Unit 2

Ecosystem

A system, or a group of interconnected elements, formed by the interaction of a community of organisms with their environment.

Wolf

A wild carnivorous mammal of the dog family, living and hunting in packs. It is native to both Eurasia and North America, but has been widely exterminated.

Amphibians

Any cold-blooded vertebrate of the class Amphibia, comprising frogs and toads, newts and salamanders, and caecilians, the larvae being typically aquatic, breathing by gills, and the adults being typically semiterrestrial, breathing by lungs and through the moist, glandular skin.

Trophic Cascade

Trophic cascades occur when predators in a food web suppress the abundance or alter the behavior of their prey, thereby releasing the next lower trophic level from predation (or herbivory if the intermediate trophic level is a herbivore).

Yellowstone

a river flowing from NW Wyoming through Yellowstone Lake and NE through Montana into the Missouri River in W North Dakota. 671 miles (1080 km) long.

Endangered

in unsafe conditions; for a species, subject to possible extinction

Ungulates

mammals with hooves

Reintroduction

the process of returning animals to their native habitat

Eradicated

to remove or destroy utterly; extirpate