A few years ago, I wrote, “although male Hooded Mergansers are stunning, hens are ducks with unruly coiffures.” Perhaps I wrote in haste. This merganser hen that Erika and I found on Monday in eastern Northfield is quite a beauty in her own right. Assuming, of course, that this bird is a female. Sexes of Hooded Mergansers are hard to tell apart in their first fall. Eventually males’ eyes become yellow, while female eyes remain brown. By spring, males acquire their yellow eyes and striking plumage.