Marc, I was paying a lot of attention to all of the male goldeneyes as they
moved about, including under the bridge I was standing on. Because of the
full sun, I could see the sheen on most of the males and it seemed
consistently purple on all but this one male. He was consistently green.
I've been looking over about 50 photos, comparing the various males, and I
definitely think that there was something more going on than just light
angle. I think this guy has some Common Goldeneye genes, maybe several
generations back. However, I'll try to remain open-minded about lighting and
other kinds of variability. When I think about iridescent feathers, like the
gorget of a hummingbird or the speculum of a Mallard, I can recall the
variation in color that comes with light angle but I don't think that
variation goes very far outside a predictable range. To me, this male
goldeneye had a head color that was outside the normal range for the
Barrow's Goldeneye. But, I could be wrong.



Kelly