These are the Prince 'n Princess King Eiders present at Cape Spear. In the following pictures note the following features. The male is an immature, hatched in the summer of 2017. The broad orange lobes of the upper bill where it meets the forehead makes an immature King Eider stand out in an eider flock. The gray breast gradually turns white through the winter.
Female King Eiders are less obvious but are pretty easy to pick out when you know what their trademarks are. 1) bill is largely gray including tip but there is often a pale ring around bill just before the nail. 2) there is usually a pale spot of feathering next to the base of the bill. This contrasts with the dark gray bill. At close range there is an upturn at the corner of the mouth (gape) creating a 'grin' expression which is characteristic of King Eider. 3) Note the pale eye shadow on the eye lids. This is especially evident in the female. Nothing so obvious on Common Eiders 4) Both male and female King Eiders have a slight bump on the ridge line of the bill. It is more pronounced on the male. This contrasts with the long straight sloping bill (like a doorstop) of the Common Eider.
There is at least one King Eider in each of the following pictures. Can you pick them all out?