Common Eider Somateria mollissima
In the UK at least, more commonly known simply as Eider.
Common Eiders, Farne Islands (Northumberland, UK), 13th May 2004
Common Eiders, Forvie Sands, Amble (Northumberland, UK), 19th March 2014
Common Eiders, Seahouses (Northumberland, UK), 5th Febaruary 2023
Common Eiders, Forvie Sands, Ythan Estuary (South Ayrshire, UK), 1st June 2015
Common Eiders, Boddam (Aberdeenshire, UK), 18th March 2014
Common Eiders, Buckie (Moray, UK), 17th March 2014
Common Eider, Burnham Overy (Norfolk, UK), 30th November 2013
Common Eider, Peterhead Harbour (Aberdeenshire, UK), 3rd January 2002
Common Eiders, Seahouses (Northumberland, UK), 13th May 2004
Common Eiders, Scrabster Harbour (Highland, UK), 25th February 2012
Common Eider, Snettisham (Norfolk, UK), 30th September 2015
Common Eiders, Girvan (South Ayrshire, UK), 28th December 2005
Common Eider, Loch Fleet (Highland, UK), 24th February 2012
Common Eiders, St Andrews (Fife, UK), 27th December 2010
Common Eiders, Troon Harbour (South Ayrshire, UK), 28th December 2005
Common Eider, Forvie Sands, Ythan Estuary (South Ayrshire, UK), 18th March 2014
Common Eider, Embo (Highland, UK), 24th February 2012
Common Eiders, Kinnaird Head (Aberdeenshire, UK), 18th March 2014
Common Eider, Montrose (Angus, UK), 30th December 2013
7x Common Eiders (right, with 6x Common Scoters left), Sheringham (Norfolk, UK), 1st November 2016
Flocks of Eider migrating past coastal headlands often fly higher than most other ducks...
Common Eiders, Sheringham (Norfolk, UK), 21st October 2019
...but not always...
Common Eiders, Sheringham (Norfolk, UK), 9th October 2010
Common Eiders, Sheringham (Norfolk, UK), 25th September 2003
Common Eider, Sheringham (Norfolk, UK), 13th May 2006
Common Eider, Forvie Sands, Ythan Estuary (South Ayrshire, UK), 15th October 2003
This species is sometimes found in wildfowl collections and the following were in captivity (at least they were in wildfowl collections - some certainly belonged there but I suppose it's possible that others involved wild birds that were visiting the collections).
captive Common Eiders, Grange-over-Sands collection (Cumbria, UK), 28th December 2011
captive Common Eiders, Grange-over-Sands collection (Cumbria, UK), 27th December 2012
2x captive Common Eiders, Blakeney qyayside collection (Norfolk, UK), 26th October 2016
captive Common Eider, Blakeney qyayside collection (Norfolk, UK), 3rd December 2016
captive Common Eider, Blakeney qyayside collection (Norfolk, UK), 21st February 2017
captive Common Eider, Blakeney qyayside collection (Norfolk, UK), 24th September 2018
captive Common Eider, Blakeney qyayside collection (Norfolk, UK), 27th October 2018
captive Common Eider, Blakeney qyayside collection (Norfolk, UK), 17th March 2019