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
Ring-necked Duck
Aythya collaris
Ring-necked ducks are small to medium-sized diving ducks with the following length, weight, and wingspan measurements: Length: 15.3–18.1 in (39–46 cm) Weight: 17.3–32.1 oz (490–910 g) Wingspan: 24.4–24.8 in (62–63 cm) The adult male is similar in color pattern to the Eurasian tufted duck, its relative. Males are a little bit bigger than the female. It has two white rings surrounding its gray bill, a shiny black angular head, black back, white line on the wings, a white breast and yellow eyes.
ID text from Wikipedia, CC BY-SA 4.0

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Play today's Daily BirdPhotos and recordings are credited to their authors under the licence shown. Full profiles: Lesser Scaup and Ring-necked Duck.