How to Identify a Canvasback (Aythya valisineria)

• Head pattern: Male and Female: long sloping 'ski-jump' profile of the head and bill is distinctive among diving ducks
• Flight silhouette: Male and Female: slender appearance with a sloped forehead and relatively deep wing strokes in flight
• Head pattern: Male: chestnut-red head, black bill, black breast, white back and wings
• Head pattern: Female: pale tan head and neck, dark bill, grayish body, drab brown with mottled plumage
• Bill: Male and Female: black bill in males, dark bill in females, both long and merging smoothly with the sloped forehead

Male Redhead has a steeper (not sloped) forehead, a bluish-gray bill with a white saddle and dark tip, and a yellow-gold iris, versus the Canvasback's sloped forehead, black bill, and red iris; female Canvasback is darker than female Redhead and lacks the pale bill saddle The Redhead page lists its own marks.

Greater Scaup shows a rounder, larger head, a wider bill, and a white wing stripe extending into the primary feathers, unlike the Canvasback's sloped head profile The Greater Scaup page lists its own marks.

Lakes, salt bays, estuaries; fresh marshes in summer; winters mainly near the coast on protected bays and estuaries, also on interior lakes Breeds across Alaska, western Canada, and the northern Plains prairie pothole region; winters across the coasts and interior lakes of the US

Redheads often lay their eggs in Canvasback nests (brood parasitism)

Shoot from water level if you can, with the sun behind you, so head pattern and the wing patch show their true colors. Get one frame with the bird side-on and one as it stretches or flaps, which exposes the speculum and belly. Note who it is swimming with; ducks flock by species. The app names the likely species; confirm with the marks above, and check the female separately, since females of many ducks look alike.