Distinguishing Characteristics

Medium-sized diving duck. Total length, early spring mass: males 45–51 cm, 1000 g; females 40–50 cm, 800 g. Compact, “chunky” appearance with short neck and round body; short, gray-black bill. Adult sexes strongly dimorphic in size and plumage most of year. Breeding males have striking pattern of iridescent greenish-black head with bright, oval white patch at hind base of bill; brilliant white sides, breast, belly, and secondaries contrast with black back, wings, and tail. Females have chocolate brown head; slaty gray back, wings, and tail; and white flanks, belly, and breast. Immature and eclipse males are difficult to distinguish from females. Both sexes have bright amber irides (hence the name “goldeneye”); irides are more brownish in young. Wingbeat is rapid with a relatively deep arc; produces distinctive “whistle.”

Adult male may be confused with male Barrow’s Goldeneye (Bucephala islandica) but Common Goldeneye has oval rather than crescent white patch on head, more white on secondaries, and head more peaked with a longer, sloped bill. Females are easily confused; Common Goldeneye hen has a longer, more sloped forehead and bill and more white secondaries (5–8 pure white) than does female Barrow’s Goldeneye (0–4 pure white secondaries; JME). Female Barrow’s Goldeneyein w. North America typically has all-yellow bill, but in eastern population bill is usually black with yellow tip (as in Common Goldeneye); female Common Goldeneye rarely has all-yellow bill.

Common Goldeneye hatchlings are similar to those of Barrow’s Goldeneye and Bufflehead (B. albeola). Bare parts of some Common Goldeneyes hatchlings are paler and grayer or bluer in hue than in Barrow’s Goldeneyes. Common Goldeneyes also always lack dorsal spot that exists on some Barrow’s Goldeneyes. Common Goldeneye and Bufflehead hatchlings also can be identified in all cases in the hand by differences in the ratio of the width of the nail (on tip of bill) divided by the distance between the anterior corners on the nostrils (Fjeldså 1977) or by the length of the nail multiplied by the width of the nail , the product divided by the width of the bill at the posterior end of the nail (Nelson 1993). Compared to Common Goldeneyes, Buffleheads often have a less well-defined breast band, are smaller (Palmer 1976b), have a squarish white cheek-patch lobed well above the ear, and have neutral gray feet rather than contrastingly patterned bluish or greenish feet (see Appearance: bare parts) (Palmer 1976b, Nelson 1993). Buffleheads also have a smaller nail area relative to bill size (Linsdale 1933) and do not undergo the relatively rapid and dramatic changes in eye color with age exhibited by both goldeneye species (Nelson 1983).

Regarding discrimination of Common Goldeneyes from Barrow’s Goldeneyes, and aging and sexing of Common Goldeneyes, see Tobish 1986, Carney 1983, 1993, and Nelson 1983, 1992, 1993 .