The epithet thula is possibly from a Mapudungun word for the black-necked swan (Cygnus melancoryphus), or possibly from Thule (“The northernmost location of the ancient world”), an allusion to the whiteness of snow in the region. The epithet was given by Chilean naturalist Juan Ignacio Molina (1740-1829) in his work Saggio sulla Storia Naturale del Chili (1782). See also Egretta.
- Gill, F. and Wright, M. (2006) Birds of the World: Recommended English Names, Princeton University Press, ISBN 978-0691128276
- 2014, The Scientific Nomenclature of Birds in the Upper Midwest. James Sandrock. p52.
- 1993, The Oxford Dictionary of British Bird Names. W. B. Lockwood.