1. The Nature Conservancy, 201 Mission St., 4th Floor, San Francisco, CA 94105
2. Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, MRC 5503, Washington, DC 20013
3. Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523
4. Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013