torsdag den 31. oktober 2013

'Sailed' Eiders with flags at half mast in Denmark

Maybe not surprisingly, but the more flocks of Eiders I scan through the more individuals I find with some degree of white scapular sails. When I began digging in to this subject I had the impression that presence of white sails was considered to be a guarantee of Arctic or Nearctic origin; however, on current knowledge there seem to be some degrees overlap in characters between borealis and mollissima including presence of white sails.

The five different individuals in this video only have rather small scapular sails and as such you could argue that they are 'Sailed' Eiders with flags at half mast. Unfortunately we do not know whether such individuals are true borealis – at least you’ll find similar individuals within borealis range; or they are migrants originating from a hybrid zone between borealis and mollissima and as such could be considered some kind of ‘subborealis’; or they are the result of a continues flow of genes from northern populations into south Scandinavian Eiders due to abmigration.

Maybe time will tell and until then I will keep searching for the full-rigged ‘Sailed’ Eider or the odd dresseri Northern Eider

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