Monday, March 27, 2017

Thoughts on an predator-prey active learning exercise

Today was a very exciting day for me in my BI111 class, as I got to try out a role-playing game that I have been thinking / planning for a long while. At this point in the semester, my course (Biological Diversity & Evolution) has reached the topic of community ecology. One of the phenomenon I talk about this week is how predators and prey can become linked into cyclical patterns. A well-known example of this involves the  Candian Lynx, Lynx canadensis and its prey, the snowshoe hare, Lepus americanus. I've been wanting to try and let my students seem how this pattern, arises, so I devised an exercise that could be done in my two sections for BI111.
For context, this class has ~400 students per section, and I run i out of a lecture hall that holds 450 students (see pictures below)




Here is the set of rules I came up with, and shared with the students before today's lecture.

Now before you get too worried, I chose soft foam practice golf balls (I bought 4 sets from amazon) for use by the "lynx".

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OK. So, flash forward to the exercise in question. Overall. I felt it went well, but there are a few tweaks that I'm going to consider for next year's implementation.
1. Lynx - it was perhaps too easy for the lynx to survive and reproduce. In my 10:30 class, I followed the original plan, and it it didn't take long for the lynx population so rapidly rise. Things were a bit better in the second round, where I changed the rule to 4 hits =survival, 5=1 offspring and 6 hits=2 offspring. Lynx numbers still did increase pretty high, but it took a bit longer (I'll upload some scans of the data sheets later).
2. Hares. It became clear early on that the hares that survived needed bigger litters. Perhaps it was the orientation of the room, or the skill of the lynx at throwing, but predation success was greater than I anticipated. I tired out 3 offspring per litter. That seemed to work.
3.Time. I had expected that 5-6 rounds of predation + instructions preamble would take ~20 minutes (to give time for cycles to become apparent). It ended up taking about 30. Perhaps reducing the number of balls/lynx/round might speed things up.
4. Loundness. This was loud exercise. I knew it would, but - wow! Lots of excitement from the students (good), but hard to keep focus on the exercise. I'll need to think about what can be done.

That's it for now,  but I'll update this post when I get the student feedback on the exercise.
TL