Along with the M&M Sampling Design and the Transect/Quadrat Sampling for Abundance activities, I also did an activity with my students that I remembered from an Introduction to Biology course in college. I thought I would share, as the students seemed to enjoy (and learn from) it.
I started by having students tell me everything they know about Spinner Dolphins. I then told them that they were a part of a team of scientists who had been charged with the task of surveying the number of Spinner Dolphins that lived along the Leeward Coast of Oahu and asked them how they would go about doing that. Eventually, they arrived at the idea of tagging dolphins and at that point, I told them about the capture-recapture method and gave them the formula for the technique (total population) = (number marked * number captured in second attempt) / (number recaptured). I then asked for 4 volunteers to be the scientist team, while the rest of the class was the dolphin population. 2 scientists were given a certain number of "tags" and were directed to randomly capture and tag "dolphins" throughout the classroom. The dolphins were told that if tagged, they were to hold the tag in a closed hand and the second group of scientists (who had been waiting outside the room so that they would remain unbiased) were allowed in to capture a second sampling of dolphins at random, keeping tally of how many dolphins in their second capture were tagged. We then "plugged" all of the data into the formula to calculate the estimated population size. Each time we did it, we were within the ballpark of total students in the room.
Sat, 05/25/2013 - 19:21
I do this activity too with beans simulating termites but I love your idea to do it with students as the dolphins. I could see how this could be used in a larger lesson where the dolphin students would be asked to simulate certain typical behaviors that had previously been studied and the scientists would be asked to observe the behaviors as well as tagging the dolphins and then recapturing them.
Tue, 05/21/2013 - 20:10
What a great idea! Similarly, I used a printed lesson using beans and "tagged" the organisms with a black pen and had students put them back in a paper bag. Do you think your lesson would work with 7th graders in a class of 30? What are some accommodations or changes make?