Pierotti, Raymond J., and Thomas P. Good. 1994. “Herring Gull (Larus argentatus).” 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/hergul doi: 10.2173/bna.124