The Tufted Duck is a Eurasian species but it commonly nests in Iceland. It is an irregular visitor to Nova Scotia and can be considered rare.
They hybridize with Greater Scaup and telling the difference can be challenging.
We had one last year so this example could be the same bird that never left the Nova Scotia area.
Tufted Duck or Hybrid Greater Scaup/Tufted Duck
Tufted Duck with Lesser Scaup
