Richard S. Ostfeld is Senior Scientist at the Institute of Ecosystem Studies in Millbrook, New York. His research interests involve interactions between pathogens, vertebrate hosts, vectors, and the surrounding landscapes. Current projects include the impacts of variation in host diversity on Lyme disease and West Nile Virus risk via the “dilution effect,” and the effects of acorn masting on interaction webs involving white-footed mice, chipmunks, deer, gypsy moths, songbirds, raptors, ticks, and pathogens. He is engaged in both national (e.g., NEON) and international (UNEP and WHO) initiatives that link ecology with infectious disease.