In the spring they are often seen feeding on grasses, tubers, and fresh green shoots in the large river estuaries of the mainland.
Grizzly Bear coats can vary from creamy yellow to almost black. In coastal British Columbia, most are light brown to dark brown; in the Rockies, most have a “silver tip” pattern, in which the long hairs of the shoulder and back are frosted with white.
Grizzly Bears shed their heavy winter coats in late spring and early summer, then re-grow them from mid-August to October. They have a broad head with small, rounded, heavily furred ears, a prominent shoulder hump formed by muscles used in digging, a dish-shaped facial profile, and long, slender yellow or brown claws. Although it is possible to confuse Grizzly Bears with brown-phase Black Bears, which are common in the interior of the province, there are important differences.
- Grizzly claws are much longer than those of Black Bears, and the toes are close together in a fairly straight line.
- A grizzly usually walks slowly, swinging its low-slung head from side to side.
- Grizzlies can run quickly, sometimes as fast as 55 km per hour, even on steep slopes.
- They are excellent swimmers.
- When they are alarmed, Grizzly Bears often stand upright on their hind legs to get a better view of potential dangers
|Grizzly cubs usually stay with their mother and den with her for at least two years. During that time they are fiercely protected and learn where to find food as the seasons change and when, where and how to dig a winter den. Grizzly cubs also play a great deal. The period of dependence on the mother is relatively long compared to other mammals. This prepares the cubs for an independent life. In June of the third year, adult females usually breed again, and they chase the cubs, now quite large, off to become self-sufficient.
However, the interval between litters may be four or more years in locations with limited food or a harsh environment. Sow Grizzly Bears don’t produce their first litter until they are about five or six years old or even older.
Hibernation is a very important feature in the life of a Grizzly Bear. In coastal British Columbia, bears hibernate from about early November to mid-April; in the interior, hibernation lasts from about October to May. This means that bears can survive in northern regions where their main foods – green vegetation, berries, insects, and fish – are not available in winter.
|During their winter sleep, which is not as deep as in true hibernators like marmots or ground-squirrels, a Grizzly Bear’s body temperature drops by 4 to 5ºC, oxygen consumption declines by up to 50 percent, the heart rate falls to only 8 to 12 beats per minute, and the bears do not urinate or defecate. These physio-logical changes allow the bears to live on stored fat for several months, although they usually lose a lot of weight.
Grizzly Bears are classified as carnivores; however, they eat a wide variety of foods and are really omnivores. Although grizzlies eat mostly plant material, their digestive tract is not made for a herbivorous diet.
|Grizzly Bears are particular about sites for their winter dens. They sometimes dig more than one before they are satisfied and occasionally move to a new site during the winter. They almost always dig their dens horizontally into the ground on steep slopes (20 - 40º) where prevailing winds result in deep, persistent snow cover, which provides insulation.
To avoid flooding, dens are always in well-drained sites that usually contain roots of trees, shrubs, or sod-forming grasses that bind the soil of the den roof to prevent its collapse. Dens are usually clustered in places that meet these conditions. The elevation where dens are located varies from one climatic region to another.