1 Odum School of Ecology, Department of Infectious Diseases, College of Veterinary Medicine, the Center for the Ecology of Infectious Diseases and the Center for Influenza Disease and Emergence Research (CIDER), University of Georgia, Athens, GA, USA.
2 Odum School of Ecology, the Center for the Ecology of Infectious Diseases and CIDER, University of Georgia, Athens, GA, USA.