They float deeper and more level than the dabblers. Because their legs are so far back, they sit more upright. Perhaps the best known diving duck, at least in the United States, is the Canvasback. All waterfowl share certain characteristics. Most waterfowl can be identified by a view of just the head and the bill.
Many birds have distinctive stripes or colored patches on the head.
If the eye is large, the bird probably feeds at night or lives in the shade. The shape of the bill is very distinctive in waterfowl, and can give you clues as to what types of food they eat. The bill has two parts, an upper and a lower mandible. Not true teeth made out of bone. Some waterfowl, the merganser for example, have tooth-like notches on the sides of their beaks.