[2] When in 1788 the German naturalist Johann Friedrich Gmelin revised and expanded Carl Linnaeus's Systema Naturae, he included the Cape parrot with a short description, coined the binomial name Psittacus robustus and cited Latham's work.

[8] A detailed genetic analysis of the three taxa published in 2015 confirmed the distinctness of brown-necked and cape parrots, and suggested that ancestors of the two had diverged between 2.13 and 2.67 million years ago in the late Pliocene to early Pleistocene epoch.

This contrasts with the closely related savanna species (Poicephalus fuscicollis) which feeds on a wide variety of tropical woodland trees such as marula, Commiphora spp.

To date there have not been any successful releases of captive birds and the survival of this species is dependent on habitat conservation to maintain wild populations.

Hundreds of volunteers participate on the first weekend each May in the "Cape Parrot Big Birding Day" which is an annual count of the population throughout its distribution.

The parrots are relatively easy to count at any forest patch due to their distinctive silhouettes, slow, 'rowing' flight and raucous calls.

A complete census of the population is difficult to achieve, however, as these forests are naturally fragmented and there are insufficient volunteers to count the more remote patches.

The parrots are particularly threatened by the fatal Psittacine beak and feather disease virus (BFDV), and there have been suggestions that a diet heavy in yellowwood fruits greatly reduces the symptoms, although this has not been empirically investigated.