The ecological niche of the gray wolf is a top level, or apex, predator. They prey upon vulnerable large animals, such as deer, bison and moose, controlling the population numbers through predation. This, in turn, affects how these prey animals interact with the environment.
Gray wolves have no natural predators, although they do face competition from other apex predators. Bears, tigers, cougars, coyotes and hyenas attempt to steal kills from gray wolves or kill the wolves outright. The wolves, in turn, kill the infant members of these competitors. Wolves organize into packs of five to 11, protecting each other from other competitive predators.