1. California Department of Health Services, 50 D Street, Suite 205, Santa Rosa, California 95404, USA
2. Redwood National Park, 1125 16th Street, Arcata, California 95521, USA
3. Department of Biology, Humboldt State University, Arcata, California 95521, USA
4. Present address: 4715 E. Blue Bird, Orange, California 92669, USA
5. Present address: Grand Teton National Park, P.O. Box 170, Moose, Wyoming 83012, USA
6. California Department of Health Services, 2151 Berkeley Way, Berkeley, California 94704, USA
7. Division of Vector-Borne Viral Diseases, Center for Infectious Diseases, Centers for Disease Control, Public Health Service, U.S. Department of Health and Human Services, Fort Collins, Colorado 80522, USA
8. Department of Wildlife, Humboldt State University, Arcata, California 95521, USA