Tringa semipalmata

The willet (Tringa semipalmata), formerly in the monotypic genus Catoptrophorus as Catoptrophorus semipalmatus, is a large shorebird in the Scolopacidae family. It is a relatively large and robust sandpiper, and is the largest of the species called 'shanks' in the genus Tringa. Its closest relative is the lesser yellowlegs, a much smaller bird with a very different appearance apart from the fine, clear, and dense pattern of the neck, which both species show in breeding plumage. It breeds in North America and the West Indies and winters in southern North America, Central America, the West Indies and South America. The willet was formerly regarded as being in the monotypic genus Catoptrophorus but recent studies indicate that it is better placed with the 'shanks' of the genus Tringa. It has been suggested that the two subspecies be treated as separate species as there are clear differences in distribution, behavior, morphology and genetics but this has yet to be widely adopted.