16 February 2006 ^ a b Aaars, pp. 101 116 ^ Freeman, M.M.R.; Wenzel, G.W. (March 2006). "The nature and significance o f polar bear conservation hunting in the Canadian Arctic". Arctic 59 (1): 21 30. ^ a b Wenzel, George W. (September 2004). "Polar Bear as a Resource: An Over view" (PDF). Yellowknife: 3rd NRF Open Meeting. Retrieved 3 December 2007. ^ a b "Nunavut hunters can kill more polar bears this year". CBC News. 10 Ja nuary 2005. Retrieved 15 September 2007. ^ "Rethink polar bear hunt quotas, scientists tell Nunavut hunters". CBC New s. 4 July 2005. Retrieved 20 March 2011. ^ a b c d e f Stirling, Ian; Derocher, Andrew E. (2007). "Melting Under Pres sure: The Real Scoop on Climate Warming and Polar Bears" (PDF). The Wildlife Pro fessional 1 (3): 24 27, 43. Fall 2007. Retrieved 17 November 2007. ^ a b Taylor, Mitchell K. (6 April 2006) (PDF). Review of CBD Petition. Lett er to the U.S. Fish and Wildlife Service. Retrieved 8 September 2007. ^ a b George, Jane (April 2010). "Nunavut hunters still enraged over bear qu otas". Iqaluit. Retrieved 4 April 2010. ^ "Bear Facts: Harvesting/Hunting". Polar Bears International. Retrieved 14 March 2008. ^ The Humane Society of the United States "Support the Polar Bear Protection Act"

^ "Release of the 2006 IUCN Red List of Threatened Species reveals ongoing d ecline of the status of plants and animals". World Conservation Union. Archived from the original on 12 May 2006. Retrieved 1 February 2006. ^ WWF: A Leader in Polar Bear Conservation . Retrieved 29 June 2009, from WF F Polar Bear Web site: http://www.worldwildlife.org/species/finder/polarbear/pol arbear.html# ^ a b c Stirling, Ian; and Claire L. Parkinson (September 2006). "Possible E ffects of Climate Warming on Selected Populations of Polar Bears (Ursus maritimu s) in the Canadian Arctic" (PDF). Arctic 59 (3): 261 275. ISSN 0004-0843. Retrieve d 15 September 2007. ^ Stirling, Ian; N.J. Lunn, John Iacozza, Campbell Elliott and Martyn Obbard (March 2004). "Polar Bear Distribution and Abundance on the Southwestern Hudson Bay Coast During Open Water Season, in Relation to Population Trends and Annual Ice Patterns" (PDF). Arctic 57 (1): 15 26. ISSN 0004-0843. Retrieved 15 September 2007. ^ Barber, D.G.; J. Iacozza (March 2004). "Historical analysis of sea ice con ditions in M'Clintock Channel and the Gulf of Boothia, Nunavut: implications for ringed seal and polar bear habitat" (PDF). Arctic 57 (1): 1 14. ISSN 0004-0843. ^ T. Appenzeller and D. R. Dimick, "The Heat is On," National Geographic 206 (2004): 2 75. cited in Flannery, Tim (2005). The Weather Makers. Toronto, Ontario : HarperCollins. pp. 101 103. ISBN 0-00-200751-7. ^ a b c Arctic Climate Impact Assessment (2004). Impact of a Warming Arctic: Arctic Impact Climate Assessment. Cambridge: Cambridge University Press. ISBN 0 -521-61778-2. OCLC 56942125.. The relevant paper is Key Finding 4 ^ a b Monnett, Charles; Gleason, Jeffrey S. (July 2006). "Observations of mo rtality associated with extended open-water swimming by polar bears in the Alask an Beaufort Sea". Polar Biology 29 (8): 681 687. doi:10.1007/s00300-005-0105-2. ^ Mitchell Taylor, a former polar bear researcher for the Nunavut government , believes that arctic warming has been caused by natural phenomena and is not a long-term threat to the polar bear. After his retirement, he was not re-appoint ed to the international Polar Bear Specialist Group (PBSG), giving rise to specu lation that he was excluded from the group because of his views on climate chang e. According to the PBSG chair, appointments to the PBSG are given to scientists who are currently active in polar bear research, and that as a retired research er Taylor did not qualify. (References: Booker, Christopher (27 June 2009). "Pol ar bear expert barred by global warmists". The Daily Telegraph (London). Retriev ed 12 August 2009.) ^ Regehr, E. V.; Lunn, N. J.; Amstrup, N. C.; Stirling, I. (2007). "Effects of earlier sea ice breakup on survival and population size of polar bears in wes tern Hudson Bay". Journal of Wildlife Management 71 (8): 2673 2683. doi:10.2193/20 06-180. ^ The proportion of maternity dens on sea ice has changed from 62% between t he years 1985 through 1994, to 37% over the years 1998 through 2004. Thus now th e Alaskan population more resembles the world population in that it is more like ly to den on land. Fischbach, A. S.; Amstrup, S. C.; Douglas, D. C. (2007). "Lan dward and eastward shift of Alaskan polar bear denning associated with recent se a ice changes". Polar Biology 30 (11): 1395 1405. doi:10.1007/s00300-007-0300-4. ^ "Polar Bears at the Top of POPs". The Science and the Environment Bulletin . Environment Canada. May/June 2000. Retrieved 20 October 2008. ^ Skaare, Janneche Utne et al. (2002). "Ecological risk assessment of persis tent organic pollutants in the arctic" (PDF). Toxicology 181 182: 193 197. doi:10.10 16/S0300-483X(02)00280-9. PMID 12505309. Archived from the original on 3 March 2 010. Retrieved 17 November 2007. ^ Verreault, Jonathan et al. (2005). "Chlorinated hydrocarbon contaminants a nd metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenl and, and Svalbard: 1996 2002" (PDF). Science of the Total Environment 351 352: 369 390 . doi:10.1016/j.scitotenv.2004.10.031. PMID 16115663. Archived from the original on 3 March 2010. Retrieved 17 November 2007. ^ "Marine Mammals Management: Polar Bear". U.S. Fish and Wildlife Service, A laska. Retrieved 9 June 2008.

^ "WWF Polar bear status, distribution & population". World Wildlife Foundat ion. Retrieved 22 March 2010. ^ Krauss, Clifford (27 May 2006). "Bear Hunting Caught in Global Warming Deb ate". The New York Times. Retrieved 11 March 2008. ^ a b c Derocher, Andrew. "Ask the Experts: Are Polar Bear Populations Incre asing?". Polar Bears International. Retrieved 9 March 2008. ^ Bruemmer, p. 101. In a meeting of the five circumpolar nations on 6 Septem ber 1965, estimates of the worldwide population ranged from 5,000 to 19,000. "Th e truth was, no one knew... Scientific research had been sketchy and knowledge o f the polar bear was based largely on stories brought back by explorers and hunt ers." ^ J. Scott Armstrong and Kesten C. Greene and Willie Soon (2008). "Polar Bea r Population Forecasts: A Public-Policy Forecasting Audit". Interfaces (INFORMS) 38 (5): 382 405. ^ "Nunavut MLAs condemn U.S. proposal to make polar bears threatened species ". CBC News. 4 June 2007. Retrieved 15 September 2007. ^ "Inuit reject U.S. Polar Bear Proposal". CBC News. 21 June 2007. Retrieved 15 September 2007. ^ Northern Research Forum. Polar Bear as a Resource. A position paper presen ted for the 3rd NRF Open Meeting in Yellowknife and Rae Edzo, Canada. 15 18 Septem ber 2004 ^ a b c d Hassett, Kevin A (23 May 2008). "Bush's polar bear legal disaster" . National Post. Archived from the original on 29 May 2008. Retrieved 7 June 200 8. ^ a b Barringer, Felicity (15 May 2008). "Polar Bear Is Made a Protected Spe cies". The New York Times. Retrieved 7 June 2008. ^ a b Hebert, H. Josef (8 March 2008). "Delay in polar bear policy stirs pro be". San Francisco Chronicle. Retrieved 9 March 2008. ^ Editorial (15 January 2008). "Regulatory Games and the Polar Bear". The Ne w York Times. Retrieved 20 October 2008. ^ Biello, David (30 April 2008). "Court Orders U.S. to Stop Keeping Polar Be ar Status on Ice". Scientific American News. Retrieved 8 June 2008. ^ Efstathiou, Jim (28 July 2011). "Scientist Who Reported Polar Bears Drowni ng Is Suspended by U.S. Agency". Bloomberg News. Retrieved 14 August 2011. ^ Goldenberg, Suzanne (29 July 2011). "Arctic scientist suspended over 'inte grity issues'". The Guardian. Retrieved 14 August 2011. ^ U.S. to keep Bush administration rule on polar bears, McClatchy Newspapers , 8 May 2009 ^ Joling, Dan (5 August 2008). "Alaska sues over listing polar bear as threa tened". The Globe and Mail. Retrieved 29 August 2008. ^ Kendall, Brent (2 3 March 2013). "Court Upholds Polar Bears As 'Threatened' Species" (paper). The Wall Street Journal: p. A2. ^ Brach, Bal (25 April 2008). "Experts seek more protection for polar bears" . Canwest News Service. Retrieved 9 May 2008. ^ balisunset, (2008, 8 22). The Bear in Myth, Mythology and Folklore. Retrie ved 29 June 2009 ^ Kochnev AA, Etylin VM, Kavry VI, Siv-Siv EB, Tanko IV (17 19 December 2002). Ritual Rites and Customs of the Natives of Chukotka connected with the Polar Be ar. Preliminary report submitted for the meeting of the Alaska Nanuuq Commission (Nome, Alaska, USA). pp. 1 3. ^ "Bundaberg Rum Web site history section". Bundaberg Rum Web site. Retrieve d 26 March 2008. ^ Dabcovich, Lydia (1997). The Polar Bear Son: An Inuit Tale. New York: Clar ion Books. ISBN 0-395-72766-9. References Aars, Jon, ed. (June 2005) (PDF). Polar Bears. 32. 14th Working Meeting of t he IUCN/SSC Polar Bear Specialist Group, Nicholas J. Lunn and Andrew E. Derocher . Seattle, Washington, United States: IUCN. ISBN 2-8317-0959-8. Archived from th

e original on 9 April 2008. Retrieved 19 April 2008. Bruemmer, Fred (1989). World of the Polar Bear. Toronto, Ontario, Canada: Ke y Porter Books. ISBN 1-55013-107-9. Hemstock, Annie (1999). The Polar Bear. Manakato, MN: Capstone Press. ISBN 0 -7368-0031-X. Lockwood, Sophie (2006). Polar Bears. Chanhassen, MN: The Child's World. ISB N 1-59296-501-6. Matthews, Downs (1993). Polar Bear. San Francisco, CA: Chronicle Books. ISBN 978-0-8118-0204-8. Phipps, John (1774). A voyage towards the North Pole undertaken by His Majes ty's command, 1773. London: W. Bowyer and J. Nicols, for J. Nourse. Retrieved 8 September 2008. Rosing, Norbert (1996). The World of the Polar Bear. Willowdale, ON: Firefly Books Ltd.. ISBN 1-55209-068-X. External links Wikimedia Commons has media related to: Ursus maritimus Wikispecies has information related to: Ursus maritimus View occurrences of Ursus maritimus in Biodiversity Heritage Library. National Wildlife Federation's Polar Bear Page ARKive images and movies of the polar bear (Ursus maritimus) Smithsonian National Museum of Natural History species account-Polar Bear USGS Polar Bear Studies Map of polar bear ranges and denning areas in Nunavut from Nunavut Planning Commission BBC Nature: Polar bear news, and video clips from BBC programmes past and pr esent. Photos, facts, videos from Polar Bears International which funds population, preservation and DNA studies of the polar bear [show] v t e Extant Carnivora species Categories: IUCN Red List vulnerable species Polar bears Animals described in 1774 Bears Fauna of Greenland Fauna of the Arctic Inuit culture Mammals of Asia Mammals of Canada Mammals of Europe Mammals of the Arctic Mammals of the United States Megafauna of Eurasia Megafauna of North America Vulnerable fauna of the United States Vulnerable animals Wildlife of Siberia Mammals of Norway

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