Greater Scaup

Greater Scaup (Aythya Marila) are the most marine and the most northerly of the Pochards. They are well adapted to the open sea, be it calm or rough. Easily confused with the similar Lesser Scaup, whose range is overlapped in America, they are larger and bulkier ducks, they exceed 2.5 pounds. Their bill is larger and broader, and the rounded, glossy, blackish head of males projects a greenish sheen that contrasts with the purple gloss of the smallest caup. The conspicuous white upperwing-bands are not restricted to the secondaries and extend well onto the primaries. Densely packed rafts of up to 50,000 Greater Scaup (Aythya Marila) may assemble on favorite marine foraging waters, hence they are commonly known as Raft or Troop Ducks. Feeding activity is dependent on tidal cycles, with the scaup moving back and forth with the tide. They habitually drift-feed by floating beyond productive foraging areas, only to fly back upcurrent to drift by again. Attracted to sewage outfalls that support extensive mussel beds in the shallows, Scottish Scaup formerly capitalized on the waste grain discharged from brewery and distillery outlets. Greater Scaup (Aythya Marila) seasonally prey on salmon and herring eggs, and even rotting salmon are not overlooked. Herring Gulls frequently purloin food from surfacing ducks, and submerged scaup are occasionally gulped down by predacious goose-fish. Much of their diet consists of bottom shellfish, including oysters, clams, scallops, mussels, whelks, periwinkles, barnacles and limpets. Hundreds and even thousands of Greater Scaup (Aythya Marila) often concentrate over mussel beds. The Ducks forage mostly by day, they move well out to sea if persecuted, returning to more productive inshore feeding waters at night. Drakes are inclined to winter farther north than their mates, resulting in some sexual segregation, thus courtship is more intense in the spring, when sexes come together in greater numbers. Rather compact island colonies of 50 or more pairs only several feet apart re not unusual, and the scaup commonly nest near gull and tern colonies. Ducklings are often reared on open water, where predation can be substantial. Broods may amalgamate. Juveniles gain their flight powers at about 1.5 months of age, with independence normally achieved prior to fledging.