155363 Greater Scaup - Aythila marila - flock in flight. Bulky diving duck. Recalls Tufted Duck but has rounded head without tufted crown. Gregarious outside breeding season. In flight, has striking white wingbar. Sexes are dissimilar in other respects. Adult male has green-glossed head and dark breast (look black in poor light). Belly and flanks are white, back is grey and stern is black. Has yellow eye and dark-tipped grey bill. In eclipse, dark elements of plumage are buffish brown. Adult female has mainly brown plumage, palest and greyest on flanks and back. Note white patch at base of bill. Juvenile is similar to adult female but white on face is less striking. Voice Mostly silent. Status A few pairs breed but known best as local winter visitor, mostly to sheltered coasts.