The brown bear is a wide ranging animal that requires vast tracts of wild, road-less land. Accordingly, this species of bear is considered to be an enduring symbol of true wilderness in North America.
Mama bear & cub.
Brown bears have been called the bear with too many names because of their wide variety of sizes and colors. The Kodiak, grizzly, and Russian brown are all the same species. Brown bears that live in interior Alaska or in the lower 48 states are often referred to as grizzlies or the grizzly-brown bear. Today the grizzly bear in the lower 48 is in low number after being destroyed in 98% of its former range. Roads, ranching, over hunting, and increasing human encroachments, could inevitably eliminate the species.
Habitat
- Found in a variety of habitats, but prefer wilderness regions containing river valleys, mountain forests, and open meadows.
- Home ranges are among the largest of all land mammals: up to 800 – 1000 square miles, but in good habitat some home ranges may be as small as 10 – 24 square miles.
- The coastal Alaskan brown bears fish for extensive periods at the mouths of salmon streams.
Distribution
- Widest world distribution of any bear; found in northwestern North America and Eastern and Western Eurasia.
- As many as 60,000 grizzlies once occupied the lower 48 states.
- Today, fewer than 1200 grizzlies survive in protected parks and wilderness areas within the Rocky Mountains of Wyoming, Washington, Idaho, and Montana.
- Ursus arctos was listed in 1975 as threatened in the lower 48 states.
- In western Canada, there are still significant populations of grizzlies, but Alberta, Canada has approximately 750 of the bears, a mere shadow of the 6000 which once roamed that province.
Physical Characteristics
Color
- Vary in color from blonde to black; most often they are medium brown with light tipped fur on their head and upper body.
- Coat color may change with the seasons.
- Thick coats composed of both guard hairs and under-fur which keeps them warm in the winter.
- In summer they shed a lot of under fur and look shaggy; the silver hair-tips give them a grizzled look, hence the name…. grizzly bear.
Size
- Gender and nutrition determines the size of brown bears.
- Average weight of a male grizzly is 550 pounds (247 kg) and 350 pounds (157 kg) for females.
- Brown bears of coastal Alaska may weigh over 1000 pounds (450 kg).
- Typically 3 – 4 feet (91 – 122 cm) at the shoulder on all fours, and 6 – 7 feet (183 – 213 cm) tall when standing upright.
Features
- Distinguishing features are a wide, massive head, dished face with long snout, and a shoulder hump. The hump is a thick wad of fat and muscle.
- Round, small ears and distinct cream colored, slightly curved claws that are 2 – 4 inches (5-10 cm) or more in length.
Diet
- Brown bears are omnivorous, opportunistic feeders which means they eat both plants and animals.
- Their diet varies according to the season and habitat but includes everything from grasses, roots, berries, and nuts to insects, fish and mammals including rodents, deer, elk, and moose. Grizzlies will eat on carcasses as well as kill living animals.
Behavior
Daily Activity
- Most brown bears are active during dusk and dawn, although they can be active any time of the day, especially in late summer and fall.
- They tend to rest in day beds which they make in dense vegetation within the forest in order to escape the heat.
- Brown bears are powerful diggers. They use their claws to find roots, bulbs and rodents, as well as to make winter dens on steep mountain slopes.
- Most brown bears spend their time alone except when breeding or raising cubs.
Hibernation
- Brown bears are not true hibernators, but they slow down their metabolism and sleep through most of the winter in order to save energy when there is little food available outside for them to eat.
- These bears usually sleep in remote locations where they den.
- They are able to sleep through the winter by living on reserves of fat stored on their bodies during the summer and fall.
Reproduction
- Brown bears mate in early summer, but the embryo (blastocyst) does not implant and start to grow until the mother enters the den in late fall.
- The cubs are born in January or February while the mother is sleeping.
- They usually weigh about one pound at birth and their litters range between one and four, with two on average.
- The cubs are born blind and helpless, but by drinking their mother’s rich milk they gain weight quickly.
- Usually by late April or early May the cubs are ready to leave the den and explore with their mothers.
- Because of predatory males and other threats, mother bears are renowned for their ferocity when defending their young.
- Cubs usually stay with their mothers until they are 2 – 3 years old.
People and Brown Bears
- People have been fearful of brown bears ever since people began exploring bear habitat. Many brown bears have been killed because of this fear, while others have been killed for food and the fur trade.
- Today most brown bears only survive in protected areas.
- Because grizzlies are considered a threatened species under the Endangered Species Act, wildlife managers are trying to actively protect grizzly populations in the lower 48 states and their critical habitat. (A threatened species is one that is likely to become endangered if protection measures are not implemented).
- Hopefully, with careful management and a solid recovery plan, grizzly populations will increase and will no longer need Endangered Species Act protection.
- For adequate recovery humans need to stop harassing, pursuing, hunting, and killing grizzly bears. Also, their habitat needs much better protection from human encroachment.
- People sometimes leave garbage and food in places where bears can easily find it. Once corrupted with food scraps, or even food containers or wrappers, bears can quickly develop a taste for garbage and then go looking for it.
- When a bear is habituated to garbage they get into trouble because they scare and anger people with the damage they cause to property and the danger they represent. When a bear becomes a problem it may be relocated, but it often continues to cause problems and is killed.
- Grizzlies are an important top level carnivore in the ecosystem and they are animals that can teach us a lot about living responsibly with wildlife and respecting the wilderness and habitat where they make their homes.
