BirdForum is the net's largest birding community, dedicated to wild birds and birding, and is absolutely FREE! You are most welcome to register for an account, which allows you to take part in lively discussions in the forum, post your pictures in the gallery and more.
The subspecies are distinguishable by bill length, and intensity of colour of the summer plumage. Winter and juvenile plumage birds are often not reliably distinguishable to subspecies, with only bill length differing.
C. a. schinzii Summer adult. Dull; short-billed Photo by Helios North Uist, Scotland, June 2014
C. a. hudsonia Summer adult. Bright; long-billed Photo by bobsofpa On spring passage, Bombay Hook NWR, Delaware, USA, May 2016
C. a. arcticola Summer adult. Bright; long-billed Photo by peterday St. Paul Island, The Pribilofs, Alaska, July 2017
Breeds on low or high ground, in wet short-grass or tundra habitats; on migration (in autumn, adults in late July-August, juveniles in late August-October), found in a variety of marshy or coastal habitats, but most numerous on tidal flats or on banks of seaweed on shallow shores.