# Predator-Prey Interactions -- Modeling the Number of Fishers and Porcupines in New Hampshire

#### Summary

In this Spreadsheet Across the Curriculum activity, students build an Excel spreadsheet to model the interaction between populations of a predator and a prey, in this case, porcupines and fishers. They use a simplified version of the Lotka-Volterra equations and generate graphs showing population change. They predict the results of changing the variables and then see the results by simulation. Finally, the students investigate a phase plane graph, showing population cycles of both species, and they interpret different parts of the graph.

## Learning Goals

Quantitative goals:

- algebra (interpreting equations, difference equations)
- graphs (X - Y scatter plots, time series, phase plane, scale of axes)

- modeling
- Lotka-Volterra equations
- interaction between predator and prey populations

- determining cell equations
- absolute cell reference
- graph design

## Context for Use

## Description and Teaching Materials

PowerPoint SSAC2006.QH540.BS1.1-student version (PowerPoint 302kB Dec20 06)

The module is a PowerPoint presentation with embedded spreadsheets. If the embedded spreadsheets are not visible, save the PowerPoint file to disk and open it from there.

This PowerPoint file is the student version of the module. An instructor version is available by request. The instructor version includes the completed spreadsheet. Send your request to Len Vacher (vacher@usf.edu) by filling out and submitting the Instructor Module Request Form.