Hi. Went to a local pond/marshy area and noticed these birds so I grabbed a few shots (they weren't my initial intended subject). They reminded me of the Sandpipers I've seen at the beaches...looked them up and I think I have the ID correct. Yes/No?
They were quite a ways out - these are about 50% crops. I was maxed out at 500mm.
I think there's also a difference between winter and summer plumage.
I found that, too. Less color in winter and generally less spots. But the legs should not change color. My first reference was my trusty Birds of North America field guide published by Golden and illustrated by the renowned Arthur Singer. But I'm more inclined to trust Cornell. (...and yes, I am a trouble maker and proud of it. :))
The reference I used (it's at home) was by the Smithsonian. Maybe they had the older yellow legged sandpipers around back then...you know, antiquities and all. :-P