Relationships among the Australo-Papuan Parrots, Lorikeets, and Cockatoos (Aves: Psittaciformes): Protein Evidence

Allozyme variation at 21 presumptive protein loci was examined by electrophoresis and used to assess relationships among Australo-Papuan parrots, lorikeets and cockatoos. Hypotheses of relationships were generated from the data by phenetic and cladistic analyses. The results, when taken into account with other biochemical, chromosomal and morphological data, demonstrate that cockatoos form a monophyletic lineage distant from the other Australo-Papuan parrots and lorikeets. The lorikeets are also monophyletic, but are clustered among other parrots. A core of Australian broad-tailed (platycercine) parrots is defined by the rosellas and ringnecks (Platycercus, Barnardius), Bluebonnet (Northiella), Red-capped Parrot (Purpureicephalus), Swift Parrot (Lathamus) and grass parrots (Psephotus). New Guinean Psittacella also appears to be a member of this assemblage, to which the polytelitine parrots (Alisterus-Polytelis) may be linked as well. Other "conventional" platycercine parrots--the Ground Parrot (Pezoporus), Budgerigar (Melopsittacus), Red-fronted Parakeet (Cyanoramphus), and Blue-winged and Bourke's Parrots (Neophema)--are still more distant and of disparate affinity; the two latter species are polyphyletic among the platycercines. Of psittacine parrots, Eclectus (Eclectus) and Red-cheeked Parrots (Geoffroyus) are closely related but their links to other psittacine genera are not clear. Similarly, the relationships of the fig-parrots (Cyclopsitta), pygmy-parrots (Micropsitta), lovebirds (Agapornis) and ring-necked parakeets (Psittacula) are ambiguous. Biogeographical implications of these results are canvassed in the discussion.