Canvasback
Aythya valisineria
It ranges from 48–56 cm (19–22 in) in length and weighs 862–1,588 g (1.900–3.501 lb), with a wingspan of 79–89 cm (31–35 in). It is the largest species in the genus Aythya, and the largest diving duck in North America. Canvasbacks are similar in size to a mallard but with a heavier and more compact build. 191 males wintering in western New York averaged 1,252 g (2.760 lb) and 54 females there averaged 1,154 g (2.544 lb). The canvasback has a distinctive wedge-shaped head and long graceful neck.
ID text from Wikipedia, CC BY-SA 4.0
Redhead
Aythya americana
The redhead is a pochard, a diving duck specially adapted to foraging underwater. Their legs are placed further back on the body, which makes walking on land difficult. The webbing on their feet is larger than dabbling ducks and their bills are broader to facilitate underwater foraging. In addition, pochards have a lobed hind toe. No pochard has a metallic colored speculum, something that is characteristic of other ducks. Voice: There is little information on redhead vocalizations outside of breeding calls. When the neck is fully extended in the neck-stretching display, males emit a cat-like wheee-oww. Males may also produce a soft coughing call, although this call is less frequent. Females emit a soft errrr note when inciting a male.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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