Ridgely, R. S., T. F. Allnutt, T. Brooks, D. K. McNicol, D. W. Mehlman, B. E. Young, and J. R. Zook. 2005. Digital Distribution Maps of the Birds of the Western Hemisphere, version 2.1. NatureServe, Arlington, Virginia, USA. Additional updates and changes by BirdPhotos.com 2016.
Most closely related to the [Speckled Chachalaca] which also has a scaled chest. Chachalacas further north ([Grey-headed Chachalaca], [Plain Chachalaca], [Rufous-vented Chachalaca], [Chestnut-winged Chachalaca]) are not scaled. The species is found only in Magdalena and Cauca valley at most altitudes, and does not overlap with the Speckled Chachalaca (and also has no speckles).