Interactions with Other Species
Except for mating and caring for their young, grizzly
bears primarily
lead solitary lives, but they are still considered to be the most social
bear in North America (U.S. Fish and Wildlife Service, 2000). They usually hibernate for 5 to 8 months out of the
year, so they do not have much time during the year to interact. They only
really interact with each other when they are breeding or when the mothers
are raising their young cubs. The cubs usually stay with their mothers
for about 2 to 3 years before they go off on their own (MacDonald, n.d.).
Grizzly bears are
not territorial and will roam anywhere from 50 to 500 square miles. They
usually travel to the areas where there is an abundance of food. They spend
most of their lives simply searching for food and eating. Grizzlies are
considered to be omnivores because they are hunters that eat meat such as
elk,
white tail deer,
moose, caribou, bison calves, ants, trout, and
salmon. They
also forage for berries such as
salmonberries and other plants. Even though they are such massive
animals, grizzly bears tend to feed on smaller things such as clover,
dandelion, whitebark, limber pinenuts, cow parsnip, grasses,
roots, bulbs, insects, insect nests, starchy tubers, and nuts. They usually search for foods
that they can find easily and quickly (Silverstein et al., 1998).
Adult grizzly bears are at the top of
their food chain chain (U.S. Fish and Wildlife Service, 2000). They have no
real predators besides humans and other bears, even though they try to avoid
them at all costs. Humans are not only the biggest predators of grizzlies
because humans hunt them, but also because
the increasing human population is causing the grizzly bears' habitat to be
taken over (Horejsi 2008). As detailed on the Habitat
and Geography page of this website, grizzlies and humans are often in
close proximity due to their converging territories.
U.S Department of Transportation
Grizzlies are very protective and will attack anything that seems to be a threat to their cubs or food. Grizzly bear cubs, on the other hand, are often preyed upon by mountain lions, wolves and other bears. Around 1900 the grizzly bear population started to decline, and by 1975 they had become protected under the Endangered Species Act (Brown Bear, n.d.). Today the grizzly bear population in the lower United States is around 1,200 and they are considered to be a threatened species. In Alaska however, there are estimated to be around 30,000 grizzlies. Grizzly bears are still being illegally hunted today by farmers because they damage their crops. They are also being killed by poachers for their teeth, claws, hide, and internal organs. Grizzly bears' internal organs, especially their gallbladders are sold in the Asian medical market because the bile it produces is used in medicines (MacDonald, n.d.).
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