TLĀCO-CUĀUH-TLI/CHIEN-CUAUH-TLI, Northern Harrier (Circus cyaneus) [FC: 40 Tlacoquauhtli]: “Also it is called chienquauhtli. It resembles an . It has a yellow beak, it has yellow legs.” Another multiple-named raptor with puzzling descriptions. Martin del Campo identified this as the Northern Harrier, which it might be, though the resemblance to the Aztec Rail – translated by Martin del Campo, for some unfathomable reason, as the “Black-bellied Plover” -- is a puzzle. See also CHIEN-CUAUH-TLI.
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analysis here also appearing in E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript, 2022, cited here with permission.
The Florentine Codex (Book 11, folio 42v) has 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. 42v, Getty Research Institute, 2023. https://florentinecodex.getty.edu/en/book/11/folio/42v/images/a453ddd6-1... Accessed 17 October 2025.