If scientists can determine how grizzlies accomplish this, that information may be useful in preventing human heart disease. At the top of the food chain, adult grizzly bears have little to fear from other wild animals. Grizzly cubs may fall prey to mountain lions, wolves, and other bears if they stray too far from their mother. Early in the fall, grizzly bears begin looking for a proper place to dig their dens, and may travel many miles before finding a suitable area. Generally, they seek a high, remote mountain slope where deep snow will lie until spring to serve as insulation.
Grizzlies often dig beneath the roots of a large tree to create their dens.
Obstructing roots are chewed up, and loose rocks and earth are thrust through the narrow entrance by the powerful strokes of the grizzly's forepaws. The grizzly bear will generally enter its den in October or November. During the next 5 to 6 months, the grizzly will get no water or nourishment of any kind but will use up its accumulated fat. May. When a grizzly comes out of its den, the first food is sometimes carrion from animals that did not survive the winter. A grizzly will usually travel to lower elevations to reach vegetated areas.