polar bear - wikipedia, the free encyclopedia

8/9/2019 Polar Bear - Wikipedia, The Free Encyclopedia

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Polar bear

Polar bear.

Conservation status

Vulnerable (IUCN 3.1)[1]

Scientific classification

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: CarnivoraFamily: Ursidae

Genus: Ursus

Species: U. mari timus

Binomial name

Ur sus mari timus

Phipps, 1774[2]

Polar bear range

Synonyms

Polar bearFrom Wikipedia, the free encyclopedia

Thepolar bear (Ursus maritimus ) is a carnivorous bear whose nativerange lies largely within the Arctic Circle, encompassing the ArcticOcean, its surrounding seas and surrounding land masses. It is a large bear, approximately the same size as the omnivorous Kodiak bear (Ursus arctos middendorffi ).[3] A boar (adult male) weighs around350–700 kg (770–1,540 lb),[4] while a sow (adult female) is abouthalf that size. Although it is the sister species of the brown bear,[5] ithas evolved to occupy a narrower ecological niche, with many bodycharacteristics adapted for cold temperatures, for moving acrosssnow, ice, and open water, and for hunting the seals which make upmost of its diet.[6] Although most polar bears are born on land, theyspend most of their time at sea. Their scientific name means"maritime bear", and derives from this fact. Polar bears hunt their

preferred food of seals from the edge of sea ice, often living off fatreserves when no sea ice is present.

The polar bear is classified as a vulnerable species, with eight of thenineteen polar bear subpopulations in decline.[7] For decades, largescale hunting raised international concern for the future of the species but populations rebounded after controls and quotas began to takeeffect. For thousands of years, the polar bear has been a key figure inthe material, spiritual, and cultural life of Arctic indigenous peoples,and polar bears remain important in their cultures.

Contents

1 Naming and etymology2 Taxonomy and evolution3 Population and distribution4 Habitat5 Biology and behavior

5.1 Physical characteristics5.2 Hunting and diet

6 Dietary flexibility6.1 Behavior 6.2 Reproduction and lifecycle

6.2.1 Maternity denning and early life6.2.2 Later life6.2.3 Life expectancy

6.3 Ecological role6.4 Long distance swimmer

ar bear - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Pol

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Ursus eogroenlandicusUrsus groenlandicusUrsus jenaensisUrsus labradorensisUrsus marinusUrsus polaris

Ursus spitzbergensisUrsus ungavensisThalarctos maritimus

7 Hunting7.1 Indigenous people7.2 History of commercial harvest7.3 Contemporary regulations

7.3.1 Russia

7.3.2 Greenland7.3.3 Canada7.3.4 United States

8 Conservation status, efforts and controversies8.1 Climate change8.2 Pollution8.3 Oil and gas development8.4 Predictions

8.5 Controversy over species protection9 Protection in the Noth America

9.1 U.S. Marine Mammal Protection Act9.2 U.S. Endangered Species Act9.3 Canadian endangered species legislation

10 In culture10.1 Indigenous folklore10.2 Symbols and mascots10.3 Fiction

11 See also12 Notes13 References14 External links

Naming and etymology

Constantine John Phipps was the first to describe the polar bear as a distinct species in 1774.[1] He chose thescientific nameUrsus maritimus , the Latin for ’maritime bear’,[8] due to the animal’s native habitat. The Inuitrefer to the animal asnanook [9] (transliterated asnanuq in the Inupiat language).[10] The Yupik also refer tothe bear asnanuuk in Siberian Yupik.[11] The bear isumka in the Chukchi language. In Russian, it is usuallycalled белый медведь (bélyj medvédj , the white bear), though an older word still in use is ошкуй (Oshkúj ,which comes from the Komioski , "bear").[12] In French, the polar bear is referred to asours blanc ("white bear") or ours polaire ("polar bear").[13] In the Norwegian-administered Svalbard archipelago, the polar bear is referred to as Isbjørn ("ice bear").

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 recent evolutionary divergence of the two speciesdoes not support the establishment of this separate genus, and the accepted scientific name is now thereforUrsus maritimus , as Phipps originally proposed.[1]


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Polar bears have evolved adaptationsfor Arctic life, for example, largefurry feet and short, sharp, stockyclaws give them good traction on ice.

Taxonomy and evolution

The bear family, Ursidae, is believed to have split off from other carnivorans about 38 million years ago.[15] The Ursinae subfamilyoriginated approximately 4.2 million years ago.[16] The oldest known polar bear fossil is a 130,000 to 110,000-year-old jaw bone, found on

Prince Charles Foreland in 2004.[17]

Fossils show that between ten totwenty thousand years ago, the polar bear’s molar teeth changedsignificantly from those of the brown bear.[18] Polar bears are thoughtto have diverged from a population of brown bears that becameisolated during a period of glaciation in the Pleistocene[19] or fromthe eastern part of Siberia, (from Kamchatka and the KolymPeninsula).[20]

The evidence from DNA analysis is more complex. Themitochondrial DNA (mtDNA) of the polar bear diverged from the

brown bear,Ursus arctos , roughly 150,000 years ago.[17]

Further, some clades of brown bear, as assessed bytheir mtDNA, are more closely related to polar bears than to other brown bears,[21] meaning that the polar bear would not be a true species according to some species concepts.[22] The mtDNA of Irish brown bears is particularly close to polar bears.[23] A comparison of the nuclear genome of polar bears with that of brown bears revealed a different pattern, the two forming genetically distinct clades that diverged approximately603,000 years ago,[24] although the latest research is based on analysis of the complete genomes (rather thanust the mitochondria or partial nuclear genomes) of polar, brown and black bears, and establishes the

divergence of polar and brown bears at 4–5 million years ago.[25]

However, the two species have mated intermittently for all that time, most likely coming into contact with

each other during warming periods, when polar bears were driven onto land and brown bears migratednorthward. Most brown bears have about 2 percent genetic material from polar bears, but one populationresiding in the Alexander Archipelago has between 5 percent and 10 percent polar bear genes, indicatingmore frequent and recent mating.[26] Polar bears can breed with brown bears to produce fertile grizzly–polar bear hybrids,[19][27] rather than indicating that they have only recently diverged, the new evidence suggestsmore frequent mating has continued over a longer period of time, and thus the two bears remain geneticallsimilar.[26] However, because neither species can survive long in the other’s ecological niche, and becausethey have different morphology, metabolism, social and feeding behaviors, and other phenotypiccharacteristics, the two bears are generally classified as separate species.[28]

When the polar bear was originally documented, two subspecies were identified:Ursus maritimus maritimus by Constantine J. Phipps in 1774, andUrsus maritimus marinus by Peter Simon Pallas in 1776.[29] Thisdistinction has since been invalidated. One fossil subspecies has been identified.Ursus maritimustyrannus — descended fromUrsus arctos — became extinct during the Pleistocene.U.m. tyrannus wassignificantly larger than the living subspecies.[19]

Population and distribution

The polar bear is found in the Arctic Circle and adjacent land masses as far south as Newfoundland IslandDue to the absence of human development in its remote habitat, it retains more of its original range than another extant carnivore.[30] While they are rare north of 88°, there is evidence that they range all the wayacross the Arctic, and as far south as James Bay in Canada. Their southernmost range is near the boundary between the subarctic and humid continental climate zones. They can occasionally drift widely with the seice, and there have been anecdotal sightings as far south as Berlevåg on the Norwegian mainland and the


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Polar bears investigate the submarineUSS Honolulu 450 kilometres(280 mi) from the North Pole.

Polar bears play-fighting

Polar bear jumping on fast ice

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 poorlystudied; however, biologists use a working estimate of about 20,000to 25,000 polar bears worldwide.[1][31]

There are 19 generally recognized, discrete subpopulations.[31][32]

The subpopulations display seasonal fidelity to particular areas, but

DNA studies show that they are not reproductively isolated.[33] Thethirteen North American subpopulations range from the Beaufort Seasouth to Hudson Bay and east to Baffin Bay in western Greenland andaccount for about 70% of the global population. The Eurasian population is broken up into the eastern Greenland, Barents Sea, KaraSea, Laptev Sea, and Chukchi Sea subpopulations, though there isconsiderable 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, the United States (Alaska)and Canada. These five nations are the signatories of the InternationalAgreement on the Conservation of Polar Bears, which mandatescooperation on research and conservations efforts throughout the polar bear’s range.

Modern methods of tracking polar bear populations have beenimplemented only since the mid-1980s, and are expensive to performconsistently over a large area.[34] The most accurate counts requireflying a helicopter in the Arctic climate to find polar bears, shooting atranquilizer dart at the bear to sedate it, and then tagging the bear.[34]

In Nunavut, some Inuit have reported increases in bear sightings around human settlements in recent yearsleading to a belief that populations are increasing. Scientists have responded by noting that hungry bears m be congregating around human settlements, leading to the illusion that populations are higher than theyactually are.[34] 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 traditionalecological knowledge without supporting scientific studies."[35]

Of the 19 recognized polar bear subpopulations, eight are declining, three are stable, one is increasing, andseven have insufficient data, as of 2009.[7][31]

Habitat

The polar bear is a marine mammal because it spends many monthsof the year at sea.[36] However, it is the only living "marine mammal"with powerful, large limbs and feet that allow them to cover miles onfoot and run on land.[37] Its preferred habitat is the annual sea icecovering 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.[30][38]

The polar bear tends to frequent areas wheresea ice meets water, such as polynyas and leads (temporary stretchesof open water in Arctic ice), to hunt the seals that make up most of itsdiet.[39] 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


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Skull, as illustrated by N. N.

Kondakov

Polar bear skeleton

Captive polar bear swimming

low.[40]

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.[38] In Hudson Bay, JamesBay, 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.[38] In theChukchi and Beaufort seas, polar bears retreat each summer to the ice further north that remains frozen

year-round.

Biology and behavior

Physical characteristics

The only other bear of a similar size to the polar bear is the Kodiak bear,which is a subspecies of brown bear.[41] Adult male polar bears weigh350–700 kg (770–1,540 lb) and measure 2.4–3 metres (7 ft 10 in–9 ft 10 in)

in total length.[42]

The Guinness Book of World Records listed the averagemale as having a body mass of 385 to 410 kg (849 to 904 lb) and a shoulder height of 133 cm (4 ft 4 in), slightly smaller than the average cited for maleKodiak bears.[43] Around the Beaufort Sea, however, mature malesreportedly average 450 kg (1,000 lb).[44] Adult females are roughly half thesize of males and normally weigh 150–250 kg (330–550 lb), measuring1.8–2.4 metres (5 ft 11 in–7 ft 10 in) in length. Elsewhere, a slightly larger estimated average weight of 260 kg (570 lb) was claimed for adultfemales.[45] When pregnant, however, females can weigh as much as 500 kg(1,100 lb).[42] The polar bear is among the most sexually dimorphic of

mammals, surpassed only by the pinnipeds such as elephant seals.[46] Thelargest polar bear on record, reportedly weighing 1,002 kg (2,209 lb),was a male shot at Kotzebue Sound in northwestern Alaska in1960.[43] This specimen, when mounted, stood 3.39 m (11 ft 1 in) tallon its hindlegs.[43] The shoulder height of an adult polar bear is 122to 160 cm (4 ft 0 in to 5 ft 3 in).[43][47] While all bears are short-tailed, the polar bear’s tail is relatively the shortest amongst living bears, ranging from 7 to 13 cm (2.8 to 5.1 in) in length.[48]

Compared with its closest relative, the brown bear, the polar bear hasa more elongated body build and a longer skull and nose.[28] As predicted by Allen’s rule for a northerly animal, the legs are stockyand the ears and tail are small.[28] However, the feet are very large todistribute load when walking on snow or thin ice and to provide propulsion when swimming; they may measure 30 cm (12 in) acrossin an adult.[49] The pads of the paws are covered with small, soft papillae (dermal bumps) which provide traction on the ice.[28] The polar bear’s claws are short and stocky compared to those of the brown bear, perhaps to serve the former’s need to grip heavy prey andice.[28] The claws are deeply scooped on the underside to assist indigging in the ice of the natural habitat. Research of injury patterns in polar bear forelimbs found injuries tthe right forelimb to be more frequent than those to the left, suggesting, perhaps, right-handedness.[50]

Unlike the brown bear, polar bears in captivity are rarely overweight or particularly large, possibly as areaction to the warm conditions of most zoos.


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The long muzzle and neck of the polar bear help it to search in deepholes for seals, while powerfulhindquarters enable it to drag massive prey.[62]

The 42 teeth of a polar bear reflect its highly carnivorous diet.[28] The cheek teeth are smaller and moreagged than in the brown bear, and the canines are larger and sharper.[28] The dental formula is3.1.4.2

3.1.4.3[28]

Polar bears are superbly insulated by up to 10 cm (4 in) of blubber,[49] their hide and their fur; they overheatat temperatures above 10 °C (50 °F), and are nearly invisible under infrared photography.[51] Polar bear fur consists of a layer of dense underfur and an outer layer of guard hairs, which appear white to tan but areactually transparent.[49] The guard hair is 5–15 cm (2–6 in) over most of the body.[52] Polar bears graduallymoult from May to August,[53] but, unlike other Arctic mammals, they do not shed their coat for a darker shade to camouflage themselves in the summer conditions. The hollow guard hairs of a polar bear coat weonce thought to act as fiber-optic tubes to conduct light to its black skin, where it could be absorbed;however, this theory was disproven by recent studies.[54]

The white coat usually yellows with age. When kept in captivity in warm, humid conditions, the fur may ta pale shade of green due to algae growing inside the guard hairs.[55] Males have significantly longer hairson their forelegs, which increase in length until the bear reaches 14 years of age. The male’s ornamentalforeleg hair is thought to attract females, serving a similar function to the lion’s mane.[56]

The polar bear has an extremely well developed sense of smell, being able to detect seals nearly 1.6 km(1 mi) away and buried under 1 m (3 ft) of snow.[57] Its hearing is about as acute as that of a human, and itsvision is also good at long distances.[57]

The polar bear is an excellent swimmer and often will swim for days.[58] One bear swam continuously for 9days in the frigid Bering Sea for 400 mi (687 km) to reach ice far from land. She then traveled another 1,100 mi (1,800 km)[59] With its body fat providing buoyancy, the bear swims in a dog paddle fashion usingits large forepaws for propulsion.[60] 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 mph).[60] When

sprinting, they can reach up to 40 km/h (25 mph).[61]

Hunting and diet

The polar bear is the most carnivorous member of the bear family,and throughout most of its range, its diet primarily consists of ringed( Pusa hispida ) and bearded seals ( Erignathus barbatus ).[63] TheArctic is home to millions of seals, which become prey when theysurface in holes in the ice in order to breathe, or when they haul outon the ice to rest.[62][64] Polar bears hunt primarily at the interface

between ice, water, and air; they only rarely catch seals on land or inopen water.[65]

The polar bear’s most common hunting method is called still-hunting :[66] The bear uses its excellent sense of smell to locate a seal breathing hole, and crouches nearby in silence for a seal to appear.The bear may lay in wait for several hours. When the seal exhales, the bear smells its breath, reaches into the hole with a forepaw, and dragsit out onto the ice. The polar bear kills the seal by biting its head tocrush its skull. The polar bear also hunts by stalking seals resting on the ice: Upon spotting a seal, it walks

within 90 m (100 yd), and then crouches. If the seal does not notice, the bear creeps to within 9 to 12 m (3to 40 ft) of the seal and then suddenly rushes forth to attack.[62] A third hunting method is to raid the birthlairs that female seals create in the snow.[66]

A widespread legend tells that polar bears cover their black noses with their paws when hunting. This


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Polar bear at a whale carcass

behavior, if it happens, is rare – although the story exists in native oral history and in accounts by earlyArctic explorers, there is no record of an eyewitness account of the behavior in recent decades.[60]

Mature bears tend to eat only the calorie-rich skin and blubber of the seal,which are highly digestible,[67] whereas younger bears consume the protein-rich red meat.[62] Studies have also photographed polar bears scalingnear-vertical cliffs, to eat birds’ chicks and eggs.[68][69][70] For subadult bearswhich are independent of their mother but have not yet gained enoughexperience and body size to successfully hunt seals, scavenging the carcassesfrom other bears’ kills is an important source of nutrition. Subadults may also be forced to accept a half-eaten carcass if they kill a seal but cannot defend itfrom larger polar bears. After feeding, polar bears wash themselves withwater or snow.[60]

The polar bear is perhaps unequaled by any other living land predator in itsenormous physical power. However, its primary prey species, the ringed seal,

is much smaller than itself, and many of the seals hunted are pups rather than adults. Ringed seals are born

weighing 5.4 kg (12 lb) and grown to an estimated average weight of only 60 kg (130 lb).[71][72]

They also in places prey heavily upon the harp seal ( Pusa groenlandica ) or the harbor seal.[73] The bearded seal, on theother hand, can be nearly the same size as the bear itself, averaging 270 kg (600 lb).[72] Adult male beardedseals, at 350 to 500 kg (770 to 1,100 lb) are believed to be too large for a female bear to overtake,[74] and soare potential prey only for mature male bears.[75] Enormously powerful large males also occasionally attemptto hunt and kill even larger prey items.[76] It can kill an adult walrus (Odobenus rosmarus ),[73][77] althoughthis is rarely attempted. At up to 2,000 kg (4,400 lb) and a typical adult mass range of 600 to 1,500 kg (1,3to 3,300 lb), a walrus can be more than twice the bear’s weight,[78] and has up to 1-metre (3 ft)-long ivorytusks that can be used as formidable weapons. A polar bear may charge a group of walruses, with the goal separating a young, infirm, or injured walrus from the pod. They will even attack adult walruses when theidiving holes have frozen over or intercept them before they can get back to the diving hole in the ice. Yet, polar bears will very seldom attack full-grown adult walruses, with the largest male walrus probablyinvulnerable unless otherwise injured or incapacitated. Since an attack on a walrus tends to be an extremel protracted and exhausting venture, bears have been known to back down from the attack after making theinitial injury to the walrus.[79] Polar bears have also been seen to prey on beluga whales ( Delphinapterusleucas )[73] and narwhals ( Monodon monoceros ),[73] 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.[80][81] Most terrestrial animals in theArctic can outrun the polar bear on land as polar bears 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 thecarcasses of dead adult walruses or whales, whose blubber is readily devoured even when rotten.[82] Polar bears sometimes like to go fishing where they swim underwater to catch fish like the arctic charr or theFourhorn sculpin.[64]

With the exception of pregnant females, polar bears are active year-round,[83] although they have a vestigialhibernation induction trigger in their blood. Unlike brown and black bears, polar bears are capable of fastifor up to several months during late summer and early fall, when they cannot hunt for seals because the seunfrozen.[83] When sea ice is unavailable during summer and early autumn, some populations live off fatreserves for months at a time.[51] Being both curious animals and scavengers,[78][84] polar bears investigateand consume garbage where they come into contact with humans.[73][78] Polar bears may attempt to consume

almost anything they can find, including hazardous substances such as styrofoam, plastic, car batteries,ethylene glycol, hydraulic fluid, and motor oil.[78][84] The dump in Churchill, Manitoba was closed in 2006to protect bears, and waste is now recycled or transported to Thompson, Manitoba.[85][86]


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Some characteristic postures:1. – at rest;

2. – at an estimated reaction;3. – when feeding

Dietary flexibility

Although seal predation is the primary and an indispensable way of life for most polar bears, when alternatives are present they are quiteflexible. Polar bears will consume a wide variety of other wild foods,including muskox (Ovibos moschatus ), reindeer ( Rangifer tarandus ),.[87] birds, eggs, rodents, crabs, other crustaceans and other polar bears. They may also eat plants,.[87] including berries, roots,and kelp,[87] however none of these are a significant part of their diet,[78] except that beachcast marine mammal carcasses are anexception.[88] When stalking land animals, such as muskox,reindeer.[87] and even willow ptarmigan ( Lagopus lagopus ), polar bears appear to make use of vegetative cover and wind direction to bring them as close to their prey as possible before attacking. Polar bears have been observed to hunt the small Svalbard reindeer ( R. t.

latyrhynchus ), which weigh only 40 to 60 kg (90 to 130 lb) as

adults, as well as the Barren-ground caribou ( R. t. groenlandicus ),which is about twice as heavy as that.[89][90][91] Adult muskox, whichcan weigh 450 kg (1,000 lb) or more, are a more formidablequarry.[92] Although ungulates are not typical prey, the killing of oneduring the summer months can greatly increase the odds of survival during that lean period. Like the brow bear, most ungulate prey of polar bears is likely to be young, sickly or injured specimens rather than healthadults.[90] The polar bear’s biology is specialized to require large amounts of fat from marine mammals, andit cannot derive sufficient caloric intake from terrestrial food.[93][94]

In their southern range, especially near Hudson Bay and James Bay Canada polar bears live all summer

without sea ice.[87] Here their food ecology shows their dietary flexibility. They still manage to consumesome seals, but they are food-deprived in summer as only marine mammal carcasses are an importantalternative without sea ice,[95] especially carcasses of the bowhead whale.[96] These alternatives may reducethe rate of weight loss of bears when on land.[97] One scientist found that 71% of the Hudson Bay bears hadfed on seaweed (marine algae) and that about half were feeding on birds[73] like sea ducks, especially theoldsquaw (53%), common eider, long-tailed duck or dovekieby swimming underwater to catch them. Theywere also diving to feed on blue mussels and other underwater food sources like the green sea urchin. 24%had eaten moss recently, 19% had consumed grass, 34% had eaten black crowberry and about half hadconsumed willows.[87] This study illustrates the polar bear’s dietary flexibility but it does not represent its lifhistory elsewhere. Most polar bears elsewhere will never have access to these alternatives, except for themarine mammal carcasses that are important wherever they occur.

Behavior

Unlike grizzly bears, polar bears are not territorial. Although stereotyped as being voraciously aggressive,they are normally cautious in confrontations, and often choose to escape rather than fight.[98] Satiated polar bears rarely attack humans unless severely provoked. However, due to their lack of prior human interactiohungry polar bears are extremely unpredictable, fearless towards people and are known to kill and sometimeat humans.[82] Many attacks by brown bears are the result of surprising the animal, which is not the casewith the polar bear. Polar bears are stealth hunters, and the victim is often unaware of the bear’s presenceuntil the attack is underway.[99] Whereas brown bears often maul a person and then leave, polar bear attacksare more likely to be predatory and are almost always fatal.[99] However, due to the very small human population around the Arctic, such attacks are rare. Michio Hoshino, a Japanese wildlife photographer, waonce pursued briefly by a hungry male polar bear in northern Alaska. According to Hoshino, the bear start


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Polar bear males frequently play-fight. During the mating season,actual fighting is intense and oftenleaves scars or broken teeth.

Cubs are born helpless and typicallynurse for two and a half years

Female emerging from her maternity den

running but Hoshino made it to his truck. The bear was able to reachthe truck and tore one of the doors off the truck before Hoshino wasable to drive off.[100]

In general, adult polar bears live solitary lives. Yet, they have often been seen playing together for hours at a time and even sleeping in anembrace,[82] and polar bear zoologist Nikita Ovsianikov has

described adult males as having "well-developed friendships."[98]Cubs are especially playful as well. Among young males in particular, play-fighting may be a means of practicing for serious competitionduring mating seasons later in life.[101] Polar bears have a wide rangeof vocalisations, including bellows, roars, growls, chuffs and purrs.[102]

In 1992, a photographer near Churchill took a now widely circulatedset of photographs of a polar bear playing with a Canadian EskimoDog (Canis lupus familiaris ) a tenth of its size.[103][104] The pair wrestled harmlessly together each afternoon

for ten days in a row for no apparent reason, although the bear may have been trying to demonstrate itsfriendliness in the hope of sharing the kennel’s food.[103] This kind of social interaction is uncommon; it isfar more typical for polar bears to behave aggressively towards dogs.[103]

Reproduction and lifecycle

Courtship and mating take place on the sea ice in April and May,when polar bears congregate in the best seal hunting areas.[105] Amale may follow the tracks of a breeding female for 100 km (60 mi)or more, and after finding her engage in intense fighting with other males over mating rights, fights which often result in scars and broken teeth.[105] Polar bears have a generally polygynous matingsystem; recent genetic testing of mothers and cubs, however, hasuncovered cases of litters in which cubs have different fathers.[106]

Partners stay together and mate repeatedly for an entire week; themating ritual induces ovulation in the female.[107]

After mating, the fertilized egg remains in a suspended state until August or September. During these four months, the pregnant female eats prodigious amounts of food, gaining at least 200 kg (440 lb) and oftenmore than doubling her body weight.[105]

Maternity denning and early life

When the ice floes break up in the fall, ending the possibility of hunting,each pregnant female digs amaternity den consisting of a narrow entrancetunnel leading to one to three chambers.[105] Most maternity dens are insnowdrifts, but may also be made underground in permafrost if it is notsufficiently cold yet for snow.[105] In most subpopulations, maternity densare situated on land a few kilometers from the coast, and the individuals in asubpopulation tend to reuse the same denning areas each year.[30] The polar bears that do not den on land make their dens on the sea ice. In the den, sheenters a dormant state similar to hibernation. This hibernation-like state doesnot consist of continuous sleeping; however, the bear’s heart rate slows from46 to 27 beats per minute.[108] Her body temperature does not decrease during this period as it would for a


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Cub nursing

typical mammal in hibernation.[51][109]

Between November and February, cubs are born blind, covered with a light down fur, and weighing less th0.9 kg (2.0 lb),[107] but in captivity they might be delivered in the earlier months. The earliest recorded birthof polar bears in captivity was on 11 October 2011 in the Toronto Zoo.[110] On average, each litter has twocubs.[105] The family remains in the den until mid-February to mid-April, with the mother maintaining her fast while nursing her cubs on a fat-rich milk.[105] By the time the mother breaks open the entrance to theden, her cubs weigh about 10 to 15 kilograms (22 to 33 lb).[105] For about 12 to 15 days, the family spendstime outside the den while remaining in its vicinity, the mother grazing on vegetation while the cubs becomused to walking and playing.[105] Then they begin the long walk from the denning area to the sea ice, wherethe mother can once again catch seals.[105] Depending on the timing of ice-floe breakup in the fall, she mayhave fasted for up to eight months.[105]

Cubs may fall prey to wolvesor to starvation. Female polar bears arenoted for both their affection towards their offspring, and their valiance in protecting them. One case of adoption of a wild cub has been confirmed by genetic testing.[106] Adult male bears occasionallykill and eat polar bear cubs,[111] for reasons that are unclear.[112] Asof 2006, in Alaska, 42% of cubs now reach 12 months of age, downfrom 65% 15 years ago.[113] In most areas, cubs are weaned at twoand a half years of age,[105] when the mother chases them away or abandons them. The western coast of Hudson Bay is unusual in thatits female polar bears sometimes wean their cubs at only one and ahalf years.[105] This was the case for 40% of cubs there in the early1980s; however by the 1990s, fewer than 20% of cubs were weaned this young.[114] After the mother leaves,sibling cubs sometimes travel and share food together for weeks or months.[82]

Later life

Females begin to breed at the age of four years in most areas, and five years in the Beaufort Sea area.[105]

Males usually reach sexual maturity at six years; however, as competition for females is fierce, many do no breed until the age of eight or ten.[105] A study in Hudson Bay indicated that both the reproductive successand the maternal weight of females peaked in their mid-teens.[115]

Polar bears appear to be less affected by infectious diseases and parasites than most terrestrial mammals.[112]

Polar bears are especially susceptible toTrichinella , a parasitic roundworm they contract throughcannibalism,[116] although infections are usually not fatal.[112] Only one case of a polar bear with rabies has been documented, even though polar bears frequently interact with Arctic foxes, which often carryrabies.[112] Bacterial Leptospirosis and Morbillivirus have been 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.[117] The oldest wild bears on record died at age 32, whereas theoldest captive was a female who died in 1991, age 43.[118] The causes of death in wild adult polar bears are

poorly understood, as carcasses are rarely found in the species’s frigid habitat.[112]

In the wild, old polar bears eventually become too weak to catch food, and gradually starve to death. Polar bears injured in fightor accidents may either die from their injuries or become unable to hunt effectively, leading to starvation.[112]


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Skins of hunted polar bears

Ecological role

The polar bear is the apex predator within its range. Several animal species, particularly Arctic Foxes (Vulpeslagopus ) and Glaucous Gulls ( Larus hyperboreus ), routinely scavenge polar bear kills.[60]

The relationship between ringed seals and polar bears is so close that the abundance of ringed seals in somareas appears to regulate the density of polar bears, while polar bear predation in turn regulates density and

reproductive success of ringed seals.[65] The evolutionary pressure of polar bear predation on seals probablyaccounts for some significant differences between Arctic and Antarctic seals. Compared to the Antarctic,where there is no major surface predator, Arctic seals use more breathing holes per individual, appear morrestless when hauled out on the ice, and rarely defecate on the ice.[60] The baby fur of most Arctic sealspecies is white, presumably to provide camouflage from predators, whereas Antarctic seals all have dark at birth.[60]

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 disputesover carcasses,[119] and dead polar bear cubs have been found in brown bear dens.[120]Wolves are rarely

encountered by polar bears, though there are two records of Arctic wolf (Canis lupus arctos ) packs killing polar bear cubs.[121] A rather unlikely killer of a grown polar bear has reportedly included a wolverine (Guloulo ), anecedotely reported to have suffocated a bear with a bite to the throat during a conflict over food.[122]

Polar bears are sometimes the host of arctic mites such as Alaskozetes antarcticus .[60]

Long distance swimmer

Researchers tracked 52 sows in the southern Beaufort Sea off Alaska with GPS system collars; no boars winvolved in the study due to males’ necks being too thick for the GPS-equipped collars. Fifty long-distanceswims were recorded; the longest at 354 kilometres (220 mi), with an average of 155 kilometres (96 mi). Tlength of these swims ranged from most of a day to ten days. Ten of the sows had a cub swim with them anafter a year six cubs survived. The study did not determine if the others lost their cubs before, during, or some 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 neither the need nor opportunity to swim such londistances.[123]

Hunting

Indigenous people

Polar bears have long provided important raw materials for Arctic peoples, including the Inuit, Yupik, Chukchi, Nenets, Russian Pomorsand others. Hunters commonly used teams of dogs to distract the bear, allowing the hunter to spear the bear or shoot it with arrows atcloser range.[124] Almost all parts of captured animals had a use.[125]

The fur was used in particular to sew trousers and, by the Nenets, tomake galoshes-like outer footwear calledtobok ; the meat is edible,despite some risk of trichinosis; the fat was used in food and as a fuelfor lighting homes, alongside seal and whale blubber; sinews wereused as thread for sewing clothes; the gallbladder and sometimesheart were dried and powdered for medicinal purposes; the largecanine teeth were highly valued as talismans.[126] Only the liver was not used, as its high concentration of vitamin A is poisonous.[127] Hunters make sure to either toss the liver into the sea or bury it in order to sparetheir dogs from potential poisoning.[126] Traditional subsistence hunting was on a small enough scale to not


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Road sign warning about the presenceof polar bears

significantly affect polar bear populations, mostly because of the sparseness of the human population in po bear habitat.[128]

History of commercial harvest

In Russia, polar bear furs were already being commercially traded in the 14th century, though it was of lowvalue compared to Arctic Fox or even reindeer fur.[126] The growth of the human population in the EurasianArctic in the 16th and 17th century, together with the advent of firearms and increasing trade, dramaticallyincreased the harvest of polar bears.[51][129] However, since polar bear fur has always played a marginalcommercial role, data on the historical harvest is fragmentary. It is known, for example, that already in thewinter of 1784/1785 Russian Pomors on Spitsbergen harvested 150 polar bears in Magdalenefjorden.[126] Inthe early 20th century, Norwegian hunters were harvesting 300 bears a year at the same location. Estimatesof total historical harvest suggest that from the beginning of the 18th century, roughly 400 to 500 animalswere being harvested annually in northern Eurasia, reaching a peak of 1,300 to 1,500 animals in the early20th century, and falling off as the numbers began dwindling.[126]

In the first half of the 20th century, mechanized and overpoweringly efficient methods of hunting andtrapping came into use in North America as well.[130] Polar bears were chased from snowmobiles,icebreakers, and airplanes, the latter practice described in a 1965 New York Times editorial as being "about assporting as machine gunning a cow."[130] The numbers taken grew rapidly in the 1960s, peaking around 1968with a global total of 1,250 bears that year.[131]

Contemporary regulations

Concerns over the future survival of the species led to thedevelopment of national regulations on polar bear hunting, beginningin the mid-1950s. The Soviet Union banned all hunting in 1956.Canada began imposing hunting quotas in 1968. Norway passed aseries of increasingly strict regulations from 1965 to 1973, and hascompletely banned hunting since then. The United States beganregulating hunting in 1971 and adopted the Marine MammalProtection Act in 1972. In 1973, the International Agreement on theConservation of Polar Bears was signed by all five nations whoseterritory is inhabited by polar bears: Canada, Denmark, Norway, theSoviet Union, and the United States. Member countries agreed to place restrictions on recreational and commercial hunting, banhunting from aircraft and icebreakers, and conduct further research.[132] The treaty allows hunting "by local people using traditional methods". Norway is the only country of the five in which all harvest of polar beais banned. The agreement was a rare case of international cooperation during the Cold War. Biologist IanStirling commented, "For many years, the conservation of polar bears was the only subject in the entireArctic that nations from both sides of the Iron Curtain could agree upon sufficiently to sign an agreement.Such was the intensity of human fascination with this magnificent predator, the only marine bear."[133]

Agreements have been made between countries to co-manage their shared polar bear subpopulations. Afteseveral years of negotiations, Russia and the United States signed an agreement in October 2000 to jointlyset quotas for indigenous subsistence hunting in Alaska and Chukotka.[134] The treaty was ratified in October 2007.[135]

Russia

The Soviet Union banned the harvest of polar bears in 1956, however poaching continued and is believed


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Dogsleds are used for recreational

hunting of polar bears in Canada. Useof motorized vehicles is forbidden.

pose a serious threat to the polar bear population.[32] In recent years, polar bears have approached coastalvillages in Chukotka more frequently due to the shrinking of the sea ice, endangering humans and raisingconcerns that illegal hunting would become even more prevalent.[136] In 2007, the Russian government madesubsistence hunting legal for Chukotka natives only, a move supported by Russia’s most prominent bear researchers and the World Wide Fund for Nature as a means to curb poaching.[136]

Greenland

In Greenland, hunting restrictions were first introduced in 1994 and expanded by executive order in 2005.[32]

Until 2005 Greenland placed no limit on hunting by indigenous people. However, in 2006 it imposed a limof 150, while also allowed recreational hunting for the first time.[137] Other provisions included year-round protection of cubs and mothers, restrictions on weapons used, and various administrative requirements tocatalogue kills.[32]

Canada

About 500 bears are killed per year by humans across Canada,[138]

arate believed by scientists to be unsustainable for some areas, notablyBaffin Bay.[31] Canada has allowed sport hunters accompanied bylocal guides and dog-sled teams since 1970,[139] but the practice wasnot common until the 1980s.[140] The guiding of sport hunters provides meaningful employment and an important source of incomefor native communities in which economic opportunities are few.[34]

Sport hunting can bring CDN$20,000 to $35,000 per bear intonorthern communities, which until recently has been mostly fromAmerican hunters.[141]

The territory of Nunavut accounts for the location 80% of annual killsin Canada.[138] In 2005, the government of Nunavut increased thequota from 400 to 518 bears,[141] despite protests from some scientific groups.[142] In two areas whereharvest levels have been increased based on increased sightings, science-based studies have indicateddeclining populations, and a third area is considered data-deficient.[143] While most of that quota is hunted by the indigenous Inuit people, a growing share is sold to recreational hunters. (0.8% in the 1970s, 7.1% inthe 1980s, and 14.6% in the 1990s)[140] Nunavut polar bear biologist, Mitchell Taylor, who was formerlyresponsible for polar bear conservation in the territory, insists that bear numbers are being sustained under current hunting limits.[144] In 2010, the 2005 increase was partially reversed. Government of Nunavutofficials announced that the polar bear quota for the Baffin Bay region would be gradually reduced from 1 per year to 65 by the year 2013.[145] The Government of the Northwest Territories maintain their own quotaof 72 to 103 bears within the Inuvialuit communities of which some are set aside for sports hunters.Environment Canada also banned the export from Canada of fur, claws, skulls and other products from po bears harvested in Baffin Bay as of 1 January 2010.[145]

Because of the way polar bear hunting quotas are managed in Canada, attempts to discourage sport huntinwould actually increase the number of bears killed in the short term.[34] Canada allocates a certain number of permits each year to sport and subsistence hunting, and those that are not used for sport hunting arere-allocated to Native subsistence hunting. Whereas Native communities kill all the polar bears they are permitted to take each year, only half of sport hunters with permits actually manage to kill a polar bear. If sport hunter does not kill a polar bear before his or her permit expires, the permit cannot be transferred toanother hunter.[34]


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This map from the U.S. Geological Survey shows projected changes in polar bear habitat from 2001 to2010 and 2041 to 2050. Red areas indicate loss of optimal polar bear habitat; blue areas indicate gain.

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 polar bear parts (except polar bear pelts taken legally in Canada), and banned the harassment of polar bears. On 15 May 2008, theUnited States department of Interior listed the polar bear as a threatened species under the EndangeredSpecies Act and banned all importing of polar bear trophies. Importing products made from polar bears ha

been prohibited from 1972 to 1994 under the Marine Mammal Protection Act, and restricted between 1994and 2008. Under those restrictions, permits from the United States Fish and Wildlife Service (FWS) wererequired to import sport-hunted polar bear trophies taken in hunting expeditions in Canada. The permit process required that the bear be taken from an area with quotas based on sound management principles.[146]

Since 1994, more than 800 sport-hunted polar bear trophies have been imported into the U.S.[147]

Conservation status, efforts and controversies

Estimates of the status of the global population of polar bears vary widely. As of 2008, the World ConservationUnion (IUCN) reports that the global population of polar bears is 20,000 to 25,000, and is declining.[1] In 2006,the IUCN upgraded the polar bear from a species of leastconcern to a vulnerable species.[148] It cited a "suspected population reduction of >30% within three generations(45 years)".[1] However, a report published in July 2013,estimates that the global population of polar bearsincreased by an average of almost 4,200 bears since2001.[149] Risks to the polar bear include climate change, pollution in the form of toxic contaminants, conflictswith shipping, stresses from recreational polar-bear watching, and oil and gas exploration anddevelopment.[1] The IUCN also cited a "potential risk of over-harvest" through legal and illegal hunting.[1]

According to the World Wildlife Fund, the polar bear isimportant as an indicator of arctic ecosystem health.Polar bears are studied to gain understanding of what ishappening throughout the Arctic, because at-risk polar bears are often a sign of something wrong with thearctic marine ecosystem.[150]

Climate change

The IUCN, Arctic Climate Impact Assessment, United States Geological Survey and many leading polar bear biologists have expressed grave concerns about the impact of climate change, including the belief thathe current warming trend imperils the survival of the species.[30][151][152][153][154][155] The polar bear hassurvived several periods warmer than at present.[156]

The key danger posed by climate change is malnutrition or starvation due to habitat loss. Polar bears huntseals from a platform of sea ice. Rising temperatures cause the sea ice to melt earlier in the year, driving th bears to shore before they have built sufficient fat reserves to survive the period of scarce food in the latesummer and early fall.[114] Reduction in sea-ice cover also forces bears to swim longer distances, whichfurther depletes their energy stores and occasionally leads to drowning.[157] Thinner sea ice tends to deformmore easily, which appears to make it more difficult for polar bears to access seals.[65] Insufficient


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Mothers and cubs have highnutritional requirements, which arenot met if the seal-hunting season istoo short.

Swimming

nourishment leads to lower reproductive rates in adult females and lower survival rates in cubs and juvenil bears, in addition to poorer body condition in bears of all ages.[30]

In addition to creating nutritional stress, a warming climate isexpected to affect various other aspects of polar bear life: Changes insea ice affect the ability of pregnant females to build suitablematernity dens.[27] As the distance increases between the pack ice and

the coast, females must swim longer distances to reach favoreddenning areas on land.[30] Thawing of permafrost would affect the bears who traditionally den underground, and warm winters couldresult in den roofs collapsing or having reduced insulative value.[30]

For the polar bears that currently den on multi-year ice, increased icemobility may result in longer distances for mothers and young cubs towalk when they return to seal-hunting areas in the spring.[30] Disease-causing bacteria and parasites would flourish more readily in awarmer climate.[65]

Problematic interactions between polar bears and humans, such as foraging by bears in garbage dumps, hahistorically been more prevalent in years when ice-floe breakup occurred early and local polar bears wererelatively thin.[151] Increased human-bear interactions, including fatal attacks on humans, are likely toincrease as the sea ice shrinks and hungry bears try to find food on land.[151][158]

The effects of climate change are most profound in the southern partof the polar bear’s range, and this is indeed where significantdegradation of local populations has been observed.[155] The WesternHudson Bay subpopulation, in a southern part of the range, alsohappens to be one of the best-studied polar bear subpopulations. This

subpopulation feeds heavily on ringed seals in late spring, whennewly weaned and easily hunted seal pups are abundant.[143] The latespring hunting season ends for polar bears when the ice begins tomelt and break up, and they fast or eat little during the summer untilthe sea freezes again.[143]

Due to warming air temperatures, ice-floe breakup in western Hudson Bay is currently occurring three weearlier than it did 30 years ago, reducing the duration of the polar bear feeding season.[143] The bodycondition of polar bears has declined during this period; the average weight of lone (and likely pregnant)female polar bears was approximately 290 kg (640 lb) in 1980 and 230 kg (510 lb) in 2004.[143] Between

1987 and 2004, the Western Hudson Bay population declined by 22%.[159]

In Alaska, the effects of sea ice shrinkage have contributed to higher mortality rates in polar bear cubs, andhave led to changes in the denning locations of pregnant females.[113][160] In recent years, polar bears in theArctic have undertaken longer than usual swims to find prey, resulting in four recorded drownings in theunusually large ice pack regression of 2005.[157]

Pollution

Polar bears accumulate high levels of persistent organic pollutants such as polychlorinated biphenyl (PCB

and chlorinated pesticides. Due to their position at the top of the food pyramid, with a diet heavy in blubbein which halocarbons concentrate, their bodies are among the most contaminated of Arctic mammals.[161]

Halocarbons are known to be toxic to other animals, because they mimic hormone chemistry, and biomarksuch as immunoglobulin G and retinol suggest similar effects on polar bears. PCBs have received the mos


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study, and they have been associated with birth defects and immune system deficiency.[162]

The most notorious of these chemicals, such as PCBs and DDT, have been internationally banned. Their concentrations in polar bear tissues continued to rise for decades after the ban as these chemicals spreadthrough 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.[163]

Oil and gas development

Oil and gas development in polar bear habitat can affect the bears in a variety of ways. An oil spill in theArctic would most likely concentrate in the areas where polar bears and their prey are also concentrated, suas sea ice leads.[1] Because polar bears rely partly on their fur for insulation and soiling of the fur by oilreduces its insulative value, oil spills put bears at risk of dying from hypothermia.[83] Polar bears exposed tooil spill conditions have been observed to lick the oil from their fur, leading to fatal kidney failure.[83]

Maternity dens, used by pregnant females and by females with infants, can also be disturbed by nearby oilexploration and development. Disturbance of these sensitive sites may trigger the mother to abandon her d prematurely, or abandon her litter altogether.[1]

Predictions

The U.S. Geological Survey predicts two-thirds of the world’s polar bears will disappear by 2050, based onmoderate projections for the shrinking of summer sea ice caused by climate change.[65] The bears woulddisappear from Europe, Asia, and Alaska, and be depleted from the Arctic archipelago of Canada and areaoff the northern Greenland coast. By 2080, they would disappear from Greenland entirely and from thenorthern Canadian coast, leaving only dwindling numbers in the interior Arctic archipelago.[65]

Predictions vary on the extent to which polar bears could adapt to climate change by switching to terrestriafood sources. Mitchell Taylor, who was director of Wildlife Research for the Government of Nunavut, wroto the U.S. Fish and Wildlife Service arguing that local studies are insufficient evidence for global protectiat this time. The letter stated, "At present, the polar bear is one of the best managed of the large Arcticmammals. If all Arctic nations continue to abide by the terms and intent of the Polar Bear Agreement, thefuture of polar bears is secure ... Clearly polar bears can adapt to climate change. They have evolved and persisted for thousands of years in a period characterized by fluctuating climate."[144] Ken Taylor, deputycommissioner for the Alaska Department of Fish and Game, has said, "I wouldn’t be surprised if polar bealearned to feed on spawning salmon like grizzly bears."[34]

However, many scientists consider these theories to be naive;[34] it is noted that black and brown bears at

high latitudes are smaller than elsewhere, because of the scarcity of terrestrial food resources.[143] Anadditional risk to the species is that if individuals spend more time on land, they will hybridize with browngrizzly bears.[155] The IUCN wrote:

Polar bears exhibit low reproductive rates with long generational spans. These factors makefacultative adaptation by polar bears to significantly reduced ice coverage scenarios unlikely.Polar bears did adapt to warmer climate periods of the past. Due to their long generation timeand the current greater speed of climate change, it seems unlikely that polar bear will be able toadapt to the current warming trend in the Arctic. If climatic trends continue polar bears may

become extirpated from most of their range within 100 years.[1]

Controversy over species protection


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Captive polar bear

Warnings about the future of the polar bear are often contrasted withthe fact that worldwide population estimates have increased over the past 50 years and are relatively stable today.[164][165] Some estimatesof the global population are around 5,000 to 10,000 in the early1970s;[166] other estimates were 20,000 to 40,000 during the 1980s.[38][51] Current estimates put the global population at between 20,000and 25,000.[32]

There are several reasons for the apparent discordance between pastand projected population trends: estimates from the 1950s and 1960swere based on stories from explorers and hunters rather than onscientific surveys.[167][168] Second, controls of harvesting were introduced that allowed this previouslyoverhunted species to recover.[167] Third, the recent effects of climate change have affected sea iceabundance in different areas to varying degrees.[167] Finally, the prediction methods used to predict thedecline in the future population of bears excluded key forecasting principles and included questionableassumptions.[169]

Debate over the listing of the polar bear under endangered species legislation has put conservation groupsand Canada’s Inuit at opposing positions;[34] the Nunavut government and many northern residents havecondemned the U.S. initiative to list the polar bear under the Endangered Species Act.[170][171] Many Inuit believe the polar bear population is increasing, and restrictions on sport-hunting are likely to lead to a lossincome to their communities.[34][172]

Protection in the Noth America

The polar bear is protected by many US laws, most naotably the Marine Mammal Protection Act and the

Endangered Species ActU.S. Marine Mammal Protection Act

Polar bears are protected under the Marine Mammal Protection Act, which prohibits the take (i.e., harass,hunt, capture, or kill) of all marine mammals.[173]

U.S. Endangered Species Act

On 14 May 2008 the U.S. Department of the Interior listed the polar bear as a threatened species under the

Endangered Species Act, citing the melting of Arctic sea ice as the primary threat to the polar bear.[174]

Canadian endangered species legislation

In Canada, the Committee on the Status of Endangered Wildlife in Canada recommended in April 2008 ththe polar bear be assessed as a species of special concern under the federal Species at Risk Act (SARA). Alisting would mandate that a management plan be written within five years, a timeline criticized by the WoWide Fund for Nature as being too long to prevent significant habitat loss from climate change.[175]

In culture

Indigenous folklore

For the indigenous peoples of the Arctic, polar bears have long played an important cultural and material


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Engraving, made by Chukchi carversin the 1940s on a walrus tusk, depicts polar bears hunting walrus.

Coat of arms of theChukotka AutonomousOkrug in the RussianFederation

role.[125][126] Polar bear remains have been found at hunting sitesdating to 2,500 to 3,000 years ago[128] and 1,500 year old cave paintings of polar bears have been found in the ChukchiPeninsula.[126] Indeed, it has been suggested that Arctic peoples’skills in seal hunting and igloo construction has been in part acquiredfrom the polar bears themselves.[126]

The Inuit and Alaska Natives have many folk tales featuring the bearsincluding legends in which bears are humans when inside their ownhouses and put on bear hides when going outside, and stories of how the constellation which is said toresemble a great bear surrounded by dogs came into being.[124] These legends reveal a deep respect for the polar bear, which is portrayed as both spiritually powerful and closely akin to humans.[124] The human-like posture of bears when standing and sitting, and the resemblance of a skinned bear carcass to the human bohave probably contributed to the belief that the spirits of humans and bears were interchangeable.[124]

Eskimo legends tell of humans learning to hunt from the polar bear.

Among the Chukchi and Yupik of eastern Siberia, there was a longstanding shamanistic ritual of

"thanksgiving" to the hunted polar bear. After killing the animal, its head and skin were removed and cleanand brought into the home, a feast was held in the hunting camp in its honor. In order to appease the spirit othe bear, there were traditional song and drum music and the skull would be ceremonially fed and offered a pipe.[176] Only once the spirit was appeased would the skull be separated from the skin, taken beyond the bounds of the homestead, and placed in the ground, facing north.[126] Many of these traditions have fadedsomewhat in time, especially in light of the total hunting ban in the Soviet Union (and now Russia) since1955.

The Nenets of north-central Siberia placed particular value on the talismanic power of the prominent caninteeth. They were traded in the villages of the lower Yenisei and Khatanga rivers to the forest-dwelling

peoples further south, who would sew them into their hats as protection against brown bears. It was believthat the "little nephew" (the brown bear) would not dare to attack a man wearing the tooth of its powerful"big uncle" (the polar bear).[126] The skulls of killed polar bears were buried at specific sacred sites andaltars, called sedyangi , were constructed out of the skulls. Several such sites have been preserved on theYamal Peninsula.[126]

Symbols and mascots

Their distinctive appearance and their association with the Arctic have made polar bears popular icons, especially in those areas where they are native. The

Canadian Toonie (two-dollar coin) features the image of a polar bear and boththe Northwest Territories and Nunavut license plates in Canada are in theshape of a polar bear. The polar bear is the mascot of Bowdoin College inMaine and the University of Alaska Fairbanks (see also Alaska Nanooks) andwas chosen as mascot for the 1988 Winter Olympics held in Calgary.

Companies such as Coca-Cola, Polar Beverages, Nelvana, Bundaberg Rum or Good Humor-Breyers have used images of the polar bear in advertising,[177]

while Fox’s Glacier Mints have featured a polar bear named Peppy as the brand mascot since 1922.

Fiction

Polar bears are also popular in fiction, particularly in books aimed at childrenor teenagers. For example,The Polar Bear Son is adapted from a traditional


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Coat of arms of theGreenlandic Self-Rulegovernment (Kalaallit Nunaat)

Inuit tale.[178] Polar bears feature prominently in East (also released as NorthChild ) by Edith Pattou,[179]The Bear by Raymond Briggs (adapted into ananimated short in 1998),[180] and Chris d’Lacey’sThe Fire Within series.[181]

The panserbjørne of Philip Pullman’s fantasy trilogy His Dark Materials aresapient, dignified polar bears who exhibit anthropomorphic qualities, andfeature prominently in the 2007 film adaptation of The Golden Compass .[182]

The television series Lost features polar bears living on the tropical islandsetting.[183]

See also

Arctic National Wildlife RefugeList of solitary animalsPolar Bears International

Notes

a b c d e f g h i j k Schliebe, S., Wiig, Ø., Derocher, A. & Lunn, N. (IUCN SSC Polar Bear Specialist Group)(2008). "Ursus maritimus " (http://www.iucnredlist.org/details/22823). IUCN Red List of Threatened Species.

Version 2013.1 . International Union for Conservation of Nature. Retrieved 2013-07-24.

1.

^ Phipps, pg. 1852.

^ "Polar bear, (Ursus maritimus)" (http://www.fws.gov/endangered/esa-library/pdf/polar_bear.pdf) (PDF). UnitStates Fish and Wildlife service. Retrieved 9 September 2009. "Appearance. The polar bear is the largest membof the bear family, with the exception of Alaska’s Kodiak brown bears, which equal polar bears in size."(Overview page (http://ecos.fws.gov/speciesProfile/SpeciesReport.do?spcode=A0IJ))

3.

^ Kindersley, Dorling (2001). Animal . New York City: DK Publishing. ISBN 0-7894-7764-5.4.^ Wozencraft, W. C. (2005). "Order Carnivora" (http://www.bucknell.edu/msw3/browse.asp?id=14000987). InWilson, D. E.; Reeder, D. M. Mammal Species of the World (http://www.google.com/books?id=JgAMbNSt8ikC& pg=PA589) (3rd ed.). Johns Hopkins University Press. p. 589. ISBN 978-0-8018-8221-0. OCLC 62265494(https://www.worldcat.org/oclc/62265494).

5.

^ Gunderson, Aren (2007). "Ursus Maritimus" (http://animaldiversity.ummz.umich.edu/site/accounts/informatio/Ursus_maritimus.html). Animal Diversity Web . University of Michigan Museum of Zoology. Retrieved27 October 2007.

6.

a b IUCN Polar Bear Specialist Group, 2009.15th meeting of PBSG in Copenhagen, Denmark 2009: PressRelease (http://pbsg.npolar.no/en/meetings/press-releases/15-Copenhagen.html). Retrieved 10 January 2010.

7.

^ Kidd, D.A. (1973).Collins Latin Gem Dictionary . London: Collins. ISBN 0-00-458641-7.8.^ The Marine Mammal Center (https://web.archive.org/web/20090604063108/http://www.marinemammalcenter.org/learning/education/mammalinfo/polarbear.asp)

9.

^ The Arctic Sounder (http://www.thearcticsounder.com/news/show/1309)10.^ The fourth world: the heritage of the Arctic and its destruction , Sam Hall, Vintage Books, 1988, pp. 29, 232.11.^ "Этимологический Словарь — Piotr Czerwinski — Oshkuy" (http://www.nicomant.fils.us.edu.pl/jrn/2000/j12/pril/etim-zv.html). Nicomant.fils.us.edu.pl. Retrieved 20 March 2011.

12.


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^ "Grand Quebec" (http://grandquebec.com/faune-quebecoise/ours-polaire). Grand Quebec. Retrieved 20 Marc2011.

13.

^ This combines the Ancient Greek wordsthalassa /θαλασσα ’sea’, andarctos /αρκτος ’bear’ and also, withreference to Ursa Major, ’northern’ or ’of the north pole’Liddell, Henry George and Robert Scott (1980). A Greek-

English Lexicon (Abridged Edition) . United Kingdom: Oxford University Press. ISBN 0-19-910207-4.

14.

^ Nakagome et al., Shigeki (2008). "Unequal Rates of Y Chromosome Gene Divergence during Speciation of th

Family Ursidae.". Molecular biology and evolution 25 (7): 1344–1356.

15.

^ Wayne et al., RK (1991). "Molecular distance and divergence time in carnivores and primates.". Mol Biol Evol

9: 297–319.16.

a b Lindqvist, Charlotte; Schuster, Stephan C.; Sun, Yazhou; Talbot, Sandra L.; Qi, Ji; Ratan, Aakrosh; TomshoLynn P.; Kasson, Lindsay et al. (2010). "Complete mitochondrial genome of a Pleistocene jawbone unveils theorigin of polar bear" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2841953). Proceedings of the National

Academy of Sciences 107 (11): 5053–5057. doi:10.1073/pnas.0914266107 (https://dx.doi.org/10.1073%2Fpnas.0914266107). PMC 2841953 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2841953).PMID 20194737 (https://www.ncbi.nlm.nih.gov/pubmed/20194737).

17.

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Wikimedia Commons hasmedia related to Ur sus maritimus .

Wikispecies hasinformation related to:Ur sus mari timus

References

Aars, Jon, ed. (June 2005). "Polar Bears" (http://web.archive.org/web/20080409082137/http://pbsg.npolar.no/docs/PBSG14proc.pdf) (PDF). 14th Working Meeting of the IUCN/SSC Polar Bear Specialist Group32 . Nicholas J. Lunn and Andrew E. Derocher. Seattle, Washington, United States:IUCN. ISBN 2-8317-0959-8. Archived from the original (http://pbsg.npolar.no/docs/PBSG14proc.pdon 9 April 2008. Retrieved 19 April 2008.Bruemmer, Fred (1989).World of the Polar Bear . Toronto, Ontario, Canada: Key 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. ISBN 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 Majesty’s command, 1773(http://www.biodiversitylibrary.org/page/628763). 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

View occurrences of Ursus maritimus

(http://www.biodiversitylibrary.org/name/Ursus_maritimus) inBiodiversity Heritage Library. National Wildlife Federation’s Polar Bear Page(http://www.nwf.org/polarbear)ARKive — images and movies of the polar bear (Ursus

maritimus ) (http://www.arkive.org/species/GES/mammals/Ursus_maritimus/)Smithsonian National Museum of Natural History species account-Polar Bear (http://www.mnh.si.ed

/mna/image_info.cfm?species_id=418)USGS Polar Bear Studies (http://www.usgs.gov/newsroom/special/polar%5Fbears/)Map of polar bear ranges and denning areas in Nunavut from Nunavut Planning Commission(http://www.nunavut.ca/en/map?zoom=0&lat=69.59292&lon=-86.95845&layers=BTFTTFFFFFFFFFFFFTFFFFFFTTT)BBC Nature: Polar bear news, and video clips from BBC programmes past and present.(http://www.bbc.co.uk/nature/life/Polar_bear)Photos, facts, videos from Polar Bears International which funds population, preservation and DNA

studies of the polar bear (http://www.polarbearsinternational.org/)Map: Here’s where the polar bears are vanishing (http://www.vox.com/2014/12/18/7415843/polarbears-vanishing)


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