1. Department of Ecosystem Sciences and Management, The Pennsylvania State University, 414 Forestry Resources Building, University Park, Pennsylvania 16802, USA
2. US Geological Survey, Patuxent Wildlife Research Center, SO Conte Anadromous Fish Research Center, 1 Migratory Way, Turners Falls, Massachusetts 01376, USA
3. Center for Wildlife Health, University of Tennessee Institute of Agriculture, 2431 Joe Johnson Dr., Knoxville, Tennessee 37920, USA