Polar bears are dangerous

Polar bear in the species dictionary

Polar bears are those largest species of carnivore on land and live in the polar region around the North Pole. Their way of life has been adapted to the special conditions in the Arctic for thousands of years. You are hiking with the pack ice northward in spring and back south in autumn. In winter they eat up reserves from which they can feed in summer. But nowadays this cycle becomes vital through climate change sensitively disturbed and interrupted. Polar bears are hungry and get weaker and weaker. The stocks are shrinking. So are they for Symbol of climate protection become.

relationshipOrder of predators, family of bears
size1.8 - 2.8 m head trunk length, up to 1.7 m shoulder height, males larger than females
Weightlarge differences between males and females, males weigh 300 - 1,000 kg, females 150 - 250 kg, in addition large seasonal differences
particularitieslargest predator species on land, belongs to the mammals with the greatest difference in weight between the sexes, fur appears white, but hair is actually transparent, dark skin absorbs solar energy, fur forms an insulating air cushion, thick body fat, claws like spikes, paws like snowshoes, nictitating skin on Eye like snow goggles, super nose
Social organizationloner
ReproductionMating season from March to June, delayed implantation of the egg in the uterus, resulting in a gestation period of 6.5 - 8.5 months, births in birth caves, particularly low reproductive rate
Young animals1 - 4, mostly 1 - 2 young animals per litter, nestling, particularly high-fat breast milk, self-employment at 2 years of age
Life expectancyup to 30 years in the wild
Geographical distributionPolar region around the North Pole
habitatarctic polar ice, coasts of the adjacent regions
nutritionCarnivores, prey almost exclusively on seals, seasonal build-up of fat reserves, females fast for up to 8 months while rearing young, play an important role in the ecosystem as top predators
Stock size22,000 to 31,000 (as of 2020), trend: uncertain, some stocks with a significant decline
Endangerment status"Endangered" (International Red List)

Where are polar bears classified in the zoological system?

Of orders, families and species

The ice Bear (Ursus maritimus) belongs in the order of the Predators to the bear family. Within this systematic group of eight bear species, polar bears, brown bears, American black bears and collar bears form the common genus Ursus. The polar bear is most closely related to the brown bear. Their lines probably only separated around 400,000 years ago. Hybrid of the two species occur in the overlapping regions of the distribution areas. No subspecies are distinguished in polar bears.

Features, properties and special features

Polar bears are the largest species of predator on land. There are seldom individual particularly large brown bears larger than them and some aquatic predators such as elephant seals. The size of the polar bear varies by region. The smallest are found in the eastern part of Greenland, the largest on the Bering Sea. The body weight also depends on the season and the related Nutritional status from. Overall, the length of the head body is 180 to 280 centimeters and the shoulder height is up to 170 centimeters. Male polar bears weigh 300 to 1,000 kilograms, the females 150 to 250 kilograms. This makes them one of the mammals with the biggest difference in weight between the sexes.

Polar bears, like all bears, have one elongated, stocky body, a muscular neck, a large head with round ears and a long muzzle, short, strong legs with large paws and a short stubby tail. Compared to other bears, polar bears have a longer neck, a smaller, flatter skull, especially small eyes and ears and especially large, broad paws.

The polar bear bite has 42 teeth and is more similar to that of the omnivorous bear relatives than that of other carnivorous predators such as cats and dogs. The strong canines are used in the fight against rival conspecifics and to kill prey.

The polar bear's fur appears white or pale yellow and has no other markings. However, both the top hair and the undercoat hair are actually transparent. After a meal, polar bears' fur is often blood-smeared and oily. The top hairs are hollow. This is how a insulating air cushion in the fur of the polar bear. The summer fur is shorter than the winter fur. The skin is black. So it absorbs them well Solar energy. Under the skin there is a round to protect the body temperature in freezing cold ten centimeters thick layer of fat.

Polar bears are like all bears Sole walker. In the step seal of the front paw you can see about half the sole as well as five toes and five claw prints. In the step seal of the rear paw you can often see the entire sole as well as five toes and five claw prints. The claws of polar bears are shorter and more curved than those of brown bears and serve on a smooth surface as spikes. In addition, the thick hair on the soles of the feet reduces the risk of slipping. Also the numerous small, soft papillae under the feet that like small suction cups work, support traction. The paws, which are up to 30 centimeters wide, act like snowshoes in deep snow, improve weight distribution on fragile ice and serve as a paddle when swimming.

To protect against damage to the eyes from strong UV radiation and snow blindness, polar bears have a nictitating membrane that resembles a Snow goggles is working.

All bears smell extremely good, even better than dogs, and perhaps best of all mammals on earth. With their super nose, polar bears are even capable of prey under the ice to locate.

Polar bears are excellent swimmers and can dive for up to two minutes. On land they can gallop at speeds of up to 40 kilometers per hour.

The social organization, activity and communication

Polar bears are loner. While it used to be thought that polar bears drift more or less passively with the polar ice, today we know that they do despite the ice drift fixed grazing areas occupancy. Both the whereabouts and the activity within the home areas vary greatly over the course of the year. In contrast to the other bears, polar bears are the grazing areas of the males about the same size like that of the females. Because the grazing areas of several females overlap strongly, those of the males nevertheless overlap with those of several females. The size differs depending on the habitat quality, habitat stability and stage of life and is average 20,000 to 250,000 square kilometers.

Polar bears particularly show high activitywhen there are many prey to be found. In other predators, the relationship is typically the other way around.

In the high season of availability of prey, polar bears eat excessively for themselves To eat up fat reserves. When the polar ice border shifts northward in spring and southward in autumn, polar bears cover greater distances than in winter and summer.

What is known about polar bear reproduction?

From mating through the development of the young to adulthood

Female polar bears are using four to five years sexually mature. The competition between males and females is great. Polar bears mating season is from March to June. However, the implantation of the egg in the uterus of female polar bears is delayed until autumn after mating. It only occurs when the female has over the summer enough fat reserves for pregnancy and was able to create the first time of raising young. Studies in Canada show that pregnant female polar bears have deteriorated over the past 30 years due to the climate crisis.

While the average weight in 1980 was 266 kilograms, in 2019 they weighed an average of 226 kilograms. This corresponds to a A decrease of around 15 percent. The worse the nutritional status of a female, the lower it ultimately is Chances of survival of the young. In addition, there comes a point at which the reserves of the females are no longer sufficient for pregnancy and they do not even become pregnant. The female with the lowest known body weight during pregnancy weighed 189 kilograms.

Pregnant females then relate so-called in the autumn months Birth cavities. These are located on the pack ice, in Snowdrifts or at Depend on the mainland near the coast.

Due to the delayed implantation of the egg, a total of six and a half to more than eight and a half months pass between mating and the birth of the young. The polar bear babies are coming between November and January in the birth caves to the world. Young mothers usually give birth to a single cub with a litter, older females two young, more rarely triplets and very rarely quadruplets. you will be blind, thinly haired and born with a birth weight of about 600 grams. The proportion of fat in breast milk is initially over 30 percent, so that the little polar bears grow quickly in the first weeks and months of life. To around three monthswhen they leave the birth cavity for the first time, they already weigh around ten to twelve kilograms.

The Boy mortality in the first year of life is high. The probability of survival depends primarily on the nutritional status of the mothers. The children of females who were able to eat up large reserves of fat in the summer before giving birth, thrive faster and better. The young animals are around two years old self-employed enough to get by on their own and are abandoned by their mothers. These then mate again.

By around the age of around their late twenties, females get around offspring every three years. In comparison to other mammals, polar bears, similar to other bears, have one of the due to their relatively late sexual maturity and a relatively small litter size lowest reproduction rates within the class of mammals.

Their area of ​​distribution then and now

Polar bears live in the polar region around the North Pole. Their distribution area extends south to the pack ice border and in summer also beyond, when they wait on the coasts for the pack ice to return. It extends into the Bering Sea, to the north and west coast of Alaska, to the north and east coast of Canada, to south of Greenland, to south of Svalbard and to the north coast of Russia.

The southernmost part of the polar bear range is located off the coast of Newfoundland. The Canadian island of Akimiski Island in James Bay, the southern branch of Hudson Bay, is the southernmost region where polar bears build birth caves. When the pack ice limit closes Beginning of the summer half-year shifts north, most polar bears follow their prey. However, some polar bears, especially those of the southern subpopulations, cannot and do not have to follow the sometimes rapid retreat of the ice without pack ice stay behind on the mainland.

In the north, individual polar bears have been observed up to 25 kilometers south of the North Pole. However, the Arctic Ocean only offers polar bears little foodbecause the ice is too thick and the sea too deep for seals to live.

Overall, polar bears are in the Countries Greenland (Denmark), Canada, Norway, Russia and the US state of Alaska are native to and come to the Marine regions Northeast Atlantic, Northwest Atlantic, Northeast Pacific, Northwest Pacific and Arctic Ocean. Occasionally loners are driven to Iceland on an ice floe.

In which habitat do polar bears occur?

The scientific name of the polar bear Ursus maritimus actually means "Sea bear”. Polar bears spend most of their life at sea, namely on the arctic polar ice. In the polar region around the North Pole, there is continental ice in the form of ice sheets and caps that cover the mainland, and sea ice in the form of ice mud, floating ice floes and extensive annual to perennial pack ice with a closed or almost closed ice cover. However, this ice sheet is melting through that Climate heating but now at breakneck speed. The prognosis is that in around 15 years the Arctic will be completely free of ice in summer and only freeze over in winter.

Overall is the preferred habitat of polar bears annual offshore pack ice in regions with shallow sea depths, where the bioproductivity is high due to the upwelling of the deep water and currents and there are therefore many prey. Where there are holes and crevices in the ice cover and the prey animals appear to breathe, polar bears have optimal hunting conditions. On the pack ice with fewer breathless holes for several years, such as at the North Pole, there are fewer seals and therefore fewer polar bears. Polar bears also live in coastal regions. In some southern regions of the range, polar bears have to spend up to six months on land in summer. In doing so, they often get caught in Conflicts between humans and animals.

How do polar bears feed?

Everything about their food and diet

Polar bears are the only members of the bear family that usually feed exclusively from meat and are among the top predators in their habitat. As the end of the food chain, they represent a particularly important part of the ecosystem.

Polar bears primarily pursue two hunting strategies. For one thing, they are lurking Holes and crevices in the ice sheet and wait there until a prey appears to take a breath. At that moment they grab at lightning speed and drag the prey onto the ice. On the other hand, they feel with hers very good nose Seals break up in their birth caves under the ice, then break with the help of their body weight with momentum from above into the caves and snatch the prey. Occasionally, polar bears cautiously sneak up on a seal lying around on the ice and then attack it from a short distance. Sometimes they stalk each other while swimming. in the free water or on land Polar bears, on the other hand, have almost no chance of hunting success. When the weather is favorable, polar bears can smell carrion, such as whale carcasses, which are occasionally part of their diet, over a distance of up to 30 kilometers.

Polar bears are particularly good at Digest fat and specialize in hunting particularly fatty prey. With a large meal, they consume up to 20 percent of their own body weight. Their access to prey varies greatly depending on the season. The polar bears eat from this in winter large fat reserves from which you can live in summer. In the high season, when the polar bears have more than enough to eat, they typically only consume the body fat of their prey and leave the rest. Polar bears can digest up to two kilograms of fat per day and utilize around 97 percent of this.

Polar bears mainly feed on young ringed seals. Bearded seals and harp seals are also among their preferred diets. Occasionally, hooded seals and ribbon seals are also on their menu. Adult polar bear males in particular can also prey on particularly large marine animals such as walruses, narwhals and beluga whales. Polar bears also eat carrion, for example Whale carcass of gray or bowhead whales. On land, polar bears seldom prey also include musk ox, reindeer, small rodents, sea birds, shellfish and fish. They also feed there in the ice-free time of eggs, seaweed, berries and other parts of plants as well as rubbish.

Although polar bears can survive for a few months on a lower-energy diet, they are still on that Seal hunt instructed in winter and the build-up of fat reserves. Polar bears are unlikely to be without pack ice could survive permanently.

Female polar bears survive longest known Lent in the class of mammals. When new polar bear mothers and their offspring leave the birth cavity for the first time in spring, they have up to Nothing eaten for eight months and are very hungry.

How many polar bears are there?

Their existence in the past, present and future

According to the latest investigations, the inventory is currently around 22,000 to 31,000 polar bears estimated. The total population is divided into 19 subpopulations. Most polar bears live in Canada. The Canadian polar bear population is estimated to be 60 to 80 percent of the total population. Overall, the polar bear density is highest on annual pack ice. The polar bear experts of the World Conservation Union IUCN (IUCN Polar Bear Specialist Group) regularly publish the latest findingsabout the stock developments of the individual subpopulations. In 2019 it was said that only two of the 19 subpopulations are currently developing positively, five are stable, four subpopulation stocks are declining and the development of eight more cannot be assessed due to a lack of data.

Are polar bears critically endangered?

Your endangerment and protection status

According to the IUCN Red List, polar bears are considered to be endangered. In the Washington Convention on CITES, polar bears are listed in Appendix II. All international commercial trade is thus strictly regulated. In the individual distribution countries, polar bears are protected differently according to national legislation. In Alaska, Canada and Greenland, polar bear hunting for indigenous people and national trade are permitted. Canada also offers the opportunity to Trophy hunting on polar bears. In Norway and Russia, however, there are polar bears strictly protected. A total of 700-800 polar bears are hunted annually in the entire distribution area. This corresponds to three to four percent of the total population.

The ice bears are melting away, they live on thin ice, because that Climate change threatens the basis of life the polar bear. The survival of polar bears depends on the fact that they can eat enough fat reserves in winter for the food-poor summer and autumn. As carnivores, they need Pack iceto be able to hunt seals successfully. Due to climate change, the hunting season for the polar bears is now shortened. The ice melts earlier at the beginning of the summer half-year and freezes again later towards winter. This is how the polar bears build less reserves up and are in worse shape. In some regions of the range it has been observed that less time to hunt seals each week means a body weight reduction of around 10 kilograms. The worse the nutritional status of the polar bears or female polar bears, the lower it is Rate of reproduction as well as that Chances of survival of the young.

Another threat is the ingestion of Environmental toxins. As top predators, polar bears ingest a large amount of pollutants that have accumulated in the food chain through their prey. These environmental toxins affect the Body functions of polar bears such as the formation of antibodies, the absorption of vitamins and fertility. The pollutants are also passed on through breast milk and lead to early poisoning of the young.

In addition to the direct effects of climate change on polar bears, there is an indirect threat related to global warming. As the icing decreases, so does the Oil industry more and more access to the polar bear distribution area. It is not only disruptions caused by oil production that have a negative impact on the polar bears. Spilled oil is dangerous for polar bears. On the one hand, reduce Pollution the isolation of their fur, on the other hand, causes oil ingested through food Poisoning and organ damage. In the case of oil spills, the conditions for rescue operations in arctic waters are particularly difficult and a particularly large amount of ecological damage can be expected.

The hunger ultimately also leads to more frequent so-called Human-wildlife conflicts, because the search for food alternatives drives the polar bears more and more into settlements, where they find garbage and plunder food stores. Polar bears can be very dangerous for people, pets, farm animals and property. In the past 15 years, more than 20 fatal attacks reported to humans by polar bears.

WWF projects to protect polar bears

The Polar bear protection has been a big topic for the WWF for decades. Polar bears, like rhinos, elephants, great apes, tigers, giant pandas and other species are among the flagship species of the WWF. The WWF is involved in numerous projects around the world Protection and research into threatened species active and has already achieved a lot.

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