Predator/Prey Simulation Final Write up is due 9/16

Planning Purpose/Question: How does the predatory and prey relationship of ______ and _______ effect the negative feedback process seen in the natural environment? Hypothesis: The negative feedback process can be seen through the linked population fluctuations of predators and prey over time.

Planning Variables: To understand your ratios and variables, you will need to first research which predator and prey relationships you want to use. 1.Determine the Independent variable and the dependent variable 2.Decide which variables are constant, (ie the ratios, drop height, territory size etc.)

Planning Predicting ratios: Determine how many prey will feed 1 predator and keep them alive for 1 reproductive cycle. Determine how many prey will feed 1 predator in order to care for future offspring. Determine the reproduction ratio of prey and reproduction ratio of predators. Determine the counting of prey eaten by predator when landing on more than 1 prey.

Planning Examples of ratios: – fox: hare Predator survival – 1:2 Predatory survival and produces offspring for next trial– 1:4 Reproduction rate of prey – 2hares:4offspring Reproduction rate of predators – 1parent:2 offspring Starting population sizes: 3:30 – If all predators die, start next simulation with 3 predators

Planning Materials: – Masking tape (for outline of territory) – ”X2” squares for predators – 300 – 1”X1” squares for prey – Notebook/graph paper for data table – Pen or pencil for recording data

Planning (PL) Procedure: 1.Each lab group will need to research a specific predator and prey relationship including the population and territory size. 1.Needs to also include how many prey a predator needs to eat to survive in the wild for one year and how much more prey is needed to produce and raise offspring. 2.Set your parameters for the simulation as follows. 1.Territory size - Shape 2.Ratios of: 1.Start populations of predator: prey 2.Predator survival: prey eaten 3.Predator + offspring : prey eaten 4.Predator survival: predator offspring produced 5.Prey survival: prey offspring produced 3.Drop height 3.Using masking tape, outline your tiles and specific shape and area for your territory. 4.Using a metric ruler (1m), stand it up in the middle of your territory and take your determined number of start prey and drop them from the center of territory all at once. (randomness is key) 5.Using the metric ruler again, same as with prey, drop your pre-determined start population of predators into the territory. 6.Determine the number of prey that has been eaten by each predator. Count the remaining prey within the territory and the surviving number of predators. 7.Calculate the reproductive and survival ratios of the predator and prey. 8.Record data. 9.Add the new calculated number of prey offspring (if any) to your territory by the drop method listed in step 4 10.Add the new calculated number of predator offspring (or use start number of predators if all predators died), to your next drop/hunting group simulation. 11.Repeat steps 4-10 for 25 simulations total (needed to see pattern). Each simulation represents one reproductive cycle of the predator. 12.Graph the data and analyze the results. 13.Write your findings and include your model limitations/evaluation and discussion in your conclusion.

Data: Population Changes of Predators and Prey Trials (reproductive cycle) Starting Population of Predators Ending Population of Predators Starting Population of Prey Ending Population of Prey 1 Pre-determinedcountedPre-determinedcounted 2 calculatedcountedcalculatedcounted etc.

Analysis Graph the ending populations in one graph Graph calculated populations in a separate graph. Look for patterns (that is the analysis) Write a brief qualitative analysis of what the graphs are quantitatively showing. DO NOT forget to give titles to each graph and (figure1 etc) to the axis. Include units!

Example graph