I had an opportunity today to visit Connaught Water in Epping Forest (Essex) to see the North American Green-winged Teal that had been present there for several weeks. On my arrival, it was one of 19 Teals present on the lake and was paired up with a female Teal on one of the wooded islands and roosting. I must admit that on seeing it, I was very unimpressed - it shouted 'hybrid' to me.
On one side of its body, the vertical stripe was pale buff coloured - the same colour of the breast - and on the other side white - but this was very restricted in length and nothing like as obvious and bright as a typical carolinensis. Furthermore, it had an obvious pale border to the deep green facial mask
The bird is very reminiscent of a drake once present at Chew Valley Lake in Avon and in my opinion is a hybrid, although as David Bradnum exclaimed to me on the phone, not an obvious one.
Arguments have been put forward to it being a first-summer drake and hence its appearance but I see no evidence of this and as far as I know, neither Common or Green-winged Teal can be safely aged in the field post-October
I have attached a selection of David Bradnum's excellent images below for your perusal
Intriguingly, Lothian birder Mike Thrower sent me some superb images of a drake Green-winged Teal that has been present all winter at Caerlaverock WWT that had been questioned by some observers; however for me this is a fairly typical carolinensis.
What do others think?