This medium-sized sea duck occurs in northern latitudes along coastal Alaska and easternmost Russia, as well as in the Bering Sea. Although well known by people living in these sparsely populated regions, it is rarely seen outside its breeding and wintering ranges. Until recently, the locations of its primary molting and wintering areas were unknown. As a result of severely declining populations in western Alaska, and possible declining populations in easternmost Russia and northern Alaska, the Spectacled Eider was listed as Threatened under the U.S. Endangered Species Act in 1993.
There are 3 disjunct coastal breeding populations of Spectacled Eiders: 2 in Alaska and 1 in Russia. In the 1970s, more individuals nested in western Alaska than in arctic Russia and the remainder of Alaska. Currently (1993-1999), the Russian population is much larger than those in western and northern Alaska. Spectacled Eiders molt at sea, 2-45 kilometers from shore, north of 63°N. Their primary wintering area is in the Bering Sea south of St. Lawrence Island.
At sea, Spectacled Eiders feed on benthic invertebrates, primarily clams; on the breeding grounds, insects and insect larvae form the bulk of the diet. Birds arrive on breeding grounds paired in early spring. Males leave their mates within a few weeks and return to sea; females and young leave the breeding grounds in fall as ponds begin to freeze. Thus, adult males are at sea approximately 11 months a year, adult females 8-9 months. Most nonbreeding subadults probably remain at sea when 1 year old and first arrive at breeding areas as 2- or 3-year-olds. Spectacled Eiders are dispersed nesters over much of their range but are considered semicolonial at some locations.
The breeding biology of Spectacled Eiders is best known from studies in western Alaska and arctic Russia. Key studies on breeding biology include those by Kistchinski and Flint ( Kistchinski and Flint 1974 ), Kondratev and Zadorina ( Kondratev and Zadorina 1992 ), and Pearce et al. ( Pearce et al. 1998a ) in arctic Russia, and by Dau ( Dau 1974 , Dau 1976 ) and Grand and Flint ( Grand and Flint 1997 ) in western Alaska (Yukon-Kusko-kwim Delta). Studies in North America include those on survival by Flint and Grand ( Flint and Grand 1997 ) and Grand et al. ( Grand et al. 1998 ); on population status by Stehn et al. ( Stehn et al. 1993 ) and Ely et al. ( Ely et al. 1994 ); on lead and heavy-metal poisoning by Franson et al. ( Franson et al. 1995b , Franson et al. 1998 ) and Flint et al. ( Flint et al. 1997 ); on parasites by Dau ( Dau 1978 ) and Schiller ( Schiller 1954 , Schiller 1955b ); on migration by Bernard ( Bernard 1923 ); on foods at sea by Petersen et al. ( Petersen et al. 1998 ); on behavior by Allen and Allen ( Allen III and Allen 1982 ) and Johnsgard ( Johnsgard 1964a , Johnsgard 1964b ); and on seasonal movements and distribution by Buturlin ( Buturlin 1910 ), Dau and Kistchinski ( Dau and Kistchinski 1977 ), and Petersen et al. ( Petersen et al. 1995 , Petersen et al. 1999 ).
Historically, Spectacled Eiders were used in clothing and rugs and for food by native peoples ( Portenko 1981 ). Currently a few birds are taken in spring and autumn by hunters in western Alaska and at St. Lawrence Island, Alaska (C. Wentworth pers. comm.), and an unknown number are taken each year in arctic Russia and northern Alaska.