“Danger–Mad Marmot” warned the sign on the laboratory door. Inside stuffed woodchucks and other woodchuck memorabilia cover Stam Zervanos’s desk and study area. Zervanos, a biology professor at Penn State University’s Berks-Lehigh Valley College near Reading, has been studying woodchucks, the least social of the marmot genus, for eight years. As a physiological ecologist, he…