American Black Duck
Anas rubripes
The American black duck weighs 720–1,640 g (1.59–3.62 lb) and measures 54–59 cm (21–23 in) in length with a 88–95 cm (35–37 in) wingspan. This species has the highest mean body mass in the genus Anas, with a sample of 376 males averaging 1.4 kg (3.1 lb) and 176 females averaging 1.1 kg (2.4 lb), although its size is typically quite similar to that of the familiar mallard. The American black duck somewhat resembles the female mallard in coloration, although the black duck's plumage is darker.
ID text from Wikipedia, CC BY-SA 4.0
Northern Pintail
Anas acuta
The northern pintail is a fairly large duck with a wing chord of 23.6–28.2 cm (9.3–11.1 in) and wingspan of 80–95 cm (31–37 in). The male is 59–76 cm (23–30 in) in length and weighs 450–1,360 g (0.99–3.00 lb), and therefore is considerably larger than the female, which is 51–64 cm (20–25 in) long and weighs 454–1,135 g (1.001–2.502 lb). The northern pintail broadly overlaps in size with the similarly widespread mallard, but is more slender, elongated and gracile, with a relatively longer neck and (in males) a longer tail.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
Learn this pair in BeakBrain
Photo and call practice, free in any browser.
Play BeakBrainPhotos and recordings are credited to their authors under the licence shown. Full profiles: American Black Duck and Northern Pintail.