Hidden in plain sight

Little Birds are dining
Warily and well,
Hid in mossy cell:
Hid, I say, by waiters
Gorgeous in their gaiters -
I've a Tale to tell.                     Lewis Carroll
 

I think these sneaky little broad-daylight lurkers might be Turnstones - (unless any bona fide twitcher or birder cares to enlighten me further). Whatever they are, they have clearly developed the evolutionary advantage of looking exactly like the shoreline while they sneak a secret lunchtime snack