Oops, you are correct teircel. When I found the nest the only birds nearby were a pair of Dunlins and even though the eggs look slightly different as you'll know they can vary slightly from one area to another. After you posted there was a doubt in my mind so I went back up to see if I could spot the bird going onto or coming off the nest and sure enough it was a Common Sandpiper, seen the Dunlins again but they were only flying up and down the burn, Cheers.