Is it safe to assume any ducks I see around Seattle that look like female
Mallards with yellow bills are American Black Ducks? So often when they are
swimming or walking they have their scapulars hidden (and I have a hard time
telling a flash of blue from a flash of purple, anyway). What color are the
bills of juvenile Mallards? What if such a duck is light in body
coloration -- would that be a hybrid?

Thanks in advance,

-Kevin Moore
Seattle, WA
bush-is-so-dumb at home.com