This bird has less orange in the bill than have any of the other female Barrow's that I've photographed, but has more color, and a less sharp demarcation, than the typical Common. In fact its bill pattern closely matches Sibley's illustration of a female Barrow's. The bird was moving together with a male Barrow's Goldeneye. On the other hand, its head shape looks more like a Common, a forehead more rounded than steeply vertical. The bird could be a Barrow's/Common hybrid.