Drilling, Nancy E., Rodger D. Titman, and Frank McKinney. 2002. “Mallard (Anas platyrhynchos).” 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/mallar doi: 10.2173/bna.658