1. Department of Biology; New Mexico State University; Las Cruces New Mexico 88003 USA
2. U.S. Fish and Wildlife Service; Migratory Bird Office, Region 2; Albuquerque New Mexico 87103 USA
3. Kalamath Basin National Wildlife Refuge Complex; Tulelake California 96134 USA
4. Department of Economics, Applied Statistics, & International Business; College of Business; New Mexico State University; Las Cruces New Mexico 88003 USA