Grizzly Bear

scientific name

Ursus arctos horribilis

size

Head/Tail Length. 9'
Shoulder Height. 3-4'
Weight. 300-850 lbs.
size notably related to available food

characteristics

Adaptations/Coloration. extremely variable - cream, cinnamon, brown to almost black " fur bleaches in sun
Body. large " heavily built
Claws. non-retractile " for digging tubers, burrowing rodents, & stripping branches
Ears. small
Eyes. small
Fur. thick " good insulation
Head. massive
Hearing. moderate
Jaws. powerful
Limbs. powerful
Smell. excellent
Snout. large
Speed. maximum 30 mph " fast as a deer
Teeth. flattened cheek teeth " piercing canines
Vision. poor

behavior

adult males solitary with range encompassing several adult females' ranges " males reduce potential competition by evicting (even killing) sub-adult males " females vigorously defend young
Territory. marked by scraping bark from tree & rubbing against leaving scent
Winter. enter dormancy period " body temperature/pulse doesn't drop " don't eat (live off fat built-up during fall) " reasons - chiefly food (succulent vegetation) not available " not classified as hibernators

reproduction/life span

Life span. wild 25-30 yr. " captivity maximum 47 yrs. (documented)
Mature. 6-8 yrs.
Breed. May-June
Implantation. delayed until Oct-Nov when female dens
Gestation. 210-255 days
Birth Interval: 3-5 yrs. " dependent on available food
Litter. 2-3
Cubs. weigh 12-14 oz " born naked & helpless " can't regulate body temperature " remain with mom 1½-4½ yrs.
Den. snug environment providing warmth " leave den Apr-June
Reproduction Activity (female 1st birth, litter size, birth interval). controlled by nutritional factors

diet

omnivore
Wild. almost anything " includes succulent vegetation, tubers, berries, insect grubs, small rodents, salmon, trout, carrion, young hoofed mammals (deer, etc.), & livestock if opportunity arises " eats 26-35 lbs. daily
Zoo. omnivore chow, carrots, apples, herring, & bone 1 day/week

habitat/range

chiefly mountainous forests " NW North America, especially Alaska, Idaho, Wyoming, Montana, & Yellowstone National Park

status

us Threatened " cites App II

other

may be serious problems with bears coexisting with humans, even in parks & wildlife areas

oregon zoo exhibit

Alaska Tundra