Long-billed Dowitcher

I had a surprise at Fernhill Wetlands the Saturday before last. Dabblers Marsh was filled with about 50 Long-billed Dowitchers. I very rarely see shorebirds other than Killdeers there. They were busy feeding and really didn't seem to care too much that I was watching them. In fact, they seemed to take their cues from the few Killdeers that were there. If a Killdeer let out some sharp calls, the Dowitchers would take off, flying in formation around the pond until deciding it was safe to resume feeding.
I slowly worked my way down one of the large tree trunks fallen into the water until I got pretty close to them, then waited while they slowly moved along the edges of the water towards me.
They were all in some state of molting to basic plumage, either from pre-basic juveniles or from alternate adults. I'm still not totally sure how you tell the difference, but I have some pretty good pictures here to do some studying. Interestingly enough, I've found that my National Geographic field guide actually does a more complete job of describing the different plumage states than my Sibley.