Wader ID conundrums No. 1

Not much time out today. Two Little Gulls bathing in the burn near the car park were a bit unexpected - both immatures; a first-summer and a second-summer. Nice to see here at this time of year.

More perplexing were distant views of a wader feeding with a group of Dunlin & Ringed Plovers. Similar in size and jizz to the former, but not quite right - long winged and long legged, but long though I looked at it from 400m distant (as close as I could get), I couldn't turn it into anything more than a strange Dunlin in non-breeding plumage. But that one's going to nag away at me. Maybe I'll get better views at high tide tomorrow, if it hasn't buggered off...