Brown bears make their homes in cold places, such as northern forests, mountains and barren tundra. They feed on a range of fruits, plants and small animals. Only grizzlies regularly attack larger animals, such as deer and even smaller black bears.
Brown bears are generally solitary animals, although they may gather in groups around large food supplies, such as schools of salmon beneath waterfalls. As winter approaches, the bears dig themselves dens for semi-hibernation. Although they sleep during most of the winter, they often come out of the den for short periods between sleeps. Mating takes place in early summer. The female gives birth in spring, and her cubs stay with her for at least two years.