Marks, Jeffrey S., Dave L. Evans, and Denver W. Holt. 1994. “Long-eared Owl (Asio otus).” 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/loeowl doi: 10.2173/bna.133