Gould observed 'as spring approaches these white and light-grey birds change their plumage, and by April and May are richly coloured with marblings of red and black...'

Adult birds are depicted in winter, summer and autumn plumage.

DISTRIBUTION: Breeds northern Palaearctic and northern North America. Winters from west and south Europe, south Asia, Philippines, Hawaiian Islands, and coastal North America south to south Africa, islands in the Indian Ocean, Australia, Polynesia and south South America