1. U.S. Geological Survey, Eastern Ecological Science Center , 12100 Beech Forest Road, Laurel, Maryland 20708 , USA
2. National Museum of Natural History, MRC-116, Smithsonian Institution , P. O. Box 37012, Washington, DC 20013-7012 , USA
3. Cornell Laboratory of Ornithology , 159 Sapsucker Woods Rd., Ithaca, New York 14850 , USA
4. Department of Biology, San Diego State University , San Diego, California 92182-4614 , USA
5. Museum of Vertebrate Zoology, 3101 Valley Life Sciences Building, University of California, Berkeley , California 94720-3160 , USA
6. 24 Idaho Street , Bishop, California 93514 , USA
7. Departamento de Biología Evolutiva, Facultad de Ciencias, Museo de Zoología, Universidad Nacional Autónoma de México , Apartado Postal 70-399, Ciudad de México , México
8. Escuela de Biología, Universidad de San Carlos de Guatemala , Ciudad de Guatemala , Guatemala
9. Florida Museum of Natural History, P. O. Box 117800, University of Florida , Gainesville, Florida 32611 , USA
10. Museum of Natural Science and Dept. Biological Sciences, Louisiana State University , Foster Hall 119, Baton Rouge, Louisiana 70803 , USA
11. Michigan State University Museum and Department of Integrative Biology , West Circle Drive, East Lansing, Michigan 48824-1045 , USA
12. University of Alaska Museum , 907 Yukon Drive, Fairbanks, Alaska 99775-6960 , USA