All illustrations by Mike Langman
1. Goldeneye Bucephala clangula (above)
40–48cm. Eclipse male is similar to female, developing a brown head, but retains traces of white at base of bill.
2. Mallard Anas platyrhynchos
50–60cm. Moulting male resembles female, but has an all-yellow bill and
a much more rufous chest.
3. Gadwall Anas strepera
46–56cm. Eclipse male looks like a small, greyish female mallard, but has a white speculum (wing flash).
4. Garganey Anas querquedula
37–41cm. A scarce summer visitor to UK. Eclipse male has a pale throat, dark cheek stripe and all-grey bill.
5. Teal Anas crecca
34–38cm. Easy to identify by its tiny size and green speculum (wing flash). Eclipse male near-identical to female.
6. Wigeon Anas penelope
42–50cm. A white forewing patch and bold chestnut tones separate the moulting male from the female.
7. Shoveler Anas clypeata
44–52cm. Unique bill confirms this species’ identity in all plumages; in eclipse, male is browner and plainer.
8. Tufted duck Aythya fuligula
40–47cm. In eclipse, male has just a hint of a crest, with dusky flanks and a brown tinge to black areas.
9. Pochard Aythya ferina
42–49cm. Male becomes drabber during eclipse, with a dull, mottled-grey (not glossy black) breast.
10. Red-breasted merganser Mergus serrator
52–58cm. One of two similar ‘sawbill’ ducks in UK; eclipse male looks like female, but with a white wing patch.
11. Goosander Mergus merganser
58–68cm. Larger than merganser, its close relative. White on wing helps separate moulting male from female.
12. Eider Somateria mollissima
60–70cm. Our largest sea duck. In eclipse, male is dark and mottled, with extensive white on wings.