Purple sandpiper
Calidris maritima    
Identification Tips:
-  Small shorebird                                                 
-  Medium-sized, thin, dark bill with yellow base
-  Yellow legs
-  Black patch on rump extending onto tail
-  Thin, white wing stripe
-  Sexes similar                                                                 
Adult alternate:                        
-  Dark gray streaked head
-  Pale indistinct supercilium with dark cheeks and crown
-  Black back feathers and wing coverts with thin white edges
-  Dark gray breast with dark streaks and spots extending onto white
underparts
Adult basic:                            
-  Dark gray head without darker streaks
-  Dark gray breast with streaks extending onto flanks
-  Very dark back with thin gray edges
Juvenile:                            
-  Similar to adult alternate
-  Black back feathers and wing coverts with neat white edges
-  Dark streaking on breast
Similar species:                        
This sandpiper is most likely to be found on rocks in coastal areas.  Other
small shorebirds are paler and lack the yellow legs and yellow-based bill.
In flight, turnstones and sanderlings have more white in the wings.