All Sanderlings?
I appreciate your help on this one: are these all Sanderlings? Photos were taken from May 7th to 16th on Sanibel Island, Florida. You can click on them to enlarge.
I am neither sure of the white-ish nor the brown-reddish ones. Thanks for your help!
Black-bellied Plover in the background.
Dreamfalcon 
They all look like Sanderlings to me – in various stages of plumage. Except the Black-bellied Plover which you already noted. I’m sure someone more knowledgeable could tell you the molt cycle and ages of the birds, but thats beyond my level of interest.
Thanks Greg for stopping bye and commenting. But why would they have all different stages of plumage in the same time and area? That I don’t understand, maybe someone can explain 🙂
Yes they are all but at different stage of plumage… The two last one are more like I see them here…. They tend to become reddish at breeding season… The first shots are more like winter plumage…. Beautiful pictures…