The Photos Of Roy Cunningham

This shot was taken at Leighton Moss yesterday, late in the afternoon and into the sun. I can’t make out the particular bird – assuming they are all the same – but I would guess at knot or dunlin. If anyone can tell me for definite(!), I’d be interested to know.
Camera: Canon EOS 5D Mk II w/ Canon 400mm f5.6L; Exposure: 1/3200th sec @ f18; ISO: 500