This video from Canada says about itself:
White-rumped Sandpiper (feeding and preening)
White-rumped Sandpiper (Calidris fuscicollis, Vitgumpsnäppa) and Semipalmated Sandpiper (Calidris pusilla, Sandsnäppa), Tommy Thompson Park (Leslie Street Spit), Toronto, Ontario, Canada, 6 June 2010. Digiscoped with a Swarovski ATM-80 HD spotting scope and a Casio Exilim EX-Z750 snapshot camera using the Swarovski digital camera base (DCB) adapter.
From Rare Bird Network on Twitter in Britain today:
The white-rumped sandpiper is in capital letters, being a North American bird, rare in Europe.