Portuguese-ringed Lesser Scaup in Wales

Here Mark Waldron relates a quite exceptional resighting at Llangorse Lake in south Wales:

"On 17th October, scanning through a flock of 100 or so Tufted Duck that were feeding just off Llangasty car park, I came across a duck which had a bright orange or red nasal saddle. At first I was so concerned with reading the saddle that I hadn't taken much notice of what the duck actually was.

It