Question

The diagram shows part of the food web in Yellowstone National Park. Humans began removing gray wolves from the park in the early 1900s.
An image of Yellowstone food web. Text that reads: Coyote. Gray wolf. Elk. Grasses. Willow. Aspen. Beaver.
How is removing the gray wolf from this food web most likely to affect other species in the food web?

A.
The grass population will stay the same.
B.
The coyote population will decrease.
C.
The elk population will increase.
D.
The aspen population will increase.

Answer 1

C. The elk population will increase.

Removing gray wolves removes a top predator that keeps elk numbers in check. With fewer wolves, elk experience less predation and their population grows, which then leads to more browsing and can reduce grasses, willow, and aspen (a trophic cascade).