I should mention that there is another similar species found in savannahs further north called Grey-headed Parrots (Poicephalus fuscicollis suahelicus). They were once a subspecies of Poicephalus robustus but have now been separated out into their own species. If you look at maps in field guides, it can be very confusing as they aren’t very detailed as to which species is near which town. Scientific taxonomy is not my field of expertise so I’ll refer you to Dr Steve Boyes’ explanation on Safari Talk. There are also a number of researchers and biologists in the Cape Parrot Group on Facebook who can help if anyone needs more information.