Yellowstone National Park Wildlife Quiz

What year were grey wolves reintroduced into the Greater Yellowstone Ecosystem?

• 1985

• 1995

• 2005

• 2015

What effect did the reintroduction of wolves have on beaver populations in Yellowstone National Park?

• Decreased the beaver populations

• Increased the beaver populations

• Had no effect on the beaver populations

• Exterminated the beaver populations

According to the text, what is a direct consequence of the flourishing beaver population in Yellowstone?

• Decrease in elk population

• Increase in water quality

• Restoration of aspen and willow trees

• Reduction of water bodies

What was the impact of the absence of wolves on Yellowstone elk before their reintroduction?

• Elk populations decreased

• Elk populations remained stable

• Elk populations increased too well

• Elk migrated out of Yellowstone

How did the reintroduction of wolves in Yellowstone indirectly affect the plant life according to the document?

• Led to overgrowth of invasive plant species

• Reduced the diversity of plant species

• Helped in the recovery of certain plant species like willow and aspen

• Caused a significant decrease in plant biomass

What was the state of the willow stands in Yellowstone in 1968 compared to today?

• The willow stands were more robust in 1968.

• The willow stands are three times more robust today.

• The willow stands have decreased in number since 1968.

• The willow stands have remained the same since 1968.

Why do willow stands in Yellowstone recover better during the winter?

• Due to decreased number of elk.

• Because of intense elk browsing.

• Because of reduced predatory pressure from wolves.

• Because elk are on the move due to wolf presence.

What effect did the reintroduction of wolves have on the Yellowstone ecosystem according to the article?

• It led to the extinction of certain species.

• It decreased the robustness of willow stands.

• It helped improve the health of willow stands.

• It had no significant impact on the ecosystem.

According to the U.S. Geological Survey research, how much more un-browsed willow biomass was there compared to browsed plants after three years?

• 10 times more

• 6 times more

• 84 percent more

• 84 times more

What additional environmental changes have affected the Yellowstone ecosystem besides the reintroduction of wolves?

• Only the 1988 Yellowstone fires.

• Ongoing drought and warmer, drier winters.

• Increased rainfall and colder winters.

• No other changes have been noted.