When food is scarce, it is not uncommon for cubs to stay with their mothers until they are 5 years of age. While in this semi-sleep state, the bear's body temperature, heart rate and other metabolic rates are greatly reduced. The need for food and water is eliminated entirely. Pregnant female brown bears are the first to enter dens, and do so in early fall months. The female bear and newborn cubs are then subsequently the last to exit the den in the spring.
Adult males have just the opposite behavior, entering dens last and leaving first.
National parks and zoos house a small number of Eurasian brown bears and as few as 9 or 10 populations of Alaskan brown bears still live in their native coastal area. Alaska contains over 98 percent of the United States population of brown grizzly bears. Today, the Alaska Department of Fish and Game is responsible for managing Alaskan bears and their population. The grizzly bear is still a hunted animal in Alaska. Brown bears in the wild have a lifespan of 22-26 years.