Grizzly Bear

Grizzly Bear

[ Ursus arctos ]

Quick Facts

 
BODY LENGTH:  5.5 to 9 feet 
HEIGHT: standing height: 7 to 9 feet
WEIGHT:

160 to 1,200 pounds or more

WILD DIET: vegetation such as berries, grasses, roots, bulbs, moss, tubers, and nuts; insects, grubs, small mammals, and salmon; occasionally moose and elk (calves, mainly)
ZOO DIET: Natural Balance Zoo Carnivore diet (Beef), fish, lettuce, vegetables, fruits, berries, hard boiled eggs, nuts, and dog chow.
DISTRIBUTION: northwestern North America
HABITAT: old growth forests and meadows

 

Big Bear Necessities

Solitary Life…Mostly

Grizzly bears tend to spend most of their time alone, with the exception of females and the cubs.  Huge gatherings of grizzly bears often take place at prime fishing spots during the annual salmon run for summer spawning.  During this period of time, dozens of bears gather and feast on fresh, fatty salmon, which provide necessary nutrients for grizzlies heading into winter.


Grizzly bears dig dens under rocks or tree hollows for winter hibernation.  They enter the den between October and December, remaining until early spring.  The protective layer of fat helps them stay warm.  Female grizzly bears give birth during this winter rest, and mom and cubs emerge together in the spring.

I’ll have everything
Next to polar bears, grizzly bears are North America’s largest land carnivore. Grizzly bears are generalists—they'll eat almost anything. But the bulk of their diet is berries, nuts, and roots. So why are they classified as carnivores? Because the recent bear ancestors had scissors-like premolars to shear through flesh—just like cats and dogs of today. Modern bears have evolved all-purpose, flatter side teeth that are primarily good for grinding plant matter, but can also cut through meat. They also have four formidable canine teeth characteristic of many carnivores.

In some areas, brown bears fatten up on salmon they catch with their quick claws and strong jaws. These same powerful weapons allow brown bears to successfully hunt animals as large as moose.

 

Widespread, but rare

Grizzly bears once lived throughout most of western North America as well as the Great Plains.  As people settled into bear country, grizzlies were slowly eliminated.  Today only about 1,000 grizzly bears remain in the continental United States, where luckily they’re protected by federal law. 

Bears in mind
The bears of our imagination might be big, snarling beasts that attack at a moment's notice. That image was born, in part, from accounts of 18th and 19th century explorers and settlers who moved west across North America. Used to the smaller and generally more docile black bear of the east, explorers would use the "shoot and ask questions later" tactic on grizzly bears. But a wounded grizzly bear proved to be a dangerous and tenacious opponent, and gave the species an almost mythic reputation for ferocity. Grizzly bears will aggressively defend their territories and young. Unprovoked attacks on people are extremely rare, though.

 

Grizzly Bears at Brookfield Zoo
Angoon Axhi and Kootznoowoo Jim (or Axhi and Jim for short) live in Great Bear Wilderness. They are orphaned brothers from Admiralty Island in southeastern Alaska. The bears were rescued as cubs in 1995, through a cooperative effort between Brookfield Zoo and the Alaska Department of Fish and Game. Thanks to the zoo’s excellent care, Jim and Axhi are healthy and strong, and each weighs about 900 pounds!

 

Get Involved

Conservation Fund of the Chicago Zoological Society