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, second only to the elephant seal in size. 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. The average 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, through 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 she-bear bears 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 is one of the largest predators on our planet, which lives in very harsh conditions. Nature endowed him with great strength and endurance, and took care that this animal did not suffer from extreme cold. Let's find out where polar bears live!
habitats
Polar bears are solitary animals that do not live in packs or even families. They are used to wandering alone in the most remote regions of the Far North. Their native home is the Arctic, located in the central part of the Arctic Ocean.
In these parts, a strong cold reigns all year round. And even in summer it is very cold here, and the earth never warms up. That is why the Arctic is called an icy desert: trees, grasses, flowers do not grow here. The entire territory is covered with ice at least 2-3 m thick.
Rice. 1. Arctic.
In winter, the air temperature in the Arctic can drop to -50C. To survive such harsh weather, the polar bear may leave its native Arctic for a while. Then it can be found in Greenland, Canada, Alaska, Norway, Russia. But with the advent of summer, he always returns to the Arctic - this animal is able to live only in a cold climate.
The polar bear is a rare animal and is protected by all northern states. This means that it cannot be hunted, otherwise poachers will face severe punishment.
Features of the polar bear
The polar bear is an eternal wanderer who constantly travels. He is not used to living in one place, and all the time he moves around the Arctic and neighboring countries. Very often he makes long journeys on floating drifting ice.
TOP 4 articleswho read along with this
Rice. 2. Polar bear on an ice floe.
The polar bear is an incredibly strong and hardy animal. Just think - he is able to swim in icy water without rest up to 80 km!
The King of the Arctic - and this is how the polar bear is often called - only at first glance may seem clumsy and slow. Despite its size and heavy weight (up to 450 kg), it runs very fast, and swims perfectly in the water and dives deep.
But how does the polar bear survive in the harsh conditions of the Arctic? He comes to the rescue:
- Very thick dense wool, which warms the animal not only on land, but also in cold water.
- A thick layer of subcutaneous fat that can be up to 10 cm thick. He warms the bear and helps him survive the hungry times.
- The white coat color is the best camouflage when hunting.
- The polar bear has excellent sight, hearing and sense of smell. He can see his prey at a distance of several kilometers, and smell it for 800-900 meters.
Rice. 3. She-bear with a cub.
The main prey of the polar bear is walruses, ringed seals and other marine animals. With severe hunger, he can eat seaweed, bird eggs, fish.
What have we learned?
When studying one of the topics in the program of the world around us for grade 1, we learned on which mainland the polar bear lives. We learned how this animal adapted to life in a harsh climate, how it lives, what it eats and how it tolerates extreme cold.
Topic quiz
Report Evaluation
Average rating: 3.9. Total ratings received: 94.
Common belief: penguins and polar bears live wherever there is a lot of ice and snow. Although both species prefer extreme conditions, they do not live in the same area in the natural environment. The polar bears liked the Arctic, which the penguins did not like - they preferred Antarctica.
Polar bears have chosen the North Pole, and penguins - the South. Clubfoot enjoys a life associated with drifting ice. They would not have gone to land at all, if not for the period of raising babies. Bear cubs are born in dens on land, and as adults, they get used to life on floating ice.
The main "bear maternity hospitals" are located in the Arctic - on about. Vrungel, Severnaya Zemlya, Franz Josef Land. Male polar bears are eternal wanderers. They are excellent swimmers and are able to swim more than a hundred kilometers.
About 25 thousand individuals live around the North Pole. True, polar bears do not like the pollution of the seas and global warming. These majestic beauties live near the northern coasts of Eurasia and America on floating ice. They are also found on the territory of Russia, on the islands of the Arctic Ocean.
Some wonder: could a polar bear live without ice? The answer to this question was given by nature itself, as well as to the question of where penguins and polar bears live. In the 60s, a colony of individuals was discovered on the coast of Hudson Bay (Canada). The bears spent most of their time on the ice, feeding on seals.
During the period when the ice melted, they went deep into the mainland. Moulting birds and their eggs became their food. But due to global warming, the population has almost halved in 10 years - from 1600 to 900 individuals. Because of the melting ice, the bears simply did not have enough of their usual food.
And what will happen if the penguins are still settled in the Arctic? According to the director of the Museum of the Arctic and Antarctic, Viktor Boyarsky, the population simply would not have survived there - there is no ecological niche. For natural movement towards the Arctic, there are no currents that unite the North and South Poles. The tropical belt for penguins is an insurmountable barrier.
The polar bear does not even look into the territory where the birds live. After all, there are no extensive floating ice with polynyas. And this is the main "love" of polar bears. Therefore, in the habitats of penguins, clubfoot from the Arctic would not have survived either. They wouldn't be able to get their own food. Yes, and the nature of Antarctica is poorer, only the underwater world is rich. But polar bears have a chance to occupy these spaces. After all, the ice in the Artik is gradually melting. In the northern part of Antarctica, on the contrary, they are increasing.
Penguins like the Southern Hemisphere. They can be found in Antarctica and on the islands adjacent to the continent. There are also penguin colonies in Peru, southern Brazil and even Africa (southwest)! There are penguins in New Zealand and even in southern Australia. There are 16 different species, all of them are perfectly adapted to the aquatic way of life. True, they prefer a different landscape. Most prefer a rocky surface, but some love sandy beaches and grassy areas. There are even colonies of penguins that have preferred coastal forests.
The king of the Arctic deserts and the eternal ice of the Arctic Ocean, the largest and most dangerous predator of the Arctic is the polar bear. Its habitat extends from the border of the tundra and arctic desert zones to 88º N. In the scientific world, he is known as Ursus maritimus - sea bear. The indigenous population of the Arctic knows the polar bear, it is an important part of folklore, art, mythology and magical rituals (for example, initiation). Chukchi call it umka, Eskimos - nanuk, Nenets - yavva, Yakuts - uryungage, Pomors - oshkuy.
Polar bears have lived in the Arctic for hundreds of thousands of years - the formation of a separate species occurred about 600 thousand years ago. But the Arctic bear known to us is a descendant of a hybrid that came from crossing an ancient polar bear with a brown relative, which confirms that the polar species has a small percentage of genes characteristic of brown bears. At the same time, polar and brown bears have enough genetic similarity so that "interracial marriages" give fertile offspring, called grolar, or polar grizzly.
Polar bears breed quite slowly - after puberty at 4-8 years old, a female bear gives birth to 1-3 cubs every 2-3 years. With a maximum lifespan of 25-30 years, this is 10-15 new individuals. However, up to 40-70% of cubs die in the first year of life - they are threatened by adult males, the need for long swims (the subcutaneous fat of the cubs is not sufficiently developed), and poachers.
Why is the polar bear in the Arctic
The white color is generally characteristic of the animals of the Arctic, and polar bears wear a luxurious snow-white fur coat all year round. Why exactly white? The most obvious answer to such a question is disguise. To successfully hunt against the backdrop of polar ice, he must successfully merge with the surrounding landscape.
But there are other reasons, for example, thermoregulation. Animals of the Arctic live in regions with extremely low insolation, and the pigment melanin, which is also responsible for the color of animal fur, serves as an additional obstacle to the penetration of ultraviolet radiation. The skin devoid of pigment better transmits UV rays to the skin of a bear - no longer white, but black. Saturated with melanin, it easily absorbs the ultraviolet passed through by the wool, using it for heating and other processes. Thus, an ideal “mechanism” is obtained, which makes it possible to make the most of the weak insolation in the Arctic regions.
By the way, if we talk about color, the hairs of a polar bear are not white. They are devoid of pigmentation, that is, color. In addition, they are hollow inside (this is also characteristic of the animal world of the Arctic regions, and is found, for example, in reindeer). This structure of the hair has the best thermal insulation properties, in addition, the inner cavity of the hair is uneven, and the light, reflected at different angles, gives the illusion of a white color of the skin. The wool is covered with a layer of sebum, allowing the bear to literally come out dry from the water, which is very important, because the polar bear in the Arctic often has to swim to hunt, or move from one ice field to another. The polar bear is an excellent swimmer, it moves in water at a speed of more than 6 km / h, can spend several minutes under water, and the maximum recorded duration of a polar bear swim was 685 km.
What does a polar bear eat in the Arctic?
The nutrition of a polar bear is determined by its habitat and characteristics of the organism. Perfectly adapted to the harsh polar winters and long swims in cold water, it preys primarily on marine wildlife on land, on ice and in water.
Ringed seals, bearded seals and walruses he motionlessly lies in wait at the polynya, throwing them onto the ice with a blow of his mighty paw or creeps up to animals on land during their rest. In the water, bears can compete in dexterity and strength with the beluga (Arctic whale), narwhal, they can catch fish, although the bear is far from primarily interested in it. They eat polar bears and eggs, chicks, cubs of animals, which are much easier to catch than an adult. They do not disdain carrion - the corpses of marine animals, fish thrown ashore. However, they will never touch the meat of their own species.
If possible, the polar bear eats very selectively - it eats skin and fat from a caught seal or walrus, the rest is eaten only if it is very hungry, what it has not eaten is usually left to scavengers - birds and animals, which often accompany the "owner", eating the remnants of his meals . Berries and moss are also included in the diet of the polar bear, but they are not included in his diet so often.
Currently, due to climate change, what the polar bear is used to eating often becomes inaccessible to him, then the bear switches to hunting for land animals of the Arctic and birds (deer, lemming, goose), raids warehouses and dumps of Arctic villages. In the Canadian city of Churchill, a prison has even been built, where "recidivists" are placed who disturb the peace of the city's residents.
Why the polar bear is not cold in the Arctic
The Arctic is a harsh and icy place. So why isn't the polar bear cold in the Arctic? The answer is simple. The Arctic inhabitants have a very thick layer of fat. Its thickness reaches up to 10-12 cm. The subcutaneous fat of polar bears tends not to freeze at low temperatures. Also, bears have black skin, which allows you to quickly warm up in the sun. Therefore, they are not afraid of the Arctic ice and polar snowdrifts.
Polar bears live in the Arctic or Antarctica
In this matter, not only schoolchildren, but also adults are often confused. The distribution area of polar bears is limited to the Arctic. Even if the bears managed to overcome the distance from one pole to another, they would hardly have managed to survive in the Antarctic latitudes. The temperature there is lower, the thickness of the ice is hundreds of meters (in the Arctic - about a meter), which excludes the possibility of a favorite way of hunting for marine life near a polynya or a crack. The fauna of Antarctica is also not adapted to the appearance of such a predator. In addition, this would put many species at risk of destruction - for example, penguins, which feel great in the Antarctic latitudes and do not live in the Arctic.
