This activity incorporates the use of real scientific data to explore ecosystem dynamics among three Antarctic penguin species. Students will analyze two Long-Term Ecological Research (LTER) data sets and supporting graphics to cause and effect and feedback relationships driving changes observed in Adelie, Chinstrap, and Gentoo penguins between 1975 and 2010 along the West Antarctic Peninsula. The penguin population datasets were collected from the Palmer Station Study region, which is part of the Long-Term Ecological Research program. The LTER program began in 1974 and has been collecting annual data in this region (as well as numerous other regions in Antarctica) on a variety of ecological interactions.