yacapitzahuac.

YACA-PITZA-HUAC, literally, “has a pointed nose,” Eared Grebe (Podiceps nigricollis) [FC: 37 Yacapitzaoac]: “Also [it is called] nacaztzone because its bill is small and pointed, something like a small nail, and it pierces one sharply. And it swims underwater; it always feeds under water. And it is named nacaztzone because its feathers which are over its ears, inclined toward the back of its neck, are somewhat long, tawny. Those at the top of the head are dark ashen…. Its eyes are like fire, chili-red…. It does not rear its young here; it also migrates. Its food is its own feathers, only sometimes it eats fish.” I agree with Martin del Campo that this is an excellent description of the Eared Grebe. It is an “irregular and local breeder in the cen[tral] volcanic belt” (Howell & Webb). See also NACAZTZONE.
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); Steven N. G. Howell and Sophie Webb. A Guide to the Birds of Mexico and Northern Central America (Oxford University Press, Oxford, New York, Tokyo, 1995); 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analysis here also appearing in E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript, 2022, cited here with permission.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 includes a painting of this bird in Book 11, folio 38r.
Available at Digital Florentine Codex/Códice Florentino Digital, edited by Kim N. Richter and Alicia Maria Houtrouw, "Book 11: Earthly Things", fol. 38r, Getty Research Institute, 2023. https://florentinecodex.getty.edu/en/book/11/folio/38r/images/0 Accessed 17 October 2025.