Why is the polar bear white? Human service Properties of protective hairs.
Polar bears are some of the most amazing animals to ever roam our planet. The fact that these magnificent creatures manage to survive in the cold deserts of the Arctic is almost unique.
Everyone knows that polar bears are distinguished by their strength, endurance and beauty, but not everyone is aware that they are, in addition, very smart and inventive animals.
In addition, polar bears are the largest and strongest of all bears, and also the most recognizable and popular. Unfortunately, polar bear populations are currently declining and endangered due to global climate change.
Here are amazing little-known facts that will help us solve all the mysteries and learn all the secrets of these amazing animals.
Males can weigh a ton
An adult male polar bear typically weighs between 350 and 550 kilograms, or about half a dozen healthy, strong males. The largest polar bear ever recorded was a male weighing exactly one ton.
Unlike males, females weigh two to three times less, up to 300 kilograms. At birth, cubs are very small, bald and weigh less than a kilogram.
No to hibernation!
These unique animals remain active all year round, despite the lack of food. Females spend the winter in snow dens with their cubs. They prefer to dig dens in old snow rather than in freshly fallen snow. Some females build a den with several rooms and even a ventilation system. While females are denning (January to March), they do not eat, drink, or produce waste.
They may slow down your metabolism
Since the optimal habitat of polar bears turns into a snowy desert with no food for several months, they can fast longer than any other member of the animal kingdom.
If a polar bear doesn't eat for 10 days, it can slow down its metabolism until it catches prey. Bears survive on fat reserves (when food is plentiful, they prefer to eat only fat). However, warming is making food harder and harder to find, forcing bears to resort to cannibalism.
Polar bears have non-white fur
Although they look white, their fur is actually colorless and transparent. Each hair is a kind of tube filled with air. It appears white because, like everything transparent, it reflects visible light. For example, snow. It is also not white, but transparent.
The polar bear's skin underneath the fur is black to better absorb and retain heat.
To those representatives of the animal world who perceive only visible rays of light (that is, to us), it seems that bears merge with the snow. But the reindeer, which occasionally becomes a victim of a hungry bear, sees in ultraviolet radiation, which helps it see the lurking predator.
Sometimes polar bears' fur turns dirty yellow or even green. The yellowing is due to the bear's age or dirt, while the green color is caused by algae that can grow on a polar bear's fur in an unnaturally warm and humid environment.
Among other things, the fur of polar bears is oily, which allows them not to get wet while swimming and quickly shake off water.
Polar bear paws
The polar bear is so strong that it can kill an animal with one blow of its huge paw.
These same massive and strong paws help polar bears swim. And it is worth noting that polar bears are excellent swimmers: their hind legs help them stay afloat, and their front legs help them move forward. They can swim up to 160 kilometers at a time.
Their paws are equipped with special pads made of hard wool, which allow them not to slip on ice, and also to walk almost silently when sneaking up on prey.
By the way, during the hunt, the female cubs are forced to remain absolutely motionless. If they break a rule, mom slaps them in the face with that very powerful paw.
Supernaturally sensitive nose
These amazing animals have an unusually acute sense of smell, which they use for hunting.
A polar bear can detect prey by following tracks left on ice at a distance of 30 kilometers.
Most polar bears could disappear by 2050
Polar bears rely on ice to successfully forage for food. Scientists predict that global warming will melt sea ice so much that the result will lead to the extinction of two-thirds of the world's polar bear population by 2050.
Bears will be forced to swim too long distances, expending energy that they must conserve for hunting and simply for survival.
Delayed fertilization
Bears mate from March to June, but the egg is not fertilized until September. The time of fertilization depends on the health of the female and the environment. This most often occurs between September and November.
The process of delayed fertilization ensures that polar bear cubs are born to healthy mothers at a time when conditions for survival are most optimal. Female polar bears do not give birth to offspring before the age of 4-5 years.
Climate change leads to hybrids
Warmer and longer summers are pushing some animals to expand their habitat. New species enter new territory and come into contact with previously isolated animals. Sometimes meetings of new neighbors are especially friendly.
Over the past decade, scientists have documented several hybrid descendants of polar bears and grizzly bears. Researchers have predicted that the Arctic will become a breeding ground for species as widespread and dramatic melting of ice opens up previously blocked areas.
Polar bears are more likely to overheat than freeze
Even without the black skin underneath the clear fur to absorb heat, polar bears have other tools to survive in the cold Arctic.
They have two layers of fur and a thick layer of fat that are excellent insulators, and their small ears and short tails and small snouts help minimize heat loss.
It sounds a little paradoxical, but polar bears are more likely to overheat than freeze during Arctic frosts. They overheat very quickly when running. This is why they tend to move slowly and try not to overexert themselves.
Bear fur coats are perfect for those who always want to be on trend. There are few such fur products on sale, so they are of particular value. Bear fur was popular many years ago, then it was replaced by mink and fox.
Product Features
A bear fur coat is highly resistant to low temperatures. Perfect for wearing in harsh winter conditions; it is impossible to freeze in such a fur coat, even if you spend the whole day outside. If properly made, the product will serve its owner for a long time.
Another advantage of this fur, in addition to its resistance to frost, is its rich range of colors. A natural bear can be:
- brown,
- fawn,
- brown,
- white.
The photo shows that bear fur has a characteristic thickness, full of undercoat and high hair. In addition, it has the following characteristics:
- elasticity,
- softness,
- shine,
- moisture resistance.
The only disadvantage of a bear fur coat is that it is very heavy. The skin is never lightened, as is done with beaver and sheepskin products. Because of this disadvantage, such things are not sold en masse on the market.
Advantages and disadvantages
Bear fur coats for men and women have pros and cons that are worth evaluating when purchasing a product.
The advantages include:
- original look;
- good wear resistance;
- frost resistance;
- unpretentiousness in care and maintenance.
The following are noted as negative points:
- high cost;
- the heaviness of the fur coat;
- unusual type of product.
The choice of models made from such fur is very limited. The product is most often made to order.
Forest representatives
Brown bear is a solid fur for a man. It is chosen by extraordinary individuals who strive to emphasize their individuality in everything.
The fur of a brown bear has the following characteristics:
- density,
- warm,
- elasticity.
Men value bear coats for these qualities. The best products are made from fur obtained in winter, when the bear grows fur to keep warm during hibernation. The color of such a product will be uniform, and the quality will be much higher, since during this period of time the animal sleeps peacefully.
You should not choose men's fur coats made from the skins of spring and summer bears, despite the fact that they can be significantly cheaper. The appearance of such a product is unaesthetic, and the fur does not have the characteristic shine and thickness.
Bear fur coats are quite simple, straight-cut and too heavy, so such a thing is considered purely masculine.
Guest from a frosty country
Polar bear fur is a kind of exotic. The cost of such skins is quite high, since the polar bear has fur of higher quality, as well as a more interesting appearance.
The main advantages of white fur are that:
- a polar bear fur coat retains heat even at extremely low temperatures;
- white fur does not get wet, since the polar bear spends a sufficient amount of time in the water;
- The polar bear is one of the rare animals listed in the Red Book.
A polar bear fur coat for men is super exclusive. The cost of such a product will be high.
Product selection
The polar bear is presented on the market in limited quantities. The fur of a polar animal has many advantages, as products made from it are warm and wear-resistant. Usually men make the choice in favor of a polar bear.
There are also products made from white fur for women, but before purchasing you should evaluate your strength, since fur coats made from polar animals are quite heavy.
Men can choose a long fur coat or a midi, but short polar bear fur coats are suitable for the fair sex.
Despite the fact that the polar bear is listed in the Red Book, its fur is still harvested. If the skin is not processed in a handicraft way and is obtained legally, then the cost of the product will be decent. Brown fur is mined more often, but products made from it do not go to the big market; more often such things are sewn to order.
When buying such a fur coat, you can be sure that the appearance will be the most attractive. Such fur will emphasize the individuality and originality of its owner. It is really worth choosing a bear coat for a harsh winter, since in the European climate it will be quite hot. In a fur coat, you don’t have to worry about getting wet; thanks to its high water-repellent properties, it’s not afraid of water.
It is believed that with global warming and the melting of the Arctic, the polar bear may disappear. But the real threat to the life of the strongest and most intelligent predator on earth is not the climate.
“I have never before had as much pleasure as I get from working with a polar bear,” says Nikita Ovsyannikov, deputy director of the Wrangel Island Nature Reserve. - This is an absolutely magical beast, in twenty-two years there has not been a moment when I got tired of watching it. You look at him every time with fascination, like a child.”
Ovsyannikov wears a T-shirt with a polar bear covering its face with its paws and the inscription “Think again!” Few people in Russia know the habits, ecology and lifestyle of polar bears better than Nikita.
The polar bear is truly fascinating. It is the largest land predator in the world and the only one adapted to live in the bitter Arctic cold. Of course, there are also other predators such as arctic fox, wolf and wolverine, but they live in many places, and the polar bear is ideally adapted to the northernmost latitudes. The bear is the only land dweller capable of spending his entire life in the sea: he swims and hunts well in the water, and the best place for him to relax is not land, but ice floes. Therefore, it is classified as a marine mammal (“Mormlek”) along with pinnipeds and cetaceans. It is protected from hypothermia by a thick layer of fat (unlike people, the fatter the bear, the healthier it is) and thick fur. A polar bear's fur coat consists of hollow hairs that retain heat well. Sometimes in the summer you can see a bear with a green tint, which means that microscopic algae have grown in the cavities of its fur.
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In terms of intelligence, polar bears are hardly inferior to primates: they are able to solve complex problems, navigate in three-dimensional space and have excellent memory. Each animal, like a person, has its own bright personality. Ovsyannikov says: “Cape Blossom on Wrangel Island used to be a traditional place for bears to hang out, and it was convenient to watch them there. When you look at dozens of bears day after day, you begin to distinguish their character, they are all different, just like us. And they have very rich facial expressions. One geologist once told me that brown bears have a dead face. I answer: did you see your own face when you met them? Bears would also say that a person always has the same expression and bulging eyes.”
Over the years of observations, Ovsyannikov noticed and described another unique property of bears - their great social plasticity. They are not at all solitary predators, as was believed, and although they do not gather in packs, they can coexist, especially if there is enough food for everyone: “I saw up to twenty-two bears around a seal carcass. They may growl and push each other while sharing a meal, but serious conflicts do not arise. There is a strict hierarchy: adult males eat only the tasty morsels - fat, leaving the meat on the bones for the younger cubs."
Polar bears are not individualists, although they do not need to cooperate. Unlike, for example, lions, they hunt on their own, but they butcher the prey together. Moreover, they can even share with strangers who come from other places.
Healthy lifestyle
In the spring, the season of love begins, and adult female bears become pregnant every three years. More often it is impossible due to the unusual duration of the process: after intercourse, the fertilized egg divides only a few times, but does not attach and does not develop for almost six months, until the female bear goes into a den for hibernation. The female bear devotes the rest of spring and summer to hunting, gaining weight and preparing for hibernation. In September-October, she comes to land, climbs the mountains, finds a quiet place and digs a den in deep snow.
When the female bear hibernates, her pregnancy begins to develop. In January, she gives birth to cubs - blind, almost naked and weighing only 500 grams. For the first three months, the bear feeds and licks them without leaving the den. In March-April, the cubs, having grown to 3-5 kilograms, come out into the light, first play near the den, and then the mother takes them to the ice. Polar bears mature very slowly: usually a mother bear leads her offspring with her for two and a half years. This is the time she feeds them and teaches them everything she knows. However, even an adult three-year-old bear during the first years feeds on what is left of its more respectable adult relatives. Males do not sleep in winter and prefer to remain on the ice all year round if conditions permit. However, such an opportunity presents itself less and less often. “According to my own observations, the climate has changed a lot, there is more rain and fog, and most importantly, less ice,” says Ovsyannikov. “That’s why the bear comes to the ground more and more often.” The weather has become less predictable, and winter thaws have appeared.”
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Bears prefer to feed on marine mammals, but in hungry years they do not disdain smaller prey such as arctic foxes and lemmings, and even carrion. And in the North there is a rich folk epic about how bears steal food from polar explorers and meteorologists.
Due to warming, life expectancy on the coast is increasing and the number of populations is declining, especially those that live further south than others. In addition, it increasingly happens that a bear left on an ice floe far from the ground is forced to lie down in a den right there, and this is quite dangerous, since the ice moves and breaks. No one knows exactly how the climate in the Arctic will change, but according to the most confident scenario, by the end of the century the average annual temperature may rise by 4–7 degrees, and the ice-free period will increase to six months. In itself, this may not be so scary. According to paleontological reconstructions, the polar bear evolved from the brown bear about 120,000 years ago, and according to new genetic data (analysis of mitochondrial DNA of species), even earlier, about 600,000 years ago. Thus, the polar bear survived at least six global warming events of antiquity.
In addition, two cases of crossing a polar bear with a brown bear have already been described. Several years ago, a hunter in Canada killed a polar bear, which upon closer inspection turned out to be unusual, with dark glasses around the eye and a body structure unusual for this species. Genetic analysis showed that it is a hybrid of a polar and brown bear. They are different species, but they can interbreed and, importantly, their offspring can also give birth to children. “Everyone repeats like a spell that with the melting of the ice the bear can disappear,” says Ovsyannikov. “But they are too smart, environmentally and socially flexible, I am sure that they will be able to adapt to changes. Of course, it is more convenient for a bear to live and hunt on ice, but it also endures long periods without ice on land, where, if necessary, it can at least feed itself and not die out. If it is not destroyed by a person. But this is a real threat.”
Real threat
There are 19 geographic populations of polar bears in the world, three of which live in Russia: the Chukchi-Alaskan, Laptev and Kara-Barents Sea populations. Satellite tagging has shown that they are conservative and prefer to move along known routes.
It is almost impossible to estimate the size of the population, because every year the bear's main habitat - ice shelves - disappears and some animals move further north, while others migrate to the mainland. On the IUCN/SSC Polar Bear Specialist Group website you can find an approximate estimate - from 20,000 to 25,000. “This is taken from the ceiling, in reality there cannot be so many of them now,” says Nikita Ovsyannikov. - Moreover, it is not known how many bears remain in Russia. In the 1970s, there was the last attempt to estimate the size of the Chukotka-Alaskan population, then it was about 2000–5000 individuals. In fact, now there cannot be more than 1500–1700. Even in the early 2000s, we observed many more animals on Wrangel Island than now, tens and hundreds of animals in an area of two kilometers. Today, according to my observations, the density reaches 38 animals per hectare. Now we can see no more than 60–70 bears on Wrangel, but in the 1990s there were 300–400.”
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In 1973, five Arctic states - the USA, Canada, Denmark, Norway and the USSR - signed an agreement on measures to preserve the polar bear population. According to it, hunting was allowed only to the indigenous peoples of the Far North, since it is believed that this is their traditional trade. Norway subsequently introduced a complete ban on hunting. And in the USSR it was first installed in 1957. In Alaska (USA), Canada and Greenland (Denmark), quotas are still issued to indigenous people. This is one of the benefits the government gives to endangered Aboriginal people as compensation for their difficult colonial past. “I have repeatedly told my American and Canadian colleagues that they are paying with bearskin for the destruction of small nations,” says Ovsyannikov. “This is cynicism and politics.”
In America, Canada or Denmark, wealthy people often come to the North, negotiate with the locals, treat them to whiskey and take one with them on a hunt for protection from rangers. And in Canada, Aboriginal people are officially allowed to sell their quotas. As a result, an attempt to preserve the traditions of small nations turns into an entertainment industry in which animals die.
Despite wonderful laws, in Russia bears are shot no less than in other countries - due to poaching. By law, you can only shoot a bear if it poses a danger to life, but in reality, many locals shoot out of pure excitement, as soon as they see the animal, and then present it as self-defense. Buying a polar bear skin in RuNet or a trophy store is not difficult. All over the world, 300–400 animals are shot annually, and a third of them are bear cubs under three years old. At this rate, the polar bear can be exterminated within 20–25 years.
The study of polar bears in Canada and the United States consists mainly of estimating numbers in order to decide each year how many quotas should be issued. For this purpose, the capturerecapture method (“capture and recapture”) is used. To catch a bear, it is tracked from a helicopter, immobilized with a shot of a syringe containing Telazol, then the petrified animal is examined and samples are taken. This way you can install the floor, measure the weight and size. To find out the exact age, you need to pull out a tooth from the animal. Along the way, you can take a tissue sample for a biopsy or genetic studies, and also put on a collar with a satellite tracking tag to then study migrations. At first glance, this method allows you to collect a lot of objective data. But in reality, this method of studying has more disadvantages than advantages, Ovsyannikov insists. “This approach will say nothing about the natural behavior of the bear,” he says. - Moreover, after experiencing a severe shock, a bear may behave inappropriately, and observing it leads to erroneous conclusions. If you are studying the natural biology and ecology of bears, then you should not disturb them, much less torture them. Americans collect data year after year, but know nothing about the habits or lifestyle of the bear. They only see him running away from the helicopter and then writhing in agony.”
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The joy of human communication
Ovsyannikov himself studies the polar bear in exactly the opposite way. For him, this is an adventure: to live close, but not to disturb or frighten the animal. This is the only way to explore his natural life. Ovsyannikov began his project in 1990. He moved to Wrangel Island to spend there all year round. Most of the time he lived alone, in recent years - with his wife Irina, who studies snowy owls and arctic foxes. Today Ovsyannikov comes only from spring to autumn. “We survey key polar bear habitats every year, covering thousands of kilometers by ATV,” he says. “We often spend the night in primitive ravines, which are also broken apart by bears, so there is nowhere to sleep. But there you can see them up close. On Wrangel I could count all 200–300 bears, because I already know where they are most likely to be found.”
This observation method allows us to accumulate unique data on the size, composition and average age of the population, and most importantly, on behavior and social organization - how bears interact with each other, hunt and generally live, as well as how they react to human activity and what factors influence their behavior. life limiting population growth. The job of an animal sociologist is to assemble a pattern of behavior, like a mosaic, from individual events that can be recorded. The more you observe, the clearer the picture emerges and the clearer what gaps remain to be filled. For example, if you need to understand how a mother bear and her cubs hunt, you need to find a place where this is likely to happen and patiently wait for the event.
“When you live among animals, you need to maintain a balance: on the one hand, you cannot disturb them, on the other, it is impossible to hide or become invisible,” explains Ovsyannikov. - Arctic foxes, owls, and other animals are always aware that you are nearby. Therefore, you need to build relationships with animals so that they are familiar with you and treat you as a part of the landscape that is present, but not annoying. You need to show that you are such an aggressive monkey, which, however, is harmless if you don’t touch it.”
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The most effective way to explain this to a bear is to make noise, but not shout. Sharp sounds, such as metallic ones, frighten the animal, but a lively voice, on the contrary, is usually characteristic of a frightened victim. Ovsyannikov uses a method that requires special courage: he quickly and aggressively walks straight towards the animal, stomping heavily and waving his arms. Bears learn quite quickly and soon learn that it is better not to approach a person. “True, new animals appear in the population all the time, with which we need to build relationships anew,” says Ovsyannikov. - If a problem animal appears, you can see it right away, it is so brutal and self-confident, it is immediately clear that there will be difficulties with it. So, of course, there is no universal recipe; each bear needs to be looked at separately.”
Polar explorers love stories of friendship with tamed bears. Usually, however, friendship begins with the murder of the mother: bear cubs without a mother are completely helpless and die of hunger. If you pick up such a bear cub and feed it, it can grow up tame. One hunter picked up a polar bear cub, named it Aika and kept it in his apartment in Norilsk, and when the bear grew up, he gave it to the zoo. On Schmidt Island, another man tamed a bear, named her Masha and fed her by hand. On Kotelny Island, meteorologists back in Soviet times raised a bear named Umka, who lived under the porch like a dog. “All these games do not lead to anything good either for bears or for people,” says Ovsyannikov. - The bear accepts a person as one of his own and communicates with him as an equal. At any moment, if he doesn’t like something, he can hit with his paw or bite, as is their custom. And for a person, even a slight slap with a paw by bear standards can be fatal. This happened to one German trainer who had a very tender relationship with the beast, but at some point he killed her, according to eyewitnesses, completely unintentionally. Rather than trying to establish unnatural relationships, it would be much more useful if people stopped disturbing bears, much less exterminating them. That would be true friendship."
Photo: HEIDI AND HANS-JURGEN KOCH EAST NEWS (x10)
We have already looked at it in detail and were surprised. Let's now take a closer look at the familiar Polar Bear in more detail.
Polar bear- the largest bear, it is the largest carnivorous mammal in the world. The body length of an adult male can be up to 3 meters, and the weight can reach a ton. The largest representatives of the polar bear were spotted along the shores of the Intracoastal Sea.
The polar bear is listed in the IUCN Red Book and the Russian Red Book. Bear hunting is allowed only to the indigenous population of the North.
The skin of a polar bear is black, just like a brown bear. But the color of the skin is from white to yellowish. Also, the polar bear’s fur has a peculiarity: the hairs inside are hollow.
The bear seems clumsy due to its size and dimensions, but this is only an appearance. Polar bears can run quite fast and swim well too. The North bear travels 30 km per day. The bear's paw is unique. No deep snow can stop the bear, thanks to its size of the foot and column-shaped legs, even compared to other polar animals it very quickly and deftly overcomes any snow and ice obstacles. The resistance to cold is simply amazing. In addition to hollow hairs, the polar bear also has a subcutaneous layer of fat, which in winter can be up to 10 cm thick. Therefore, a polar bear can easily travel up to 80 km in icy water. In the summer, a bear can even swim to the mainland on an ice floe, then it is euthanized and sent back by helicopter.
In Russia, polar bears are found on the coast of the Arctic Ocean, in Greece and Norway, Canada and Alaska.
The main food of the polar bear is seals. One bear eats about 50 seals per year. However, catching a seal is not easy. A polar bear can watch its prey near a hole for hours, waiting for a seal to appear on the surface. After the seal surfaces to take a breath of air, the bear instantly hits the prey with its paw and throws it onto the ice. The predator eats the skin and fat, preferring to leave the rest, although in winter, in case of hunger, the bear eats the entire carcass. The bear is often accompanied arctic foxes, who get the remains of the seal. Polar bears also do not disdain carrion; the bear can smell the smell of prey from a distance of several kilometers. For example, beached whale will definitely become a meeting place for several bears. 2 bears or 3 bears may not share the food, then a skirmish occurs. It is unknown how many bears may be encountered. This is why a bear can enter the territory of human habitation. More often, of course, this is simple curiosity, although evil hunger can drive the beast into a hopeless situation. Although a bear can be a vegetarian, they like cereals, lichens, sedges, berries and mosses.
Spring is a heavenly time for bears. Baby sea animals are born, which, due to inexperience and weakness, do not provide adequate resistance and often do not even run away.
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The polar bear has incomparable resistance to cold. Its thick, long fur consists of hairs that are hollow in the middle and contain air. Many mammals have similar protective hollow hairs - an effective means of insulation - but those of the bear have their own characteristics. Polar bear fur retains heat so well that it cannot be detected by aerial infrared photography. Excellent thermal insulation is also provided by the subcutaneous layer of fat, which reaches 10 cm in thickness with the onset of winter. Without it, the bears would hardly be able to swim 80 km in icy Arctic water.
By the way, polar bears are the only large predators on Earth that still live in their original territory, in natural conditions. This is largely due to the fact that seals, their favorite and main food, live on drifting ice in the Arctic. For every bear there are approximately 50 seals per year. However, hunting seals is not easy. Ice conditions change from year to year, and seal behavior is unpredictable. Bears have to travel thousands of kilometers in search of the best places to hunt.
In addition, the hunt itself requires skill and patience. The bear watches the seal at the hole for hours, waiting for it to come up for air. He instantly strikes with his paw the head of a sea animal that has emerged from the water and immediately throws it onto the ice. First of all, the predator devours the skin and fat, and the rest of the carcass only in case of great hunger. A bear hunting a seal is usually accompanied by one or more arctic foxes, eager to take advantage of the remains of the killed animals. Polar bears themselves do not disdain carrion, thus compensating for the lack of seal fat and meat. The owners of the ice kingdom can smell carrion several kilometers away. And if suddenly a whale, falling into shallow water, dries up and dies, a whole company of white, eternally hungry bears will immediately come running from all sides.
Hunting seals is no easier. Shy seals, at the slightest danger, dive under the ice and emerge in another hole to breathe. And the bear rinses its face in icy water in vain. But in the spring, a fertile time comes for the bear - cubs of sea animals are born, which have never seen a polar bear before and therefore do not realize the danger. But even here the clumsy bear has to show miracles of ingenuity. In order not to scare away the cubs, the bear has to be very careful, because even the slightest crunch can give away its presence and deprive it of food.
Difficulties in obtaining food are aggravated by climate changes on Earth. As a result of climate warming, the ice in the bays begins to melt earlier than usual, summers become longer every year, winters become milder, and the problems of polar bears become more acute. Summer, in general, is a difficult time for polar bears. There is very little ice left and it is almost impossible to get close to the seals. Over the past 20 years, the polar bear hunting season has been shortened by two to three weeks. As a result, the weight of the animals decreased: if previously a male weighed about 1000 kg, now, on average, 100 kilograms less. The females also lost weight. This, in turn, has an extremely negative impact on population reproduction. Increasingly, females are giving birth to only one cub...
However, polar bears are not only suffering from warming temperatures and a shortened hunting season. In the recent past, the polar bear was an important commercial target. Fur and bear paws, which are the most important components of popular and expensive oriental soups, prompted members of polar expeditions to mercilessly exterminate this beautiful animal. The profits from such business are so great that the international black market continues to flourish, despite all attempts to stop it. The fight in this area has reached the same intensity as the fight against drug smuggling.
In July, many of the polar bears that traveled with drifting ice move to the coasts of continents and islands. On land they become vegetarians. They feast on cereals, sedges, lichens, mosses and berries. When there are a lot of berries, the bear does not eat any other food for weeks, gorging on them to the point that his face and butt turn blue with blueberries. However, the longer the bears starve, forced to prematurely move to land from the melting ice as a result of warming, the more often they go in search of food to people who have been actively exploring the Arctic in recent decades.
The question of whether an encounter with a polar bear is dangerous for a person is difficult to answer unequivocally. Sometimes bears attacked people out of curiosity, quickly realizing that they were easy prey. But most often, tragic incidents happen at campsites, where bears are attracted by the smell of food. Usually the bear goes straight to the smell, crushing everything in its path. The situation is complicated by the fact that the animal, in search of food, tears into pieces and tastes everything it comes across, including people who turn up by chance.
It should be noted that bears, unlike wolves, tigers and other dangerous predators, have virtually no facial muscles. They never warn of impending aggression. By the way, circus trainers claim that because of this feature, it is most dangerous to work with bears - it is almost impossible to predict what to expect from them in the next moment.
Now, thanks to the efforts of Greenpeace, they try not to kill bears that wander into the city in search of food, resorting to temporarily tranquilizing shots from a special gun. The sleeping animal is weighed, measured and recorded. A colored tattoo is applied to the inside of the lip - a number that remains for the entire bear's life. Females, in addition, receive a collar with a miniature radio beacon as a gift from zoologists. The euthanized bears are then transported by helicopter back to the ice so that they can continue living a full life in their natural habitat. Moreover, females with cubs are transported first.
For a polar bear, the world is limited by ice fields, and this primarily determines the characteristics of its behavior. Judging by animals kept in captivity, this bear, compared to the brown one, seems less intelligent and not so dexterous; he is less trainable, more dangerous and excitable, and therefore can be seen relatively rarely in the circus arena. True, he is characterized by a certain “straightforwardness” in his actions, due to a rather monotonous lifestyle, narrow food specialization, and the absence of enemies and competitors. But it is enough to observe this animal in a natural environment for even a short time to be convinced of the high level of its psyche, its exceptional ability to assess the conditions of the natural environment, including the quality of ice, adapt to them and, depending on them, flexibly change hunting tactics, find the easiest and passable paths among piles of hummocks, confidently move along young, fragile ice fields or areas of ice replete with cracks and leads.
The strength of this beast is amazing. He is capable of dragging and lifting up a slope a walrus carcass weighing over half a ton, with one blow of his paw he can kill a large sea hare that has almost the same mass as his, and, if necessary, he can easily carry it in his teeth for a considerable distance (a kilometer or more).
Polar bears are eternal nomads. Ice transports them over vast distances. It often happens that even such experienced “travelers” suffer disaster. Thus, animals caught in the zone of the cold East Greenland Current are carried on drifting ice along the southeast of Greenland, and in the Davis Strait the ice melts, and most polar bears, despite all their dexterity, die.
It would seem that living in the deserted polar spaces, the polar bear should not suffer from humans. However, it is not. The Arctic is already quite settled. Sailors, hunters, and people of other professions now constantly meet with polar bears, and these “contacts” do not always end favorably for the huge, but very curious and generally harmless animals.
And the biology of the beast itself has “weak” sides. During the mating season, the male has to travel enormous distances to find a female, and often endure a battle with a rival. Often searches are not crowned with success at all and no family is formed. Mother bears bear offspring (one or two cubs) every two years and become sexually mature only at the age of about four years.
The presence of food (seals and fish), suitable places for breeding and the absence of human disturbance are the main conditions for the existence of polar bears in the Arctic. But strangely enough, there are not so many places like this at first glance. The unique “maternity hospital” of these animals is Wrangel Island. In addition, polar bears make dens on the northeastern islands of Spitsbergen, Franz Josef Land, northeast and northwest Greenland, southwest Hudson Bay and some Arctic islands of Canada. The main territory of the Arctic is essentially unsuitable for habitation, much less breeding, of this species.
All pregnant female polar bears spend the winter in snowy shelters, which are relatively identical in structure and located, with rare exceptions, on land; Everywhere in the Arctic they go into dens and leave them at almost the same times. The physiological state of animals in dens is similar to that of brown bears, i.e. it is shallow sleep or torpor with a slight decrease in body temperature, respiratory rate and pulse, but not hibernation (as, for example, in marmots, gophers, etc.) . Apparently, at the beginning of winter, female bears lying in dens are more active than in the middle of winter, although in the spring in most dens one can see traces of the digging activity of females of varying ages.
The question of the winter activity of males, spawning females and young individuals is not clear enough. Obviously, in a significant part of their range, especially in the south of the Arctic, they are active all year round, with the exception of periods of severe snowstorm, from which the animals take refuge among hummocks or coastal rocks; finding here before. the layer of snow is quite deep, they even dig shallow shelters in it. With the end of the blizzard, bears leave such shelters and continue to roam and hunt.
In the high latitudes of the Arctic, especially in places with a harsh climate, frequent and strong winds, and possibly where animals have great difficulty in feeding, most of them lie down in dens relatively regularly. On the northern coast of Greenland, 90% of all animals spend the winter in shelters, in the northern part of Baffin Island - 50 and in the south of Greenland - 30%; in the whole range, 70-80% of all bears spend the winter in shelters, and older males go to shelters earlier and leave them earlier.
In the Canadian Arctic, male polar bears use refuges from early August to late March (most frequently in September, October, and January); young ones, as well as females with one-year-old cubs, were found here in shelters from early October to early April. The state allocates funds to build shelters made of laminated waterproof plywood, this significantly helps the animals.
In the north of the Taimyr Peninsula (Cape Chelyuskin area), all animals spend the winter in dens, but the duration of their stay there varies and depends on gender, age and whether the female is pregnant or barren. For the shortest period of time (according to the latest dates 52 days - from mid-December to early February) young bears go to shelters in the north of Taimyr; There are almost as many adult males in them. Females with young of the year spend 106 days in dens, spawning females - 115-125, and pregnant female bears - 160-170 days.
There is information in the literature about encounters of male polar bears in dens on Franz Josef Land, in the east of Taimyr, in the Kolyma Territory, etc., although everywhere here animals of various sex and age categories were observed and caught outside dens, which means that they remained active throughout the winter. The dens of such animals (obviously, the dens of barren females and young bears) are often located on sea ice and are more diverse in structure (shape, size) than the dens of pregnant bears. It is also obvious that the timing of their use is relatively variable.
The polar bear is the world's largest terrestrial carnivore, living in the Arctic: in the remote northern regions of Greenland, Norway, Canada, and Russia.
And although northern bears traditionally look white, surprisingly, their fur lacks white pigment, in fact it is translucent, and its skin is black. So why is the polar bear white? The answer to this question is provided by scientists' research into what the polar bear's fur is made of, as well as the study of optical phenomena that affect the color of this animal's fur.
: The polar bear is the largest land predator on Earth. The length of the animal is about 3 meters, weight – up to 1 ton.
What is polar bear fur made of?
The polar bear's fur contains two layers of hairs: an outer protective layer consisting of long (5-15 cm) guard hairs; and a dense insulating undercoat, the hairs of which are shorter and finer than those in the protective layer.
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Properties of protective hairs:
- translucent;
- hollow, i.e. empty inside;
- rough, narrowed (gradually reaching the base);
- contain particles that scatter light;
- contain salt particles;
- consist of the protein “keratin”.
The translucent hairs of the bear's fur also appear white due to the thickness of the animal's fur.
Influence of optical phenomena
The fur of the northern bear is translucent, but due to the properties of the protective hairs, which are involved in creating the optical effect, this animal's fur appears white. From an optical point of view, the reason why a polar bear appears white is due to the effect of light on the animal's hair.
Luminescence
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When the sun's rays fall on a polar bear's fur, some of this light gets trapped in the fur. This light energy is reflected inside the hollow part of the hairs, causing a reaction that is the emission of light - luminescence. This happens every time a beam of light comes into contact with an animal's fur.
Luminescence is accelerated by light-scattering particles in the hairs, which destroy the light beam. When light hits a light-scattering particle, it splits into more rays that move in different directions. Light scattering particles are found both on the inner surface of the hairs and on the outer surface. The scattering of light causes more white color to appear and be further emitted by the animal's hair. Thus, the bear's translucent fur reflects sunlight. This is the reason why polar bears are especially bright in direct sunlight. The brighter the lighting, the more light is reflected by the polar bear's translucent fur.
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Salt particles
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Polar bears spend a lot of time in the water, which explains the Latin name of these representatives of the bear family, ursus maritimus, which means “sea bear.” Polar bears collect salt particles while swimming or staying near salty sea water. Salt particles along the rough surface of the wool also act as light scattering particles, which increase the number of light rays and enhance luminescence.
Ultraviolet light
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When the sun shines on a polar bear, ultraviolet light travels along the guard hairs to their base and penetrates the animal's dark skin. When ultraviolet light hits the skin, it causes a whitish color due to fluorescence (the ability to release absorbed energy as cool light radiation). Fluorescence is a type of luminescence. Thus, ultraviolet radiation also causes the bear's fur to turn white.
Interesting fact: Ultraviolet rays, which are transmitted through translucent hairs, give the polar bear's fur its insulating properties.
Keratin
Keratin is a common natural protein found in skin, nails and hair. Similar to humans, bear hairs contain keratin. The protein molecules of keratin give off a whitish color, which further contributes to the appearance of white fur in the bear.