Except
for the wing marks, greater and lesser scaup appear
nearly identical in the field. The light band near
the trailing edges of the wings runs almost to the
tip in the greater scaup, but only about half way
in the lesser.
Greater
scaup prefer large open water areas; lesser scaup
often use marshes and ponds. Both species migrate
late, sometimes just before freezeup. Flock movements
are rapid, often erratic, usually in compact groups.
Hens are silent; drake lesser scaup purr; drake greater
scaup have a discordant scaup, scaup.
