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
_____________________________________________________________________________________
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 an 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 pyrilia 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."