Leonard, David L., Jr. 2001. “American Three-toed Woodpecker (Picoides dorsalis).” 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/attwoo1 doi: 10.2173/bna.588