5 caught this summer
LTDU Long-tailed Duck, Clangula hyemalis (Linnaeus, 1758). Adult male, winter. Chesapeake Bay at North Beach, Calvert Co., Maryland, USA. Photo by David L. Govoni ©2013.
I'm interested in second opinions. I'm not confident in identifying greater scaups. Is the green sheen a reliable difference? Probably about 40 scaups seen within the vicinity of the marina.
About eight herons, huddling in the marsh together. Perhaps this is an overnight spot?
Mostly lesser scaups, with possibly an embedded greater scaup female?
This observation is for the female in the center of the image. I suspect she might be a greater scaup, because of the shape of the head without a conspicuous tuft and because of the amount of white at the base of the bill (compare to other females), but I'm not sure.