U.S. Fish & Wildlife Service Grizzly Bear Facts Ursus arctos horribilis

A symbol of America’s wildlands, the grizzly or brown bear is one of the largest North American land mammals. The grizzly bear’s historic range covered much of North America from the mid-plains westward to California and from central Mexico north throughout Alaska and Canada. Today, the grizzly bear is found in only about 2 percent of its original range in the lower 48 states. The grizzly has the second slowest reproductive rate of all North Grizzly bears need a very large home American mammals (the musk ox has range (50 to 300 square miles for omnivore, meaning it eats both plants the slowest), making it harder for it to females; 200 to 500 square miles for and other animals. About 80 to 90 rebound from threats to its survival. males), encompassing diverse forests percent of the grizzly’s food is green interspersed with moist meadows and vegetation and insects. Grizzlies eat grasslands in or near mountains. In the wild fruits and berries, nuts, bulbs or Early in the fall, grizzly bears begin spring, bears usually range at lower roots of certain plants, and sometimes looking for a proper place to dig their elevations and go to higher altitudes for tear rotten logs apart or turn over dens and may travel many miles before winter hibernation. heavy stones in search of insects or finding a suitable area. Generally, they their larvae. seek a high, remote mountain slope Larger than the black bear, male where deep snow will lie until spring to grizzly bears stand about 7 feet tall Most of the meat in the grizzly’s serve as insulation. Grizzlies sometimes and weigh from 300 to 600 pounds diet comes from carcasses (carrion) dig beneath the roots of large trees to (and occasionally more than 800). of big game animals, although it will create their dens. Obstructing roots are Females are smaller, usually weighing sometimes prey on elk or moose calves chewed up and loose rocks and earth between 200 and 400 pounds. Although or smaller mammals. For grizzlies are thrust through the narrow entrance a standing grizzly is commonly along the west coast of Canada and in by the powerful strokes of the grizzly’s perceived to be a threatening pose, Alaska, salmon is an important food forepaws. bears stand when they are simply source. curious or surveying their The grizzly bear will generally enter its surroundings. Otherwise they The grizzly bear must eat enough to den in October or November. During generally remain on all fours. store huge amounts of fat needed to the next 5 to 6 months, the grizzly will sustain it through its long winter sleep. get no water or nourishment of any The grizzly can be distinguished from The grizzly’s ability to eat large kind but will use up its accumulated fat. the black bear by its concave face, quantities of rich food and store fat high-humped shoulders, and long, without suffering from heart disease or Male grizzly bears usually emerge from curved claws. Its thick fur, which varies cholesterol problems is of great interest the den in March or April while females from light brown to nearly black, may to medical scientists. If scientists can emerge in mid-April and May. When a appear frosted, hence the name determine how grizzlies accomplish grizzly comes out of its den, the first “grizzly,” or the less common this, that information may be useful in food is sometimes carrion from animals “silvertip.” The grizzly has shorter, preventing human heart disease. that did not survive the winter. A rounder ears than the black bear. grizzly will usually travel to lower At the top of the food chain, adult elevations to reach vegetated areas. Except for mating and caring for the grizzly bears have little to fear from young, grizzly bears lead primarily other wild animals. Grizzly cubs may Mating season is from June through solitary lives, spending most of their fall prey to mountain lions, wolves, and July. Grizzly bear embryos do not begin time foraging, (looking for food). The other bears if they stray too far from to develop until the mother begins her grizzly is North America’s largest their mother. winter hibernation, although mating may have taken place up to 6 months hunting, and the perception that before. As with other bears, if the grizzlies threatened human life were mother has not accumulated enough fat leading causes of the animal’s decline. to sustain herself as well as developing cubs, the embryos may not implant In 1975, the U.S. Fish & Wildlife Service (develop). listed the grizzly bear as a threatened species under the Endangered Species In January, usually one to three cubs, Act, meaning it is considered likely to each weighing only a pound or less, are become endangered (“endangered” born. The cubs gain weight quickly and means a species is considered in danger often have reached 20 pounds by the of extinction within all or a significant time they come out of the den. As many portion of its range). as half of all cubs may not reach The grizzly can be distinguished from breeding age — a leading reason for Many of the current threats to the the black bear by its concave face, the grizzly’s low numbers. survival of grizzly bears are associated high-humped shoulders, and long, with degradation of habitat due to rural curved claws. Cubs remain dependent upon their or recreational development, road mother’s milk for almost a year, stay building, and energy and mineral with their mother for 2 to 3 years, and exploration. Habitat destruction in grizzly bears are Yellowstone reach breeding maturity at about 41⁄2 to valley bottoms and riparian areas is (northwestern Wyoming, southwestern 51⁄2 years. In some cases they may not particularly harmful to grizzlies Montana, and eastern Idaho), Northern breed until 81⁄2 years of age. When they because they use these “corridors” to Continental Divide and Cabinet-Yaak do reach breeding age, females only travel from one area to another when (northwestern Montana), Bitterroot breed every 3 or more years. Males they are searching for food. Some (central Idaho and western Montana), compete with each other for breeding private landowners and companies are Selkirks (Idaho and eastern opportunities and seek females each trying to help grizzlies by voluntarily Washington), and the North Cascades year. Grizzlies usually live to be 15 to protecting grizzly habitat. (Washington). There is currently no 20 years of age. A few survive up to scientific evidence of grizzlies in the 30 years. Some grizzly bears are accidentally Bitterroot ecosystem (although they killed by hunters who mistake them for previously inhabited the area), so Between 1800 and 1975, grizzly bear black bears, which are legal game. reintroduction of bears from other areas populations in the lower 48 states Grizzlies also become habituated to is necessary to recover that population. decreased from estimates of more than humans because of what biologists call 50,000 to fewer than 1,000. The grizzly “attractants,” which include garbage, The grizzly bear recovery effort has was eliminated from much of the West pet foods, livestock carcasses, human been met with some successes thus far. by the late 1800s. As mountainous areas foods, and items associated with Grizzlies in the Yellowstone ecosystem were settled, development contributed improper camping practices. This can have increased significantly. There has to an increase in human-caused eventually lead to conflicts between also been some success in the Northern mortality. Livestock depredation people and bears both in populated Continental Divide ecosystem but more control, habitat deterioration, areas of the grizzly’s range and in back work needs to be done in all of the commercial trapping, unregulated country recreation sites. areas to reach recovery.

Today, in the lower 48 states, grizzlies These successes have been largely due The grizzly’s den is often dug beneath can be found in Wyoming, Montana, to efforts of the Interagency Grizzly the roots of a large tree on a mountain Idaho, and Washington. There are at Bear Committee. Established in 1983, slope where snow will lie through the least 300–400 grizzlies living in the the committee includes representatives winter months to serve as insulation. northwestern Montana Rockies, about from the U.S. Fish & Wildlife Service; 400–600 in and around Yellowstone U.S. Forest Service; National Park National Park, about 45–50 in the Service; Bureau of Indian Affairs; Selkirk Mountains in northern Idaho Bureau of Land Management; state and northeast Washington, another 35– agencies in Idaho, Montana, 40 in the Cabinet-Yaak ecosystem in Washington, and Wyoming; and northern Idaho and western Montana, Canadian wildlife agencies in Alberta and 5–30 in the North Cascades. In and British Columbia. Alaska, where they are called brown bears, they are estimated to number more than 30,000. There are about U.S. Department of the Interior 22,000 grizzly bears in Canada. U.S. Fish & Wildlife Service

One goal of the Fish and Wildlife http://www.fws.gov Service’s plan to restore the grizzly bear in the lower 48 states is to recover April 2000 grizzly populations in all of the ecosystems known to have suitable habitat. The six ecosystems in the conterminous U.S. that have been identified by biologists as suitable for