Adult male Common Eider with brown neck -- Parker River NWR, MA, USA -- 11.19.22 (1 Viewer)

[willkirby]

This Common Eider has all the features of an adult male, except a reddish brown lower neck and shoulders. Unless it is a hybrid the species seems clear cut to me, but curious if anyone can comment on whether this is just a plumage I'm unfamiliar with, an unusual subspecies (Dresser's would be expected here, and anything else quite rare, I think), a hybrid, an intersex bird, or something else I haven't thought of. Thanks in advance for any ideas!

 

[Butty]

Common eider - presumably immature and/or moulting. They come in all sorts of patterns - and the sun is low so will be causing warm coloration.