1. U.S. Geological Survey; Alaska Science Center; 250 Egan Drive Juneau AK 99801 USA
2. Am Fügsee 29 D-82418 Seehausen am Staffelsee Germany
3. Max Planck Institute for Ornithology; Am Obstberg 1 78315 Radolfzell Germany
4. North Carolina Museum of Natural Sciences; 11 West Jones St Raleigh NC 27601 USA
5. Fisheries, Wildlife, and Conservation Biology Program; NC State University; Raleigh NC 27695 USA
6. Biology; University of Konstanz; Dj-78464 Konstanz Germany
7. Department of Civil, Environmental & Geodetic Engineering; The Ohio State University; Columbus OH 43210 USA