More Amazonian parakeets

The vast Amazonian region still holds many unravelled ornithological mysteries and detailed research into any complex group is likely to reveal revised taxonomic affinities or even as yet undescribed taxa, such as the newly described Bald Parrot Pionopsitta aurantiocephala (see above). The Psittacidae prove to be a rewarding subject in this respect, as is shown by a recently published paper about Amazonian Pyrrhura parakeets (Joseph, L 2002. Geographical variation, taxonomy and distribution of some Amazonian Pyrrhura parakeets. Ornitologia Neotropical 13: 337-363; an electronic appendix of colour images supplementing the paper can be found on the Internet at www.acnatsci.org/publication/appendix4.html). In this paper, Leo Joseph substantiates that Painted Parakeet (or Painted Conure) P picta, belonging to the group of 25-30 Neotropical Pyrrhura parakeets and hitherto treated as a single polytypic species, is actually better considered as consisting of six different species. Two of these have not been described before. The author examined 231 specimens from various collections and obtained general data on an additional 110 specimens, divided over seven geographical groupings. Each specimen was scored for seven morphological characters, as well as for morphometric statistics. On basis of these examinations, the specimens grouped into five forms next to P picta (sensu stricto), with each form best treated as a separate species. The status of a sixth form is ambiguous and, awaiting genetic analysis, is left to debate. The author indicates that treating the five forms '... as subspecies of P picta under the Biological Species Concept perpetuates blind adherence to the arrangement Peters (1937) introduced with no justification...'. Instead, Joseph advocates that P picta and Red-crowned Parakeet P roseifrons should be treated as two species by all modern species concepts, even if gene flow from P picta is suggested in some specimens. The other four groups could possibly be treated as subspecies of P roseifrons (rather than P picta) but given their disjunct distribution, there is no hard case to consider them one and the same species. In fact, Joseph reverses the burden of proof ('species until proven subspecies'), preferring to treat diagnosable allopatric forms as species rather than subspecies until there is falsifiable evidence that forms could and would interbreed when they might come into contact. Therefore, he proposes to treat every group as a distinct species, based on consistent but often subtle plumage differences. Joseph acknowledges that, with further knowledge, two or more groups may prove to be so closely related that a rearrangement as subspecies under one species could be justified but states that this speculation should not stand in the way of a revised current taxonomic treatment. In his words: 'Far from setting taxonomy back 100 years as some critics of this approach argue, interim use of a binominal nomenclature does precisely what a taxonomy should do: summarize present understanding of relationships in the group in question'. Since other taxa in Pyrrhura have been diagnosed by one or a few subtly varying characters, Joseph considers it justified (or even inevitable) that weakly but consistently differentiated forms are also recognized as species since this treatment accords with previous taxonomic treatment of the genus.

As a result of Joseph's research, in addition to Painted Parakeet (P picta sensu stricto) from northern Brazil, the Guianas and southern Venezuela, and Red-crowned Parakeet from two disjunct populations in western Amazonia, four more species are proposed. Two of them were described before and are now provisionally upgraded to species level: Deville's Parakeet P lucianii, known only from Tefé on the Rio Solimões and the Rio Purús in Brazil, and Hellmayr's Parakeet P amazonum from eastern and south-eastern Amazonia. Two taxa are new to science and first described in this paper: Madeira Parakeet P snethlageae from the drainage of the Rio Madeira in Bolivia and Brazil, and Wavy-breasted Parakeet P peruviana, known from two separate populations in Amazonian Peru. Because of this disjunct distribution, further taxonomic subdivision of P peruviana may be warranted after closer study of both populations. The name P snethlageae honours Emilia Snethlage, who first recognized the distinctiveness of this form in 1914. The scientific name of P peruviana acknowledges the fact that this taxon occurs only in Peru; the vernacular name refers to the extensive subterminal bands on the feathers of the throat and breast. The main plumage differences separating the six taxa are related to the absence or presence and extent of bright red in the plumage, the extent of blue on the forehead and the absence or presence of broad subterminal bands on the throat and breast. Joseph advocates further study of the group, indicating that his revised taxonomic basis in this paper is developed as a platform for full systematic study. In this respect, he emphasizes the need for freshly collected, well-labelled specimens from all the populations under study.
Enno B Ebels