Unusual Blackbird

 

A ringing session on Leith Hill on Tuesday was relatively quiet but turned up this unusual Blackbird.  It is obvious by its active moult that it is a first calendar year bird, still showing some juvenile plumage in its body, tail, flight feathers, primary coverts and greater coverts.  Its all black bill is also a sign of a first year bird.

What is unusual is its new adult plumage colour which although is definitely a male has a far more grey than black colouration and the breast feathers are also heavily scalloped with a very pale fringe.  All these features seem to point to this bird being more reminiscent of the continental subspecies sometimes known as 'stockamsel'.  Any comments welcome?