There have been several different taxonomic treatments of this species in the past, most commonly the separation into two species: the Eastern or Mallee Ringneck Barnardius barnardi and the Western or Port Lincoln Ringneck B. zonarius.

Photos 1 and 2 show B. z. barnardi (the Mallee Ringneck) which has a dark red forehead, the yellow rear collar and a smallish yellow breast patch. Unfortunately these photos don't show the dark blue back which is a feature of this race.

Photos 3 and 4 were taken at Wilpena Pound in the Flinders Ranges of South Australia. These show hybrids of the races B. z. barnardi and the nominate B. z. zonarius. These have a larger yellow patch on the breast, a greyish-brown crown and a green back.

Photos 5 and 6 taken at Alice Springs, NT show the nominate sub-species while photos 7 to 9 show the sub-species B. z. semitorquatus. This latter has no yellow on the breast and has a prominent red forehead.