Since the mid-1970s a minimum of 50,000 Oldsquaw have wintered in Nantucket Sound, Massachusetts. These birds fly to their feeding grounds on the Nantucket Shoals passing by Nantucket, Tuckernuck, and Muskeget Islands at dawn and dusk. During the 1988 Nantucket Christmas Bird Count over 178,000 Oldsquaw were counted in this area.
A long-tailed duck of cold northern waters. Often the most abundant bird in the high Arctic. Large flocks are often far out at sea; many spend the winter on such northern waters as Bering Sea, Hudson Bay, and Great Lakes. Flocks fly low over sea, with stiff shallow wingbeats, often tilting from side to side. Far more vocal than most ducks, and loud melodious calls of flocks can be heard from some distance.
Field MarksThis is the only sea duck combining much white on the body and unpatterned dark wings. It flies in bunched, irregular flocks. Male, winter: Note the needlelike tail, pied pattern, dark cheek; summer: dark, with white flanks and belly. Note the white eye patch. Female, winter: Dark unpatterned wings, white face with dark cheek spot; summer: similar, but darker. Immatures lack the long tail feathers.
SizeMale 21" (53 cm), female 16" (40 cm)
VoiceTalkative; a musical ow-owdle-ow, or owl-omelet.
RangeArctic, circumpolar. Winters to southern United States, central Europe, central Asia. Rare in winter within dash line.
MigrationMigrates relatively late in fall and early in spring. In travel over land, fly very high. Many migrate around coastlines rather than going overland; for example, huge numbers move north through the Bering Straits in spring.
HabitatOcean, large lakes; in summer, tundra pools and lakes. For breeding season favors both low-lying tundra and hilly areas, barren ground and edges of northern forest, as long as open water is nearby. At other seasons mostly on ocean, including far from shore among pack ice; also on Great Lakes and sometimes elsewhere on fresh water.
FeedingDiet: Mollusks, crustaceans, insects. Diet at sea mainly mollusks (including mussels, clams, periwinkles) and crustaceans (including amphipods and isopods); also a few small fish. In summer on breeding territory eats mostly aquatic insects, also crustaceans, mollusks, fish eggs, and some plant material including grasses and pondweeds.
Behavior: Forages by diving and swimming underwater, with wings partly opened but propelled mainly by feet. Most feeding is within 30' of surface; supposedly able to dive more than 200', deeper than any other duck.
NestingCourtship display begins by early winter, but most pair formation occurs in early spring. Displays of male include shaking head back and forth, raising long tail high in air, tossing head back with bill pointed up while calling.
Nest: Site is on dry ground close to water, often partly hidden under low growth or among rocks. Nest is a depression lined with available plant material and with large amount of down, the down being added after some eggs are laid.
Eggs: 6-8, sometimes 5-11. Olive-buff to olive-gray. Incubation by female, 24-29 days. Female covers eggs with down when leaving nest.
Young: Leave nest shortly after hatching, can swim and dive well when quite small. Young are tended by female, but feed themselves; may feed on items dislodged to surface by diving of female. Age at first flight about 35-40 days.
ConservationAbundant, with population in the millions. Dense concentrations are vulnerable to oil spills and other pollution in northern seas. Large numbers are sometimes caught and killed in fishing nets.