alo.

ALO, Scarlet Macaw (Ara macao) [FC: 23 Alo] “It lives especially in [the province of] Cuextlan, in crags and in the dense forest. It is tamable. Yellow, curved is its bill…. Flaming red are its eyes; yellow are its breast [and] belly…. Its tail, its wing [feathers] are ruddy, reddish,… They are called cueçalin (cuezalin). The wing coverts and tail coverts are blue, becoming ruddy, reddish, bright reddish, orange.” This is certainly the Scarlet Macaw, though certain descriptive details seem a bit off. Though not mentioned in the Codex, the other Mexican macaw, the Military Macaw (Ara militaris) is distinguished as CUAUH ALO, literally, “forest macaw” (“large, green parrot” (Molina).
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); Alonso de Molina as translated in Stephanie Wood, editor. Online Nahuatl Dictionary. Eugene, Ore.: Wired Humanities Projects, University of Oregon, 2000–present; 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analysis here also appearing in E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript, 2022, cited here with permission.

This is an example of a suffixless noun (no -tl, -tli, or -in ending).
Michel Launey, An Introduction to Classical Nahuatl, translated and adapted by Christopher MacKay (Cambridge: Cambridge University Press, 2011), 232.

alo = loro
Rémi Siméon, Diccionario de la lengua náhuatl o mexicana (Mexico: Siglo XXI, 1996), xxxvii.