Common Eiders winter in good numbers around the Pribilof Islands. A winter survey revealed them to be the second most numerous wintering Eider, outnumbered 10 to 1 by King Eider. On most years the large Eider flocks are long gone by the time our tour season begins, but occasionally one or two Common Eiders hide amongst the King Eider flocks in May and early June. There is only one summer sighting, of a single bird in Antone Lake on July 1, 1999. The identification of male Eiders is straightforward (at least in spring), but to separate a female Common Eider from a flock of King Eiders requires more effort. Look for Common Eider’s larger size, paler overall color, well-defined vertical flank barring, and long straight bill with a noticeable hook on the end to rule out King Eider. All Pribilof sightings pertain to the Pacific subspecies of Common Eider,v-nigra, which is quite distinctive from the Atlantic form that most visiting birders may be more familiar with.