Everything you need to know about Polar Bears and a few interesting facts Polar Bear facts.
Polar Bears, sea bears, white bears, ice bears or the great white northern bears are hyper carnivorous bears that belong to “Ursidae” or the great bear family.
In scientific terms, polar bears are named Ursus Maritimus, the Latin word for ‘maritime bear.’
Polar bears are the largest extant bear species and the largest land carnivore alive. Polar bears inhabit the Arctic region, encompassing the Arctic Ocean and the Arctic Circle.
Naming and Etymology
Polar Bears have been named “Ursus Maritimus” due to their native habitat. They have been called several names throughout the years by various communities.
The Inuit and Yupik refer to a polar bear as ‘Nanook’ while the bear is ‘umka’ in the Chukchi language.
In Qubec, polar bears are ‘ours blanc’ (“white bear”) or ‘ours polaire’ (“polar bear”).
In the Norwegian Svalbard archipelago, the polar bear is referred to as Isbjørn (“ice bear”).
Taxonomy and Evolution
It is believed that the bear family “Ursidae” had split millions of years ago, which led to the birth of various sub-families. “Ursinae”, or the polar bear family, was born, a subfamily separate from the brown bears.
Polar bears are believed to have diverged from the population of brown bears, which isolated themselves during the glaciation period in Eastern Siberia.
Although the white polar bear population and brown population may have diverged long back, there are pieces of evidence that show the intermittent mating and mingling of the two bear populations.
Polar bears have no natural predators and know no fear of humans, making these natural predators hazardous animals.
Polar bears get to mate with brown bears during the warm months when the arctic ice melts, and polar bears are driven onto land while the brown bears migrate northward.
This breeding of polar bears with brown bears produces fertile and grizzly polar bear hybrids.
Population and Distribution of Polar Bears
The polar bear inhabits the entire Arctic Circle and the landmasses beyond South till Newfoundland. The absence of human communities in the remote region makes the place a perfect habitat for the polar bear populations.
The habitat ranges from the Arctic to the far south to James Bay in Canada. The southernmost range is between the subarctic and humid continental climate zones.
Polar bears occasionally drift widely due to ice floes and have been spotted many times near the Norweigan mainland.
Though the polar bears are thought to have existed on low densities in the Arctic Basin, 19 discrete subpopulations of polar bears have been identified.
A few subpopulations of the polar bears include Viscount Melville Sound, Norwegian Bay, Kane Basin, Lancaster Sound, Baffin Bay, Davis Strait, Southern Hudson Bay, Western Hudson Bay, Foxe Basin, Gulf of Boothia, M’Clintock Channel, Southern Beaufort Sea, Northern Beaufort Sea, and Arctic Basin.
The subpopulations have shown seasonal fidelity to certain habitats. American subpopulations range from the Beaufort Sea south to Hudson Bay and east to the Baffin Bay in western Greenland and account for about 54% of the global population.
This range includes the territory of five nations: Denmark (Greenland), Norway (Svalbard), Russia, the United States (Alaska) and Canada.
These nations have signed up for the International Agreement on the Conservation of Polar Bears, which mandates cooperation on research and conservation efforts throughout the endangered species’ range.
It is costly and challenging to track polar bear populations. Still, new methods of tracking polar bears have been implemented since the mid-1980s, making tracking polar bears a bit easier, estimating the endangered species of having a count of 21,000 to 31,000.
Where Do Polar Bears Live?
The polar bear is a marine mammal. Polar bears spend half of their life in the sea. Its preferred habitat is the annual sea ice covering the waters over the continental shelf and the Arctic inter-island archipelagos.
They are the only living marine mammals with powerful large limbs and feet to move quickly on the ice.
The annual sea ice, covering the waters over the continental shelf and the Arctic inter-island archipelagos are the preferred habitats of polar bears.
These habitats are the “Arctic rings of life” and have high biological productivity compared to the deep waters of the high Arctic.
The polar bears frequent the sea ice meets water known as polynyas. Freshwater is limited in these environments because it is either locked up in snow or is saline.
Polar bears can produce water through the metabolism of fats found in seal blubber, where seals are found in plenty.
Polar bears are therefore found primarily along the perimeter of the polar ice pack, rather than in the Polar Basin close to the North Pole, where the density of seals is low.
Annual sea ice contains areas of water that appear and disappear throughout the year due to weather changes. Seals migrate into freshwater, and polar bears follow seals to hunt their prey.
During warm months, ice melting or ‘ice-floe breakup’ forces polar bears to migrate to land and wait the entire duration for the winter season to arrive so that the waters start freezing again, giving these marine mammals their homelands once again.
The polar bears are homies of the Arctic Sea ice, which has ice-covered waters and extremely cold weather where it is impossible to stay alive. They have been provided with boons and blessings for their survival! Then how do these bears survive and live their lifetimes?
Let’s take a look at some of the distinctive body features of polar bears, which help them brave the harsh conditions of the sea ice.
Polar Bears and their distinctive features
Polar bears are stocky, with a long neck, relatively small head, short, rounded ears and a short tail. The large feet distribute their body weight while walking in deep snow or on thin melting ice and provide propulsion while swimming in the icy waters. These stocky paws also provide traction on ice.
The pads of paws are covered with small, soft papillae, and claws are short and stocky to have a firm grip on ice and hunt prey. These stocky claws are deeply scooped on the underside to help dig the ice in their natural habitat.
Male polar bears or boars are much larger and heavier than female polar bears. A male polar bear weighs around 350-700 kgs and measures 2.4 meters in length.
Generally, a female polar bear weighs about half the size of male polar bears, i.e., 150-350kgs and are 1.8-2.4 meters long, but pregnant polar bears can sometimes weigh up to 500kgs.
Polar Bear Fur
Urus Martimus or our very own polar bears are the intensely insulated bears alive! They are protected up to 10 cm with adipose tissue, their thick hide and fur.
The polar bear fur consists of a thick hide, a layer of dense underfur, and an outer layer of guard fur, which is transparent but appears white in the sun.
Sunlight passes through the polar bear’s fur and is absorbed by the bears’ black skin. The thick layer of underneath body fat that a polar bear’s body has acted as a repellant, insulating the body against icy winds and cold waters.
What Do Polar Bears Eat?
Having an insulated body against the harsh weather is not enough! The polar bears have to hunt for their food, which can sometimes prove difficult as habitats are affected due to climate change.
A sea bear’s (polar bear) primary prey is a ringed seal, but the Ursus Maritimus can also survive on bearded seals and pinnipeds.
They hunt seals at the interface of ice, water and air when the prey emerges from the holes to breathe in air. Rarely does a sea bear catch its prey on land or in water.
Polar bears are the only bears who have shown flexibility in their eating habits. A polar bear’s curious nature and scavenging habits make it flexible enough to feed on whale carcasses or garbage near human settlements.
A mature adult male feeds on a whale’s digestible calories rich skin and blubber, and the young bears prefer to devour red meat.
While seal predation is the indispensable way of life for most polar bears, many polar bears also devour berries, leaves, fruits, birds, rodents, musk deers or fish.
The summer months deprive bears of gorging on seals and whales, but the fat stores from winter catch help them survive until the next fresh time hunting season.
White bears are whimsical creatures with some amazing traits. But do you know some fascinating facts about them?
Then look here because we have got some fascinating facts about polar bears for you.
The Nine Amazing Polar Bear Facts
1. Polar Bears are black bears and not white!
Polar bears have fine fur that appears white as the furry cover reflects the sun’s visible light.
The upper layer of skin consisting of fur appears white, and the skin below it is jet black—however, the white appearing fur yellows as the bears’ age.
2. A Polar Bear can swim on for days
The polar bear is an excellent swimmer and can swim on for long durations with speeds that match up to 6mph in water to shift from one sea ice to another.
However, pregnant females can face difficulties while swimming due to their excessive weight.
Their large paws have adapted over the years for swimming, which they use to paddle through the water while holding their hind legs flat like a rudder.
3. Scientists can draw Polar Bear DNA from their footprints itself
No matter how surprising it may sound, Yes!, the bear footprints do contain their DNA which scientists can quickly extract.
And not only DNA, but the scientists can also gather info on the ringed seals it has preyed on.
4. A Sea Bear can sense its prey from a kilometre away
Sea bears have a very strong sense of smell and are far better and more efficient than other bears in sensing their prey. They can find prey and small mammals from breathing holes very quickly.
5. Dinner plate-sized paws!
A polar bear has 30 cm wide paws, which are the size of a dinner plate! Along with hind legs, the paws act as a natural snowshoe to pave their way through the snow.
6. Three eyelids! Gone crazy…haven’t you?
This may sound crazy enough to say, but a polar bear does have 3 eyelids. The extra eyelid layers protect the sensitive eyes from elements in harsh weather.
7. Blue tongued polar bears
Polar bears have a bluish tongue as their dark and pigmented black skin extends to the tongue to absorb heat and keep polar bears warm.
8. A polar bear’s health determines its pregnancy!
Polar bears have got amazing physiology. They are one species that benefit from “delayed implantation”. This means that although polar bears generally mate between April and June on the sea ice, the fertilized eggs do not implant until late in the autumn.
The eggs are only implanted if the female bear has gained enough weight during her hunting season.
So, if a female polar bear has not gained enough weight to support her pregnancy, she will not get pregnant, and the eggs will remain frozen until she gains enough weight in the hunting season.
9. Razor-sharp teeth
Polar bears have good razor-sharp teeth and can give you quite a bite!!!
Climate change: A danger to Ursus Maritimus?
Leading polar bear biologists have expressed grave concerns about the impact of climate change on the polar bear population. Changing the arctic region has become the biggest threat to polar bear populations raising concerns of their extinction by 2100.
The key concern is the life loss of polar bears due to habitat loss, leading to starvation and malnutrition deaths. A polar bear generally has a life span of about 25 years, but the rapid melting of ice glaciers due to temperature rise is causing water levels to rise.
A high water level prevents bears from hunting prey, leading to starvation. Insufficient nourishment will lead to lower reproductive rates in adult females. This will also lower survival rates in cubs and juvenile bears and poorer body conditions in bears of all ages.
Climate change will affect various aspects of polar bear lives, too, especially their maternity months.
Rising water makes it difficult for those mammals who traditionally den underground and warm winters increase the risk of collapsing den roofs, reducing insulative value.
It also makes it difficult for a mother bear to swim with her cubs from the mainland to the ice-lands once the maternity period is over.
A polar bear is just another mammal that gives birth, eats, breathes, feeds its cubs, ovulates, sexually reproduces and is intelligent. But these mammals are on the verge of extinction and have been included in the endangered species list.
It is high time, and stern steps need to be taken to protect polar bears. Innovative methods should be developed to track polar bears and improve their habitat.
Countries should join hands and collectively decide on steps to prevent climate change and conserve natural habitats before time slips away. Ursus Maritimus is no longer seen on the earth!