Long-tailed duck (Clangula hyemalis) Exton Devon

There was a  female Long-tailed duck (Clangula hyemalis) on the  Exe Estuary today. It is highly unusual that a bird that breeds in the Arctic north specifically, circumpolar,  on the Arctic coasts of  Europe (Iceland and Norway), and Asia (Russia) North America (Canada, Alaska, USA and Greenland).  There is no explanation for one  seen here in Devon today right in the middle of the European summer. I took some photographs of the bird that was fishing in the shallow tidal waters right in front of Exton Station on the Avocet Line.  This is a pretty little duck and a massive rarity in the south of England at this time of the year.