Grizzly Bears
Grizzly bears make their home generally in
the uplands of western North America. Except
for cubs and females, grizzlies are normally solitary, active animals, but in coastal
areas, the grizzly congregates alongside streams, lakes, rivers, and ponds
during the salmon spawn. Every other year, females (sows) produce one to four
young (commonly two) which are small and weigh only about 500 grams
(1 lb). A sow is protective of her offspring and will attack if she thinks
she or her cubs are threatened.
Grizzly bears are a known as a keystone
species. A keystone species is a species that plays a critical role in
maintaining the structure of an ecological community and whose impact on the
community is greater than would be expected based on its relative abundance or
total biomass.[1]
Grizzly bears regulate prey species and
disperse the seeds of many plant species, such as blueberry and buffaloberry.
They also help to maintain plant and forest health, both by aerating the soil
as they dig for roots, pine nuts and ground squirrels, and by moving thousands
of kilograms of spawning salmon carcasses into the forest, where trees and
other plants absorb their high levels of nitrogen.
[1] "Grizzly Bears." David Suzuki Foundation. N.p.,
n.d. Web. 13 June 2012.
<http://www.davidsuzuki.org/issues/wildlife-habitat/science/critical-species/grizzly-bears/>.
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