Earth Day (April 22)

Meet the animal influencers that play an oversize — and often surprising — role in shaping our world.

When wolves were reintroduced to Yellowstone National Park, the most remarkable trophic cascade occurred.

While all life has the right to exist, there are two groups of animals that are more important to an ecosystem than other animals. These are known as keystone species and the indicator species.

Keystone plant genera are unique to local food webs within ecoregions. Remove keystone plants and diversity will be diminished.

A keystone species helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether. Learn who some of the keystone species are.

An umbrella species is a species whose wellbeing and population numbers are suggestive of the entire ecosystem’s health.

With large and diverse home ranges, the grizzly bear is an ecological umbrella species, meaning its presence on the landscape ensures a healthier ecosystem for countless other animals and plants.

The Umbrella species concept is a brilliant conservation strategy to use a single species to protect an entire ecosystem, but how effective is it?