The young Greater Yellowlegs do not have a uniformely dark bill as the adults do. Instead they can have a considerably lighter base. I didn't really ralize this until I saw this bird with the early morning light on it. As I passed it I did a doubletake wondering what the yellowbilled bird would be (thinking that godwits have light bases to their bills), and I backed up to check it out. I could see that it was a Greater Yellowlegs and decided to take this shot for my collection of different ages etc. I'm surprised that I don't recall ever seeing this before. Interesting variation!