There are two subspecies which are geographically isolated at present: "Ara ambiguus" ssp. "ambiguus", which has the largest distribution range (Central and northern South America), and "Ara ambiguus" ssp. "guayaquilensis", which only occurs in Ecuador. The Ecuadorian subspecies is sometimes referred to as Chapman's macaw or Chapman's green macaw. American naturalist Frank M. Chapman shot the type specimen of his proposed new taxon in 1922 on a hill in the Cordillera de Chongon, twenty miles northwest of Guayaquil, Ecuador, and first described the taxon in 1925 in a report on the newly collected bird skins he had brought back to the US from Ecuador.