Comparative Behavior and Relationships of the Eiders

In my earlier paper several behavior patterns of the eiders were either unknown to me or were uncertain, and only general behavioral features of the sea ducks were discussed. Since that time I have obtained behavioral observations on all of the species of eiders. I have been able to make extended observations on captive specimens of the European race of the Common Eider (Somateria mollissimna mollissima), the King Eider (S. spectabilis), and the Steller Eider (Polysticta stelleri) at the Wildfowl Trust, and recently I observed the sexual behavior patterns of wild Spectacled Eiders (Somateria fischeri) near Igiak Bay, Alaska. These latter observations have provided important additional evidence relating to my earlier views on the relationships of the eiders and make it possible to conclude with greater certainty behavioral homologies and probable isolating mechanisms in the eiders and their nearest relatives. The nomenclature used in this paper follows that of Delacour (1959). Previous behavioral studies on the eiders have been relatively few. Hoogerheide (1950) described the behavior of the European race of the Common Eider in detail, and