Ā-TEPONAZ-TLI, literally, “log drum of the water,” American Bittern (Botaurus lentiginosus): “And it is called ateponaztli because it sounds from a distance like a two-toned drum” [FC: 33]: In FC: 57 “Atoncuepotli” is contrasted with “Ateponaztli” as if they were two species, though both sound the same, “as if someone beat the two-toned drum.” However, acoyotl <Ā-COYO-TL> is the Neotropic Cormorant and atotlin <Ā-TŌTO-LIN> is the American White Pelican. It is said that all three are so-called “because [they are drowners] of men.” Despite this confusion, I believe that Ā-TEPONĀZ-TLI and Ā-TONCUEPO-TLI are synonyms for the American Bittern, as this bittern does in fact produce a sound like a TEPONĀZ-TLI, “lateral log drum ” (Karttunen: 231). See also Ā-TONCUEPO-TLI and the main heading, TOLCOMOC-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); Frances Karttunen, An Analytical Dictionary of Nahuatl (University of Oklahoma, Norman, 1983); 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analysis here also appearing in E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript, 2022, cited here with permission.