Proposal (149) to South American Classification Committee

 

Recognize Pionopsitta aurantiocephala as a valid species

 

Effect on South American Check-list: This proposal would add a recently described species to our official list.

 

Background: R. Gaban-Lima, M. Raposo and E. Hšfling (2002) described a new species of Pionopsitta (P. aurantiocephala) based on the recent collection of four specimens from the Rio Cururu-au (an affluent of the lower Rio Teles Pires; headwaters region of the Rio Tapaj—s), and, on a reexamination of an additional 7 specimens already in museums. The new species, which is distinguished from all other parrots by its naked orange head, had historically (e.g. Forshaw and Cooper 1977, Sick 1997) been treated as an immature stage of Pionopsitta (= Gypopsitta) vulturina, a species in which adults have a largely naked, black head, bordered by a collar of yellow and black feathers. Juveniles of vulturina have feathered heads (the feathers being variably green and/or yellow). The prior operating assumption was that the few extant specimens with bare orange heads represented some transitional stage from the feathered head of juvenile vulturina to the bare black-headed adults. Gaban-Lima et al. Examined 74 specimens of the latter species, and found no evidence of any transitional stage to adulthood in which birds were bare-headed without black skin coloring. Three sub-adult specimens of vulturina from MZUSP and one from ANSP showed developing black head skin, a yellow collar, and a black band on the nape (all characters of adult vulturina) before the head had completely lost the green and yellow feathering of the juvenal condition. Furthermore, of the 4 recently collected orange-headed specimens, 3 had fully ossified skulls and well-developed gonads, exhibiting no signs of immaturity. The new species has been collected on both banks of the middle and upper Rio Tapaj—s, meaning that it may be at least locally sympatric with vulturina. The authors consider aurantiocephala to be the sister species to vulturina.

 

Analysis: Interestingly, Juniper and Parr (1998), in describing the immature condition of vulturina, say "Immature head fully feathered (except for pale periophthalmic ring); greenish on cheeks and more olive-yellow on rest of head, with no yellow collar." Either their interpretation of the extant orange-headed specimens (which I see no mention of) was different from that of Sick and Forshaw & Cooper, or, they overlooked these specimens entirely. In either case, Juniper and Parr apparently also found no evidence of any unusual transitional condition between juvenal and adult plumages in vulturina. In addition to evidence presented by Gaban-Lima et al., many good field observers have reported uniform flocks of orange-headed birds from both banks of the Tapaj—s, and from the right bank of the lower and middle Rio Madeira (some of these anecdotal reports are mentioned in the Gaban-Lima paper). I know of no reports, either in the literature, or anecdotal, of flocks in which both black-headed birds and orange-headed birds were together. Sick (1997) even mentions that presumed immature vulturina (with bare orange heads) were seen flying in flocks separate from adults. One weakness of the type description of aurantiocephala is that no mention is made of vocalizations. I have tape-recorded aurantiocephala on the Rio Mapia south of Borba (right bank lower R. Madeira), and, although the vocalizations are recognizably similar to those of vulturina, they are still different (at least as different as are those of P. barrabandi, which also has some vocalizations similar to those of vulturina). There is some indication that aurantiocephala may occur primarily in forests growing on white sandy soils along black-water drainages. If so, it may be regionally sympatric with vulturina, while replacing it on a finer scale in the aforementioned habitats.

 

Recommendation: I recommend recognition of Pionopsitta aurantiocephala as a distinct species, following Gaban-Lima et al. (2002). The authors present solid evidence for the validity of the taxon, and this evidence has been corroborated by field observations by a number of reliable observers, as well as by tape recordings documenting unpublished vocal differences between aurantiocephala and its presumed nearest relatives. The new species should immediately precede P. vulturine in a linear taxonomic sequence. The authors of the species description did not suggest an English name. If the SACC accepts the addition of aurantiocephala to our list, we will need a separate proposal regarding the English name. "Bald Parrot" has already found its way into informal usage, and would seem to be an appropriate choice.

 

Literature Cited:

FORSHAW, J. M. AND W. T. COOPER. 1977. Parrots of the world, 2nd Edition. T.F.H. Publications, Neptune City, New Jersey.

GABAN-LIMA, R., M. A. RAPOSO, AND E. HOFLING. 2002. Description of a new species of Pionopsitta (Aves: Psittacidae) endemic to Brazil. Auk 119:815-819.

JUNIPER, T., AND M. PARR. 1998. Parrots: A guide to parrots of the world. Yale University Press, New Haven and London.

SICK, H. 1997. Ornitologia Brasileira. Editora Nova Fronteira, Rio de Janeiro, Brazil.

 

Kevin J. Zimmer, December 2004

 

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Comments from Robbins: "YES. Gaban-Lima et al. provided convincing evidence to demonstrate that orange-headed birds deserve recognition as a species and are not simply a plumage stage of Pionopsitta vulturina."

 

Comments from Pacheco: "YES. O trabalho de Gaban-Lima, Raposo e Hšfling descreveu sobejamente este novo (mas n‹o menos surpreendente) t‡xon. Eu mesmo sou (em companhia de F‡bio Olmos) um dos que reconheceu a espŽcie em campo, no sudeste do Par‡ (artigo submetido ˆ Ararajuba)."

 

Comments from Jaramillo: "YES _ I had a look at the paper, and the data are convincing. It sure does make a lot more sense than the idea of this being a transitional stage in the maturation of P. vulturina. I appreciate the additional information on voice given, which supports the contention that this is a new and valid species. I look forward to voting on the English name, "Bald Parrot" is so grotesque and off-putting that I will surely vote yes for that! "

 

Comments from Stiles: "YES. Clearly a distinct new species, quite bizarre in fact: the most "vulturine" of the lot! "Bald Parrot seems OK as an English name."

 

Comments from Nores: "YES, estoy de acuerdo en considerar a P. aurantiocephala como una especie v‡lida y "Bald Parrot" como su nombre en InglŽs. Los fundamentos aportados por Gaban-Lima et al. son lo suficientemente documentados como para no dejar dudas de que se trata de una nueva especie."

 

Comments from Silva: "YES. Although the proposal has passed, I would like to present some molecular evidence about this species that has been presented in a unpublished thesis that I have read and evaluated. The thesis was written by Camila Cherem Ribas and is titled "Filogenias moleculares e biogeografia hist—rica em psitacideos (Aves: Psittacidae): padr›es e processos de diversifica‹o no Neotropical". The advisor is Cristina Miyaki, from Universidade de Sao Paulo. She used all Cyt b sequence (1140 pb) and ND2 (1041 bp) for all species of Pionopsitta/Gypopsitta. She found several interesting things, but I will focus on the relationship of aurantiocephala. First, aurantiocephala is sister species of vulturina. Second, the genetic difference between aurantiocephala and vulturina is 1% in cyt b and 1.5% in ND2 and is significantly smaller than the distances among the other sister-species within the genus. For instance, barrabandi is sister of pyrilla and the genetic distance is 6% (cyt b) and 9% (ND2). She said that these two taxa should be treated as separated species under the PSC, but she did not mention anything about the case under BSC."