A couple weeks ago there was a tame flock of 16 eiders at Cape Spear. One of which was a female King Eider and offered me my best ever opportunity to study this species.
It was only 12 months ago that I wondered/worried about how easy it really is to pick out female King Eiders from a large flock of Common Eiders. Now that I've seen a grand total of 6 I've learned that it really isn't so difficult.
How quickly can you find the female King Eider (aka Queen Eider) in this photo:
The best thing to look for when scanning through a flock of eiders is to find the females/immatures that have paler heads and smaller darker bills. Both of which contrast with the rest of the body.
Once you've got a candidate lined up, take a closer look to see the size and shape of the bill and also look for the small white eyebrow which surprisingly is visible from a fair distance.
Male King Eiders are decidedly easier to pick out ;)
Note that there is quite a bit of variation in Common Eider plumages:
I would call the two left most eiders 1st winter males due to the yellow/bright bills and hint of white speckling on the breast.
The centre bird is quite pale and has a pale eyebrow. But the bill should be the give away that it is not a King Eider.
Did you notice the King Eider above?
The eider swimming away from the camera has a noticeably reddish tone. To me this means adult female. But something I should/need to explore further.
A close up of one of the 1st winter males. Looking at the shape of the base of the bill allows for sub-species identification. The two 'expected' sub-species here are borealis (East Arctic) and dresseri (Atlantic). The vast majority of Newfoundlands wintering eiders are borealis, which this one is.
Despite being somewhat regular, I always get a small burst of excitement when I see a King Eider.
Looks like she has a preference for starfish!
White-beaked Dolphins were swimming by that same day.