I have placed below two images of what I consider to be a fairly straightforward female FERRUGINOUS DUCK present at Cockshoot Broad in Norfolk Broadland for the past week. I enjoyed excellent views of this bird at the weekend and noted all of its typical salient pointers. I am well versed at the likelihood and appearance of hybrids but this bird seemed 'typical' for me, with the less obvious duller white undertail coverts, dark mahogany plumage (including sides), classic head shape and size and dark bill.
I have since received emails from local watchers informing me that this is a long-staying 'hybrid' Ferruginous Duck which I must admit did surprise me, but I am posting the images here to see what others think.
There is a drake Ferruginous Duck nearby (at Ormesby Little Broad) that is exceptionally tame and is presumably a local escape and this bird does perhaps have some previous hybrid history as the head shape is not typical (although everything else is).
Likewise, there is what is being touted as a first-winter female Ferruginous Duck near Needham Market in Suffolk (see photographs in January Bird News of SuffolkBINS website), which again, apart from a few anomalies - very pale sides and much sky-blue in the bill - appears quite typical from the images.