Grizzly bears are uniquely adapted to live in harsh, cold environments such as Alaska, the Rocky Mountains and Siberia. They survive the changing seasons by consuming massive amounts of food in the warmer, summer months. This allows them to live off their body fat during a long period of hibernation in winter when food is scarce.
A grizzly bear may eat up to 90 pounds of food a day in preparation for the cold winter months. The bears are highly adaptable in their food choices that vary with the season. The food may include anything nutritious they can find such as nuts, leaves, salmon, fruits and insects. They also prey on a variety of mammals that range from small rodents to mountain goats, moose and elk.
To prepare for winter, a grizzly has anatomical adaptations. It uses its long, sharp, rounded claws and the massive muscles on its back to dig a den. During hibernation, a grizzly bear’s body temperature drops and its heart rate slows from 40 beats a minute to only 8 to conserve energy. It will spend the winter in a deep slumber without food or water.