We explain what the polar bear is, its habitat, food, reproduction and more. Also, what risks do you face as a species?
What is a polar bear?
It is known as a polar bear or also a white bear (due to the color of its fur, ideal for hunting between ice and snow). a species of quadruped mammal, typical of the frozen regions of the arctic, which is one of the largest terrestrial carnivores today. Its scientific name is Ursus maritimus.
The polar bear belongs, logically, to the family of bears (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 approximately 130,000 to 110,000 years ago, at which time it separated 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 was actually known by Inuit peoples for a long time and referred to in their language as “nanook”.
It is the only super predator in the Arctic habitat: an animal as beautiful as it is fierce, an excellent swimmer and adapted to the inclement temperatures near the pole.
Their black skin, which attracts more solar radiation and helps to conserve heat, is covered with a translucent fur, which, due to the effect of solar radiation, appears white or sometimes yellowish, although in captivity it can become greenish due to growth. of algae on its surface; something that, in its natural habitat, would never have happened.
See also: Wild animals
Characteristics of the polar bear
The polar bear is a fascinating animal that has the following characteristics:
- It is quadruped, that is, it walks on its four legs, ending in sharp and short claws, designed for sea hunting.
- His fur is white and it 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 muzzle.
- Males of the species are typically 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. It is, therefore, a very bulky and heavy animal.
- They are lonely 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 diet is always dry. Your skin is also waterproof.
- They do not hibernate during the harsh arctic winter, and they spend about 50% of their life searching for something to eat.
Where does polar bears live?
The habitat of polar bears 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 has an almost exclusively carnivorous diet, interrupted only in the arctic summer to eat a small serving of vegetables. Being the highest predator in the region, it tends to hunt young and adults of other marine mammals, such as seals, and belugas, which they capture when they break the ice to go up to breathe, or the eventual young and defenseless walrus.
They can also feed on fish, or on the eggs and young of seabirds, and even on food leftovers from human colonies. The polar bears they do not ingest water, but obtain it from the bodily fluids of their prey, since in the Arctic the water is salty and acidic. And in conditions of scarcity, they can resort to cannibalism.
How do polar bears reproduce?
The mating period is the only time of year when polar bears are friendly with each other, even though fights between males for access to the female are common. Like all higher animals, its reproduction is sexual and through internal fertilization, although the fertilization of the ovum of the female takes place in a delayed way, almost four months after the copulation with the male.
This allows the female to store as much fat as possible to bear without eating, not just during parturition, in which one or two puppies are usually given birth, but during lactation time, which lasts about five months.
How long do polar bears live?
The life span of polar bears can reach a maximum of 30 years.
Is the polar bear in danger of extinction?
Currently, according to the International Union for Conservation of Nature, the polar bear is registered as a species in a vulnerable conservation situation (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%, touching an estimated population between 20,000 and 25,000 individuals, due to indiscriminate hunting, to the point that their hunting is prohibited in many countries.
Nevertheless, the greatest risk for polar bears is represented by 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 the females, after mating, do not have enough time to accumulate their fat stores, which has caused a 15% drop in the polar bear birth rate.