No interactions present.
Not so much coming into winter plumage as already there. Once they moult in the autumn, they are straight into the plumage they will keep through to the next autumn. This is a male and already has the black feathers on its head which will be its bright spring breeding plumage. Those feathers have pale tips though, at the moment; they will gradually wear away as the winter passes, eventually revealing the glossy black head at just the right time for breeding. Clever stuff!
My Flickr photos...
Wow, that sure is clever stuff - I never realised that the black head appeared due to the pale feather tips wearing away - amazing!
Lat/Lng: 0.9, 1.9