Grizzly Bear (Ursus arctos horribilis)

 

Family:                Ursidae

Status:                 Endangered in the U.S.; vulnerable in Canada; extirpated on the Canadian plains.

Size:                    Height is 6 to 8 ft and weight is 200–900 lbs. 

Diet:                    Omnivore.

Characteristics:    Solitary, nocturnal, fierce, aggressive.

Area:                   Western North America and the northern tundra.

Offspring:            1 litter (1 to 4 cubs) every 3 years.

Predators:            None, with the exception of man.

 

Trivia:

·        Man is the biggest threat to grizzlies.

·        Grizzlies are the fiercest and most aggressive of all bears.

·        One swipe of a grizzly’s paw is all it takes to crush a person’s skull.

·        They can consume up to 40 kg (90 lbs) of food per day.

·        Grizzly bear encounters (with humans) and/or attacks are extremely rare.

 

Lifestyle

Except for during the June mating season, grizzlies prefer to remain solitary. Their eating habits depend on the season and can be found along rivers when the salmon migrate upstream to spawn. At other times, they will eat many different kinds of plants, berries and insects, as well as other mammals (large or small) and carrion. From late summer to fall, it is imperative that these bears put on as much as 400 pounds of fat to carry them through the winter. When the bear emerges in April or May, it will be severely underweight and will need to find food sources immediately.

 

Territory

The home range of a grizzly can extend from 10,000 to 27,000 square miles. Younger bears are more territorial than older bears, who will often accept other grizzlies within close proximity as long as they don’t intrude upon their hunting space, especially along the river during salmon season. The largest and fiercest bears will obtain the choicest spots and will defend them by doing battle with any bear that dares to approach. Grizzlies have become endangered in the U.S. and threatened in Canada due to over hunting and hysteria by campers. Grizzlies, like other bears, will go into campgrounds to get garbage or food not properly stored and once that occurs, they are hunted down and killed to prevent the possibility that they have lost their fear of humans and may attack in the future.

 

Reproduction

Although mating takes place in June, fertilization doesn’t occur until fall, giving the female time to store food for herself and her cubs. Females will mate with up to four males during a two-day period. The cubs (usually two, but up to four) will be born in the safety of the mother’s den, during the winter. Newborns are very tiny, weighing only one pound each and are born blind, with nearly no fur. The fathers are not involved with the mothers or children at all, and the cubs stay with their mother the entire season and den with her the following winter and through the summer, after which they will leave her side and find their own den. Females can mate at the age of three but usually don’t reproduce until the age of five. The life span of a grizzly in the wild is 15 to 30 years.