What makes grizzly bears unique

A large female will weigh up to pounds kilograms. Grizzly bears once roamed throughout the entire western United States south into Mexico, including the Great Plains and along rivers in desert habitats. Control actions and habitat loss extirpated them from 98 percent of their original habitat in the U. A large population of grizzly bears lives inland in Alaska and northern Canada. Thanks to conservation efforts since about , grizzly bears are recovering well in Yellowstone and elsewhere in the Northern Rockies and are even beginning to recolonize prairie habitats along the Rocky Mountain Front in Montana.

Grizzly bears can be found in woodlands, forests, alpine meadows, and prairies. In many habitats they prefer riparian areas along rivers and streams. Grizzly bears are omnivores. The most commonly eaten kinds of plants are fleshy roots, fruits, berries, grasses, and forbs. If grizzly bears are on the hunt, their prey can include fish especially salmon , rodents like ground squirrels, carrion, and hoofed animals like moose , elk, caribou, and deer.

They are especially good at catching the young of these hoofed species. Grizzly bears can also target domestic animals like cattle and sheep and cause economically important losses for some ranchers.

The National Wildlife Federation has a program on National Forest lands surrounding Yellowstone Park to prevent attacks on domestic livestock by purchasing the grazing allotments from ranchers. Grizzly bears use sounds, movement, and smells to communicate. They growl, moan, or grunt, especially when females are communicating with their young or during mating season when male bears can fight each other fiercely for the opportunity to mate with receptive females.

Grizzly bears also rub their bodies on trees to scratch and to let other bears know they are there. Winter can be very tough for many species of wildlife, because the season brings harsh weather and little food.

Grizzly bears hibernate in warm dens during the winter to minimize energy expenditure at a time when natural foods are not available and to permit their tiny young to be born in a warm and secure environment. Throughout the summer and autumn, grizzly bears build up fat reserves by consuming as much food as they can find. In late fall or winter, the bears find a hillside and dig a hole to serve as their winter den.

When inside the den, grizzly bears slow down their heart rate, reduce their temperature and metabolic activity, and live off stored fat reserves. Pregnant females give birth in the dens and nurse their cubs until they are large enough to venture outside in the spring as snow melts and new food become available.

Depending on the length of the winter season, grizzly bears can stay in their dens for up to seven months. Grizzly bear hibernation is not as deep of a sleep as some other hibernators, like bats or ground squirrels, and they will quickly wake up when disturbed.

Females with newborn cubs are the last to leave their dens in the spring. Females with older cubs emerge earlier and solitary females and males are the first to exit dens in the spring. Pregnant females are the first to enter dens in the fall followed by females with cubs; solitary males enter dens the latest. Grizzly bears begin to look for mates in the spring and early summer.

Females can mate with more than one male during her breeding season. If a female bear is unable to gain enough weight during the summer and fall, her body will tell her to not proceed with the pregnancy and the embryo will reabsorb. Grizzly bears have been seen moving through boulder fields and turning over heavy rocks to feed on masses of army cutworm moths. A grizzly bear in Yellowstone National Park was seen to have consumed over 40, moths in one day. However, eating this many in a day is uncommon.

Canada is famous for its grizzly bears. Unfortunately, however, grizzly bears have been assessed as a species of special concern, meaning they could become threatened or endangered in the future. They are threatened by climate change, unsustainable hunting, habitat loss and extremely low reproductive rates. There are about 33, grizzly bears in the U. Hopefully, Canadians are willing to protect grizzly bears and their habitat, because a future without these amazing animals would, indeed, be unbearable.

Roots is helping to protect Canadian habitat and the species that they sustain, including grizzly bears. Find out how, here. Karin Lehnardt has been a university writing tutor and writing instructor for many years and loves researching, reading, writing and discussing ideas. Read more about Karin Lehnardt.

More by this author ». Donor inquiries donors natureconservancy. Visit our FAQ page. Land Lines. Grizzly bear Photo by Caroline Henri. The hump on a grizzly bear's back is a huge muscle Photo by Getty Images. These animals need a lot of space—their home range can encompass up to square miles —so their ideal habitat is one that is isolated from development and has plenty of food and places to dig their dens. Though European settlement gradually eliminated the bears from much of their original habitat, grizzly populations can still be found in parts of Wyoming, Montana, Idaho, and Washington State.

Many grizzlies also still roam the wilds of Canada and Alaska, where hunters pursue them as big game trophies. At its peak, the grizzly population numbered more than 50, Aggressive hunting in the early 20th century also threatened the survival of the grizzly bear. By the s and s, these bears had been reduced to less than 2 percent of their historical range.

In the s, it was estimated that there were only to remaining in the wild. In , grizzly bears were listed as threatened under the U. Endangered Species Act. Today, grizzlies are considered a conservation success story. Ever since they gained protections under the U. Endangered Species Act, the population of grizzly bears has grown. The U. Fish and Wildlife Service established recovery zones for the bears and set out to improve relationships between humans and bears by educating the public about these animals and establishing programs to reimburse ranchers for livestock bears killed.

Now there are more than five times the number of grizzlies than there were in —and about 1, to 1, in the contiguous U. While the U. Fish and Wildlife Service has tried to delist grizzly bears twice, both attempts have been blocked.

In , the second attempt was blocked in federal courts over concerns about the lack of genetic diversity among this subspecies whose various populations live so far apart. Conservationists also worry that delisting grizzly bears would lead to renewed hunting that would again deplete the population. All rights reserved. Animals Photo Ark. Grizzly bears once lived across much of western North America until European settlements and aggressive hunting eliminated most of the population.

Common Name: Grizzly bears. Scientific Name: Ursus arctos horribilis.