Abstract
The migration patterns of the Thick-billed Parrot (Rhynchopsitta pachyrhyncha) remain poorly known. The species usually migrates to the southern Sierra Madre Occidental for the winter, and only rarely occurs in Chihuahua during that season. A careful reading of Carl Lumholtz’s ‘Unknown Mexico’ revealed two records of the Thick-billed Parrot in Chihuahua during the winter, one at Colonia Pacheco in January 1892, and the other at Cerro Mohinora in January 1893. These historical records suggest recent changes to the species’ migration patterns because of habitat destruction or other factors.