Sanderling

I'm certainly not doubting you. I've just struggled to understand/see the differences as I've looked at the couple of field guides that we have.

They are really tough to differentiate. I'm using Sibley's Guide to Birds which has the different plumages and I try to find the closest match. I could very easily have mis-IDed this one.

Great shot, love the reflection and leg pose. Question for you - how do you differentiate between the Sanderling and a Sand Piper? I think we have both over here on Atlantic coast and we're never quite sure which is which.