Polar Bear - Facts | Profile | Traits | Cub | Cute | Size

(Last Updated On: April 15, 2021)

A Polar bear looks cute, cuddly, and even pleasant. But do not be fooled. They’re skilled hunters and ferocious with it. Here are all the explanations you need to maintain a decent distance and admire them from afar. In this article, I am going to talk about Polar bear baby, size, cub, height, cute, profile, diet, facts, etc.

Adult polar bears don’t have any natural predators, although walruses and wolves can kill them. Longevity within the wild is 25 to 30 years, however, in captivity, a number of polar bears have lived to more than 35 years old.

Polar bear profile

The polar bear, scientific name Ursus maritimus is a hyper carnivorous bear whose native range lies largely inside the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas, and surrounding land plenty.

It is the most important extant bear species, in addition to the most important extant land carnivore. A boar (adult male) weighs around 350–700 kg (770–1,540 lb), whereas a sow (adult feminine) is about half that size.

Although it’s the sister species of the brown bear, it has advanced to occupy a narrower ecological area of interest, with many body traits tailored for chilly temperatures, for shifting throughout snow, ice, and open water, and for searching seals, which make up most of its diet. Although most polar bears are born on land, they spend most of their time on the ocean ice.

Their scientific name means “maritime bear” and derives from this reality. Polar bears hunt their most well-liked meals of seals from the sting of sea ice, typically dwelling off fats reserves when no sea ice is present. Because of their dependence on ocean ice, polar bears are categorized as marine mammals.

Because of anticipated habitat loss brought on by local weather change, the polar bear is classed as a weak species. For many years, large-scale searching raised worldwide concern for the way forward for the species, however, populations rebounded after controls and quotas started to take impact.

For hundreds of years, the polar bear has been a key determine within the materials, spiritual, and cultural life of circumpolar peoples, and polar bears stay essential of their cultures. Historically, the polar bear has additionally been referred to as the “white bear”. It is typically known as the “nanook”, based mostly on the Inuit time period nanuq.

Distribution

The polar bear is discovered within the Arctic Circle and adjoining land plenty as far south as Newfoundland. Due to the absence of human growth in its distant habitat, it retains more of its unique range than some other extant carnivore.

While they’re uncommon north of 88°, there’s proof that they range all the way in which throughout the Arctic, and as far south as James Bay in Canada.

The range contains the territory of 5 nations: Denmark (Greenland), Norway (Svalbard), Russia, the United States (Alaska), and Canada. These 5 nations are the signatories of the International Agreement on the Conservation of Polar Bears, which mandates cooperation on analysis and conservation efforts all through the polar bear’s range.

Bears typically swim to Iceland from Greenland—about 600 sightings for the reason that nation’s settlement within the ninth century AD, and 5 within the 21st century as of 2016—and are at all times killed due to their hazard, and the fee and issue of repatriation.

Polar bear Description

The solely different bear-related in size to the polar bear is the Kodiak bear, which is a subspecies of brown bear. Adult male polar bears weigh 350–700 kg (770–1,500 lb) and measure 2.4–3 meters (7 ft 10 in–9 ft 10 inch) in total size.

Around the Beaufort Sea, nevertheless, mature males reportedly average 450 kg (1,000 lb). Adult females are roughly half the size of males and usually weigh 150–250 kg (330–550 lb), measuring 1.8–2.4 meters (5 ft 11 in–7 ft 10 in) in size.

Elsewhere, a barely bigger estimated average weight of 260 kg (570 lb) was claimed for adult females. When pregnant, nevertheless, females can weigh as a lot as 500 kg (1,100 lb).

The polar bear is among the many most sexually dimorphic mammals, surpassed solely by the pinnipeds equivalent to elephant seals. 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. This specimen, when mounted, stood 3.39 m (11 ft 1 in) tall on its hindlegs.

The shoulder height of an adult polar bear is 122 to 160 cm (4 ft 0 inch to 5 ft 3 in). While all bears are short-tailed, the polar bear’s tail is comparatively the shortest amongst dwelling bears, starting from 7 to 13 cm (2.8 to 5.1 in) in size.

Polar bear Body Shape and Size

Compared with its closest relative, the brown bear, the polar bear has a more elongated body construct and an extended skull and nostril. As predicted by Allen’s rule for a northerly animal, the legs are stocky and the ears and tail are small.

However, the feet are very massive to distribute load when strolling on snow or skinny ice and to offer propulsion when swimming; they could measure 30 cm (12 in) throughout in an adult.

The pads of the paws are lined with small, tender papillae (dermal bumps), which offer traction on the ice. The polar bear’s claws are brief and stocky in comparison with these of the brown bear, maybe to serve the previous’s need to grip heavy prey and ice. The claws are deeply scooped on the underside to help in digging within the ice of the natural habitat.

Research of harm patterns in polar bear forelimbs discovered accidents to the right forelimb to be more frequent than these to the left, suggesting, maybe, right-handedness.

Unlike the brown bear, polar bears in captivity are hardly ever obese or significantly massive, presumably as a response to the nice and cozy situations of most zoos.

Teeth

The 42 teeth of a polar bear reflect its extremely carnivorous diet. The cheek teeth are smaller and more jagged than within the brown bear, and the canines are bigger and sharper. The dental formulation is 3.1.4.23.1.4.3.

Polar bear fur

Polar bears are fantastically insulated by as much as 10 cm (4 in) of adipose tissue, their cover, and their fur; they overheat at temperatures above 10 °C (50 °F), and are almost invisible underneath infrared images. Polar bear fur consists of a layer of dense underfur and an outer layer of guard hairs, which seem white to tan, however, are literally transparent.

Two genes that can be identified to affect melanin manufacturing, LYST, and AIM1, are each mutated in polar bears, presumably resulting in the absence of this pigment of their fur. The guard hair is 5–15 cm (2–6 in) over many of the bodies.

Polar bears step by step moult from May to August, however, not like different Arctic mammals, they don’t shed their coat for a darker shade to offer camouflage in summer season situations.

The hole guard hairs of a polar bear coat had been as soon as thought to behave as fiber-optic tubes to conduct light to its black pores and skin, the place it might be absorbed; nevertheless, this speculation was disproved by a examine in 1998.

Swimming

The polar bear is a superb swimmer and sometimes will swim for days. One bear swam repeatedly for 9 days within the frigid Bering Sea for 700 km (400 mi) to achieve ice removed from the land. She then traveled one other 1,800 km (1,100 mi).

During the swim, the bear lost 22% of her body mass and her yearling cub died. With its body fats offering buoyancy, the bear swims in a dog paddle vogue utilizing its massive forepaws for propulsion. Polar bears can swim 10 km/h (6 mph).

When strolling, the polar bear tends to have a lumbering gait and maintains an average pace of around 5.6 km/h (3.5 mph). When sprinting, they’ll attain as much as 40 km/h (25 mph).

Coat

The white coat normally yellows with age. When stored in captivity in heat, humid situations, the fur might flip a pale shade of green because of algae rising contained in the guard hairs.

Males have considerably longer hairs on their forelegs, which improve in size till the bear reaches 14 years of age. The male’s decorative foreleg hair is believed to draw females, serving the same performance as the lion’s mane.

Smell

The polar bear has an especially properly developed sense of odor, with the ability to detect seals almost 1.6 km (1 mi) away and buried underneath 1 m (Three ft) of snow. Its listening to is about as acute as that of a human, and its vision can also be good at long distances.

Habitat

The polar bear is a marine mammal as a result of it spends many months of the year at sea. However, it’s the solely dwelling marine mammal with highly effective, massive limbs and feet that enable them to cover kilometers on foot and run on land. Its most well-liked habitat is the annual sea ice covering the waters over the continental shelf and the Arctic inter-island archipelagos.

These areas referred to as the “Arctic ring of life”, have high organic productiveness compared to the deep waters of the high Arctic. The polar bear tends to frequent areas the place sea ice meets water, equivalent to polynyas and leads (temporary stretches of open water in Arctic ice), to hunt the seals that make up most of its diet.

Freshwater is proscribed in these environments as a result of it’s both locked up in snow or saline. Polar bears are in a position to produce water by means of the metabolism of fat present in seal blubber and are due to this fact discovered primarily alongside the perimeter of the polar ice pack, relatively than within the Polar Basin near the North Pole the place the density of seals is low.

Hunting

The polar bear’s commonest searching technique is known as still-hunting: the bear makes use of its glorious sense of odor to find a seal respiration gap, and crouches close by in silence for a seal to look.

The bear might lie in anticipate a number of hours. When the seal exhales, the bear smells its breath, reaches into the outlet with a forepaw, and drags it out onto the ice.

The polar bear kills the seal by biting its head to crush its skull. The polar bear additionally hunts by stalking seals resting on the ice: upon recognizing a seal, it walks to inside 90 m (100 yd), after which crouches.

If the seal doesn’t discover, the bear creeps to inside 9 to 12 m (30 to 40 ft) of the seal after which all of a sudden rushes forth to assault. A 3rd searching technique is to raid the start lairs that feminine seals create within the snow.

The polar bear is essentially the most carnivorous member of the bear family, and all through most of its range, its diet primarily consists of ringed (Pusa hispida) and bearded seals (Erignathus barbatus).

The Arctic is residence to thousands and thousands of seals, which turn out to be prey once they floor in holes within the ice with a view to breathing, or once they haul out on the ice to relaxation. Polar bears hunt primarily on the interface between ice, water, and air; they solely hardly ever catch seals on land or in open water.

The long muzzle and neck of the polar bear assist it to look in deep holes for seals, whereas highly effective hindquarters allow it to pull large prey.

Long-distance swimming and diving

Researchers tracked 52 sows within the southern Beaufort Sea off Alaska with GPS system collars; no boars had been concerned within the examine because of males’ necks being too thick for the GPS-equipped collars.

Fifty long-distance swims had been recorded; the longest at 354 kilometers (220 mi), with an average of 155 kilometers (96 mi).

The size of those swims ranged from most of a day to 10 days. Ten of the sows had a cub swim with them and after a year, six cubs survived. The examine didn’t decide if the others lost their cubs before, throughout, or a while after their long swims.

Researchers have no idea whether or not or not this can be a new behavior; before polar ice shrinkage, they opined that there was most likely neither the need nor alternative to swimming such long distances.

Polar bear Diet and feeding habit

Mature bears are likely to eat solely the calorie-rich pores and skin and blubber of the seal, which is extremely digestible, whereas youthful bears eat the protein-rich red meat.

They additionally eat birds’ chicks and eggs, scavenge the carcasses from different bears’ kills is a vital source of vitamin.

Subadults may additionally be pressured to simply accept a half-eaten carcass in the event that they kill a seal however can not defend it from bigger polar bears. After feeding, polar bears wash with water or snow.

Although polar bears are terribly highly effective, their main prey species, the ringed seal, is way smaller than themselves, and lots of the seals hunted are pups relatively than adults.

Ringed seals are born weighing 5.4 kg (12 lb) and grown to an estimated average weight of solely 60 kg (130 lb). They additionally in locations prey closely upon the harp seal (Pagophilus groenlandicus), the harbor seal (Phoca vitulina), or the hooded seal (Cystophora cristata). The bearded seal, alternatively, maybe almost the identical size because the bear itself, averaging 270 kg (600 lb).

Adult male bearded seals, at 350 to 500 kg (770 to 1,100 lb) are too massive for a feminine bear to overhaul, and so are potential prey just for mature male bears. Large males additionally sometimes try to hunt and kill even bigger prey objects. It can kill an adult walrus (Odobenus rosmarus), though that is hardly ever tried.

At as much as 2,000 kg (4,400 lb) and a typical adult mass range of 600 to 1,500 kg (1,300 to three,300 lb), a walrus may be more than twice the bear’s weight, has extraordinarily thick pores and skin, and has as much as 1-meter (Three ft)-long ivory tusks that can be utilized as formidable weapons. A polar bear might cost a gaggle of walruses, with the goal of separating a younger, infirm, or injured walrus from the pod.

They will even assault adult walruses when their diving holes have frozen over or intercept them before they’ll get back to the diving gap within the ice. Yet, polar bears will very seldom assault full-grown adult walruses, with the most important male walrus most likely invulnerable except in any other case injured or incapacitated.

Since an assault on a walrus tends to be an especially protracted and exhausting enterprise, bears have been identified to back down from the assault after making the preliminary harm to the walrus.

Polar bears have additionally been seen to prey on beluga whales (Delphinapterus leucas) and narwhals (Monodon monoceros),[95] by swiping at them at respiration holes.

The whales are of comparable size to the walrus and almost as troublesome for the bear to subdue. Most terrestrial animals within the Arctic can outrun the polar bear on land as polar bears overheat rapidly, 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 the carcasses of useless adult walruses or whales, whose blubber is instantly devoured even when rotten. Polar bears typically swim underwater to catch fish just like the Arctic charr or the fourhorn sculpin.

Polar bear Behavior

Unlike brown bears, polar bears will not be territorial. Although stereotyped as being voraciously aggressive, they’re usually cautious in confrontations, and sometimes select to flee relatively than a struggle.

Satiated polar bears hardly ever assault people except severely provoked. However, because of their lack of prior human interplay, hungry polar bears are extraordinarily unpredictable, fearless in direction of people, and are identified to kill and typically eat people. Many assaults by brown bears are the result of shocking the animal, which isn’t the case with the polar bear.

Polar bears are stealth hunters, and the sufferer is usually unaware of the bear’s presence till the assault is underway. Whereas brown bears typically maul an individual after which depart, polar bear assaults are more more likely to be predatory and are nearly at all times deadly.

However, as a result of very small human inhabitants across the Arctic, such assaults are uncommon. Michio Hoshino, a Japanese wildlife photographer, was as soon as pursued briefly by a hungry male polar bear in northern Alaska.

According to Hoshino, the bear began working however Hoshino made it to his truck. The bear was in a position to attain the truck and tore one of many doorways off the truck before Hoshino was in a position to drive off.

In common, adult polar bears reside solitary lives. Yet, they’ve typically been seen taking part in collectively for hours at a time and even sleeping in an embrace.

Hibernation

With the exception of pregnant females, polar bears are lively year-round, though they have got a vestigial hibernation induction set off of their blood.

Unlike brown and black bears, polar bears are able to fast for as much as a number of months throughout the late summer season and early fall, once they can not hunt for seals as a result of the ocean is unfrozen.

When sea ice is unavailable throughout summer and early autumn, some populations reside off fats reserves for months at a time, as polar bears don’t ‘hibernate’ any time of the year.

Reproduction

Courtship and mating happen on the ocean ice in April and May, when polar bears congregate in the very best seal searching areas. A male might observe the tracks of a breeding feminine for 100 km (60 mi) or more, and after discovering her have interaction in intense preventing with different males over mating rights, fights that always lead to scars and damaged teeth.

Polar bears have a typically polygynous mating system; current genetic testing of moms and cubs, nevertheless, has uncovered circumstances of litters during which cubs have totally different fathers. Partners keep collectively and mate repeatedly for a whole week; the mating ritual induces ovulation within the feminine.

After mating, the fertilized egg stays in a suspended state till August or September. During these 4 months, the pregnant feminine eats prodigious quantities of meals, gaining at least 200 kg (440 lb) and sometimes more than doubling her body weight.

Denning

When the ice floes are at their minimal within the fall, ending the potential of searching, every pregnant feminine digs a maternity den consisting of a slender entrance tunnel main to 1 to 3 chambers.

Most maternity dens are in snowdrifts, however may additionally be made underground in permafrost if it isn’t sufficiently chilly but for snow. In most subpopulations, maternity dens are located on land a couple of kilometers from the coast, and the people in a subpopulation are likely to reuse the identical denning areas every year.

The polar bears that don’t den on land make their dens on the ocean ice. In the den, she enters a dormant state just like hibernation.

This hibernation-like state doesn’t encompass steady sleeping; nevertheless, the bear’s heart fee slows from 46 to 27 beats per minute. Her body temperature doesn’t lower throughout this era as it could for a typical mammal in hibernation.

Polar bear Cub

Between November and February, cubs are born blind, lined with a light down fur, and weighing lower than 0.9 kg (2.0 lb), however in captivity, they may be delivered within the earlier months.

The earliest recorded start of polar bears in captivity was on 11 October 2011 within the Toronto Zoo. On average, every litter has two cubs. The family stays within the den till mid-February to mid-April, with the mom sustaining her quickly whereas nursing her cubs on fat-rich milk. By the time the mom breaks open the doorway to the den, her cubs weigh about 10 to 15 kilograms (22 to 33 lb).

For about 12 to 15 days, the family spends time outdoors the den whereas remaining in its neighborhood, the mom grazing on vegetation whereas the cubs turn out to be used to strolling and taking part in. Then they start the long stroll from the denning space to the ocean ice, the place the mom can as soon as once more catch seals.

Depending on the timing of the ice-floe breakup within the fall, she might have fasted for as much as eight months. During this time, cubs playfully imitate the mom’s searching strategies in preparation for later life.

Cub Care

Female polar bears have been identified to undertake different cubs. Multiple circumstances of the adoption of untamed cubs have been confirmed by genetic testing.

Adult bears of both gender sometimes kill and eat polar bear cubs. As of 2006, in Alaska, 42% of cubs had been reaching 12 months of age, down from 65% in 1991. In most areas, cubs are weaned at two and a half years of age, when the mom chases them away or abandons them.

The Western Hudson Bay subpopulation is uncommon in that its feminine polar bears typically wean their cubs at just one and a half years. This was the case for 40% of cubs there within the early 1980s; nevertheless, by the 1990s, fewer than 20% of cubs had been weaned this younger. After the mom leaves, sibling cubs typically travel and share meals collectively for weeks or months.

Later life

Females start to breed at the age of 4 years in most areas, and 5 years within the space of the Beaufort Sea. Males normally attain sexual maturity at six years; nevertheless, as competitors for females is fierce, many don’t breed till the age of eight or ten.

An examination in Hudson Bay indicated that each the reproductive success and the maternal weight of females peaked of their mid-teens. Maternal success appeared to say no after this level, presumably due to an age-related impairment within the capacity to retailer the fats necessary to rear cubs.

Polar bears seem much less affected by infectious ailments and parasites than most terrestrial mammals. Polar bears are particularly vulnerable to Trichinella, a parasitic roundworm they contract by means of cannibalism, though infections are normally not deadly.

Only one case of a polar bear with rabies has been documented, regardless that polar bears ceaselessly work together with Arctic foxes, which frequently carry rabies.

Bacterial leptospirosis and Morbillivirus have been recorded. Polar bears typically have issues with numerous pores and skin ailments that could be brought on by mites or different parasites.

Life expectancy

Polar bears hardly ever reside past 25 years. The oldest wild bears on report died at age 32, whereas the oldest captive was a feminine who died in 1991, age 43. The causes of loss of life in wild adult polar bears are poorly understood, as carcasses are hardly ever discovered within the species’ frigid habitat.

In the wild, old polar bears finally turn out to be too weak to catch meals, and step by step starve to loss of life. Polar bears injured in fights or accidents might both die from their accidents, or turn out to be unable to hunt successfully, resulting in hunger.

Ecological position

The polar bear is the apex predator inside its range and is a keystone species for the Arctic. Several animal species, significantly Arctic foxes (Vulpes lagopus) and glaucous gulls (Larus hyperboreus), routinely scavenge polar bear kills.

The relationship between ringed seals and polar bears is so shut that the abundance of ringed seals in some areas seems to manage the density of polar bears, whereas polar bear predation in flip regulates the density and reproductive success of ringed seals. The evolutionary strain of polar bear predation on seals most likely accounts for some important variations between the Arctic and Antarctic seals.

Compared to the Antarctic, the place there isn’t any main floor predator, Arctic seals use more respiration holes per particular person, seem more stressed when hauled out on the ice, and barely defecate on the ice.

The child fur of most Arctic seal species is white, presumably to offer camouflage from predators, whereas Antarctic seals all have darkish fur at birth.

Polar bear Conservation

Polar bear inhabitants’ sizes and traits are troublesome to estimate precisely as a result of they occupy distant residence ranges and exist at low inhabitants densities.

Polar bear fieldwork may also be hazardous to researchers. As of 2015, the International Union for Conservation of Nature (IUCN) studies that the worldwide inhabitants of polar bears are 22,000 to 31,000, and the present inhabitant’s pattern is unknown.

Nevertheless, polar bears are listed as “Vulnerable” under criterion A3c, which signifies an anticipated number of inhabitants lower of ≥30% over the next three generations (~34.5 years) because of “decline in area of occupancy, the extent of occurrence and/or quality of habitat”.

Risks to the polar bear embody local weather change, air pollution within the type of poisonous contaminants, conflicts with transport, oil and gasoline exploration and growth, and human-bear interactions together with harvesting and possible stresses from leisure polar-bear watching.

Polar Bear – Facts | Profile | Traits | Cub | Cute | Size | Height