#sea_duck__seaduck  any of various large diving ducks found along the seacoast: eider; scoter; merganser
  supertype:  duck  small wild or domesticated web-footed broad-billed swimming bird usually having a depressed body and short legs
  subtype:  eider_duck__eiderduck  duck of the northern hemisphere much valued for the fine soft down of the females
  subtype:  scoter__scooter  large black diving duck of northern parts of the northern hemisphere
     subtype:  common_scoter__Melanitta_nigra  a variety of scoter
  subtype:  old_squaw__oldsquaw__oldwife__clangulahyemali  a common long-tailed sea duck of the northern parts of the United States
  subtype:  merganser__fish_duck__sawbill  large crested fish-eating diving duck having a slender hooked bill with serrated edges
     subtype:  goosander__Mergus_merganser  common merganser of Europe and North America
     subtype:  American_merganser__Mergus_merganser_americanus  common North American diving duck considered a variety of the European goosander
     subtype:  red-breasted_merganser__Mergus_serrator  widely distributed merganser of America and Europe
     subtype:  smew__Mergus_albellus  smallest merganser and most expert diver; found in northern Eurasia
     subtype:  hooded_merganser__hooded_sheldrake__Lophodytes_cucullatus  small North American duck with a high circular crest on the male's head

No statement uses or specializes sea_duck; click here to add one.