Lesser Scaup

Aythya affinis

The more common of the two Scaup species to migrate through the state, as the Greater Scaup is generally more common along the coast.  Lesser Scaup can be differentiated from the Greater Scaup by differences in the general head shape.  Many books say there's a difference in the sheen of the head between the two, with the Greater Scaup supposedly having a greenish sheen, and the Lesser Scaup having a purplish sheen.   However, this is generally not a reliable way to differentiate between the two.

Habitat: Marshes, lakes, and rivers, either in forested or prairie settings. 

Diet: Omnivorous.  Includes large amount of animal matter such as insects, snails, and crustaceans, as well as plant material such as pondweeds and their seeds.

Behavior: Lesser Scaup are a diving duck, primarily foraging by diving below the surface of the water in search of food.  They will also sometimes feed at the water's surface, either by grabbing food items from the water's surface or by dipping their head and neck below the water.

Nesting: June through July

Breeding Map: Breeding bird survey map

Song: Low whistled whew from mating males.

Migration: Summers in parts of the western United States, and much of western and central Canada.  Winters along both U.S. coasts, in the southern U.S., and points south.

Similar Species: Greater Scaup, Ring-Necked Duck

Conservation Status: Widespread and common, with no discernible major trends in populations.

Further Information: 1) USGS Patuxent Bird Identification InfoCenter, Lesser Scaup

2) Cornell University's "All About Birds - Lesser Scaup"

Photo Information: March 26th, 2006 - Lake Vermillion, South Dakota - Terry Sohl

Additional Photos: Click on the image chips or text links below for additional, higher-resolution Lesser Scaup photos.