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.
The plumage patterns are comparable, with McKay's having more white and less black compared to other species. Adult breeding males of both species exhibit a predominantly white appearance with contrasting black markings on their wings, though these colors may be duller in winter.