Modeling the CMR Method

In this project we are going to simulate the CMR (Capture-Mark-Recapture) method discussed in the demonstration without actually trapping any animals. To do this, you should fill a bucket or hat with 20 pieces of paper, all cut to the same size. For the first data point, pull out a handful of the pieces of paper (without looking.) These are the "animals'' that you caught on the first try and will be the number of new individuals marked in your table. Mark these with a pen or pencil, put them back into the hat, and mix them up. Pull out another handful for the second catch. Disregard the marked ones and count the number of unmarked ones. Mark the unmarked papers and put them all back in the hat. Continue this procedure until you have data points for 5 trapping periods. Fill in the following table with your data.

Use a statistical package or a graphing calculator to make a scatterplot for your data and find the "best fit'' line.

Interpret the R² value for this data.

Find the x intercept and the y intercept for your line. Interpret what these intercepts mean for the CMR method.