How do wolves change rivers?

What is a trophic cascade?

• An ecological process that starts at the bottom of the food chain

• An ecological process that starts at the top of the food chain

• An ecological process that occurs in the middle of the food chain

• An ecological process that occurs randomly in the food chain

What happened in Yellowstone National Park when wolves were reintroduced?

• The number of deer decreased

• The number of deer increased

• The vegetation in the park was destroyed

• The vegetation in the park started to regenerate

How did the behavior of the deer change when wolves arrived?

• They started avoiding certain parts of the park

• They became more aggressive towards other animals

• They started hunting smaller prey

• They migrated to a different location

What happened to the height of the trees in certain areas of the park?

• They remained the same

• They decreased

• They doubled

• They quintupled

Which animals started moving in after the trees started to regenerate?

• Wolves and coyotes

• Bears and rabbits

• Songbirds and migratory birds

• Hawks and weasels

What did the beavers do to the rivers?

• They polluted the rivers

• They built dams in the rivers

• They caused erosion in the rivers

• They changed the course of the rivers

How did the regenerating forests affect the stability of the river banks?

• They caused more erosion

• They had no effect on the stability

• They stabilized the banks

• They made the banks collapse more often

What did the wolves do to the physical geography of the park?

• They had no impact on the physical geography

• They caused more soil erosion

• They changed the course of the rivers

• They stabilized the banks of the rivers