The grizzly bear, once found over most of western North America, now is restricted mainly to western Canada and Alaska. It is listed as threatened in the lower 48 states, where it survives only in parts of the northern Rockies and northern Cascades. Conflict with humans and loss of habitat led to its present status. The last grizzly bear was killed in the Black Hills in 1894.
Yellowstone, with about 200 grizzlies in the Greater Yellowstone Area, Glacier, with 200, and North Cascades National Park, with an unknown number of bears, are protected sanctuaries for a large part of the population remaining in the lower 48 states. Intensive research on grizzly bears in Yellowstone and Glacier national parks has led to the current management practices. Unnatural food sources such as garbage dumps have been closed and visitors and employees are educated to store food away from bears. Steps are taken to reduce the likelihood of bear-human encounters in the backcountry. A guideline coordinates grizzly bear management in all the northwestern states. Interagency cooperation is a key element in all three park areas, but especially in the Greater Yellowstone region, which includes the national park, several national forests, and other adjacent lands. North Cascades National Park in Washington is gathering data on its grizzlies and their habitat so protective measures can be taken.
The grizzly bear is the undisputed "king" amongst all North American animals. It spends most of its waking hours foraging for food in dense forests, tundra, and lower alpine regions associated with mountain ranges in Western Canada, Alaska, Wyoming, Montana, Idaho and Washington. The grizzly is also found in small pockets in Russia, Europe and Asia.
The grizzly is the second largest terrestrial carnivore in North America, next to the polar bear. The grizzly bear is synonymous with mountain ranges whereas the polar bear frequents flat tundra and ice packs in the north. The grizzly is more accurately described as an omnivore, not a carnivore. It consumes a variety of plants and the occasional meat from carrion or prey.
Adult boars or male grizzlies can weigh in at 1100 pounds (500 kilograms), but average between 550 and 780 pounds (250 and 350 kilograms). Grizzly sows or females weigh about half as much as their male counterparts. Grizzlies have heavy stout bodies with powerful legs. They have relatively large heads with a dish-like profile and a characteristic muscle hump over the shoulders. The tips of the guard hairs on a grizzly can turn white or gray, giving it a "grizzled" appearance. Grizzlies have much longer claws than black bears. They are strong diggers with an appetite for plant roots or burrowing animals. Grizzlies are powerful, can run 35 mph (60 kph), have excellent eyesight and a legendary keen sense of smell. These traits make it a formidable animal at the top of the food chain.
The female grizzly or sow attains sexual maturity at 2 to 3 years of age. A pregnant sow usually gives birth to 2 or 3 cubs (up to a maximum of 4) in the month of January or February and begins to nurse them in the den. A newborn cub weighs 1.25 to 1.5 pounds (600 to 700 gms) and is blind, hairless and toothless. By the time the sow and its cubs are ready to emerge from the den in April, the cubs weigh in at 18 pounds (8 kilograms). The sow stays with her cubs for a period of 2½ to 3 years and will defend them against any thread, including a much bigger and stronger boar. During this period of time she teaches them how to survive in the wild. After this "personal development" session is completed, she chases the cubs away so they can fend for themselves.
Before the onset of winter, grizzlies forage for food around the clock to gain enough weight to survive their winter sleep. Unlike smaller hibernating animals that lower their core temperature considerably, grizzlies drop their body temperature by a mere 5 degrees Celsius. As a result, they can easily be aroused from sleep. After they have prepared their dens for the winter, they often remain outside the den for 3 weeks or so without feeding. They plod along until their bodies tell them to shut down for the long hard winter.