Alaska, zomer 2010

The grizzly bear (Ursus arctos horribilis), also known as the silvertip bear, the grizzly, or the North American brown bear, is a subspecies of brown bear (Ursus arctos) that generally lives in the uplands of western North America. This subspecies is thought to descend from Ussuri brown bears which crossed to Alaska from eastern Russia 100,000 years ago, though they did not move south until 13,000 years ago.

Except for cubs and females, grizzlies are normally solitary, active animals, but in coastal areas, the grizzly congregates alongside streams, lakes, rivers, and ponds during the salmon spawn. Every other year, females (sows) produce one to four young (commonly two) which are small and weigh only about 500 grams (1 lb). A sow is protective of her offspring and will attack if she thinks she or her cubs are threatened.

Bears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, Europe, and Asia.

Common characteristics of modern bears include large bodies with stocky legs, long snouts, shaggy hair, plantigrade paws with five nonretractile claws, and short tails. While the polar bear is mostly carnivorous and the giant panda feeds almost entirely on bamboo, the remaining six species are omnivorous, with varied diets.

With the exceptions of courting individuals and mothers with their young, bears are typically solitary animals. They are generally diurnal, but may be active during the night (nocturnal) or twilight (crepuscular), particularly around humans. Bears are aided by an excellent sense of smell, and despite their heavy build and awkward gait, they can run quickly and are adept climbers and swimmers. In autumn, some bear species forage large amounts of fermented fruits, which affects their behaviour. Bears use shelters, such as caves and burrows, as their dens; most species occupy their dens during the winter for a long period of sleep similar to hibernation.

The fauna of the United States of America is all the animals living in the Continental United States and its sorrounding seas and islands, the Hawaiian Archipelago, Alaska in the Arctic, and several island-territories in the Pacific and in the Caribbean. The U.S. has arguebly the most diverse fauna in the world and has many distinctive indigenous species found nowhere else on Earth. With most of the North American continent, the U.S. lies in the Nearctic faunistic realm, a region containing an assemblage of species similar to Northern parts of Africa and Eurasia . An estimated 432 species of mammals characterize the fauna of the continental U.S. . More than 800 species of bird and there are more than 100 000 known species of insects . There are 311 known reptiles, 295 amphibians and 1154 known fish species in the U.S. . Known animals that exist in all of the Lower 48 include white-tailed deer, bobcat, raccoon, muskrat, striped skunk, barn owl, American mink, American beaver, North American river otter, red fox and gray wolf.

In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.

Collective offspring may be known as a brood or progeny in a more general way. This can refer to a set of simultaneous offspring, such as the chicks hatched from one clutch of eggs, or to all the offspring, as with the honeybee.

Human offspring (descendants) are referred to as children (without reference to age, thus one can refer to a parent's "minor children" or "adult children" or "infant children" or "teenage children"); male children are sons and female children are daughters. See kinship and descent. Offspring can occur after mating or after Artificial Insemination