Artuso, Christian, C. Stuart Houston, Dwight G. Smith, and Christoph Rohner. 2013. “Great Horned Owl (Bubo virginianus).” The Birds of North America, edited by Paul G. Rodewald. Ithaca: Cornell Lab of Ornithology. Retrieved from the Birds of North America: https://birdsna.org/Species-Account/bna/species/grhowl doi: 10.2173/bna.372