Gowaty, Patricia A., and Jonathan H. Plissner. 2015. “Eastern Bluebird (Sialia sialis).” 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/easblu doi: 10.2173/bna.381