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85-512: Competitors raced in teams of 3, many joining as individuals and forming teams when they meet other individuals during the training that led up to the race. The competitors were from different walks of life (not necessarily explorers or people with mountaineering experience), sharing a quest for adventure and to achieve something that only a few others had done. The race took place in one of the world's most extreme and hostile environments, with temperatures dropping as low as -35 °C, and where 80% of

170-487: A decline in sea ice , giving the polar bear less access to its favoured prey and increasing the risk of malnutrition and starvation. Less sea ice also means that the bears must spend more time on land, increasing conflicts with people. Polar bears have been hunted, both by native and non-native peoples, for their coats, meat and other items. They have been kept in captivity in zoos and circuses and are prevalent in art, folklore, religion and modern culture. The polar bear

255-495: A " Roman nose ". They have 34–42 teeth including 12 incisors , 4 canines , 8–16 premolars and 10 molars . The teeth are adapted for a more carnivorous diet than that of the brown bear, having longer, sharper and more spaced out canines, and smaller, more pointed cheek teeth (premolars and molars). The species has a large space or diastema between the canines and cheek teeth, which may allow it to better bite into prey. Since it normally preys on animals much smaller than it,

340-500: A 2011 study concluded that living polar bear populations derived their maternal lines from now-extinct Irish brown bears. Later studies have clarified that gene flow went from polar to brown bears rather than the reverse. Up to 9 percent of the genome of ABC bears was transferred from polar bears, while Irish bears had up to 21.5 percent polar bear origin. Mass hybridization between the two species appears to have stopped around 200,000 years ago. Modern hybrids are relatively rare in

425-419: A bear spots a seal hauling out on the sea ice, it slowly stalks it with the head and neck lowered, possibly to make its dark nose and eyes less noticeable. As it gets closer, the bear crouches more and eventually charges at a high speed, attempting to catch the seal before it can escape into its ice hole. Some stalking bears need to move through water; traversing through water cavities in the ice when approaching

510-588: A carcass when they see an adult male approaching, though are less likely to if they have not eaten in a long time. Whale carcasses are a valuable food source, particularly on land and after the sea ice melts, and attract several bears. In one area in northeastern Alaska, polar bears have been recorded competing with grizzly bears for whale carcasses. Despite their smaller size, grizzlies are more aggressive and polar bears are likely to yield to them in confrontations. Polar bears will also scavenge at garbage dumps during ice-free periods. Polar bear mating takes place on

595-473: A combination of both. The inside of these shelters can be around 1.5 m (4.9 ft) wide with a ceiling height of 1.2 m (3.9 ft) while the entrance may be 2.1 m (6.9 ft) long and 1.2 m (3.9 ft) wide. The temperature of a den can be much higher than the outside. Females hibernate and give birth to their cubs in the dens. Hibernating bears fast and internally recycle bodily waste. Polar bears experience delayed implantation and

680-405: A day are more common during the former. The species is generally diurnal , being most active early in the day. Polar bears sleep close to eight hours a day on average. They will sleep in various positions, including curled up, sitting up, lying on one side, on the back with limbs spread, or on the belly with the rump elevated. On sea ice, polar bears snooze at pressure ridges where they dig on

765-495: A disused airstrip where planes could land. The 2007 challenge took place in April/May 2007 and was won by team Bearing 360 North and saw the following teams compete: In 2007 but not part of the main event; the route was filmed by a BBC Television crew for Top Gear: Polar Special , undertaking the same journey with modified Toyota Hilux pickup trucks and a dog sled . The Polar Challenge 2008 took place in April/May 2008 and saw

850-676: A female, a male will try to isolate and guard her. Courtship can be somewhat aggressive, and a male will pursue a female if she tries to run away. It can take days for the male to mate with the female which induces ovulation . After their first copulation, the couple bond. Undisturbed polar bear pairings typically last around two weeks during which they will sleep together and mate multiple times. Competition for mates can be intense and this has led to sexual selection for bigger males. Polar bear males often have scars from fighting. A male and female that have already bonded will flee together when another male arrives. A female mates with multiple males in

935-441: A marine environment, some taxonomists, such as Theodore Knottnerus-Meyer, have placed the polar bear in its own genus, Thalarctos . However Ursus is widely considered to be the valid genus for the species on the basis of the fossil record and the fact that it can breed with the brown bear. Different subspecies have been proposed including Ursus maritimus maritimus and U. m. marinus . However these are not supported and

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1020-494: A mid-sized seal out of the water or haul a beluga carcass for quite some distance. Polar bears only occasionally store food for later—burying it under snow—and only in the short term. Arctic foxes routinely follow polar bears and scavenge scraps from their kills. The bears usually tolerate them but will charge a fox that gets too close when they are feeding. Polar bears themselves will scavenge. Subadult bears will eat remains left behind by others. Females with cubs often abandon

1105-529: A more efficient circulatory system . The polar bear's thicker coat is the result of more copies of genes involved in keratin -creating proteins. The polar bear is the largest living species of bear and land carnivore , though some brown bear subspecies like the Kodiak bear can rival it in size. Males are generally 200–250 cm (6.6–8.2 ft) long with a weight of 300–800 kg (660–1,760 lb). Females are smaller at 180–200 cm (5.9–6.6 ft) with

1190-418: A season and a single litter can have more than one father. When the mating season ends, the female will build up more fat reserves to sustain both herself and her young. Sometime between August and October, the female constructs and enters a maternity den for winter. Depending on the area, maternity dens can be found in sea ice just off the coastline or further inland and may be dug underneath snow, earth or

1275-723: A soft pulsing call, is made by mother bears presumably to keep in contact with their young. During the breeding season, adult males will chuff at potential mates. Unlike other animals where chuffing is passed through the nostrils, in polar bears it is emitted through a partially open mouth. Cubs will cry for attention and produce humming noises while nursing. Teeth chops, jaw pops, blows, huffs, moans, growls and roars are heard in more hostile encounters. A polar bear visually communicates with its eyes, ears, nose and lips. Chemical communication can also be important: bears secrete their scent from their foot pads into their tracks, allowing individuals to keep track of one another. The polar bear

1360-420: A thick layer of fat. It is more slender than the brown bear, with a narrower skull, longer neck and lower shoulder hump. Its teeth are sharper and more adapted to cutting meat. The paws are large and allow the bear to walk on ice and paddle in the water. Polar bears are both terrestrial and pagophilic (ice-living) and are considered marine mammals because of their dependence on marine ecosystems . They prefer

1445-452: A time and travel an average of 154.2 km (95.8 mi). They can dive for as long as three minutes. When swimming, the broad front paws do the paddling, while the hind legs play a role in steering and diving. Most polar bears are active year-round. Hibernation occurs only among pregnant females. Non-hibernating bears typically have a normal 24-hour cycle even during days of all darkness or all sunlight , though cycles less than

1530-467: A weight of 150–300 kg (330–660 lb). Sexual dimorphism in the species is particularly high compared with most other mammals. Male polar bears also have proportionally larger heads than females. The weight of polar bears fluctuates during the year, as they can bulk up on fat and increase their mass by 50 percent. A fattened, pregnant female can weigh as much as 500 kg (1,100 lb). Adults may stand 130–160 cm (4.3–5.2 ft) tall at

1615-425: A weight of around 600 g (21 oz). Their eyes remain closed for a month. The mother's fatty milk fuels their growth, and the cubs are kept warm both by the mother's body heat and the den. The mother emerges from the den between late February and early April, and her cubs are well-developed and capable of walking with her. At this time they weigh 10–15 kilograms (22–33 lb). A polar bear family stays near

1700-538: A wide variety of habitats throughout most of the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America , South America , and Eurasia . Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails. While the polar bear

1785-530: A wider frequency range than expected given that their prey mostly makes low-frequency sounds. The nasal concha creates a large surface area, so more warm air can move through the nasal passages. Their olfactory system is also large and adapted for smelling prey over vast distances. The animal has reniculate kidneys which filter out the salt in their food. Polar bears inhabit the Arctic and adjacent areas. Their range includes Greenland, Canada, Alaska, Russia and

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1870-608: A year, while drifting ice allows them to move further. Depending on ice conditions, a bear can travel an average of 12 km (7.5 mi) per day. These movements are powered by their energy-rich diet. Polar bears move by walking and galloping and do not trot . Walking bears tilt their front paws towards each other. They can run at estimated speeds of up to 40 km/h (25 mph) but typically move at around 5.5 km/h (3.4 mph). Polar bears are also capable swimmers and can swim at up to 6 km/h (3.7 mph). One study found they can swim for an average of 3.4 days at

1955-480: Is Latin for ' sea bear ' . Carl Linnaeus classified the polar bear as a type of brown bear ( Ursus arctos ), labelling it as Ursus maritimus albus-major, articus in the 1758 edition of his work Systema Naturae . Constantine John Phipps formally described the polar bear as a distinct species, Ursus maritimus in 1774, following his 1773 voyage towards the North Pole . Because of its adaptations to

2040-669: Is a hypercarnivore , and the most carnivorous species of bear. It is an apex predator of the Arctic, preying on ice-living seals and consuming their energy-rich blubber . The most commonly taken species is the ringed seal , but they also prey on bearded seals and harp seals . Ringed seals are ideal prey as they are abundant and small enough to be overpowered by even small bears. Bearded seal adults are larger and are more likely to break free from an attacking bear, hence adult male bears are more successful in hunting them. Less common prey are hooded seals , spotted seals , ribbon seals and

2125-500: Is a 130,000- to 110,000-year-old jaw bone, found on Prince Charles Foreland , Norway, in 2004. Scientists in the 20th century surmised that polar bears directly descended from a population of brown bears, possibly in eastern Siberia or Alaska . Mitochondrial DNA studies in the 1990s and 2000s supported the status of the polar bear as a derivative of the brown bear, finding that some brown bear populations were more closely related to polar bears than to other brown bears, particularly

2210-414: Is a large bear native to the Arctic and nearby areas. It is closely related to the brown bear , and the two species can interbreed . The polar bear is the largest extant species of bear and land carnivore , with adult males weighing 300–800 kg (660–1,760 lb). The species is sexually dimorphic , as adult females are much smaller. The polar bear is white- or yellowish-furred with black skin and

2295-524: Is from the Proto-Indo-European word *ǵʰwḗr- ~ *ǵʰwér "wild animal". This terminology for the animal originated as a taboo avoidance term: proto-Germanic tribes replaced their original word for bear— arkto —with this euphemistic expression out of fear that speaking the animal's true name might cause it to appear. According to author Ralph Keyes , this is the oldest known euphemism . Bear taxon names such as Arctoidea and Helarctos come from

2380-516: Is mostly carnivorous , and the giant panda is mostly herbivorous , the remaining six species are omnivorous with varying diets. With the exception of courting individuals and mothers with their young, bears are typically solitary animals . They may be diurnal or nocturnal and have an excellent sense of smell . Despite their heavy build and awkward gait, they are adept runners, climbers, and swimmers. Bears use shelters, such as caves and logs, as their dens; most species occupy their dens during

2465-1086: Is one of eight extant species in the bear family, Ursidae, and of six extant species in the subfamily Ursinae . Giant panda ( Ailuropoda melanoleuca ) [REDACTED] Spectacled bear ( Tremarctos ornatus ) [REDACTED] Sloth bear ( Melursus ursinus ) [REDACTED] Sun bear ( Helarctos malayanus ) [REDACTED] Asian black bear ( Ursus thibetanus ) [REDACTED] American black bear ( Ursus americanus ) [REDACTED] Polar bear ( Ursus maritimus ) [REDACTED] Brown bear ( Ursus arctos ) [REDACTED] Giant panda ( Ailuropoda melanoleuca ) [REDACTED] Spectacled bear ( Tremarctos ornatus ) [REDACTED] Sloth bear ( Melursus ursinus ) [REDACTED] Sun bear ( Helarctos malayanus ) [REDACTED] Asian black bear ( Ursus thibetanus ) [REDACTED] American black bear ( Ursus americanus ) [REDACTED] Polar bear ( Ursus maritimus ) [REDACTED] Brown bear ( Ursus arctos ) [REDACTED] Fossils of polar bears are uncommon. The oldest known fossil

2550-459: Is the primary hunting method from winter to early spring. Bears hunt walrus groups by provoking them into stampeding and then look for young that have been crushed or separated from their mothers during the turmoil. There are reports of bears trying to kill or injure walruses by throwing rocks and pieces of ice on them. Belugas and narwhals are vulnerable to bear attacks when they are stranded in shallow water or stuck in isolated breathing holes in

2635-403: Is thought to signal their fitness to females. The outer surface of the hairs has a scaly appearance, and the guard hairs are hollow, which allows the animals to trap heat and float in the water. The transparent guard hairs forward scatter ultraviolet light between the underfur and the skin, leading to a cycle of absorption and re-emission, keeping them warm. The fur appears white because of

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2720-465: Is too specialized for animal matter, though they have been recorded eating berries, moss, grass and seaweed . In their southern range, especially near Hudson Bay and James Bay, polar bears endure all summer without sea ice to hunt from and must subsist more on terrestrial foods. Fat reserves allow polar bears to survive for months without eating. Cannibalism is known to occur in the species. Polar bears hunt their prey in several different ways. When

2805-467: The ABC Islands bears of Southeast Alaska . A 2010 study estimated that the polar bear lineage split from other brown bears around 150,000 years ago. More extensive genetic studies have refuted the idea that polar bears are directly descended from brown bears and found that the two species are separate sister lineages . The genetic similarities between polar bears and some brown bears were found to be

2890-639: The Bering land bridge may have been possible during a major sea level low stand as early as the late Eocene (about 37 Mya) and continuing into the early Oligocene. European genera morphologically very similar to Allocyon , and to the much younger American Kolponomos (about 18 Mya), are known from the Oligocene, including Amphicticeps and Amphicynodon . There has been various morphological evidence linking amphicynodontines with pinnipeds , as both groups were semi-aquatic, otter-like mammals. In addition to

2975-717: The Guinness Book of Records by being the first people to reach the Southern Pole of Inaccessibility by foot & kite ski in 2007. They were guided here by veteran guide Paul Landry whom they met during training in Resolute Bay prior to the race starting. The Polar Challenge route covered 284 nautical miles (526 km). Competitors began by participating in a 4-day, 65-nautical-mile (120 km) training expedition in which they set off from Resolute , Nunavut in northern Canada to Polaris Mine on Little Cornwallis Island ,

3060-620: The Isthmus of Panama . Their earliest fossil representative is Plionarctos in North America (c. 10–2 Ma). This genus is probably the direct ancestor to the North American short-faced bears (genus Arctodus ), the South American short-faced bears ( Arctotherium ), and the spectacled bears, Tremarctos , represented by both an extinct North American species ( T. floridanus ), and

3145-534: The Russian Far East ) and Eastern Basin (Greenland east to Siberia). The polar bear is dependent enough on the ocean to be considered a marine mammal . It is pagophilic and mainly inhabits annual sea ice covering continental shelves and between islands of archipelagos . These areas, known as the "Arctic Ring of Life", have high biological productivity . The species tends to frequent areas where sea ice meets water, such as polynyas and leads , to hunt

3230-678: The Svalbard Archipelago of Norway. Polar bears have been recorded as close as 25 km (16 mi) from the North Pole . The southern limits of their range include James Bay and Newfoundland and Labrador in Canada and St. Matthew Island and the Pribilof Islands of Alaska. They are not permanent residents of Iceland but have been recorded visiting there if they can reach it via sea ice. As there has been minimal human encroachment on

3315-442: The backscatter of incident light and the absence of pigment. Polar bears gain a yellowish colouration as they are exposed more to the sun. This is reversed after they moult . It can also be grayish or brownish. Their light fur provides camouflage in their snowy environment. After emerging from the water, the bear can easily shake itself dry before freezing since the hairs are resistant to tangling when wet. The skin, including

3400-470: The seals that make up most of its diet. Polar bears travel in response to changes in ice cover throughout the year. They are forced onto land in summer when the sea ice disappears. Terrestrial habitats used by polar bears include forests, mountains, rocky areas, lakeshores and creeks. In the Chukchi and Beaufort seas, where the sea ice breaks off and floats north during the summer, polar bears generally stay on

3485-399: The spectacled bear ), and Ursinae (containing six species divided into one to three genera, depending on the authority). Nuclear chromosome analysis show that the karyotype of the six ursine bears is nearly identical, each having 74  chromosomes ( see Ursid hybrid ), whereas the giant panda has 42 chromosomes and the spectacled bear 52. These smaller numbers can be explained by

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3570-466: The Asian bile bear market. The IUCN lists six bear species as vulnerable or endangered , and even least concern species, such as the brown bear , are at risk of extirpation in certain countries. The poaching and international trade of these most threatened populations are prohibited, but still ongoing. The English word "bear" comes from Old English bera and belongs to a family of names for

3655-640: The Challenge, the BBC's Top Gear programme presenters became the first people to drive to the 1996 location of the magnetic north pole in the Hilux Arctic Challenge . It was later broadcast as the Top Gear: Polar Special . The current race record holders are Team Hardware.com , consisting of Henry Cookson , Rupert Longsdon & Rory Sweet who won the challenge in 2005, they then went on to enter

3740-464: The Polar Challenge every year. In 2004 the race was filmed for a BBC documentary series called ‘The Challenge’ which aired on worldwide television. Paul “Seamus” Hogan, a sales manager from London , England, with no experience of the outdoors whatsoever, was asked to enter the Challenge for the program. His team, Team Fujitsu led by Chris McLeod went on to win the race. In 2007, at the same time as

3825-464: The Polar Challenge starting point. The race itself was from Polaris Mine to Isachsen on Ellef Ringnes Island through 3 checkpoints. The first two checkpoints were re-supply points where competitors rested for 12–24 hours and took on new food and fuel supplies, and the third was the 1996 position of the Magnetic North Pole. The finish line was a further 25 miles beyond the third checkpoint, near

3910-501: The ancient Greek ἄρκτος ( arktos ), meaning bear, as do the names " arctic " and " antarctic ", via the name of the constellation Ursa Major , the "Great Bear", prominent in the northern sky. Bear taxon names such as Ursidae and Ursus come from Latin Ursus/Ursa , he-bear/she-bear. The female first name " Ursula ", originally derived from a Christian saint 's name, means "little she-bear" (diminutive of Latin ursa ). In Switzerland,

3995-564: The annual sea ice but live on land when the ice melts in the summer. They are mostly carnivorous and specialized for preying on seals , particularly ringed seals . Such prey is typically taken by ambush; the bear may stalk its prey on the ice or in the water, but also will stay at a breathing hole or ice edge to wait for prey to swim by. The bear primarily feeds on the seal's energy-rich blubber . Other prey include walruses , beluga whales and some terrestrial animals. Polar bears are usually solitary but can be found in groups when on land. During

4080-756: The bear family with other carnivorans is shown in the following phylogenetic tree , which is based on the molecular phylogenetic analysis of six genes in Flynn (2005) with the musteloids updated following the multigene analysis of Law et al. (2018). Feliformia [REDACTED] Canidae [REDACTED] Ursidae [REDACTED] Pinnipedia [REDACTED] Mephitidae [REDACTED] Ailuridae [REDACTED] Procyonidae [REDACTED] Mustelidae [REDACTED] Note that although they are called "bears" in some languages, red pandas and raccoons and their close relatives are not bears, but rather musteloids . There are two phylogenetic hypotheses on

4165-463: The bear in Germanic languages , such as Swedish björn , also used as a first name. This form is conventionally said to be related to a Proto-Indo-European word for "brown", so that "bear" would mean "the brown one". However, Ringe notes that while this etymology is semantically plausible, a word meaning "brown" of this form cannot be found in Proto-Indo-European. He suggests instead that "bear"

4250-605: The bears' remote habitat, they can still be found in much of their original range, more of it than any other large land carnivore. Polar bears have been divided into at least 18 subpopulations labelled East Greenland (ES), Barents Sea (BS), Kara Sea (KS), Laptev Sea (LVS), Chukchi Sea (CS), northern and southern Beaufort Sea (SBS and NBS), Viscount Melville (VM), M'Clintock Channel (MC), Gulf of Boothia (GB), Lancaster Sound (LS), Norwegian Bay (NB), Kane Basin (KB), Baffin Bay (BB), Davis Strait (DS), Foxe Basin (FB) and

4335-549: The breeding season, male bears guard females and defend them from rivals. Mothers give birth to cubs in maternity dens during the winter. Young stay with their mother for up to two and a half years. The polar bear is considered a vulnerable species by the International Union for Conservation of Nature (IUCN) with an estimated total population of 22,000 to 31,000 individuals. Its biggest threats are climate change , pollution and energy development. Climate change has caused

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4420-619: The breeding season. They have been recorded forming stable "alliances", travelling, resting and playing together. A dominance hierarchy exists among polar bears with the largest mature males ranking at the top. Adult females outrank subadults and adolescents and younger males outrank females of the same age. In addition, cubs with their mothers outrank those on their own. Females with dependent offspring tend to stay away from males, but are sometimes associated with other female–offspring units, creating "composite families". Polar bears are generally quiet but can produce various sounds. Chuffing ,

4505-521: The brown bears (which includes the polar bear ). Modern brown bears evolved from U. minimus via Ursus etruscus , which itself is ancestral to the extinct Pleistocene cave bear . Species of Ursinae have migrated repeatedly into North America from Eurasia as early as 4 Mya during the early Pliocene. The polar bear is the most recently evolved species and descended from a population of brown bears that became isolated in northern latitudes by glaciation 400,000 years ago. The relationship of

4590-425: The den for roughly two weeks; during this time the cubs will move and play around while the mother mostly rests. They eventually head out on the sea ice. Bear Bears are carnivoran mammals of the family Ursidae ( / ˈ ɜːr s ɪ d iː , - d aɪ / ). They are classified as caniforms , or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in

4675-516: The early Pleistocene. By 3–4 Mya, the species Ursus minimus appears in the fossil record of Europe; apart from its size, it was nearly identical to today's Asian black bear . It is likely ancestral to all bears within Ursinae, perhaps aside from the sloth bear. Two lineages evolved from U. minimus : the black bears (including the sun bear , the Asian black bear, and the American black bear ); and

4760-418: The fertilized embryo does not start development until the fall, between mid-September and mid-October. With delayed implantation, gestation in the species lasts seven to nine months but actual pregnancy is only two months. Mother polar bears typically give birth to two cubs per litter. As with other bear species, newborn polar bears are tiny and altricial . The newborns have woolly hair and pink skin, with

4845-627: The following teams compete: The 2010 Polar Challenge was won by Team Avilton (formerly Team Dark Horse) who completed the race in 9 days 14 hours and 15 minutes, missing out on the race record by just 2 hours and 20 minutes. Race standings The 2010 polar challenge was the first time all competitors and teams successfully completed the entire race. Polar bear Ursus eogroenlandicus Ursus groenlandicus Ursus jenaensis Ursus labradorensis Ursus marinus Ursus polaris Ursus spitzbergensis Ursus ungavensis Thalarctos maritimus The polar bear ( Ursus maritimus )

4930-560: The fusing of some chromosomes, and the banding patterns on these match those of the ursine species, but differ from those of procyonids, which supports the inclusion of these two species in Ursidae rather than in Procyonidae , where they had been placed by some earlier authorities. The earliest members of Ursidae belong to the extinct subfamily Amphicynodontinae, including Parictis (late Eocene to early middle Miocene , 38–18  Mya ) and

5015-454: The genus Ursavus during the early Oligocene (30–28 Mya); this genus proliferated into many species in Asia and is ancestral to all living bears. Species of Ursavus subsequently entered North America, together with Amphicynodon and Cephalogale , during the early Miocene (21–18 Mya). Members of the living lineages of bears diverged from Ursavus between 15 and 20 Mya, likely via

5100-461: The ice and then pokes its head in to catch the pup before it can escape. A ringed seal's lair can be more than 1 m (3.3 ft) below the surface of the ice and thus more massive bears are better equipped for breaking in. Some bears may simply stay still near a breathing hole or other spot near the water and wait for prey to come by. This can last hours and when a seal surfaces the bear will try to pull it out with its paws and claws. This tactic

5185-463: The ice, though a large portion of the population (15–40%) has been observed spending all summer on land since the 1980s. Some areas have thick multiyear ice that does not completely melt and the bears can stay on all year, though this type of ice has fewer seals and allows for less productivity in the water. Polar bears may travel areas as small as 3,500 km (1,400 sq mi) to as large as 38,000 km (15,000 sq mi) in

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5270-399: The ice. When stalking reindeer, polar bears will hide in vegetation before an ambush. On some occasions, bears may try to catch prey in open water, swimming underneath a seal or aquatic bird . Seals in particular, however, are more agile than bears in the water. Polar bears rely on raw power when trying to kill their prey, and will employ bites and paw swipes. They have the strength to pull

5355-646: The lone surviving representative of the Tremarctinae, the South American spectacled bear ( T. ornatus ). The subfamily Ursinae experienced a dramatic proliferation of taxa about 5.3–4.5 Mya, coincident with major environmental changes; the first members of the genus Ursus appeared around this time. The sloth bear is a modern survivor of one of the earliest lineages to diverge during this radiation event (5.3 Mya); it took on its peculiar morphology, related to its diet of termites and ants, no later than by

5440-418: The male first name "Urs" is especially popular, while the name of the canton and city of Bern is by legend derived from Bär , German for bear. The Germanic name Bernard (including Bernhardt and similar forms) means "bear-brave", "bear-hardy", or "bold bear". The Old English name Beowulf is a kenning , "bee-wolf", for bear, in turn meaning a brave warrior. The family Ursidae is one of nine families in

5525-478: The more temperate-living harbour seals . Polar bears, mostly adult males, will occasionally hunt walruses both on land and ice. They mainly target young walruses, as adults, with their thick skin and long tusks, are too large and formidable. Besides seals, bears will prey on cetacean species such as beluga whales and narwhals , as well as reindeer , birds and their eggs, fish and marine invertebrates . They rarely eat plant material as their digestive system

5610-417: The nose and lips, is black and absorbs heat. Polar bears have a 5–10 cm (2.0–3.9 in) thick layer of fat underneath the skin, which provides both warmth and energy. Polar bears maintain their core body temperature at about 36.9 °C (98 °F). Overheating is countered by a layer of highly vascularized striated muscle tissue and finely controlled blood vessels. Bears also cool off by entering

5695-526: The polar bear does not have a particularly strong bite. Polar bears have large paws, with the front paws being broader than the back. The feet are hairier than in other bear species, providing warmth and friction when stepping on snow and sea ice. The claws are small but sharp and hooked and are used both to snatch prey and climb onto ice. The coat consists of dense underfur around 5 cm (2.0 in) long and guard hairs around 15 cm (5.9 in) long. Males have long hairs on their forelegs, which

5780-413: The polar bear is considered to be monotypic . One possible fossil subspecies, U. m. tyrannus , was posited in 1964 by Björn Kurtén , who reconstructed the subspecies from a single fragment of an ulna which was approximately 20 percent larger than expected for a polar bear. However, re-evaluation in the 21st century has indicated that the fragment likely comes from a giant brown bear. The polar bear

5865-628: The relationships among extant and fossil bear species. One is all species of bears are classified in seven subfamilies as adopted here and related articles: Amphicynodontinae , Hemicyoninae , Ursavinae , Agriotheriinae , Ailuropodinae , Tremarctinae , and Ursinae . Below is a cladogram of the subfamilies of bears after McLellan and Reiner (1992) and Qiu et al. . (2014): † Amphicynodontinae [REDACTED] † Hemicyoninae † Ursavinae † Agriotheriinae Ailuropodinae [REDACTED] Tremarctinae [REDACTED] Ursinae [REDACTED] The second alternative phylogenetic hypothesis

5950-525: The result of interbreeding. A 2012 study estimated the split between polar and brown bears as occurring around 600,000 years ago. A 2022 study estimated the divergence as occurring even earlier at over one million years ago. Glaciation events over hundreds of thousands of years led to both the origin of polar bears and their subsequent interactions and hybridizations with brown bears. Studies in 2011 and 2012 concluded that gene flow went from brown bears to polar bears during hybridization. In particular,

6035-424: The sea ice and during spring, mostly between March and May. Males search for females in estrus and often travel in twisting paths which reduces the chances of them encountering other males while still allowing them to find females. The movements of females remain linear and they travel more widely. The mating system can be labelled as female-defence polygyny , serial monogamy or promiscuity . Upon finding

6120-463: The seal or swimming towards a seal on an ice floe. The polar bear can stay underwater with its nose exposed. When it gets close enough, the animal lunges from the water to attack. During a limited time in spring, polar bears will search for ringed seal pups in their birth lairs underneath the ice. Once a bear catches the scent of a hiding pup and pinpoints its location, it approaches the den quietly to not alert it. It uses its front feet to smash through

6205-670: The sheltered side and lie down. After a snowstorm, a bear may rest under the snow for hours or days. On land, the bears may dig a resting spot on gravel or sand beaches. They will also sleep on rocky outcrops. In mountainous areas on the coast, mothers and subadults will sleep on slopes where they can better spot another bear coming. Adult males are less at risk from other bears and can sleep nearly anywhere. Polar bears are typically solitary, aside from mothers with cubs and mating pairs. On land, they are found closer together and gather around food resources. Adult males, in particular, are more tolerant of each other in land environments and outside

6290-418: The shoulder. The tail is 76–126 mm (3.0–5.0 in) long. The largest polar bear on record, reportedly weighing 1,002 kg (2,209 lb), was a male shot at Kotzebue Sound in northwestern Alaska in 1960. Compared with the brown bear, this species has a more slender build, with a narrower, flatter and smaller skull, a longer neck, and a lower shoulder hump. The snout profile is curved, resembling

6375-530: The slightly younger Allocyon (early Oligocene , 34–30 Mya), both from North America. These animals looked very different from today's bears, being small and raccoon -like in overall appearance, with diets perhaps more similar to that of a badger . Parictis does not appear in Eurasia and Africa until the Miocene. It is unclear whether late-Eocene ursids were also present in Eurasia, although faunal exchange across

6460-540: The species Ursavus elmensis . Based on genetic and morphological data, the Ailuropodinae (pandas) were the first to diverge from other living bears about 19 Mya, although no fossils of this group have been found before about 11 Mya. The New World short-faced bears (Tremarctinae) differentiated from Ursinae following a dispersal event into North America during the mid-Miocene (about 13 Mya). They invaded South America (≈2.5 or 1.2 Ma) following formation of

6545-434: The suborder Caniformia , or "doglike" carnivorans, within the order Carnivora . Bears' closest living relatives are the pinnipeds , canids , and musteloids (some scholars formerly argued that bears are directly derived from canids and should not be classified as a separate family). Modern bears comprise eight species in three subfamilies: Ailuropodinae (monotypic with the giant panda ), Tremarctinae (monotypic with

6630-509: The support of the pinniped–amphicynodontine clade, other morphological and some molecular evidence supports bears being the closest living relatives to pinnipeds. The raccoon-sized, dog-like Cephalogale is the oldest-known member of the subfamily Hemicyoninae , which first appeared during the middle Oligocene in Eurasia about 30 Mya. The subfamily includes the younger genera Phoberocyon (20–15 Mya), and Plithocyon (15–7 Mya). A Cephalogale -like species gave rise to

6715-556: The water. The eyes of a polar bear are close to the top of the head, which may allow them to stay out of the water when the animal is swimming at the surface. They are relatively small, which may be an adaption against blowing snow and snow blindness . Polar bears are dichromats , and lack the cone cells for seeing medium, mainly green, wavelengths. They have many rod cells , which allow them to see at night. The ears are small, allowing them to retain heat and not get frostbitten . They can hear best at frequencies of 11.2–22.5 kHz,

6800-577: The western and southern Hudson Bay (WHB and SHB) populations. Bears in and around the Queen Elizabeth Islands have been proposed as a subpopulation but this is not universally accepted. A 2022 study has suggested that the bears in southeast Greenland should be considered a different subpopulation based on their geographic isolation and genetics. Polar bear populations can also be divided into four gene clusters : Southern Canadian, Canadian Archipelago , Western Basin (northwestern Canada west to

6885-493: The wild. Analysis of the number of variations of gene copies in polar bears compared with brown bears and American black bears shows distinct adaptions. Polar bears have a less diverse array of olfactory receptor genes, a result of there being fewer odours in their Arctic habitat. With its carnivorous, high-fat diet the species has fewer copies of the gene involved in making amylase , an enzyme that breaks down starch , and more selection for genes for fatty acid breakdown and

6970-527: The winter for a long period of hibernation , up to 100 days. Bears have been hunted since prehistoric times for their meat and fur; they have also been used for bear-baiting and other forms of entertainment, such as being made to dance . With their powerful physical presence, they play a prominent role in the arts , mythology , and other cultural aspects of various human societies. In modern times, bears have come under pressure through encroachment on their habitats and illegal trade in bear parts, including

7055-482: The world’s population of polar bears live. Competitors raced on skis , pulling their supplies in 120 lb pulkas , stopping en route at 3 staffed checkpoints to re-supply. In 2003, Chris McLeod and Tony Martin captained the first and second place teams, respectively, in the first ever Polar Race . On their return to England , they decided to set up and run an alternative challenge themselves, and formed Polar Challenge Limited . Since then, they have organised and run

7140-827: Was given its common name by Thomas Pennant in A Synopsis of Quadrupeds (1771). It was known as the "white bear" in Europe between the 13th and 18th centuries, as well as "ice bear", "sea bear" and " Greenland bear". The Norse referred to it as isbjørn ' ice bear ' and hvitebjørn ' white bear ' . The bear is called nanook by the Inuit . The Netsilik cultures additionally have different names for bears based on certain factors, such as sex and age: these include adult males ( anguraq ), single adult females ( tattaq ), gestating females ( arnaluk ), newborns ( hagliaqtug ), large adolescents ( namiaq ) and dormant bears ( apitiliit ). The scientific name Ursus maritimus

7225-491: Was implemented by McKenna et al. (1997) to classify all the bear species into the superfamily Ursoidea , with Hemicyoninae and Agriotheriinae being classified in the family "Hemicyonidae". Amphicynodontinae under this classification were classified as stem- pinnipeds in the superfamily Phocoidea . In the McKenna and Bell classification both bears and pinnipeds are in a parvorder of carnivoran mammals known as Ursida , along with

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