Greater Scaup (Aythya marila)

The Greater Scaup nests farther north than the other diving ducks of the genus Aythya, inhabiting freshwater lakes, large and small within the tundra zone and on its fringes. It also differs by having a very different winter habitat: while the rest are freshwater birds, the Scaup is very largely coastal. So, apart from the relatively few individual birds that wander to large inland lakes in the non-breeding season, the Scaup does not cross paths with the Pochard or Tufted Duck very often.

Scaups are quite fussy about their wintering sites, tending to concentrate in large numbers at relatively few favoured locations. Here flocks of hundreds or even thousands may collect, feeding on productive mussel beds or near sewage outfalls with high concentrations of worms. Being diving ducks and bottom feeders, their feeding times are dictated by the tide. They don’t like to dive too deep, only to 5-6m, so at high tide they often simply roost or loaf. In many areas they also prefer to feed at night.

The nest of a Greater Scaup is usually well hidden in low vegetation, placed very close to water. When they hatch young Scaup are less independent than, for example, Tufted Ducks, and the mother – and occasionally even the father too – usually accompanies them all the way to the flying stage.