The bird in question is on the left, with two Common Goldeneye to its right. You can see more extensive black on the back as compared to them and what looks like a somewhat smaller version of the distinctive Barrow's black spur. At the time, I thought the white spots in the black were larger than usual for a Barrow's, and the spur did not extend as far as the other pure Barrow's. Those marks seemed like a balanced mix of the two species. The spot on the face looked more like that - a rounded spot - rather than a crescent of a Barrow's. While I note these marks now, I realize they are tough to see in the photo beyond saying this bird is at the very least a Barrow's Goldeneye. The hybrid evidence in the photo primarily comes from the head.
I thought the head appeared to be brown, or maroon, as opposed to a purple pure Barrow's. That can be seen relatively well in the photo. You can clearly see the green sheen of the Common Goldeneye, and while it may appear purpler or browner to you or on your monitor, I do not think it looks like a perfect Barrow's head for anyone. I sought the opinion of two experts - Charlie Barnard and Frank Mantlik - and both feel relatively good about it being a hybrid with the obvious caveat they are looking at just one poor photo. Charlie noted most of the marks I mentioned and added that the head of the bird is sloped, and not flat, like a Common. However, it definitely looks like it has a long and puffy mane, just as a Barrow's does. I think that describes it very well. Frank agreed on both the head shape and the color looking relatively good for being a hybrid.
The Sibley Guide to Birds has an excellent depiction of everything I noted in the hybrid Barrow's X Common Goldeneye on the page for the two species. I also found a photo that I feel is relatively close to my bird (scroll down a bit): http://www.birdfellow.com/journal/2009/03/03/getting_lucky_a_primer_on_finding_rare_birds
The head and back are nearly perfectly on target. The spot on the face is larger on mine, though of the same general shape. The spur on mine does extend further down but it did not appear quite large enough for a pure Barrow's, and considering everything I think it could vary a bit. Therefore, I now feel very certain this was indeed a hybrid Barrow's X Common Goldeneye. This is one of those can't miss situations in that if I am wrong and subsequent sightings or opinions help to prove otherwise then it would "only" be another Barrow's Goldeneye. You have to love that.
The strong wind and rough waves at the time did not my examination of the ducks. Only a few minutes after finding these guys a helicopter flew low right over them before landing at Sikorsky Airport, which flushed every duck in that area. They flew off towards the mouth of the Housatonic and out of my sight at the time. No one was going to be able to run down there and see them when I found them, and it may be difficult whenever. For example, Twan also did a complete survey yesterday morning but had no goldeneye of any kind. Nevertheless, there is a decent chance one or both could stick around for a while for others to see.
Please bear in mind that the property, like any other in Connecticut, is covered in feet of snow encased by ice. Snowshoes are an absolute necessity if you want to get out of your car safely. The ever-present strong wind also means we have a lot of drifts, so while certain areas are only covered in a few inches, cracking through that ice in some places may leave you stuck in snow up to your chest (as has happened to me multiple times). It has been a harsh winter, but I sure have enjoyed finding a constant supply of great ducks off Stratford Point during our waterfowl survey work.
Photo © Scott Kruitbosch