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.
"Keeping a Wary Eye Out" by Tony Boot: This mother was with two cubs when she sensed a male approaching. As she started to check it out, one of the cubs appeared looking around her. This photo was taken on a trip to Alaska with Nat Hab.