Polar Bear no longer endangered?



by LORENZO CIOTTI

Polar Bear no longer endangered?

Is the polar bear no longer at risk of extinction? Alaska and Canada have announced that the species is no longer threatened with extinction. In 2018, the University of California Santa Cruz and the US Geological Survey published a study showing that polar bears were dwindling very rapidly and their extinction would be very close.

Since then, the efforts of associations and nations to safeguard polar bears have led to an increase in the number of animals from 26,000 to 37,500 in less than three years, thus allowing them to leave their position on the vulnerable list to join the almost threatened list, in the IUCN registry.

A new hope. The polar bear has been classified as vulnerable by the IUCN, which placed it on its red list: the species faces extinction due to the climate crisis and global warming, which is destroying its natural habitat.

The polar bear lives in the Arctic and its habitat is included in 6 countries: Canada (Manitoba, Newfoundland, Northwest Territories, Nunavut, Ontario, Québec, Yukon), USA (Alaska), Russia (Krasnoyarsk, Magadan, Northwestern Federal District, Western Siberia, Yakutia), Greenland, Norway (Svalbard), Iceland.

The current polar bear population is estimated at 20-25,000, 60% of which are in Canada. As evidence of this, a polar bear is depicted on the Canadian 2 dollar coin. The polar bear is the most meat-eating member of the Ursid family.

Its primary protein source consists primarily of seals, but also cetaceans, walruses, molluscs, crabs, fish, even sea worms, birds, young eagles and owls, wolverines, polar foxes, reindeer and lemmings. It can also eat berries and waste.

The most famous hunting method of polar bears is that used for seals: the plantigrade hears the sound of the prey under the ice, lurks near a crack and, as soon as the prey comes out to breathe, kills it with a violent paw.

Only the males have such powerful musculature and the size to attack belugas and narwhals, both up to five and a half meters long, easily over 1000 kg in weight and the latter with the long tusk typical of males. Once the prey has been identified, often a young or a female narwhal, the white bear enters the water and nimbly attacks the cetacean in the delicate points, such as the fins and the belly, avoiding the fatal blows.

The polar bear is immediately recognizable by its white fur. Unlike other Arctic mammals, its coat does not darken in the summer. The hair is not white pigmented, but is hollow and non-pigmented like white hair in humans. Polar bears' thermal insulation is extremely effective against the cold, but their bodies heat up to temperatures above 10 ° C.

Their isolation is so effective that when viewed with an infrared camera, they are barely visible. Only the legs and snout give off a perceptible heat. An interesting feature of fur is that, photographed with ultraviolet light, it appears black: it therefore has, as a further mechanism for producing thermal energy, a high absorption capacity of UV frequencies; this is possible by having a black epidermis. The high concentration of retinol makes the polar bear's liver inedible and potentially lethal.