To many scientists and conservationists, grizzly bears are viewed as a barometer of an ecosystem’s health. Grizzlies are known as an umbrella or keystone species, terms that refer to the grizzly’s functional role within its ecosystem. The foraging behavior of an umbrella or keystone species creates a top-down effect on many other species lower in the food chain, such as deer, elk, rabbits, trout, insects and plants. If the grizzly population is healthy and strong, so are these other populations from big game to native fish. Conversely, a faltering, fragmented grizzly population spells certain hardship for other wildlife, many species of which are positively affected by and dependent on the bear’s activity. To learn where grizzlies live, what they eat, and why they are threatened, see the links to the right.