This case study showcases the unique relationship between island apple snails (an invasive species) and snail kites (an endangered species). Snail kites have been evolving to better capture this new prey helping their populations to rebound. The case study is designed for AP Environmental Science, but could be used in any environmental science or biology courses. Questions are written to be similar to the Free-Response Questions on the AP Exam, using the same tasks verbs such as 'identify,' 'ex