1. Food Chain and Energy Pyramid Review

2. 1. What are the producers in this food chain?
*Producers = Grasses

3. 2. What are the primary consumers in this food chain?
*Primary Consumers = Rabbits

4. 3. What are the secondary consumers in this food chain?
*Secondary Consumers = Snakes

5. 4. What are the tertiary consumers in this food chain?
*Tertiary Consumers = Hawks

6. 5. In the energy pyramid below, which consumer is receiving the most energy from the producers?
*The primary consumer (rabbits) because they are the ones eating the producer.
Hint: The 10% Rule

7. Would the populations increase or decrease?
How would doubling the rabbit population affect the grass, snake and hawk populations at first?
Would the populations increase or decrease?
Grass population?
Snake population?
Hawk population?
decrease
increase
increase

8. Increasing the hawk population
How would increasing the hawks affect the rabbit population? Explain why.
*If the hawks increased in population, then the snakes would decrease in population due to increased hunting. Since there would be fewer snakes to hunt the rabbits, the rabbit population would increase.

9. Predator/Prey Relationships
What effect does removing prey have on predator populations?
The predator will decrease in population because there is not enough food to go around.

10. Predator/Prey Relationships
10. What effect does removing predators have on prey populations?
Without predators hunting the prey and killing them, the prey will increase in population.

11. How Wolves Change Rivers https://www.youtube.com/watch?v=ysa5OBhXz-Q
In the video, how did the absence of Wolves affect Yellowstone National Park’s ecosystem?
Without wolves, the deer population increased significantly. This in turn caused the producer populations to decrease causing a drastic effect to take place. Without grasses and vegetation to hold the soil in place, more erosion occurred along the river creating a meandering river. Not just producers were effected but also many of the consumers within this ecosystem suffered due to the increased deer population.

12. How Wolves Change Rivers
When the wolves were reintroduced back into the park, what happened to the producers within the ecosystem? Why?
The producers began to increase in population in certain areas because the deer began staying away from those areas where wolves could easily hunt them.

13. How Wolves Change Rivers
How did the reintroduction of the wolves change the river?
The rivers began to meander less because less erosion was taking place along the banks of the river. Essentially, the rivers were locked in place. This was due to the increase in populations of grasses, vegetation, and forests which lock the soil in place with their roots.