1. Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA
2. Present address: USGS, Biological Resources Division, Kansas Cooperative Fish and Wildlife Research Unit, 204 Leasure Hall, Kansas State University, Manhattan, Kansas 66506, USA
3. Plague Section, Bacterial Zoonoses Branch, Division of Vector-borne Infectious Diseases, Centers For Disease Control and Prevention, Fort Collins, Colorado 80522-2087, USA
4. Deceased