Dudley Carlson confirms: "I think all of your goldfinches are Lesser. The chief mark of distinction is the greenish head and back, and on the males the cap comes back and down farther over the head than in the American. My only quibble would be on gender on a few; I think #4, 5,and 6 are probably male (amount of dark on head); 19 is probably male; 34 male, 35 female. 40 Could be either; the shadow on the head camouflages the cap, so I can't tell."