At Sea Distribution of Spectacled Eiders: A 120-Year-Old Mystery Resolved
ABSTRACT.-The at-sea distribution of the threatened Spectacled Eider (Somateria fischeri) has
remained largely undocumented. We identified migration corridors, staging and molting areas, and
wintering areas of adult Spectacled Eiders using implanted satellite transmitters in birds from
each of the three extant breeding grounds (North Slope and Yukon-Kuskokwim Delta in Alaska and
arctic Russia). Based on transmitter locations, we conducted aerial sur veys to provide visual