coztlotli.

COZ-TLOH-TLI, literally, “yellow falcon,” American Kestrel (Falco sparverius) [FC: 44 Coztlhotli] “It is quite small. And the cock is called turcuello {in Spanish}. It is named “yellow” falcon because its feathers are yellow. It also feeds three times [a day]; it hunts in the same way [as previously related ].” This is most likely the American Kestrel. Martin del Campo agreed.
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 11 – Earthly Things, no. 14, Part XII, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1963); Rafael Martín del Campo, “Ensayo de interpretación del Libro Undecimo de la Historia General de las Cosas de Nueva España de Fray Bernardino de Sahagún – 11 Las Aves (1),” Anales del Instituto de Biología Tomo XI, Núm. 1 (México, D.F., 1940); and, with quotation selections, synthesis, and analysis here also appearing in E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript, 2022, cited here with permission.

See the Florentine Codex for a painting of this bird:
Available at Digital Florentine Codex/Códice Florentino Digital, edited by Kim N. Richter and Alicia Maria Houtrouw, "Book 11: Earthly Things", fol. 48r, Getty Research Institute, 2023. https://florentinecodex.getty.edu/en/book/11/folio/48r/images/ce983b42-2... Accessed 18 October 2025.