Polar bears are generally voracious meat-eaters so much so that they show cannibalistic behavior at times. They become the predators of themselves. That is to say that polar bears eat polar bears. It happens quite often when adult male bear (boar) wanders around and it finds a female (sow) den with cubs in it. The soar is most likely to kill and possibly eat cubs. The boars are greater in strength as compared to sows.
Although the mother bear tries her best to drive the adult male away the latter becomes too hungry to give up. The mature male is nearly twice the size of an adult female. Thus the female stands no chance to compete with the male. As a result the mother gets injured while the cubs get killed. Boars will grab the dead cubs and eat them.
Polar Bear Cannibalism
Sometimes the younger bears also become the victims of adult bears. Very few researchers have been able to grab photos of a polar bear eating its cubs. Although male bears are far more aggressive and are infamous for cannibalism female mothers also eat their cubs. The cannibalism in female occurs when the mother cannot feed twins or three cubs.
During nursing the sows remain hungry sometimes do not eat for months. However they do have a breaking point beyond which sows are likely to become the predator of her cubs. She sacrifices one of her cubs and eats it to keep herself alive. The cannibalism in female polar bears is extremely rare because they are devoted mothers.
Researchers also observed cannibalism in adult polar bears in the southern Beaufort Sea. These mature bears eventually became too weak to hunt seals. As a consequence they started eating their own cubs. Scientists blame climate change for increasing cannibalism in polar bears. According to them the sea ice is breaking up earlier than ever in the Hudson Bay leaving many polar bear cubs susceptible to cannibalism.
Polar bears (Ursus maritmus) are the largest of the land carnivores. They are solitary predators. Unlike most other carnivores (such as wolves) white bears will never hunt in groups. The nomadic polar bear doesn’t seem to rely on one hunting technique. The bear uses unique strategies that take months to learn and which is why adults typically prefer to kill prey as compared to young bears. Young bears will spend their initial two years of training with mother. The mother teaches her kids several techniques as well as how to survive in the natural habitat.
Polar Bear Behavior – Polar Bear Behavior Facts
Feeding Behavior
Polar bears regularly feed on ringed and bearded seal but they also prey on larger prey such as beluga whale and walrus. The last two preys are rare because they are not as nutritious as seals. Seals provide blubber which is quite helpful during dormancy. However if white bears couldn’t find seals they would rely on coastal and terrestrial plants but the change in diet is temporary. Biologists believe that polar bears kill around 44% of seal pups each year. This has been observed in the Prince of Wales Island and Cornwallis Island.
Polar bears have got massive body and they need 2 kg (4.4 lbs) of fat every day. They do so by killing large number of seals in mid-June to mid-August when seals are abundant. Nonetheless, polar bears are able to spend months in starvation—an adaptation quite useful in warmer months when the sea ice melts.
Polar bears reach maturity after 5 – 6 years of age. The female gives birth to 1 – 2 cubs. The small litter size and predation at an early age are reasons for polar bear’s mortality. The female plays a major part in raising cubs. During starvation when the food is scarce the mother will not be able to raise two cubs at a time. It means that she may feed only one cub. It happens when twins are born. The birth usually occurs in November and December. Adult males rarely take part in nursing. The job must be done by a mother alone which is quite tough because alongside feeding she must protect them from adult males.
Photo by Arctic.ru
Non-territorial Carnivorous
White bears are mercurial creatures. They keep moving and they don’t seem to mark territories. This is probably an adaptation to adjust with different environmental stressors. The change in weather leads to a change in bear’s territory.
Bears rely heavily on seals. During summer when the sea ice melts bears could not hunt their primary prey i.e. seals. As it turns out, they must keep moving and make homes where seals are abundant. The movement in polar bears is associated with their survival. The only way to survive is to follow the prey. That is why polar bears do not defend their territories.
Nevertheless polar bears can be highly aggressive. Past incidents show that polar bears do attack humans but that occurs only when they are provoked. Hungry bears are highly dangerous and they may attack humans if they must. Normally white bears will walk away and avoid confrontations.
Vast Home Range
Polar bears possess extremely vast territory. The range is so wide that scientists are unable to measure the extent of its territory. This is one reason why biologists couldn’t come up with reasonable estimates of polar bear population.
The polar bear (Ursus maritimus) doesn’t seem to have any special anatomical adaptations despite the fact that it is the only bear species that spends almost the entire life in water. The large body size of a bear prevents the heat loss—thereby making it warm even in frigid arctic weather.
Polar Bear Anatomy
Musculo-Skeletal System
Reproductive System
Gastro-intestinal System
Circulatory System
Urinary System
Respiratory System
Polar Bear Musculo-Skeletal System
According to The American Society of Mammalogists the polar bear’s neck muscles are extremely strong and powerfully developed. This can be evident from the fact that ice bears can easily pull a 600-pound seal with their neck. Apart from neck muscles the hind limbs are also thought to develop perfectly not only to support the weight (when the bear stands on its hind feet only) but also for gripping on the sea ice.
The study of the American Society of Mammalogists showed that the wild specimen appear to have testes of varied sizes. Polar bear’s testes are of different sizes in different seasons. For instance in May the testes grow up to 39.4 +/- 3.5 cm² whereas in late October the size measured at 27.3 +/- 2.0 cm². The small glandular ampullae lie at the distal ends of vasa deferentia. Polar bears have small prostate gland.
A mother polar bear is nursing her cubs. Polar bear anatomy. Photo by Fine Art America.
How Many Nipples Do Polar Bears have?
The female polar bear possesses four teats or nipples all of which are functional. Four teats make up two pairs; the front pair (anterior) is only moderately posterior to the axillae and measures around 4 cm from the midline on both sides. The other two teats measure up to 15 cm further posterior. The front pair of nipples lies very close to the front legs (only just behind) whereas the second pair lies further to the back.
Functional Mammae
There are typically four functional mammae in other bear species but in female polar bear there can be four or five functional mammae. The one extra gland is situated at the posterior of the usual glands. The gland measures 4 cm from the middle on the back abdomen.
One of the females found by the Society seems to possess two extra teats measuring 15 cm anterior to the vaginal orifice. These two extra nipples are found in inguinal region. Scientists found that none of the two nipples had milk; both were non-functional. The female also possesses os clitoris.
The gastrointestinal system of polar bears behaves quite differently in summer and winter. The system is directly associated with the feeding habits which is why it responds almost immediately to the polar bear’s type of food. When polar bears eat a lot of sea blubber (mostly they do) they appear to discharge dark jellylike faeces in a liquid form. This is mainly because the seal blubber is low in fibre.
Studies further suggest that there is a significant change in the gut transit time. When an ice bear consumes seal muscle the timing is 13.8 +/- 5.4 hours and when she eats sea blubber the gut timing is 38.0 +/- 8.0 hours. Similarly if a bear feeds on fish the timing is 12.3 +/- 1.9 hours.
The polar bear faeces are more large rounded in shape and appear like a small cylinder. The color of the faeces is dark black or brown. The captive bear drops faeces after every 17 – 22 hours especially when it is fed with ringed seal carcass. However when a bear only eats blubber then the transit time increases and it reaches up to 36 hours. The fish-eating polar bear in captivity is likely to discharge faeces in 14 hours.
Polar Bear Circulatory System (Heart Beat Rate)
The average heart beat rate in adult polar bears is 60 to 90 bpm however in cubs the rate reaches high up to 130 beats per minute. The high bpm in cubs is mainly because of their activity level. When the bear relaxes the pulse rate is 45 – 60 bpm. Similarly when the polar bear is asleep the heart rate gets down to 30 – 40 bpm. The pulse rate of a polar bear during running reaches up to 150 beats per minute. However the typical pulse rate in an active bear is around 130 bpm. During winter if the bear starves the rate falls down to 27 bpm.
Polar Bear Urinary System
The polar bear’s kidneys appear to be lobulated in shape. Unlike kidneys of any other carnivore the ice bear kidneys seem to have as many as 65 lobules. This is the greatest number of lobules in any carnivorous mammal.
Polar Bear Respiratory System
Polar bears have a typical respiratory rate of 15 – 30 breaths per minute. However the breath rates go higher in warmer months. When the bear is asleep rates are only 5 breaths per minute. Polar bears are also seen panting and when they do the breath rates are as high as 105 – 133 every minute. Similarly when the bear charges for the prey in short bursts breaths are greater than usual.
Blubber Fat or Obesity in Polar Bears
The subcutaneous fat is the primary cause of obesity in polar bears. Adult bears have a dense layer of subcutaneous fat measuring 5 to 10 cm in thickness. Adult females in particular become obese weeks before they go into their materiality den. Females are thought to possess as much fat as containing 45% of the bear’s weight.
Polar bears have 4-cm-thick blubber layer which is covered with 2-mm-thick muscle sheets. The thickness of polar bear’s torso is about 0.5 to 3.0 mm. The muscle sheets are likely to be based on the broadest muscle of the back latissimus dorsi.
The supply of blood is sufficed to entertain the entire sheets of muscles. Numerous veins and arteries run from the body musculature via intramuscular blubber layer along the way to the latissimus sheets. The polar bear’s veins are 2 – 4 mm in diameter. The gap between the veins measures around 3 – 5 cm. The veins erupt from the dorsal edge of the bear’s muscle and enter the body core.
The polar bear’s limbs seem to have rich supply of blood with blood vessels go side by side—ranging from knees all the way to the ankle. The body or flesh at the top of the rear legs is known as rump. In polar bears there is a thick blubber pad that dominates the rump. The blubber pad measures about 11 mm in thickness.
Polar Bear’s Adipose Tissue
Studies further reveal that the adult polar bears’ (male and female) consist of 18.7 – 17.5% adipose fatty tissue. The content of fats is only slightly higher in captive bears as compared to the wild population. In fact the examination of few specimens reveals that the deposits of fats are almost the same in wild and captive bears. However the quantity of adipose tissue in captive polar bears is significantly greater than that of wild bears. Scientists also found that the number of adipocytes is greater than they expected.
The greater number of fatty deposits clearly reflects on the polar bear’s diet in captivity. Since the wild bears must spend days or even months in fasting the deposit of fats is relatively low. While polar bears are fairly rich in Vitamin A the level of Vitamin D3 in the bear’s blubber is estimated as 406.17 +/- 139 (mean +/- SD). The level of Vitamin D3 is quite high in fact higher than most invertebrate-eating mammals. Nonetheless, it is lower than mammals which feed on vertebrates.
It is quite amazing that polar bears have adapted to the harsh arctic environment where most land mammals could hardly survive one day. Thanks to the physiological, structural, and behavioral adaptations of a polar bear that allow her not only to survive but also to live like many Arctic mammals. These adaptations are likely to arise when animals are forced to live in different habitats. This occurs gradually during which the bear learns to adapt herself with the environment. This is called adaptation.
In order to know these adaptations in detail one must understand how polar bears have evolved to live on the sea ice. While the powerful paddle-like feet provides absolute support to the body weight dense fur, specialized teeth, and sharp nose facilitates the bear in swimming, eating, and smelling respectively. Let us discuss then how do polar bears adapt to the tundra.
How Do Polar Bears Adapt to their Environment?
Scientists believe that polar bears might have evolved from grizzly bears some 70,000 to 100,000 years ago. The white bears have probably adapted their ecological behavior from grizzly bears and both the species appear to have separated in the glacial periods. This explains why Ursus maritmusseem to share quite similar characteristics with Ursus arctos.
The formidable polar bear’s feet are strong enough to support and balance the entire weight of the body on the sea ice. Besides support feet also facilitates the bear in swimming. Adult bears have their feet measuring 30 cm across. The polar bear’s paws are very handy in walking on the snow ice. The dermal pumps on the paws assist the bear to grip.
Unlike brown bears’ polar bears have claws which provide the animal firm grip not only on the ice but also on the prey. The short but powerful claw allows the white bear to hold the prey and the latter finds it impossible to escape. The brown bear’s paw is not that stocky.
Polar bears are one of few animals that can detect smell from kilometers away. It is often said about white bears that they smell you before you see them. They are thought to discover seals from a mile away even when the prey is moving underneath the snow.
While know only little about polar bear’s hearing sense they can probably hear up to 25 kHz. They are known to possess hearing sense as powerful as that of a human. White bears have less sharp hearing as compared to dogs even though the former is able to communicate in low frequencies.
While polar bears have acute sense of smell they do possess pretty good sight. They are able to visualize things and can probably recognize colors.
Sense of touch
Polar bears are often seen touching things with their nose, tongue, and claw. However the statement lacks any scientific explanation whatsoever.
Polar bears are insulated by their dense furry coat. How do polar bears adapt to the Arctic. Photo by childrensmuseumofphoenix.org
Polar Bear Structural Adaptations
Structural adaptations of a polar help her to adapt with different environmental stressors such as the bear white fur which camouflages her in the snow. Structural adaptations also include adaptations as to how a white bear will protect her from the predators.
Fur and Coat
Polar bears possess white coat which goes pale yellow as the bear grows older. In captivity the yellowish coat is rather common and prominent because of the humid conditions. Sometimes the captive bear gives a shade of green color which is probably due to the algae that grows inside polar bear hair. Adult males seem to have longer hairs on their legs. These hairs continue to grow till the age of 14 years. Scientists say that adult males show long hairs to attract females.
The dense layer of the coat not only serves as an insulator but it virtually makes the bear to disappear in the white background. The primary prey seal finds it hard to detect the polar bear and when it does so it’s almost too late.
Polar Bear Behavioral Adaptations
Dormancy
Brown bears hibernate but polar bears do not! White bears become inactive in season as they go into dormancy state. Adult females which are expecting babies usually become dormant. Adult males, though not active, do move around in search of prey. The dormancy state is not a true hibernation. During dormancy the bear lowers her metabolism and rely exclusively on the available fats.
Feeding Behavior
Polar bears predominantly prey on ringed and bearded seals which qualifies them as the most carnivorous bear of all Ursids. They hunt seals mostly underwater and rarely on land.
How Do Polar Bears Adapt to their Environment? – Video
Polar bears are sexually dimorphic mammals in that males are significantly larger and heavier than females. They are nearly twice larger and heavier in comparison to the females. The typical weight of a male polar bear measures around 350–700 kg (772–1,543 lb). Males are highly aggressive but they usually avoid each other. However during breeding season male bears fight over the females. Male polar bears eat cubs especially when the food is scarce. The cannibalism behavior is more likely to be observed in male polar bears than female polar bears.
Male Polar Bear
Male polar bear is called a boar.
Adult male bears have shoulder height of about 122 to 160 cm (4 ft 0 in to 5 ft 3 in). Like females male bears also possess short tail measuring up to 7 to 13 cm (2.8 to 5.1 in).
The total length of a boar is 2.4–3 meters (7 ft 10 in–9 ft 10 in). The male polar bears are only slightly smaller than the male Kodiak bears.
How Much does a Male Polar Bear Weigh? | Male Polar Bear Weight
The male polar bear’s weight ranges from 350 to 700 kg (772 to 1,543 lb). According to the Guinness Bookof World Records adult male polar bears weigh up to 385 to 410 kg (849 to 904 lb) and a shoulder height measuring at 133 cm (4 ft 4 in).
Largest Male Polar Bear
The largest male polar bear ever recorded was shot in the northwestern Alaska in 1960. The bear reached the height of about 3.39 m (11 ft 1 in) on her hind legs.
Polar bear (Ursus maritimus) and Kodiak bear (Ursus arctos middendorffi) are two different species not only in their diet, habitat, and distribution but also in their behavior. The only common trait between the two predators is their size. They are almost of the same size. Some scientists believe that polar bears are the largest land mammals living today others say that Kodiak bears supersede white bears in size. Either way both animals have long fascinated biologists for their super strength and ability to take down prey nearly the size of their own.
Kodiak Bear vs Polar Bear Size Comparison
Let us first study the size of Kodiak bear and a polar bear.
Kodiak Bear Size
Kodiak bears are the largest subspecies of brown bears. They had the skull size of about 78.1 cm (30.7 in).
Adult Kodiak males weigh as much as 477–534 kg (1,052–1,177 lb) with the average weight of about 272 to 635 kg (600 to 1,400 lb). Mature males attain maximum weight of 680 kg (1,500 lb).
Females range from 181 to 318 kg (399 to 701 lb) in weight. Like polar bears Kodiak females are 25% smaller than males.
The average length in mature males is around 244 cm (8 ft 0 in) and the shoulder height is 133 cm (4 ft 4 in). Larger specimen is able to stand 1.5 m (4.9 ft) at the shoulder when it rests on four legs. However when the bear stands on her hind legs the height reaches up to 3 m (9.8 ft).
Polar Bear Size
Adult polar bear males weigh up to 350–700 kg (772–1,543 lb) with the total length measuring around 2.4–3 metres (7 ft 10 in–9 ft 10 in).
Mature females average 150 – 250 kg (331–551 lb) in weight. She had a total length of 1.8–2.4 metres (5 ft 11 in–7 ft 10 in). They can attain the maximum weight of 500 kg (1,102 lb) during pregnancy.
Males stand 122 to 160 cm (4 ft 0 in to 5 ft 3 in) at the shoulder height.
A big Kodiak Bear. Photo by exploredia.
Largest Kodiak Bear ever Recorded
The largest wild Kodiak bear ever recorded weighs up to 751 kg (1,656 lb). This is the size of an adult male. It had the hind foot measured around 46 cm (18 in).
The largest captive Kodiak bear ever recorded in Dakota Zoo in Bismarck, North Dakota. The bear weighed as much as 966 kg (2,130 lb) and it had a nickname The bear died in 1987.
Largest Polar Bear ever Recorded
The largest polar bear ever recorded at 1,002 kg (2,209 lb). The bear was shot in Kotzebue Sound in northwestern Alaska in 1960. It could reach the height of 3.39 m (11 ft 1 in) while standing on hind legs.
Kodiak vs Polar Bear Color
Kodiak bear are typically known for their blonde to orange hair color. The cubs have white ring around their neck which is quite visible in their initial years after birth. Polar bears have white hollow hair but the color of the coat turns yellowish during summer. Unlike Kodiak species white bears have black skin.
Kodiak vs Polar Bear Habitat & Distribution
The Kodiak brown bear occurs on the Kodiak Archipelago islands including Raspberry, Kodiak, Shuyak, Uganik, and Afognak islands. Polar bears inhabit the Arctic Circle as well as neighboring islands including Newfoundland but they are virtually dissimilar from Kodiak bears in their habitat and distribution.
Kodiak vs Polar Bear Population
The estimated population of Kodiak brown bears is just over 3,500 but the Endangered Species Act not yet listed it as endangered species. Polar bears on the other hand are far greater in numbers than the Kodiak species. There are more than 20,000 white bears living today.
Kodiak vs Polar Bear Reproductive Behavior
Both Kodiak bear and polar bear seem to show different behavioral traits in reproduction. The Kodiak bear female (sows) will reach the sexual maturity at 8 – 10 years age whereas the polar bear female begins to breed in 4 – 5 years.
The mating and courtship season is nearly the same in both species. Kodiak bear mates in April to May while white bears in May to June.
The average lifespan of both species is 20 years in the wild. The oldest Kodiak male bear died at 34 years age and the oldest polar bear died at 32 years age.
Polar bears are polygynous in that the male is likely to mate with multiple females at a time. However each female polar bear will only mate with one male. The couple remains connected for a week. On the other hand Kodiak bears are seriously monogamous species. The male remains faithful to her female partner all her life which is probably one of the reasons as to why they have fewer numbers.
Polar bear cubs and Kodiak bear cubs are born blind and helpless in dens. They are born in January or February. Both seem to give birth to 2 – 3 cubs. Polar cubs stay with their mother for 2 years whereas Kodiak cubs for 3 years.
The average lifespan of both species is 20 years in the wild. The oldest Kodiak male bear died at 34 years age and the oldest polar bear died at 32 years age. The mortality rate is extremely high in the first two years of their birth.
A big male polar bear. Kodiak bear vs polar bear. Photo by Mother Nature Network.
Kodiak vs Polar Bear Behavior
While polar bears make dens on the sea ice Kodiak bears typically dens in the hill sides or mountains. Polar bears have one of the largest ranges of about 465,000 sq. kilometers. Kodiak brown bears have one of the smallest ranges of about 50 sq. mi (130 km2).
Like polar bears Kodiak bears also do not defend territories.
Kodiak bears are primarily diurnal like most other bears but they have become nocturnal due to the competition of food during the day. Polar bears become naturally active during the day.
Both are solitary in nature and they only meet during the mating season.
Polar bears are outstanding swimmers but Kodiak bears are not.
Kodiak and polar bears will avoid humans if possible. However a hungry polar bear will look at humans as a potential food source especially in summer when the food is scarce.
Kodiak vs Polar Bear Feeding Habits
Unlike polar bears Kodiak bears feed exclusively on salmon fish and also supplements her diet with a variety of vegetation. White bears are pure carnivores—in fact the most carnivorous of all bear species. While Kodiak bears rely on salmon fish polar bears rely on seals for their consumption.
Kodiak vs Polar Bear Conservation Status
Although fewer than 4,000 Kodiak bears are remaining in the wild yet they are not listed as endangered species. Polar bears are threatened in some of its isolated population but certainly not endangered.
Yes polar bear is a mammal. It possesses all the required characteristics of mammals. The ice bear is the carnivorous mammal. It is in fact the most carnivorous of all bear species. Polar bear is also the world’s largest carnivorous land mammal living today.
Is a Polar Bear a Mammal?
Like all mammals, polar bear females nurse their cubs with milk. The female possesses mammary glands through which the milk is secreted.
Polar bears possess heart which has four chambers. All mammals have four-chambered heart.
White bears are viviparous in that they give birth to live young instead of laying eggs.
Is a Polar Bear a Marine Mammal?
While polar bear is the largest carnivorous land mammal she is also referred to as the marine mammal because the bear spends more than half of her life in water.
Polar bears have got the amazing ability to swim great distances. They can cover hundreds of kilometers in water without even relaxing. Characteristics such as these make polar bear the marine mammal.
Yes! Polar bear is a carnivore indeed it is the most carnivorous of all bear species. Polar bears need and eat fats all the time which they get from seals. The primary diet of the ice bear is ringed seal and bearded seal. While young bears consume the seal’s meat adult bears feed on the seal blubber to take as much fat as they possibly can. Polar bears are exclusively meat-eaters. They belong to the carnivora order. Bears may supplement their diet with hooded seal, harp seal or whale and dolphin carcasses but they may not resort to eating plants matter. Let us see if polar bear carnivore or omnivore.
Is a Polar Bear a Carnivore?
Although brown or grizzly bears and black bears also belong to the order carnivora they do not rely on meat as much as polar bears do. Asian bears and North American bears supplement their diet with grasses, shoots, sedges, fruits, and berries along with fish. But same is not the case with polar bears. They never eat plants or grasses. Polar bear eats grass only once or probably twice in two years. Sometimes male bears feed on grass soon after copulation or mating. Apart from that white bears are not generally known to consume grass. There are not many plants or trees in the Arctic which is besides the point. They would love to take proteins and fats in their regular diet.
Polar bears possess longer and sharper canines than any other bear species. These canines serve as sharp knives that can rip the flesh off and can easily cut the hardest part of the skin. Furthermore, polar bears must eat proteins to survive the frigid arctic weather.
Polar bears are greedy animals but they know what they must eat in order to survive in the arctic. In seals bears eat the fatty part which is blubber. The polar bear’s stomach is large enough to hold up to 50 – 90 kilograms of meal in one time. They are known to consume 10 kilograms of blubber in less than 30 minutes. In Russia, a captive female bear ate up to 80 kg of sea blubber in one-half of a day.
How Much Do Polar Bears Eat a Day?
It’s not every day that polar bears find animals they need to eat. Bears must rely on small animals if they couldn’t find one of their favorite meals (seals). In the harsh Arctic environment it is reasonable to assume that bears spend several weeks in starvation because the weather keeps changing and the prey keeps moving and so as the bear. White bears supplement their food source with reindeer, waterfowl, muskox, kelp, berries, and small rodents.
When polar bears prey seals they eat a lot. An adult bear eats as much as 20% of its body weight. The adult polar bear weighs up to 500 pounds. As per calculations, she will consume 100 pounds of meat in a single sitting. Bearded seals have thick dense skin. The bear tears its skin and eat the blubber first because it is a high-calorie food source. Subadults need more proteins in their diet which they get by killing seal pups.
No wonder it’s a mammoth task to observe the bear’s diet each year. There is no absolute estimate for the number of seals a polar bear kill a year probably because the bear’s home range is too wide to cover. Scientists have studied the dietary behavior of polar bears in the Canadian High Arctic and Devon Island.
The polar bear’s stomach is large enough to hold up to 50 – 90 kilograms of meal in one time. They are known to consume 10 kilograms of blubber in less than 30 minutes.
They studied the behavior from early April to early August when much of sea ice disappears. It means that biologists have not been able to know the precise behavior of polar bears for nearly 68 – 70% of the year. The Canadian High Arctic remains in darkness for the rest of the months. Besides, the polar bear’s habitat is extremely remote—making it impossible for scientists to observe the animal’s predatory behavior.
While polar bears are not lucky enough to find seal every day they do manage to hunt a single seal in 2 – 16 days especially in the peak hunting season. According to an estimate on in every five seals are ringed seals. The success rate in hunting is also not too bad. The peak hunting months of polar bears begin in March and ends on June. During these months polar bears store as much energy as they possibly can to use it in hibernation period. The ideal seal-hunting months are called hyperphagic period—a phase when icy bears eat seals inasmuch as possible.
According to an estimate, an individual polar bear consumes 43 seals let alone ringed seals a year. Biologists also calculated that 1,800 to 2,000 polar bears will require 77,400 to 128,469 seals annually. This clearly suggests that seals are the primary and dominant component of polar bear’s diet. Similarly if there are 30,000 polar bears living in the Arctic they are going to eat 1,500,000 seals in a single year.
The wild polar bear (Ursus maritimus) lives up to 20 years but the maximum lifespan rarely goes beyond 25 years. In this article we’re going to study what is the life expectancy of a polar bear. One of the wild specimens died at 32 years age which is so far the oldest on record. In captivity a female polar bear lived as long as 43 years. She died in 1991. Unluckily scientists have not been able to understand the real causes of polar bear’s mortality in the arctic habitat. This is because the carcasses of dead bears are hard to find in the frosty habitat. Let’s see how old do polar bears live in the arctic as well as in captivity.
How Long Do Polar Bears Live?
Biologists have reason to believe that polar bears have low lifespans in the wild habitat mainly because they find it hard to hunt seals as they eventually grow older. Besides, starving with age is a tough ask. On an average arctic polar bears live for 18 – 20 years. Only a handful number of bears are perhaps lucky enough to celebrate their silver jubilee.
Polar bear Lifespan in Captivity
Captive bears live longer lives because they are fed properly and on timely basis and they are given ideal environment. They do not hunt animals for they don’t need to. All these contribute to the longer lifespan of polar bears in captivity.
A mother polar bear guards her cub in the first two years. How long do polar bears live? Photo by FloridaStock/Shutterstock
How Old can Polar Bears Live up to?
Under the ideal conditions such as those provided in captivity polar bears live around 32 – 35 years with one captive specimen reaching 43 years age. However in the arctic they can hardly survive beyond 25 years due to difficulty in hunting at an old age. Males are thought to have lesser annual survival rate as compared to females within wild populations. This is probably because male polar bears get into conflict on females and their fight often leads to fatal injuries.
Probable Causes of Polar Bears’ Deaths in the Wild
Over time polar bears begin to lose strength and possibly desire to hunt seals. They will now rely on easy meal such as those that can be found without hunting i.e. carcasses. However in the frigid arctic habitat the carcasses are hard (even harder) to find. Many adult polar bears are thought to survive on dead carcasses and sometimes bird (geese) eggs. These food sources do not provide sufficient nutrition value to polar bears since they rely almost exclusively on fats. Thus the scarcity of food and a lack of will power in polar bears become the significant causes of their deaths.
Polar bears do not seem to have any natural predator in the arctic. However adult bears do sometimes fight each other just to win over a female during breeding season. The polar bear’s fight leads to serious bruises which are likely the causes of her death. The injured bear however powerful she may be is less likely to hunt. Besides fighting, adult polar bears also kill cubs to mostly to bring females into estrus and rarely to eat them as a potential food source. The interspecific conflicts also appear to become greater when the food is scarce. All these causes lead to the shorter lifespans of a polar bear in the wild habitat.
How Long Do Polar Bears Live? – Polar Bear Lifespan – Video
