More Birding at Cupsogue Suffolk County LI...

I made another run out to Cupsogue Long Island yesterday and ended up birding Pikes Beach before the sun did me in and I hightailed it to beat the banana line (traffic). Here is a photo to test your ID skills.

How many shorebirds are there in the picture above?  As you analyze the photo, think of size, structure and anything else that differentiate each species.