Jackson, Jerome A., Henri R. Ouellet, and Bette J. Jackson. 2002. “Hairy Woodpecker (Picoides villosus).” 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/haiwoo doi: 10.2173/bna.702