A Changing Ecosystem Do Now: The absence of the wolves in Yellowstone National Park severely impacted the ecosystem. Many changes occurred from the loss of this predator. The wolves are considered a keystone predator. How would you define a keystone species? Keystone species is a species that has a disproportionally large effect on its environment Compared to its relative abundance. When a keystone species is removed from a system, The ecosystem may change drastically, even if the species removed was a small part of the Ecosystem. A Changing Ecosystem

Predator-Prey Simulation Lab: A Close Look at the relationship between predator and Prey Simulate the interactions between a predator population of foxes and a prey population of rabbits Organize data in table and graph format Compare simulation data to data taken from nature, and reflect upon lab procedure and nature Describe how one population affect the other population

Meet the individuals of each population Predator – Fox Prey – Rabbit Community - Meadow

Assumptions Rabbit About the…. Fox Must capture 3 rabbits to survive Produce 1 offspring for every three rabbits capture A fox only immigrates if none left in meadow Captured ones die Surviving ones reproduce and double Meadow carrying capacity is 100 Assumptions

Refer to lab when in doubt Important notes Determine fox survival and reproduction using individual fox capture numbers. As population builds, it is important to tally each fox’s kills, removing captured rabbits after each fox is tossed. If fox captures 7 rabbits, three foxes enter next generation, original fox and two offspring for that one fox. Refer to lab when in doubt

Do Now: Questions to Ponder… What effect does the available food source have on the predator population? What is happening to the prey population over time? Can you see a pattern occurring between the predator and prey population? Do the post-lab….

Post lab with the Group Using Google Sheets 1. Create a line graph showing the two populations over time. Answer questions using the simulation data Answer questions to compare simulation and real data Be sure graph and doc are shared with all members Be sure to print out a copy for Mrs. Bombard

Is the part of an oscillation? Can you find this graph within the predator prey simulation and Nature graphs? Is the part of an oscillation?

Predator-Prey Relationship in Nature Oscillation Traits: Repetitive variation Relating to time Regular intervals Oscillating growth can describe predator-prey relationship. Each population has this pattern. How are they related?

1. Refer to the Predator-Prey Simulation Line Graph to answer the following: a. Describe what happens to the rabbit population over time. b. Describe what happens to the fox population over time. c. How did both of these populations influence each other? Support your answer d. What would have happened if a whole family of foxes immigrated into the ecosystem at Generation 2? e. Make a prediction about what would happen to both your predator and prey populations if a new predator is added to the system? Explain any new types of relationships established. 2. Refer to the Predator-Prey Line Graph of Nature to answer the following: a. How does the predator population vary when they prey numbers change? b. The term “oscillating” means to swing back and forth or to move back and forth between tow points. Explain why someone would say that the predator-prey interaction is an illustration of oscillating growth. c. Are the populations in phase with each other most of the time? Explain. 3. Refer to both Predator-Prey Line Graphs to answer the following: a. Does your group’s simulation reflection-prey relationship in nature? Explain. Post Lab Questions

Post Lab Assignment: Submit Printout of typewritten questions in complete sentence format. Printout of the simulation data and nature data. Be sure that both partners names are on the document. You should use a proper heading. Due next lab period!