Eurasian Wigeon

I found a female Eurasian Wigeon among a flock of American Wigeons at Westmoreland Park in Portland today. A male and female pair spent a large portion of the winter there last year.
Based on my National Geographic field guide, this is a rufous morph as gray morph females closely resemble American Wigeon females. My Sibley guide does not mention the rufous morph.
As the name implies, Eurasian Wigeons are native to both Europe and Asia, but it is not unusual for it to migrate down both coasts of North American, typically accompanying American Wigeons.