What key facial feature is present across several female eider species, including the Common Eider?

Answer

A pale patch around the face or throat area.

A crucial identification marker for several female eider species, such as the Common Eider, is the presence of a light-colored patch that appears around the face or throat, contrasting with their overall dark, barred plumage.

What key facial feature is present across several female eider species, including the Common Eider?
birdidentificationduckEider