They fly swiftly in flocks of up to 20. They feed in shallow waters on seeds and vegetative parts of pondweeds and other water plants, and on insects, mollusks and other aquatic animals. Common migrants through Pennsylvania during spring and fall, ring-necked ducks breed across southern Canada and the northern United States. Some occasionally winter in Pennsylvania, but most go to the coasts, the southern states and Mexico. These two nearly identical species are 16 to 18 inches in length, and weigh 1 -2 pounds.
Males are black and white, females, brownish and white.
The bill is blue for both species. Greater scaup inhabit large bays, sounds and inlets of both coasts, and the Great Lakes. The lesser scaup is the one normally seen in Pennsylvania. It frequents the larger bodies of inland waters. Scaup eat mollusks, insects, crustaceans and aquatic plants.