In this study, the authors analysed genetic data from five Poicephalus parrot species and found that the Cape parrot is genetically distinct from all of its closest relatives.
The Cape parrot is limited to mixed Afrocarpus/Podocarpus mistbelt forests above 1000 metres whilst the grey-headed parrot is found in mixed woodland habitats below 800 metres.
The Cape parrot breeds at a different time of the year, and it is a dietary specialist that predominantly feeds on Afrocarpus/Podocarpus fruits, whereas the grey-headed parrot has a more eclectic diet.
“We were surprised to see that even though the Cape parrot and the grey-headed parrot co-occur in northern South Africa, they form two completely separate genetic clusters and we detected no recent exchange of genes between these two genetic clusters”, said co-author Sandi Willows-Munro, a senior lecturer in the genetics department at the University of KwaZulu-Natal.
The team then asked whether and when any of these parrot populations were interbreeding by examining the genetic distance between Cape parrots and five other Poicephalus species and subspecies.
“Deciding what should and shouldn’t be considered a species is not a trivial exercise and many ways of making this decision have been proposed”, said conservation biologist Rowan Martin, manager for the World Parrot Trust’s Africa Conservation Programme and research associate at the Percy Fitzpatrick Institute of African Ornithology at the University of Cape Town, who was not part of this study.
“Elevation of the Cape Parrot to full species level will lead to a reassessment of its threatened status on the IUCN and CITES species lists”, said Dr Willows-Munro.