 Amazon parrots range in size from medium to large, and have relatively short, rather square tails.They are predominantly green, with accenting colours that are quite vivid in some species.The taxonomy of the yellow-crowned amazon ("Amazona ochrocephala" complex) is disputed, with some authorities listing only a single species ("A. ochrocephala"), and others splitting it into as many as three species ("A. ochrocephala", "A. auropalliata" and "A. oratrix").