1. Migratory Bird Center, Smithsonian Conservation Biology Inst., National Zoological Park Washington D.C USA
2. United States Geologic Survey, Patuxent Wildlife Research Center Laurel MD USA
3. Univ. of Southern Mississippi, Dept of Biological Sciences Hattiesburg MS USA
4. Fish and Wildlife Research Inst., Florida Fish and Wildlife Conservation Commission St Petersburg FL USA
5. Dept of Biology, Univ. of Massachusetts Amherst MA USA