There were actually 5 Goosanders on the River Ely this morning. Four stayed their distance but this one, paddling alone, came over to investigate me.
I’ve been trying to work it out. I don’t think it’s a female – though they have reddish-brown heads, they’re more generally grey in the body, without so much black on their backs.
And it seems that in juvenile Goosanders the separation between the white throat and chin and the brown head is less clear cut, more ragged – in this bird it seems well defined.
So that leaves me with a male bird in eclipse plumage, i.e. still undergoing the change from its breeding plumage (of black-dark green head and upper neck) to its winter plumage, though that would usually be complete by now, I think.
Hence my confusion. If any experienced birders reader this, I would welcome your opinions (and explanations). Thanks!