Adult male black bears can weigh between 150 and 600 pounds, and adult females usually weigh between 90 and 300 pounds. Newborn cubs weigh about 8 to 12 ounces.
A black bear's weight fluctuates depending on the availability of food. The bears also go into torpor, a state similar to hibernation, during winter. They often lose about 30 percent of their weight during this time. They occasionally eat small game such as fawns, moose calves, and beaver, but 75 to 85 percent of a black bear's diet is vegetation. They eat dandelions, pin cherry, wild plum, cranberry, hazelnuts and wild oats.