Front claws are 2-4 inches long, slightly curved, and good for digging. Claw marks are usually visible in tracks. Behavior Usually more aggressive than black bears. Females use size and strength to protect cubs. Mostly active between dusk and dawn, although grizzly bears can be active any time of day .
Strength is exceptional.
One swipe of a grizzly's front paw can kill an adult bull moose or elk. Grizzlies' powerful digging ability lets them feed on roots, bulbs, and rodents and den on steep mountain slopes. As many as 100,000 grizzlies once ranged from the Missouri River to the Pacific Ocean and from Canada to central Mexico, occupying plains, forests, mountains, beaches, and wetlands. Grizzly bears currently inhabit five, or six, areas in Montana, Wyoming, Idaho, and Washington. In 1975 the grizzly was listed as threatened -the first animal protected under the Endangered Speicies Act of 1973.