McGraw, Kevin J., and Alex L. Middleton. 2009. “American Goldfinch (Spinus tristis).” 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/amegfi doi: 10.2173/bna.80