As I have mentioned before, many female ducks are a dull, mottled brown color and difficult to tell apart, at least on first glance. Then there are the ducks, such as the Barrow’s and common goldeneyes, where the two species look almost the same to the casual eye. If a male and female pair are observed together, the field identification becomes a little easier. However, even when males and females are present, sometimes, such as in mixed flocks of ducks, determining which ducks are pairs can be a challenge. I love reading mysteries, so I approach separating similar female (or even male) ducks as a puzzle rather than a frustration.
I mentioned last week that the Barrow’s goldeneye (Bucephalia islandica) female looked almost the same as a female common goldeneye (Bucephala clangula). The females of both these goldeneye species have chocolate brown heads, grey backs, wings and tails, white breasts, bellies and flanks, yellow eyes and black bills with yellow tips. The main difference that guides mention? Common goldeneye females have more rounded heads and longer bills! Sure!! I am not adept enough to determine that in the field. One thing I have noticed though is that the common goldeneye female swims with her head more erect and the white neck collar is more visible. The Barrow’s goldeneye seems to swim with its head closer to its body. But to be certain, I usually also look for a male.
To further confuse the situation, both species will hybridize, although this hybridization is more common in the East.
Although the Barrow’s goldeneye has a more restricted range, the common goldeneye can be found in the winter throughout most of the United States where there is open water. The common goldeneye spends the breeding season in Alaska, northern Montana, and across Canada. Common goldeneyes are also found in Scandinavia and northern Russia. In parts of Scotland and Great Britain common goldeneyes have been introduced.
The females of both goldeneye species are also alike in their behavior. Like the Barrow’s, the common goldeneye female will lay her eggs in the nest of another goldeneye of either species or in the nest of any other duck that uses a tree hole for its nest. The common goldeneye female will often abandon her nest soon after the chicks hatch. Fortunately the chicks are independent and can care for themselves so will join the brood of another female.
These females were on a pond at Crystal Lake Fish Hatchery (Shasta County CA). The males were with them and did help confirm their identity.