I saw the duck this morning and it showed very well with Tufted Ducks It doesn't show any signs of a small tuft at the back of it head.I thought it could be a hybrid Scaup /Tufted Duck.There's a drawing of female hybrid Scaup/Tufted in the Colins field guide which looks very like the duck in the pic.
I know what you mean about Tufted ducks can hide there tufts.But this bird was showing very well when i saw today.It was swimming about with other tufted and it didn't show any sign of a tuft.Also i saw it feeding.To me the head shape look more scaup like.Whilst I can't rule out the possibility of this being a hybrid, I suspect that it isn't. The white around the bill is within range for Tufted Duck. Tufted Ducks can be good at hiding their tufts, especially when feeding - head structure looks fine for Tufted Duck to me. Everything else seems spot on for Tufty and there aren't any Scaup features like grey on the flanks/mantle. Given the relative scarcity of Scaup hybrids and the lack of any convincing pointers that way I'd be comfortable calling it a Tufted Duck.
To me your duck looks like Scaup it has a massive billWe have been having a similar problem with a Scaup/Tufty duck in Shropshire, this was taken today. I think the jury both on here and local to the bird are leaning slightly more towards a scaup.
http://www.birdforum.net/showthread.php?t=164501
Although yours Scuzz, has got that tufty evil eye!!
Roger
Would also tend to a agree that it looks "scaup-like". As stated it can't be a pure Scaup because it doesn't have the black nail restricted to the tip. Aythya hybrids can be a worrying nightmare. My feelings are that it is a hybrid, also from what you've described. Big white blaze, rounded head, Tufted type bill. Possibly a Scaup X Tufted.
We have been having a similar problem with a Scaup/Tufty duck in Shropshire, this was taken today. I think the jury both on here and local to the bird are leaning slightly more towards a scaup.
http://www.birdforum.net/showthread.php?t=164501
Although yours Scuzz, has got that tufty evil eye!!
Roger