Super photo, Dörthe. I'm pretty sure this is a juvenile, since it has the brown plumage..

This is what I found in Wikipedia:
Adults are gray overall; during breeding, their plumage is usually much worn and stained, particularly in the migratory populations, and looks nearly ochre.[11]

So, these two I have watched now just arrived a couple of weeks ago and are going through their breeding stage.

Thanks for that information, Dörthe. I didn't know that.

You are welcome. I didn't know it myself, so you prompted me to find the information.