Alan and Elaine Wilson are outstanding nature and bird photographers from Canada, that are happy to share their work. They recently posted some bird photos taken at Barrow, Alaska (as far north as you can go in Alaska).
Eiders are large ducks that nest in northern Alaska and Canada and are rarely seen outside their nesting grounds, which means they are rarely seen unless you make a big effort, like taking a trip to Barrow.
Eiders also exhibit a high degree of sexual dimorphism.
Male King Eiders
Female King Eider
Male Spectacled Eider
Female Spectacled Eider
Male Steller's Eider. Wonder if this guy is the origin of the phrase "odd duck?"
Enjoy more of their great photos on their web site.
http://www.naturespicsonline.com/galleries/91