In Principles of Biology II (BIOL 1107), students learned about population ecology and estimating population sizes by collecting data for the TurtlePop Project. This is a nationwide project of the Ecological Research as Education Network (EREN), and ARCC is one of approximately 30 colleges and universities nationwide studying turtle populations and submitting data for compilation and analysis. In order to evaluate whether urbanization affects the secondary sex ratio or population age distribution of turtles, students set traps to capture, measure, and mark turtles, and then reset the traps to repeat the sampling on a second (subsequent) day. They use the mark-recapture method to estimate population size of turtles, and gain valuable field sampling experience with equipment, data collection, handling turtles, and estimating population size. Turtles are sampled annually by students in Principles of Biology II (BIOL 1107) and General Ecology (BIOL 2209) at different locations. Geographic Information Systems (GIS) analyses of land use patterns surrounding the lakes will help answer questions about the effect of urbanization on sex ratio and population age structure.