Not a great shot, but good comparison of the marked difference in the head shape of sleeping Greater and Lesser Scaup. Two sleeping male Lesser Scaup, with distinctly peaked, triangular heads surrounded by Greaters with much fuller, flatter heads. This is definitely the easiest way to differentiate Scaup. Note the difference in color of the two male Lessers, with the left bird showing a green gloss.

TVA Lake is probably the easiest, most reliable place in the state to see and study Scaup. The flock today was 130 birds, 75% of which were Greater. And of course a Scoter or Long-tailed Duck is always possible!