Ecosystem Dynamics and Species Interactions

In what year were wolves reintroduced to Yellowstone National Park?

• 1990

• 1995

• 2000

Before the reintroduction of wolves, what was the primary impact of the large deer population on the Yellowstone ecosystem?

• They led to a major reduction in vegetation.

• They improved the health of the rivers.

• They migrated to other parks.

How did the reintroduction of wolves change the behavior of deer in Yellowstone?

• Deer began to avoid certain areas, particularly valleys and gorges.

• Deer formed larger herds for protection.

• Deer became less fearful of humans.

What was an immediate effect on the vegetation in areas that deer started avoiding after the reintroduction of wolves?

• The vegetation started to regenerate and grow taller.

• New species of plants were introduced.

• The vegetation became more susceptible to disease.

Which animal's population increased significantly due to the regrowth of trees, because they rely on trees for food?

• Coyotes

• Beavers

• Hawks

How do beavers, as "ecosystem engineers," contribute to the environment?

• They control the population of large predators.

• They create new habitats for other species by building dams.

• They help spread seeds for new plant growth.

• They reduce soil erosion by compacting the ground.

What was a direct consequence of wolves reducing the coyote population in Yellowstone?

• An increase in the number of deer.

• A decrease in the number of small rodents and rabbits.

• An increase in the number of rabbits and mice.

How did the reintroduction of wolves physically alter the rivers in Yellowstone?

• The rivers became wider and shallower.

• The rivers experienced increased erosion and meandering.

• The channels narrowed, and more pools and riffle sections formed.

What was the underlying reason for the physical changes observed in the rivers after the reintroduction of wolves?

• Increased rainfall in the region.

• The regenerating forests stabilized the river banks.