1. National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services , Fort Collins, CO, USA
2. Department of Economics, Colorado State University , Fort Collins, CO, USA
3. Department of Agricultural and Resource Economics, Colorado State University , Fort Collins, CO, USA
4. USDA/APHIS/ Center for Epidemiology and Animal Health, Natural Resource Research Center , Fort Collins, CO, USA