Polar Bear

We explain what the polar bear is, its habitat, feeding, reproduction, and more. Also, what risks does it face as a species?

The polar bear is one of the largest land carnivores.

What is a polar bear?

It is known as a polar bear or also white bear (due to the color of its fur, ideal for hunting between ice and snow) a species of quadrupedal mammal, typical of the frozen regions of the arctic, which is one of the terrestrial carnivores of larger size today. Its scientific name is Ursus maritimus .

The polar bear belongs, logically, to the bear family ( Ursidae ), a branch of carnivorous mammals that originated about 4.8 million years ago, and constitutes one of its youngest species, whose oldest fossils date from 130,000 or so years ago. Approximately 110,000 years ago, at which point it split from the brown bear ( Ursus arctos ).

Although it was discovered as a species by the British arctic explorer Constantine John Phipps (1744-1792) in 1774, it has actually been known to Inuit peoples for a long time and is referred to in their language as “ Nanook ”.

It is the only apex predator in the arctic habitat: an animal as beautiful as it is ferocious, an excellent swimmer, and adapted to the inclement temperatures near the pole.

Its black skin, which attracts more solar radiation and helps conserve heat, is covered with translucent fur, which due to the effect of solar radiation is perceived white or sometimes yellowish, although in captivity it can turn greenish, due to growth. of algae on its surface; something that, in its natural habitat, would never have happened.

polar bear characteristics

The polar bear is a fascinating animal that has the following characteristics:

• It is quadrupedal, that is, it walks on its four legs, ending in sharp and short claws, designed for sea hunting.
• Its fur is white and covers it completely, although underneath there is a rarely visible black skin. Beneath the skin and dermis, they have a dense layer of fat that isolates the body from the environment, and that only thins on the head and snout.
• The males of the species are usually about 2.6 meters long and weigh between 350 and 680 kg, while the females are around 2 meters and a few hundred kilograms less in weight. It is, therefore, a very bulky and heavy animal.
• They are solitary hunters, endowed with a prodigious sense of smell and a bite of 86.83 kilograms-force per square centimeter, that is, stronger than that of the white shark or the Bengal tiger.
• They have an amazing ability to swim: they can cover about 10 kilometers per hour of free-swimming. However, their food is always produced in the dry. His skin is also waterproof.
• They do not hibernate during the harsh arctic winter and spend around 50% of their life looking for something to eat.

Where do polar bears live?

Polar bear habitat is restricted to the Arctic region, around the North Pole. Their populations are distributed as follows:

• West of Alaska and Wrangel Island.
• North of Alaska.
• In the Canadian tundra (60% of polar bears live here).
• In Greenland.
• North of Russia.
• In the Svalbard archipelago and the Fritjof Nansen Archipelago, north of the European continent.

What do polar bears eat?

The polar bear usually hunts marine mammals, when they come to the surface to breathe.

The polar bear has an almost exclusively carnivorous diet, interrupted only in the arctic summer to eat a small portion of vegetables. Being the top predator in the region, it usually hunts young and adults of other marine mammals, such as seals and belugas, which they capture when they break through the ice to come up to breathe, or the eventual young and defenseless walrus.

They can also feed on fish, or the eggs and young of seabirds, and even food leftovers from human colonies. Polar bears do not ingest water, but rather obtain it from the body fluids of their prey since the water in the arctic is salty and acidic. And in conditions of scarcity, they can resort to cannibalism.

How do polar bears reproduce?

The cubs' lactation time lasts about five months.

The mating season is the only time of year when polar bears are friendly with each other, although fights between males over access to the female are common. Like all higher animals, its reproduction is sexual and through internal fertilization, although the fertilization of the female's ovum occurs in a delayed manner, almost four months after copulation with the male.

This allows the female to store as much fat as possible to endure without eating, not only during childbirth, in which she usually gives birth to one or two cubs but also during lactation, which lasts about five months. about.

How long do polar bears live?

The lifespan of polar bears can reach a maximum of 30 years.

Is the polar bear in danger of extinction?

Global warming is destroying polar bear habitats.

Currently, according to the International Union for Conservation of Nature, the polar bear is registered as a species in a vulnerable conservation status (VU), that is, its communities are under threat, but not in immediate danger of extinction.

The total number of polar bears in the last 45 years has been reduced by at least 30%, reaching an estimated population of between 20,000 and 25,000 individuals, due to indiscriminate hunting, to the point that their hunting is prohibited in many countries.

However, the greatest risk to polar bears is human pollution. Its impact not only creates the presence of harmful substances in the arctic ice, but also global warming, which has been melting the ice and, therefore, reducing the solid surface available for the polar bear to inhabit.

The melting of the ice earlier each year means that females, after mating, do not have enough time to accumulate their fat reserves, which has caused a 15% drop in the polar bear birth rate.

 

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