The polar bear is a predator or not. The polar bear is a large predator of the north. Description and photo of the polar bear. Polar bear and brown bear: comparative characteristics

03.05.2020

My daughter loves to watch the cartoon about Umka. And today she asked where Umka lives and whether he is friends with penguins. Then another series of questions followed, and I had to answer. I will tell you about all the subtleties of my answer.

Locations of polar bears

Polar bears, as my daughter expected, live at the North Pole. But they do not meet with penguins in natural conditions. This is because they live in different parts of the world. Penguins live exclusively at the South Pole, and polar bears at the North. The largest part of these bears lives in Northern Canada. In Russia Polar bears live on Vrungel Island.

Survival in extreme conditions

Polar bears look very cute and funny, but they live in the harshest places. What helps them survive?

Bears feed mainly on seals.. In one season, a polar bear can eat up to 50 seals. But they rarely eat meat. They mainly eat skin and fat., and Arctic foxes, who often follow polar bears, eat up the meat behind them. During the day the bear passes and swims long distancesin search of prey. He can spend several hours at the hole, waiting for the next seal.

With the advent of global warming, the climate is changing, glaciers are receding, and polar bears have to travel thousands of kilometers in search of seal habitats. And during the summer, when it gets warm, bears can fast for up to four months.. At this time, they lie peacefully on the shore and bask in the sun.

Polar bear, aka polar or northern bear (lat. Ursus maritimus) is a predatory mammal that belongs to the canine suborder, the bear family, the bear genus. The name of the beast is translated from Latin as “sea bear”, and the predator is also called oshkuy, nanuk or umka.

International scientific name: Ursus maritimus(Phipps, 1774).

conservation status: vulnerable view.

Polar bear - description, structure, characteristics

The polar bear is the largest land predator and one of the largest predators on the planet, which is second only to the elephant seal in its dimensions. The largest polar bear weighed just over 1 ton and was about 3 meters long. The height of this bear, standing on its hind legs, was 3.39 m. On average, the body length of males is about 2-2.5 m, the height at the withers is from 1.3 to 1.5 m, and the average weight of a polar bear varies in within 400-800 kg. Bears are 1.5-2 times smaller, usually their weight does not exceed 200-300 kg, although pregnant females can weigh up to 500 kg. Interestingly, in the Pleistocene era (about 100 thousand years ago), a giant polar bear lived on earth, its size was about 4 meters in length, and its body weight reached 1.2 tons.

The polar bear has a heavy, massive body and large, powerful paws. Unlike other representatives of the genus, the neck of polar bears is elongated, and the head with small ears has a flattened shape, but with an elongated facial region characteristic of all bears.

The jaws of the beast are extremely powerful, with well-developed, sharp fangs and incisors. In total, a polar bear has 42 teeth. Facial vibrissae are absent in animals.

The tail of a polar bear is very short, has a length of 7 to 13 cm and is almost invisible from under thick fur. The paws of the polar bear end in five fingers, armed with sharp non-retractable claws of impressive size, which allows predators to hold the largest and strongest prey.

The soles of the paws are covered with coarse wool, which prevents slipping on ice floes and does not allow the paws to freeze. In addition, polar bears are great swimmers and divers, and there is a swimming membrane between their fingers, which helps with long swims.

The fur of the polar bear is rather coarse, dense and extremely dense, with a well-developed undercoat. Such a rich fur coat and an impressive layer of subcutaneous fat up to 10 cm thick make animals practically invulnerable even in the most severe frosts and when they are in ice water. Only the paw pads and the tip of the muzzle are not protected by fur.

Polar bears are powerful and hardy predators, very agile and fast for their weight and impressive size. On land, the speed of a polar bear averages 5.6 km / h, and when running it reaches 40 km / h. During the day, the animal can cover a distance of up to 20 km. A polar bear pursued in water is capable of accelerating up to 6.5-7 km/h, and if necessary it can swim without stopping for several days. A fact is known when a female polar bear swam non-stop to the feeding place for 9 days, although during this time she lost up to 22% of her body weight and her cub.

Polar predators have well-developed hearing, sight and smell. The animal senses the prey at a distance of more than 1 kilometer, and standing over the shelter of potential prey, it is able to catch the slightest movement. Through a meter layer of snow, a polar bear can smell the place of the seal's air (holes in the ice, with the help of which the seal breathes).

Polar bear lifespan

Under natural conditions, polar bears live for about 20-30 years (males up to 20 years, females up to 25-30 years), and the recorded life expectancy record in captivity is 45 years.

Where do polar bears live?

Polar bears live in the subpolar regions of the northern hemisphere, and their range extends to 88 degrees north latitude in the north and Newfoundland in the south. The distribution area on the mainland passes through the Arctic deserts to the tundra zone in the territories of Russia, Greenland, the USA and Canada. The range of animals is closely related to the Arctic belt, covered with drifting and multi-year ice, abounding in large polynyas with a high density of marine mammals, the main source of food for polar bears.

Today, the habitat of polar bears has several large populations:

Laptev, common in the Laptev Sea, the eastern regions of the Kara Sea, in the west of the East Siberian Sea, on the New Siberian Islands and the Novaya Zemlya archipelago;
the Kara-Barents Sea, whose representatives live in the Barents Sea, the western regions of the Kara Sea, in the eastern part of the Greenland Sea off the coast of Greenland, as well as on the islands of Novaya Zemlya, Franz Josef Land and Svalbard;
the Chukchi-Alaska population is distributed in the Chukchi Sea, in the northern part of the Bering Sea, in the east of the East Siberian Sea, as well as on the Wrangel and Herald Islands.

In the north, the distribution area of \u200b\u200bpopulations captures part of the Arctic basin, although polar bears are much less common here than in more southerly seas. Interestingly, the largest polar bears live in the Barents Sea, while the smallest ones live on the island of Svalbard.

The existence of predators is tied to seasonal changes in the boundaries of polar ice. With the onset of heat, polar bears retreat to the pole along with ice, and in winter they return south, and although their usual environment is coastal areas covered with ice, predators often visit the mainland at this time.

Hibernation of the polar bear

First of all, pregnant females hibernate, the rest of the polar bears winter in the den not every year and at the same time fall into suspended animation for no more than 50-80 days.

What does a polar bear eat?

The main food source of the polar bear is various marine mammals and fish (seal, ringed seal, less often bearded seal (sea hare), walrus, white whale, narwhal).

First of all, the polar bear eats the skin and fat of the killed victim, and only when very hungry does it eat the meat of its prey. Thanks to this diet, a huge amount of vitamin A enters the animal's body, which accumulates in the liver. At one time, an adult polar bear eats about 6-8 kg of food, and when very hungry - up to 20 kg. The remnants of the meal are eaten up by arctic foxes, eternal guides and freeloaders of the polar bear. In case of an unsuccessful hunt, animals are content with dead fish, carrion, ruin bird nests, eating eggs and chicks. Polar bears are quite tolerant of their relatives when eating large prey, such as a dead whale, near which a large group of predators can gather. Wandering to the mainland, polar bears willingly dig in garbage dumps in search of food waste and rob food warehouses of polar expeditions. The plant diet of predators consists of grasses and algae.

By the way, polar bears do not eat penguins, since penguins live in the Southern Hemisphere (in Antarctica, South Africa, Australia, New Zealand, South America, on the islands), and polar bears live in the Northern Hemisphere (in the north of Russia, Canada, Alaska, in Greenland and some islands).

In summer, the ice recedes from the shores and can completely melt, which deprives the animals of their feeding places. Therefore, in summer, polar bears live off their fat reserves and starve for 4 months or more. Given the lack of competition for food during this period of the year, animals can gather in groups and lie peacefully on the shore.

A unique feature of the polar bear's behavior is its attitude towards humans, whom it sometimes purposefully hunts down and treats as prey. But most often, polar bears do not show aggression at all, they are quite trusting and curious. Usually, only females with cubs or a wounded animal are dangerous to humans.

How does a polar bear hunt?

The polar bear lies in wait for potential prey near the polynya, and as soon as the head of the victim is shown above the water, it stuns the animal with a powerful blow of the paw, after which it pulls the carcass onto the ice.

Another equally effective method of hunting is to turn over the ice floe on which the seals rest. Often, polar bears hunt walruses, especially young and weak ones, but they can only cope with an enemy armed with deadly tusks on ice. The bear sneaks up to prey at a distance of about 9-12 meters, and then attacks the victim with a sharp jump.

When a polar bear discovers seal vents (holes in the ice through which seals breathe), it tries to expand them by breaking the ice with its front paws. Then he plunges the front of the body into the water, grabs the seal with his sharp teeth and pulls it onto the ice, after which the victim can no longer cope with an unequal opponent.

Polar bear breeding

Northern bears lead a solitary lifestyle and treat their relatives quite peacefully, fights between males occur only during the breeding season, at the same time aggressive males can attack cubs.

Polar bears reach reproductive age by 4-8 years, and females become ready to reproduce offspring earlier than males. The bear rut is extended in time and lasts from late March to early June, and the female is usually accompanied by 3-4, sometimes up to 7 males. The pregnancy of polar bears lasts from 230 to 250 days (about 8 months), and it begins with a latent stage, when the implantation of the embryo is delayed.

In October, female polar bears begin to dig dens in snow drifts, and they choose certain places for this: for example, on the Wrangel Islands and Franz Josef Land, where up to 150-200 dens are set up in the coastal zone at the same time. In mid-November, when the embryonic development of the fetus begins, the bears go into hibernation, which lasts until April. Thus, offspring are born in the middle or at the end of the Arctic winter.

Taken from: polarbearscience.files.wordpress.com

From 1 to 3 cubs are usually born (usually 2 cubs), completely helpless and tiny, weighing from 450 to 750 g. In completely exceptional cases, 4 cubs can be born. The fur of cubs is so thin that they are often called naked. At first, the offspring intensively feeds on mother's milk. A month later, the cubs' eyes open, after another month, the little polar bears begin short sorties from the den, and at the age of 3 months they already leave the den and, together with their mother, set off to wander through the icy expanses of the Arctic. Up to a year and a half, the cubs continue to feed on milk and are under the protection of their mother, and after that they begin an independent life. Mortality among polar bear cubs ranges from 10 to 30%.

The mother bear brings offspring once every 3 years and during the life cycle produces no more than 15 cubs, which indicates that the potential for increasing the population of these animals is too low.

conservation status

Polar bears are listed in the Red Book of Russia as a vulnerable species, and since 1956 hunting for predators in the country has been completely prohibited. In 2013, about 5-6 thousand polar bears lived in the Russian polar ice. Other countries have established restrictions on the harvest of these animals, regulated by an annual quota.

Enemies of the polar bear in nature

Due to their gigantic size, polar bears do not have many enemies in their natural habitat. In the water, a walrus or a killer whale can attack an animal, on land, small bear cubs, left unattended by a not too vigilant or gaping mother, sometimes become victims of wolves, foxes and dogs. The main threat to the polar bear is a man with a gun: unfortunately, even the protected status does not always save this giant of the Arctic from armed poachers.

Differences between white and brown bear

According to paleontologists, the bear genus appeared on earth about 5-6 million years ago, and the polar bear is considered the youngest species that separated from the common ancestor of all bears about 600 thousand years ago. Modern polar and brown bears are genetically similar, and when crossed, they form viable offspring, called polar grizzlies, which are also capable of reproduction.

Taken from: www.spiegel.de

Polar and brown bears occupy completely different ecological niches, have distinctive phenotypic features, dietary patterns and social behavior, due to which they are classified as separate species. Below are the differences between white and brown bears.

the largest polar bear reached a length of 3 meters, while the length of a brown bear does not exceed 2.5 meters;
the weight of a polar bear can reach one ton, the brown relative weighs no more than 750 kg;
among brown bears, there are many subspecies that live in different territories. Unlike the brown bear, the white bear has no subspecies.
the neck of the polar bear is long, while that of the brown counterpart is thick and short;
the head of the polar bear is not very large and flattened, while that of the brown bear is more massive and rounded;
polar bears are inhabitants of the harsh and snowy expanses of the Arctic zone, their southern boundary of habitat is the tundra zone. Brown bears, unlike polar bears, live in a warmer climate in Russia, Canada, the USA, in Europe, from Western Asia to northern China and Korea, as well as in Japan (see habitat maps below). The northern border of their range is the southern border of the tundra;

the polar bear differs from the brown one in the food it consumes. If polar bears are carnivorous predators, then the menu of the brown bear consists not only of meat and fish: most of the diet includes berries, nuts, insects and their larvae;
in polar bears, only pregnant females mainly hibernate, and their winter sleep lasts no more than 50-80 days. The winter sleep of a brown bear, both in females and in males, can last from 75 to 195 days - it all depends on the habitat of the animal;
the polar bear's rut lasts from March to early June, for the brown bear it lasts from May to July;
polar bears usually give birth to 2, less often 3 cubs. Browns can have both 2-3 and occasionally 4-5 cubs.

On the left is a polar bear, on the right is a brown bear. Photo credits: PeterW1950, CC0 Public Domain (left) and Rigelus, CC BY-SA 4.0 (right)

Since ancient times, the indigenous population of the North has hunted the polar bear for the sake of obtaining skins and meat, and reveres this strong and ferocious beast as the embodiment of formidable natural forces. According to the legends of the Eskimos, the confrontation between a man and a polar bear becomes a kind of initiation and the formation of a man as a hunter.
In search of food, polar bears are able to swim gigantic distances: the record for the duration of the swim belongs to a bear who swam across the Beaufort Sea from Alaska to perennial ice. During the 685 km swim, she lost a fifth of her weight and her one-year-old bear cub.
The largest male polar bear was shot in Alaska in 1960, the weight of the predator was 1002 kg.
Living in conditions of extremely low temperatures, the polar bear is an extremely warm-blooded animal: its body temperature is about 31 degrees, so predators rarely run to avoid overheating.
The image of a polar bear is actively used in cinema, for example, as characters in the popular cartoons Elka, Bernard and Umka.
These animals are depicted on the logo of the confectionery production "Sever" and on the wrappers of sweets "Bear in the North" created by the Krupskaya confectionery factory.
February 27 is the officially recognized day of the Polar Bear, which is celebrated by fans of these animals all over the world.

The polar bear lives in one of the most remote corners of our Earth. His life takes place in eternal wanderings through the icy expanses of the Arctic.

The Arctic is the northern hemisphere of our planet, which includes almost the entire Arctic Ocean and nearby islands (in addition to the Norwegian ones), the margins of the continents of Eurasia and North America, and also covers the adjacent parts of the Pacific and Atlantic oceans. This entire area is the habitat of the polar bear.

Polar bears spend their lives on drifting ice floes. In the summer, the ice begins to melt actively, during this period the polar bears go north. By autumn, when there is more drifting ice, they return to the south. In winter, an immovable strip forms in the zone of drifting ice, along which bears often cross to the land of nearby islands and coasts. At this time of the year, they most often go into hibernation lasting from 50 to 80 days. Favorite places where polar bears arrange their winterings are Wrangel Island and Franz Josef Land. You can also meet a polar bear on the territory of such countries as: Norway, Canada, USA (Alaska), Denmark (Greenland), Russia.

In total, about 20,000-25,000 polar bears live in the Arctic. The largest population of 5,000-7,000 individuals lives in Russia.

What do polar bears eat in Antarctica?

The polar bear is a predator. Its main prey in the vast ice expanses are representatives of the local fauna: seals (sea hares, ringed seals), walruses. It is not easy to get food in such conditions, but the predator skillfully copes with this task. Polar bears hunt , using special tactics. They quietly approach the hole and guard near it until the seal emerges to breathe air. When the animal emerges, the bear stuns it, and then immediately pulls it out onto the ice and eats the prey. Only 1 out of 20 such hunts is successful.

In addition to food obtained as a result of hunting, bears eat carrion, whales washed ashore, narwhals, beluga whales, and fish. Sometimes, if possible, bears attack them.

In summer, the food of the polar bear becomes quite scarce. He eats berries, fish, algae, eggs of birds and chicks, carrion, lichens. During this difficult time, the bear can lose up to half of its weight.

Sometimes hungry individuals enter the houses of the Eskimos or the warehouses of polar expeditions, where they feast on various food products. Most often, polar bears eat canned food, meat, fish and other food.

Polar bear habitats often overlap with human habitation. In such cases, bears often trade in garbage dumps in search of food.

In female polar bears, offspring are born in the middle of winter. Bear cubs are born small, about the size of a cat or a rabbit. Polar bear cubs are completely helpless, they live in a den, which is warm and dark, like in an incubator.

Polar bear den

Even before the birth of the babies, but already in anticipation of offspring, the female begins to look for a suitable lair. Usually she chooses a place somewhere on the shore, but sometimes she finds a convenient place on an ice floe. Since you will have to spend the whole winter in the den, the place should be near the water. Having chosen a place, the she-bear equips a couch the size of a meter by two and about a meter in height. Before the final choice of den, the female polar bear can try several options, but then choose the most convenient one.

In a den prepared by a bear, air will circulate well, but it will always be warm. The body temperature of the female in the den does not decrease as much as, for example, in a brown bear, the deviation can be only five degrees. Throughout the wintering in the den, the female bear does not eat anything, her body uses pre-accumulated reserves of subcutaneous fat.

Birth of cubs

Bear cubs are born in December, usually there are two of them. Their body does not reach thirty centimeters in length, their weight is no more than eight hundred grams. The cubs feed exclusively on mother's milk. The mother periodically wakes up and checks if everything is in order with the cubs, then falls asleep again. Babies also sleep all the time when they are not eating. Female polar bears are able to start producing offspring at the age of about four or five years and remain fertile, sometimes up to 20 years or more.

The polar bear (Ursus maritimus) belongs to the class Mammals, order Carnivores, family Bears. Very close to canines, bears appeared about 5 million years ago. The lone lord of the Arctic, the polar bear reigns on the northern coasts of Eurasia and America on floating ice. Here is his element! All day long he wanders, passing great distances, enjoys rolling in the snow or sleeping.
Polar bears can only be classified as “terrestrial” mammals, since these animals appear very rarely on land, only on the Arctic islands and the sea coast. They spend most of their time roaming the ice of the Arctic Ocean. The polar bear is perfectly adapted to life in the polar seas. Snowstorms often occur in the Arctic. Fleeing from them, polar bears dig holes in snowdrifts, lie down in them and come out only after the storm subsides.

This is a real amphibious beast!

Its body has a streamlined shape: a pointed muzzle easily cuts through the water, very warm, thick fur and a layer of subcutaneous fat allow a well-swimming predator to stay in cold water for a long time, swimming long distances between ice fields. The hind legs serve as a rudder, and the front legs, densely covered with hair, form continuous rowing blades. The specific gravity of a bear's body is close to that of water. The fur in the water does not get wet and retains air, supports the body of this giant in the water, allowing you to swim for hours and even sleep without getting out onto the ice. Bears can swim 100 km from land!
The eyes, ears and nose are located much higher on its relatively small head than on the brown bear's more rounded head, so all the polar bear's main senses are above the water. He is also a good diver. A swimming bear develops a speed of 5-6 km / h, diving, it can stay under water for about two minutes.
The polar bear is the largest land predator and the largest bear of all existing species. Adult males reach 3 m in length and weigh 500 - 700 kg, but giants are known who weighed 1000 kg! For comparison: the weight of even the largest lions and tigers does not exceed 400 kg. The height at the withers is up to 1.5 m, the length of the tail is from 8 to 15 cm. It lives in nature for about 25 years, but in zoos, where conditions are much less severe, it can live up to 40 years.
The bear feels confident on the surface of the ice.

Extremely agile, it jumps over cracks up to 3.5 m wide and never breaks through the ice, as it evenly distributes its weight, spreading its paws wide.
Its coloration is protective, white fur with a yellowish tint is hardly noticeable against the background of ice and snow. The hollow hairs of the bear's fur work like light guides, through which the weak radiation of the northern sun reaches the bear's skin and warms it. Sharp curved claws help to easily climb slippery ice blocks. Polar bears even have fur on the pads of their paws, which allows them not to slip on the ice and warms their paws.
The polar bear is an unsurpassed hunter of sea animals. He has sharp eyesight, excellent hearing and an excellent sense of smell and is able to smell the victim, being 7 km away. With a keen sense of smell, a bear can learn a lot from the tracks left by its relatives, such as their gender or their readiness to mate.
The polar bear is selective in nutrition among the bears and is the only one of the bears who eats mainly meat. He is able to travel long distances in search of his favorite food - the seal. Polar bears have come up with different hunting techniques. Most often, they lie in wait for seals at their ventilation holes in the ice. While swimming under water, seals periodically need to take in air. For this purpose, a hole is maintained in the ice. At its edge, a polar bear guards, often for several hours.
As soon as the seal inadvertently emerges, the bear throws it out of the water with a powerful blow of its paw or jumps into the hole itself, killing the prey under water. Sometimes, in order to kill a seal, just one blow with a paw is enough. Often seals do not rest in the water, but on the edge of their holes. Then the polar bear cautiously creeps up to them. Sometimes it even crawls on its belly, hiding behind snow drifts and ice floes. However, he makes a jerk from a distance of 20-25 m. After all, if a seal finds him, he will quickly slip into the water.
In spring, female seals make burrows in the snow, almost invisible from the outside, with access to the water. In them, the seals whelp and leave the cubs, going fishing. A polar bear with an exceptionally sharp sense of smell is able to smell a seal among the ice. With a powerful jump, he breaks through the ice roof or pierces it with his paw. In this case, the seal, as a rule, has no chance of escaping.
Larger animals - young walruses, beluga whales - are caught by these predators less often. It also feeds on fish, lemmings, musk ox calves, eggs and carrion. In the summer months, even plants are eaten. Polar bears have an excellent sense of smell, which allows them to smell carrion at a distance of more than 30 km. Polar foxes and gulls often feast on the remnants of a bear meal.
In summer, he uses a different tactic: he swims under water for a long time, then suddenly emerges and attacks seals lying on an ice floe or geese, swans, and ducks resting on the waves. On the shore, bears usually do not hunt.
Polar bears have a large supply of fat under their skin, which saves them from the cold and allows them not to eat for a long time. But if a bear catches prey, it can eat 10-25 kg at once. An experienced bear catches a seal every 3-4 days.
Decent sizes do not prevent these animals from running at a speed of 40 km / h. On average, they travel about 15,000 km a year in search of food.
Male polar bears roam the Arctic all year round. They live on their own, making an exception only for the mating season. Going hunting or in search of a female to prolong the family, they move across the endless expanses of ice and sometimes cover many tens of kilometers a day. Females live in small family groups with their cubs, usually two, and sometimes more.
By the beginning of the mating season, the she-bear becomes restless, the routes of her walks lengthen. When a male stumbles upon her droppings or traces of urine, he senses that the female is ready to mate and takes her trail. At the first meetings, the she-bear demonstrates impregnability and rejects him with a roar or a blow of her paw. Standing on its hind legs and growling loudly, the bear tries to impress its partner. He stubbornly follows her, and gradually the female lets him closer. For some time the bears are together, frolicking and playing. But after a few days, their paths diverge. After one or two days, mating occurs. Both animals later mate with other partners. It can happen that cubs of the same litter have different fathers.
If several males follow the trail of a female bear ready for mating, then the issue is decided by the size and self-confidence of the applicant. Each of the males shows what he is capable of, rising to his full height, exchanging paw blows and growling loudly.
During the summer, the female polar bear accumulates fat under her skin to survive the long winter. After the mating season, the female hibernates during the coldest months of the year. She digs a lair in the snow or climbs into naturally formed snow voids to hibernate. The she-bear arranges a lair not among the ice, but on the land of the Arctic islands.
The mother bear does not eat or drink for months, getting energy by “burning” the fat reserves accumulated by autumn. A bear feeding her babies can lose more than half of her body weight during hibernation. Her body temperature remains normal - unlike animals that go into real hibernation.
It is very warm in the lair (the temperature reaches + 30 ° C), and here, by December, the she-bear cubs appear. A female bear usually has 2-3 cubs every 3 years. Polar bear cubs are born weak, blind and mothers take care of them with great love. The newborn weighs only 700 g and is 20 cm long. Mothers fiercely protect their babies, especially from male bears, who, if hungry, can kill and eat cubs.

Babies open their eyes about a month after birth, and take their first steps at the age of one and a half months. For the first few months, the cubs are in a snowy den and feed on rich mother's milk. Bear cubs are born completely without hair, but after a while it grows back and becomes thick and dense.
Four-month-old cubs weigh 10 kg each and still suckle their mother (sometimes up to a year), but the bear is already starting to feed the cubs with seal fat. Despite all the efforts of the female, out of three cubs, usually one survives.
With the end of the polar night, the cubs come out of the cramped ice lair with their mother and frolic in the open with pleasure.
Now they can leave the shelter, and no frost will be terrible for them. The bear will teach them to hunt and swim. While they are small, the mother allows them to sit on her back and rides with pleasure, like on a steamboat.
At two years old, a young bear begins to live on its own. At this age, the risk of dying is still quite high, since he is still an inexperienced hunter and often remains hungry.
On the territory of Russia, the polar bear is distributed on the islands of the Arctic Ocean: on Franz Josef Land, Novaya Zemlya, Severnaya Zemlya, the New Siberian Islands and Wrangel Island.
The polar bear prefers to stay among the floating ice or near polynyas, where you can get seals. The largest number of snow dens in which bear cubs are born is located on Franz Josef Land and Wrangel Island. In November - December, she-bears usually bring two cubs. In March-April, the cubs leave the den with their mother. By this time, their weight reaches 10-12 kg. The bear family lasts about two years.
In nature, the polar bear has no enemies. He is quite friendly towards humans. Protecting its prey (for example, a caught seal) or cubs, it can rush at a person, trying to scare him. Loud muttering serves as a warning of possible danger. There are very few actual attacks. For more than 100 years of its development, three people died on Novaya Zemlya for this reason, and there was not a single victim on Wrangel Island.
Acquaintance of a person with a polar bear has a long history. These animals were known to the ancient Romans in the 1st century AD. A written source containing information about polar bears dates back to 880.
In the XII-XIII centuries. Russian settlers who settled on the shores of the White and Barents Seas hunted polar bears, supplied bear skins to Veliky Novgorod and Moscow. Until the inhabitants of the Far North hunted bears, the damage to the livestock was small.
In the XVII-XVIII centuries. hunting vessels began to regularly penetrate the Arctic seas and the hunt for polar bears began. It increased especially sharply in the middle of the 19th century, when the stocks of bowhead whales were depleted and the attention of miners switched to walruses and bears. At the beginning of the XX century. hunting was conducted on an unusually wide scale.
On Svalbard for 1920-1930. more than 4 thousand animals were mined. According to rough estimates, only in the north of Eurasia since the beginning of the 18th century. until the middle of the 20th century. production amounted to over 150 thousand bears.
Back in the seventies of the last century, polar bears were the object of hunting with impunity in Canada, Greenland, Norway and Alaska.
By the beginning of the 70s. 20th century 5-7 thousand polar bears lived in the Russian sector of the Arctic, and throughout the Arctic their number did not exceed 20 thousand. In 1973, the International Agreement on the Conservation of the Polar Bear was signed. Ten years later, the number of bears increased and amounted to over 25 thousand people.
About 25,000 polar bears live around the North Pole in different packs, its populations are stable. But they suffer from pollution of the seas and global warming. Today they are protected by international agreements, hunting for them is prohibited, and the polar bear itself is listed in the Red Book. The polar bear is also protected in the reserve on Wrangel Island, it is included in the IUCN-96 Red List and the Red Book of the Russian Federation.
A sharp warming climate has threatened the existence of the polar bear population off the Hudson Bay in northern Canada. The sea began to freeze a month later, and this prevents them from hunting seals. Hungry bears approach settlements and rummage through garbage dumps.
Studying bears is not easy: they live scattered over large areas, cautious and too dangerous to approach them. Researchers now have effective sedatives. Polar bears, which are aggressive and very mobile, are euthanized from the air: bears are driven onto open ice by snowmobiles, and then arrows with a sedative agent are fired from a helicopter. The stunned animal is measured, examined for scars, teeth imprinted and blood taken. Integument and fat analyzes provide information about the state of his health. In female bears, based on a blood test, you can determine whether she is ready to mate or is already pregnant.

Other data about the life of bears is obtained from paw prints, analysis of wool, dens and droppings, which can determine the type of food. Behavioral observations provide additional information. In this way, it is possible to follow the development of the bear population in a certain area over the years.
Bear trails and sites are surveyed using telemetry. Animals receive radio collars, thanks to which their location can be determined. Many collars are additionally equipped with sensors that record body temperature and movements of animals.
According to them, the researcher can determine whether the bear is resting or active. Every six hours, the exact coordinates of its location are transmitted to the satellite, and from there to the computers of scientists. Many transmitters even send data continuously so that the coordinates they indicate are projected onto a map and the bears' movements can be followed on the screen.
In order to determine the age of a bear, a small, non-functioning tooth in the lower jaw is removed from the euthanized animal.
The teeth of bears form annual circles, like tree trunks. Inside they are made of dentine. The crown of the tooth is covered with tooth enamel, the root is covered with dental cement. To ensure that the tooth always remains firmly anchored in the jaw, the layer of cement is constantly growing throughout the life of the bear. Depending on the season, the growth of cement occurs in different ways: in winter it is slower, at this time only a thin dark layer forms around the tooth. At the beginning of the year and in summer, a wider light layer appears. Both lines form a layer that has grown in one year. The older the bear, the slower the cement grows and the smaller the distance between the annual rings becomes.
Polar bears have been studied quite well: the approximate size of their territories, types of food and mating behavior are known. Scientists were able to observe how mother bears raise their cubs.
Are polar bears threatened by the greenhouse effect?
The greenhouse effect and global warming are primarily a consequence of the release of gases. Carbon dioxide and other gas compounds rise into the high layers of the atmosphere, forming a layer above the Earth that traps heat at the surface of the planet, like in a greenhouse. The consequences are already visible in the Arctic: over the past 100 years, the air temperature there has risen by about 5°C. The area of Arctic ice is shrinking every year.
Environmental pollution is a problem for polar bears. Around oil rigs and oil harbors, seawater is often contaminated with oil. Thick wool protects well from cold and dampness of polar bears. But oiled wool loses its ability to hold air, so half of its insulating effect is lost. The bear cools down faster, and there is a danger of overheating in the sun. If a bear swallows oil-contaminated water or licks it from its fur while swimming, it will lead to kidney damage, intestinal bleeding and other serious illnesses. In the tissues of polar bears, such harmful substances as chlorinated hydrocarbons were found. They accumulate from food and are deposited in hair, teeth and bones. In the future, harmful substances affect not only health, but also the ability of animals to procreate.
The life of polar bears depends on the presence of ice. Only if in the summer they go to the ice to hunt seals do they manage to accumulate sufficient reserves of fat for the winter. If the ice melts earlier in the summer or crumbles into ice floes, the animals have to return to the mainland, where there is less food. This affects the ability to procreate: bears that eat worse have fewer offspring or none at all. If warming continues at the same pace, the summer ice cover in the Arctic sea will disappear by 2080 at the latest. The polar bear will have to adapt to completely different living conditions or face the threat of extinction.

Bears and people
Today, zoos try to provide animals with care appropriate to their species. Zoos play an important role in maintaining endangered species by researching animal habits, educating the public about endangered species, and coordinating breeding programs internationally.
To keep the animals entertained, more and more zoos are developing entertainment programs for their bears. Bears are not couch potatoes at all. In nature, they are constantly busy exploring and looking for food. Animals that cannot satisfy their need for movement often exhibit behavioral disturbances: they stagnate, shake their heads, jump up every now and then, or show the same type of rhythmically repeated movements.
Food is no longer served in a feeder, but is scattered around the enclosures, buried or hidden in hollow trees or under roots.
So the bears have to look for it or catch it with their paws. Balls of straw or hay are filled with food, honey is placed on the very tops of tall trees. Bears love frozen food. For example, carrots, apples and fish carcasses are placed in buckets of water or fruit juice and frozen.