Wolves Change Rivers (MSLS2.4 & MSLS2.1)

Look at the graph, which statement would be the most accurate:

• As the wolve population increased, the elk population and the puma populations decreased.
• The wolve, puma and elk populations all increased through time.
• Overall, the wolve, and puma had a positive slope, while the elk has a negative slope.
• The pumas could no longer catch the elk so their population declined.

Look at the graph, which line(s) has a positive slope.

• wolves and puma
• wolves and elk
• wolves
• pumas and elk

Look at the graph, how many wolves were there in 2002?

• 3000
• 15
• 50
• 40

Look at the graph, how many wolves were there in 2015?

• 5,000
• 10,000
• 65
• 2,000

Look at the graph, how many elk were there in 2002 and 2015?

• There were 100 elk in 2002 and 2,500 elk in 2015
• There were 2,000 elk in 2002 and 2,500 elk in 2015
• There were 8,500 elk in 2002 and 2,500 elk in 2015
• The elk population were the same in 2002 and 2015

When wolves were reintroduced to Yellowstone National Park ______

• The bear and the elk population decreased.
• The beavers could no longer build dams and the water became muddy.
• The Willow trees stopped growing
• The elk population decreased, other plants and animals increased in number and the ecosystem became more diverse.

The wolves caused _____

• a problem for other animals
• a trophic cascade
• a biomass
• a hole in the ecosystem

A keystone species is _____

• A species that kills other animals
• A species that can exist in any ecosystem
• a species that holds the entire ecosystem together.
• a hole in the ecosystem

Why are the populations of pumas and wolves so much smaller than the elk population in 2015?

• Pumas and wolves are tertiary consumers so they have less energy available to them because of the 10% rule.
• The populations of wolves and pumas are not smaller than the elk population
• Elk are bigger than pumas and wolves
• Aliens take the pumas and wolves to repopulate their planet.