The grizzly bear (Ursus arctos ssp.) is any North American subspecies of brown bear, including the mainland grizzly (Ursus arctos horribilis), Kodiak bear (U. a. middendorffi), peninsular grizzly (U. a. gyas), and the recently extinct California grizzly (U. a. californicus†) and Mexican grizzly bear (U. a. nelsoni†). Specialists sometimes call the grizzly the North American brown bear because the grizzly and the brown bear are one species on two continents. It should not be confused with the black grizzly or Ussuri brown bear (U. a. lasiotus) which is another giant brown bear subspecies inhabiting Russia, Northern China, and Korea. Read More : Click Here Since the mainland grizzly is so widespread, it is representative and archetypal for the whole subspecific group. Even so, classification is being revised along genetic lines. Except for females with cubs grizzlies are normally solitary, active animals, but in coastal areas, grizzlies gather around streams, lakes, rivers, and ponds during the salmon spawn. Every other year, females (sows) produce one to four young (usually two) which are small and weigh only about 500 grams (1 lb) at birth. A sow is protective of her offspring and will attack if she thinks she or her cubs are threatened.
The polar bear (Ursus maritimus) is a carnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is a large bear, approximately the same size as the omnivorous Kodiak bear (Ursus arctos middendorffi). A boar (adult male) weighs around 350–700 kg (770–1,540 lb), while a sow (adult female) is about half that size. Although it is the sister species of the brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet.Although most polar bears are born on land, they spend most of their time at sea. Their scientific name means "maritime bear", and derives from this fact. Polar bears hunt their preferred food of seals from the edge of sea ice, often living off fat reserves when no sea ice is present. The polar bear is classified as a vulnerable species, with eight of the nineteen polar bear subpopulations in decline.For decades, large scale hunting raised international concern for the future of the species but populations rebounded after controls and quotas began to take effect.[citation needed] For thousands of years, the polar bear has been a key figure in the material, spiritual, and cultural life of Arctic indigenous peoples, and polar bears remain important in their cultures Read More ; Click Here
