Male bears take five or six years to mature. Other than man, black bears have few enemies. Wolves may attack young bears or a pack may attack females. Grizzly bears may also attack brown bears. This seldom happens.
More brown bears die from accidents and disease than from natural enemies.
Black bears can live for 25 to 30 years in the wild, but few live longer than 10 years because of human hunting. Thousands are shot by hunters in North America each year. Bears make moaning and teeth chattering sounds to threaten other bears. Females with cubs are often aggressive if the cubs are threatened. Otherwise, few black bears attack people in the wild.