1. Center for Epidemiology and Animal Health; USDA/APHIS/Veterinary Services; 2150 Centre Avenue Fort Collins Colorado 80526 USA
2. National Wildlife Research Center; USDA/APHIS/Wildlife Services; 4101 LaPorte Avenue Fort Collins Colorado 80521 USA
3. Great Basin Institute; 16750 Mt. Rose Highway Reno Nevada 89511 USA
4. Department of Veterinary Sciences; Program in Ecology; University of Wyoming; 1000 E. University Avenue Laramie Wyoming 80271 USA