Grizzly bears can be found in the Canadian provinces of British Columbia, Alberta, Yukon, and the Northwest Territories; and the US states of Alaska, Idaho, Wyoming, Washington and Montana.
Inhabits dense forest, arctic tundra and sub-alpine mountain regions.
The fur of a grizzly bear ranges from white to cinnamon to black but most often is some shade of brown. The tips are lighter, giving a grizzled effect, hence the name. They have long front claws, ranging in length from three to six inches. They easily recognized by the large muscle mass located between their shoulders. These muscles give the bears tremendous power and strength. In fact, grizzlies have been known to move several tons of dirt while excavating a winter den site. The hump on grizzlies is also a good means of identification because the black bear shoulder muscle is hardly visible.
It also has a concave outline to the head and snout, small ears on a massive head, and high shoulders that produce a sloping back line. The bear's sense of smell is much more acute than its hearing and sight.
Grizzlies are generally solitary bears except females with cubs. One exception is that huge gatherings of grizzly bears often occur during the annual salmon run for summer spawning. During this period of time, dozens of bears gather and feast on fresh, fatty salmon. The fish provide the necessary nutrients for grizzlies heading into winter.
Large adult males will aggressively defend their place at the head of their social circle, but grizzlies are not territorial and their home ranges often overlap. Home territories vary in size depending on location, but in Yellowstone National Park, they average 50 square miles.
They have an excellent sense of smell and will use their powerful nose to detect prey, sense danger, find suitable foods, locate mates, find their cubs and avoid people. They can smell carrion (dead flesh) miles away without any wind and will travel over mountains, across rivers or through a dense forest to find it. They will often stand up on their hind legs to get a better smell or a better view of something.
Grizzly bears have a hard time finding food in the winter, so they have the ability to sleep the winter away. To do so, they begin gorging carbohydrate-rich berries and other foods, to put on weight during the summer. They may gain as much as 30 pounds per week. This helps them to stay alive all winter without eating.
As winter approaches, they pick a den site, crawl in and take a long winter nap. Each year they may return to the same den, which is usually within a sheltered slope, under a large rock, or within the roots of a large tree. During this dormancy, their body temperature drops, and their general metabolic rate decreases as well. This is not considered complete hibernation. They will occasionally emerge from their dens to forage, particularly during spells of warm weather or during years when food is scarce prior to denning. During its winter sleep, it doesn't eat or relieve itself.
Pregnant bears wake up long enough to give birth in the den to one or more cubs. They then go back to sleep, only rousing themselves every now and then to lick the cubs and otherwise tend to them. The cubs, meanwhile nurse, safely warmed against their mother's belly. At some unknown cue, mom and the cubs, which are now about three months old, leave the den behind and get on with their lives in the outside world.
Breeding occurs in May or June after two to 15 days of courtship. However, the fertilized egg does not begin its embryonic stage of development inside the womb until October or November. Bears give birth to the smallest of all mammalian young in proportion to the size of the parent.
Female grizzlies usually give birth to two cubs during denning in January or February. The newborns are blind, hairless, and tiny—weighing less than a pound. They stay in their dens until springtime, when they have reached about 20 pounds. Once they are out in the world, they remain with their mother for at least two years more. The sow generally gives birth to another litter the first spring after separating from her cubs.
• Grizzly bears have excellent senses of smell and hearing but poor eyesight.
• Adult males may lose up to one-third of their body weight when they den-up.
• These big bears can run up to 35 miles per hour!
• A grizzly's large muscular hump on its shoulders and long front claws make the bear an excellent digger.
The Zoo currently is home to three sibling grizzly bears, two females and one male.
Once ranging from Mexico to Alaska, their population has been reduced nearly to the point of extinction from habitat destruction and over-harvesting. The grizzly population has remained stable for the past 20 years, but there are probably fewer than 1,000 bears left in the western United States. They are currently classified as a “threatened” species. Grizzly bears are now facing new threats from climate change. Increased temperatures are impacting food sources such as white-bark pine, cutthroat trout and miller moths. Unfortunately, these food sources are declining in availability due to rising temperatures and more frequent droughts caused by climate change.
With less food availability, the likelihood that the bears will to turn to human sources for food and face more human-bear conflicts is also increased, further threatening their survival. The bears that live here at Utah's Hogle Zoo were orphaned in the wild after their mother had difficulty finding enough food to keep her family alive. She became a nuisance bear and had to be put down, and the United States Fish and Wildlife Service and Association of Zoos and Aquariums worked together to find a new home for her cubs. You can help protect grizzly bears by being “bear aware” when you share their habitat and by helping to keep streams and rivers free of pollution.
|Did YOU Know?|
|All grizzly bears are a subspecies of brown bears, but not all brown bears are grizzly bears. Worldwide, brown bears are found throughout the northern hemisphere in North America, Asia and Europe. The North American populations of brown bears living|
|Length:||Females measure 6-7 feet in length. Males measure 5-8 feet in length.|
|Height:||Both adult males and females stand 3-31/2 feet at the shoulder.|
|Weight:||Adult males weigh 300-850 pounds. Females are smaller, weighing 200-450 pounds.|
|Average Lifespan:||Their average lifespan in the wild is 25 years, but grizzly bears have lived as long as 50 years in|
|Wild Diet:||Eats berries, roots, bulbs, mammals, carrion, fish, insects and whitebark pine nuts.|
|Zoo Diet:||Bear chow, carnivore meat, fish, fruit and vegetables.|
|Predators:||No natural predators except humans.|
|CITES Status:||All international trade in brown bears is restricted by either CITES I (in parts of central Asia) or CITES II.|
|Where at the Zoo?||Rocky Shores|