In flight, green-wings twist and turn and flash by singly or in compact, erratic groups of five to 50 birds. Drakes have a low-pitched, rheeb call, and hens use a series of loud quacks. They travel in loose flocks with some pairing evident. Wingbeat is stiff and not very rapid. Their long neck and tail and greenish-brown speculum are distinctive features.
Drakes have a chocolate-colored head, white belly, and long, black tail.
Drakes whistle, and hens call with a series of quacks. Pintails are graceful fliers that are capable of high speeds. They have a green speculum. Both hens and drakes have an extensive white patch in front of the speculum. The bright white forewing, white belly, and white forehead are good distinguishing features of drakes.