|Body Weight||130-550 kg (287-1213 lb)||80-250 kg (176-551 lb)|
|Head/Body Length||1-2.8 m (3.3-9.2 ft)||1-2.8 m (3.3-9.2 ft)|
|Shoulder Height||Up to 1.5 m (5 ft)||Up to 1.5 m (5 ft)|
|Tail Length||60-200 mm (2-8 in)||60-200 mm (2-8 in)|
A massive bear with small, round eyes and ears, a dished-in snout, distinct shoulder hump, powerful body; only Polar Bears are heavier.
Diet largely determines size (Schwartz et al 2003)
Males 1.2-2.2 times larger than females - extreme dimorphism.
Most likely due to competition between males during breeding season.
Largest Brown Bears - Western Alaska and British Columbia; Kodiak and Admiralty Islands.
Teeth and skulls not as specialized for biting and shearing as those of many meat-eating dogs and cats. (Sacco and Van Valkenburgh 2004)
Most reliable way to distinguish a Black Bear skeleton from that of a Grizzly Bear: (Gordon 1977)
Other good ways to distinguish Black and Brown Bears:
Eyesight not keen but used for finding berries and nuts
Hearing and sense of smell acute.
Feet plantigrade (walk "flat-footed"); soles hairy
Female has 6 teats
Digestive tract similar to other carnivores except for its length (more surface for absorbing plant nutrients)
No fat deposits on artery walls (no arteriosclerosis); can gain significant weight in autumn (and lose in spring) with no ill effects. (Craighead 1979)
Physiology differs from other carnivores - have a period of winter dormancy (hibernation) with profound changes in body chemistry, metabolism, breathing rate, and moderate changes in body temperature (Schwartz et al 2003)
Polar-Bear/ Grizzly hybrids are fertile (Davis 1950)
Color can vary from pale tan, blond, gold, many shades of brown to near black, and gray or silver.
Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.
Sacco and Van Valkenburgh (2004)
Schwartz et al (2003)