Question

Elk herds in Yellowstone National Park are herbivores that eat on the available vegetation. Which factor is important to ensure the stability in this ecosystem?

Answer 1

C) The presence of predators, such as grey wolves, to keep the elk population in check

Answer 2

Answer: Presence of predators.

Explanation: predators such as hyenas or wolves would keep the here at a particular level so that they don't exhaust the primary producers which is the grass.