Disappearance of the Steller's Eider from the Yukon-Kuskokwim Delta, Alaska

The Steller's eider (Polysticta stellen) is apparently extinct as a breeding bird on the Yukon-Kuskokwim (Y-K) delta, one of two areas in Alaska where it was a regular breeder. Once considered a common breeding bird on the Y-K delta, it has not been found nesting since 1975, despite recent extensive geographic coverage of waterfowl habitats and ground searches of historically important nesting areas. The Y-K delta was the only known subarctic breeding area in the species' range. Size of the former population and reasons for its disappearance are unclear, but possible factors responsible for the decline include changes in patterns of movement and increased mortality resulting from overharvest, predation, habitat change, weather, and reduction in food. The Steller's eider is now considered a rare species in the Yakutsk Republic, U.S.S.R., the center of the world breeding range. The North American population is now restricted to a small geographical area near Barrow and it has not yet received special consideration or protection comparable to that in the U.S.S.R. Because most of the world population breeds in the U.S.S.R. and winters in Alaska, effective conservation of the species will require cooperation at the international level.