Lesser Scaup
Aythya affinis
Adults are 38–48 cm (15–19 in) long, 41.7–43 cm (16.4–16.9 in) on average. The species can weigh 454–1,089 g (1.001–2.401 lb); males weigh 820 g (1.81 lb) on average while females weigh noticeably less, at 730 g (1.61 lb) on average. Wing lengths (not wingspans) are about 7.5–7.9 in (19–20 cm) in males and 7.3–7.8 in (19–20 cm) in females. The tarsus is about 1.4–1.5 in (3.6–3.8 cm) long, and the bill is 1.4–1.7 in (3.6–4.3 cm). The wingspan is 68–78 cm (27–31 in).
ID text from Wikipedia, CC BY-SA 4.0
Tufted Duck
Aythya fuligula
The adult male is all black except for white flanks and a blue-grey bill with golden yellow eyes, along with a thin crest on the back of the head. It has a prominent tuft on its head, which gives the species its name. The adult female is brown with lighter flanks, and is more easily confused with other diving ducks. In particular, some have white around the base of the bill, resembling the scaup species, although the white is never as extensive as that of those ducks. The female's call is a harsh, growling "karr", usually given in flight.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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