15x Postcard Of A Grizzly Bear And Cubs (Ursus arctos) North American Wildlife The grizzly bear is primarily nocturnal, making its den in a cave, crevice or hollow tree. It has a low, clumsy walk and cubs are able to climb but gradually lose this ability in their first year. It feeds on plants, fungi, berries, insects, large and small mammals, and is quite adept at catching fish with a swift snap of its huge jaws. Habitat loss, hunting, illegal trade, and its fearlessness of humans account for this species threatened status. Photographer: Ron Sanford This postcard has white borders Postcard size 5x7