1. U.S. Geological Survey, Fort Collins Science Center Fort Collins Colorado USA
2. U.S. Geological Survey, North Carolina Cooperative Fish and Wildlife Research Unit, Department of Applied Ecology North Carolina State University Raleigh North Carolina USA
3. U.S. Geological Survey, Patuxent Wildlife Research Center Laurel Maryland USA
4. U.S. Geological Survey, Washington Cooperative Fish and Wildlife Research Unit, School of Environmental and Forest Sciences & School of Aquatic and Fishery Sciences, University of Washington Seattle Washington USA