These are the only images obtained of the female-type Harlequin
Duck at Lake Worth, Tarrant County, Texas on November 23, 2001; the bird flew fairly close past me at just-below eye level in a flock of Lesser Scaup, and I distinctly saw dark shiny-blue in the inner secondaries, whitish belly patch, and small white patches on the face:
the bird is the dark one that is the lowest, to the left:-
This version of the above image has the two right-most scaup transposed below the rest of the flock, in order to create a closer comaprison of all the birds:
A crop/enlargement of the top image (with first image repeated below it):
Here is another image - it is 3 or 4 birds from the left end, with short, pointed tail and both wings
raised :-
