John James Audubon, “Northern Mockingbird (Mimus polyglottos),” Havell plate no. 21. Object number 1863.17.21, New-York Historical Society. The piece was executed on paper and attached to card (75.6 x 53 cm), with watercolor, graphite, pastel, black chalk, gouache, black ink, and with selective glazing and scraping. Courtesy of the New-York Historical Society. Digital image created by Oppenheimer Editions.