Radically fast bird, quick on the wing, a true rocket of the north. In size, the male mostly closely resembles the ring-necked duck. Differentiating the two is possible on the wing but not easy -- ...

I examined the influence of age and time on female reproductive performance in a marked population of Lesser Scaup (Aythya affinis) breeding in southwestern Manitoba from 1977 to 1980. Arrival date ...

This week’s nature series features the Lesser Scaup, Aythya affinis, one of our most common diving ducks that is well known to hunters as the little bluebill or broadbill. This bird is common locally ...

Tens of thousands of migrating lesser scaup ducks have arrived on Mississippi River Pool 19. Located at Keokuk, Pool 19 is the spring migration’s most important stopover. Swarming northward from ...

They're out there right now off the shores of San Francisco Bay, sometimes rafting up in large groups to resist the wind, sometimes diving beneath the gray water to feed: big, handsome ducks with ...

The Auk, Vol. 121, No. 3 (Jul., 2004), pp. 917-929 (13 pages) The continental scaup population (Lesser [Aythya affinis] and Greater [A. marila] combined) has declined markedly since 1978. One ...