My current focus is on mercury contamination in the headwaters of the Shenandoah River in central Virginia. This project arose after a conversation with a toxicologist from the US Fish & Wildlife Service who wondered aloud whether mercury that leaked into the South River from 1929-1950 was harming birds. While everyone knows that mercury is bad for animals, the consensus ends there. During six field seasons my lab made major discoveries about the movement of mercury through the food chain and the effects (and lack thereof) of various levels of mercury on reproduction and survival in numerous bird species. Most significantly, we discovered that mercury from a river has entered the surrounding terrestrial food chain and accumulates in terrestrial spiders that are eaten by songbirds. This leads to higher levels of mercury in forest songbirds than in fish-eating birds, which have long been considered the only group at risk. Now we are carrying out research in the more controlled environment of the laboratory to determine how, when, and why mercury affects songbirds. Current students work on the effects of chronic, low level mercury exposure on songbird development, endocrine and immune function, song, reproductive success, behavioral ecology (foraging, fighting, mating, escaping, etc.) and more.