NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE The Bear Facts: Grizzly Recovery in the Bitterroot Ecosystem by
Few species have captured the imagination of the American public like the grizzly bear (Ursus arctos horribilis). It is one of the largest North American land mammals, with male grizzly bears often reaching 7 feet tall, weighing 300–600 pounds, and female grizzly bears 200–400 pounds. They are an om...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.380.9916 http://sciencecases.lib.buffalo.edu/cs/files/grizzly.pdf |
| Summary: | Few species have captured the imagination of the American public like the grizzly bear (Ursus arctos horribilis). It is one of the largest North American land mammals, with male grizzly bears often reaching 7 feet tall, weighing 300–600 pounds, and female grizzly bears 200–400 pounds. They are an omnivorous species, with a diet that includes elk carcasses, sometimes sheep, berries, and whitebark pine seeds, among other items. Although grizzly bears historically ranged throughout most of the western United States, habitat loss and excessive human-caused mortality have drastically reduced numbers of this species. It is estimated that prior to European settlement there were ~50,000 grizzly bears; it is estimated that only 800–1,000 grizzly bears exist on approximately 2 percent of their historic range in the lower 48 states now. Biologically, grizzly bears have the second slowest reproductive rate of all North American mammals, making it difficult for them to rebound from threats to their survival. Females reach maturity at 4–9 years, and generally give birth to two cubs every three years. |
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