The plumages are similar, but McKay's has more white and less black in the plumage, especially in the wings and tail. Adult breeding males of both species are mainly white with contrasting black on at least the wings, but are duller in winter.
Both plumages are similar, but McKay's has a higher proportion of white feathers and fewer black ones, especially in the wings and tail. Adult breeding males of both species are mostly white with contrasting black on their wings, although they appear less vibrant during the winter months.