Lesser
Scaup
Aythya affinis

Male
Female
Description 15-18"
(38-46 cm). Male has very light gray body, blackish chest, and black-appearing
head. Similar to the Greater Scaup, but crown is higher and forehead steeper,
giving the head a more angular appearance. Head of male glossed with purple, not
green. Female dark brown with a small white face patch; not easily
distinguishable from female Greater Scaup. In flight, white stripe is shorter
than that of the Greater Scaup, which extends three-fourths of the wing's
length.
Voice Seldom
heard; sharp whistles and guttural scolding notes.
Habitat Ponds
and marshes; during migration and in winter it occurs on lakes, rivers, and
ponds, and in the southern states on salt water.
Nesting Usually
9-12 dark olive-buff eggs in a down-lined cup of grass hidden in vegetation,
often located some distance from the edge of the water.
Range Breeds
from interior Alaska and northern Canada south to Colorado and Iowa;
occasionally farther east. Winters regularly along coasts south from British
Columbia and Massachusetts to Gulf of Mexico; also inland south of Colorado and
Great Lakes.
Discussion Both
the Lesser and Greater scaup are popularly called "Bluebills."
Confined to the New World, the Lesser Scaup is thought to be descended from an
earlier invasion of North America by the ancestor of both modern species of
scaup. Here it evolved into a distinct species, to be joined later by a second
arrival, the Greater Scaup, found in both hemispheres. In the northern states,
where the Greater Scaup is more common in winter, the Lesser is often found in
small parties on fresh water, while in the South it is seen in large flocks on
lakes and salt water.
Seasonal Distribution
| Notes | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| AAA | AAA | AAA | ACC | F | FF | AAA | AAA | AAA |