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. Höfling
(2002) described a new species of Pionopsitta (P. aurantiocephala)
based on the recent collection of four specimens from the Rio Cururu-açu (an
affluent of the lower Rio Teles Pires; headwaters region of the Rio Tapajós),
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 Tapajós, 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 Tapajós, 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 Höfling descreveu
sobejamente este novo (mas não menos surpreendente) táxon. Eu mesmo sou (em companhia
de Fábio Olmos) um dos que reconheceu a espécie em campo, no sudeste do Pará
(artigo submetido à 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 válida y "Bald Parrot" como su nombre en Inglés. 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 histórica em
psitacideos (Aves: Psittacidae): padrões e processos de diversificação 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."