The gray wolf is a predator that keeps the herd numbers of elk and deer populations in check. with the disappearance of wolves, elk and deer populations exploded, which led to overgrazing of plants, especially in riparian zones. this led to increased erosion and polluted streams.
the gray wolf is an example of

predator or consumer

Explanation:

The grey wolf is a carnivorous animal that eats other small herbivorous animals like that of the deer and the elk and keeps there population in checks as thus is consumer of the ecosystem and forms important part of the food web and the food chain and is dependent on them for ts growth and development and thereby the balance is maintained.

Asmall closed hole formed in an outwash plain or moraine. forms when a  glacier retreats then remains stationary.