The introduction of the Great-tailed Grackle (Quiscalus mexicanus) into the Valley of Mexico by Aztec Emperor Auitzotl (1486–1502) is the earliest documented case of human-mediated bird introduction in the Western Hemisphere. I investigated the origin of the account of this ancient translocation and the team that collected it: Bernardino de Sahagun's research group of elite native scholars from the Royal College of the Holy Cross, Tlatelolco. These scholars, the top academic research group in 16th-century Mexico, used expert native consultants as sources of information and an early form of peer review to detect errors and omissions. The account first appears in extant drafts written by the research group during its field work in Tlatelolco (1561–1565), 59–79 years after Auitzotl introduced the grackles. The account then successfully passed through peer review in Tenochtitlan before being added to the Florentine Codex. The research group was composed of graduates, professors, and an administrator of the Royal College. Professor Antonio Valeriano, a key member of the research group, was married to Isabel Huanitzin, an Aztec princess closely related to Auitzotl. Because all the many details of the account successfully passed peer review, and also because the account lacks the usual warning phrases used to alert the reader to doubtful information such as fables, it is clear that the research group judged the story of Auitzotl's introduction of the Great-tailed Grackle to be true. The presence of an actual conversation in the Aztec text suggests eyewitness testimony or reliance on an earlier-written native manuscript.