A review of the taxonomic status and biology of the Cape Parrot <i>Poicephalus robustus</i>, with reference to the Brown-necked Parrot <i>P. fuscicollis fuscicollis</i> and the Grey-headed Parrot <i>P. f. suahelicus</i>

Abstract

A review of the taxonomic status of the critically endangered Cape Parrot Poicephalus robustus Gmelin 1788 has important implications concerning the conservation of this species and illegal trade. It is distinguishable from the Brown-necked Parrot P. fuscicollis fuscicollis Kuhl 1820 on the morphometrics of the body and bill, two mitochondrial DNA sequences and its ecology and behaviour. The Grey-headed Parrot P. f. suahelicus Reichenow 1898 is geographically and genetically isolated from the other taxa. Grey-headed Parrots and Brown-necked Parrots are more closely related to each other than either is to the Cape Parrot. Geographically, the Grey-headed Parrot is marginally parapatric with the Cape Parrot, and this account focusses on these taxa. The Cape Parrot is a dietary specialist, and its diet differs from that of the Grey-headed Parrot, which has a wider trophic niche, although both feed on the kernels of unripe fruit. Their feeding behaviour changes in response to seasonally available food and may involve long distance movements. Both species share similar breeding habits, but they breed at different seasons in different habitat types. The two taxa have distinct habitat requirements and distributions. Cape Parrots inhabit, nest and feed in Afromontane mixed Podocarpus forest above 1 000m asl in South Africa, whereas Grey-headed Parrots inhabit a wide range of lowland woodland habitats across south-central Africa. In parapatry, there is no record of hybridisation, probably because of spatial (geographical and altitudinal) and temporal segregation (different breeding seasons). On the basis of these criteria, the Cape Parrot is, and must be recognised, as an independent species.

Ostrich 2005, 76(3&4): 195–205