Little Mama Swan had come up to say 'hello' and tugged out 2 of her wing feathers as I stood there, almost as if she were making a gift of them - there was one base feather, and one covert -- I couldn't believe my eyes on measuring it.... EIGHTEEN INCHES! It's too long to fit into the book (I'm making up a page of all the different kinds of swan feathers) so I took a picture of it beside the ruler. It's curved upward, and wouldn't lie flat, or it would show exactly 18" - Amazing, aren't they?!