These hawks are named after William Swainson, a naturalist and talented artist from Great Britain. Swainson had drawn the hawks, which were included in the four-part Fauna Boreali-Americana in the early 19th century. Originally the hawks were given the Latin name Buteo vulgaris until Charles Lucien Bonaparte discovered it was a different species (and not a buzzard) and renamed them Buteo swainsoni to commemorate Mr. Swainson.