cuappachhuitzilin.

CUAPPACH-HUĪTZIL-IN, literally “tawny hummingbird,” Cinnamon Hummingbird (Amazilia rutila),” [FC: 25 Quappachvitzilin] “[it] is smoky, dark yellow, tawny.” Martin del Campo identified this species as what is now known as the Cinnamon Hummingbird, a reasonable guess. See HUĪTZIL-IN hummingbird.
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analysis here also appearing in E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript, 2022, cited here with permission.