Proposal (212) to South American Classification Committee
Split Gypopsitta
from Pionopsitta
Effect on SACC: This proposal would remove
all but one species from current Pionopsitta and place these in a
separate genus, Gypopsitta.
Background: Traditional classifications (e.g., Peters
1937, Pinto 1937, Phelps & Phelps 1958a, Meyer de Schauensee
1970, Forshaw 1973) treated Pionopsitta vulturina in a separate
monotypic genus, Gypopsitta, but Haffer (1974), Cracraft and Prum
(1988), and others noted that vulturina was clearly a member of Pionopsitta
based on biogeography and plumage pattern. SACC classification treats vulturina
as a member of Pionopsitta on this basis.
New information: Ribas et al. (2005) found, using
mtDNA sequence data (2181 bp), that Pionopsitta as currently
constituted is not monophyletic. The type species for the genus, pileata,
is only distantly related to the others, which in fact are more closely related
to, for example, Hapalopsittaca, Amazona, Graydidasculus, Pionus,
and even Triclaria than to Pionopsitta pileata. Bootstrap and
Bayesian posterior probabilities for the nodes in their tree are generally
high. Rather than expand Pionopsitta
to include a broad array of parrot genera, Ribas et al. (2005) resurrected Gypopsitta
for the other species.
Analysis: Haffer (1974) and others long ago recognized that P. pileata was
the "oddball" in the genus, and so the genetic data are not
surprising in corroborating this. What is surprising is how distant P.
pileata is from the Gypopsitta group, and how far one would have to expand
Pionopsitta to retain it as a monophyletic group, e.g., minimally all
the genera mentioned above. Although the genetic analysis covered only two
mtDNA genes, it is difficult to imagine that mtDNA would be this misleading at
this level (intergeneric) of analysis. Comforting is that formal analysis of
plumage characters (Cracraft and Prum 1988) shows that pileata is
the outgroup to the rest; in fact, with the benefit of hindsight, if you look
at specimens, you wonder why pileata was ever associated with
the Gypopsitta group. [Perhaps someone could check Bret et al.'s parrot
CD for vocal information.]
Keeping Pionopsitta and Gypopsitta adjacent in a
linear sequence misrepresents their degree of relatedness, but major fiddling
with the linear sequence at this point seems inadvisable until we have better
data on the relationships among these parrot genera. However, Ribas et al.'s
genetic data strongly support Hapalopsittaca amazonina as the
sister taxon to Gypopsitta (H. melanotis not sampled). The
plumage similarities between Hapalopsittaca and Gypopsitta/Pionopsitta are
reflected in historical classifications of their component species (see SACC
Notes) and Cracraft and Prum's use of H. melanotis
as the outgroup taxon for their plumage analysis of Gypopsitta/Pionopsitta.
Therefore, I recommend that our sequence go Gypopsitta-Hapalopsittaca-Pionopsitta
to emphasize that there is no evidence that Gypopsitta and Pionopsitta are
sisters, but with minimum disturbance to the linear sequence until more data
are available.
Recommendation: YES. There are no data of which I am aware
that support the continued association of Pionopsitta pileata with the Gypopsitta group,
and so to continue to treat them as congeners would be highly misleading.
Literature Cited (see SACC Biblio for
the rest):
CRACRAFT, J., AND R. O. PRUM. 1988. Patterns and processes of
diversification: speciation and historical congruence in some Neotropical
birds. Evolution 42: 603-620.
RIBAS, C. C., R. GABAN-LIMA, C. Y. MIYAKI, AND J. CRACRAFT. 2005.
Historical biogeography and diversification within the Neotropical parrot genus
Pionopsitta (Aves: Psittacidae). Journal Biogeography 32:1409-1427.
V. Remsen,
March 2006
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Comments from Stiles: "YES. The genetic (as well
as morphological) data clearly mandate this change, supported by two different
studies and several genes (pity that Gypopsitta is a bit
misleading as a name for most species, but priority rules!)."
Comments from Robbins: "YES. The Ribas et al.
(2205) genetic data and their taxonomic recommendations of resurrecting Gypopsitta
seem solid. I vote 'yes'."
Comments from Nores: "YES. Es muy claro en el análisis de Ribas et al. (2005) que Pionopsitta
pileata está muy poco emparentada con el resto de las especies que
proponen poner en el género Gypopsitta. Esto también resulta evidente
cuando se comparan las especies desde el punto de vista morfológico,
principalmente la coloración."
Comments from Zimmer: "YES. The evidence presented
is convincing. As Gary notes, it is unfortunate that priority dictates the name
Gypopsitta, which is great for two of the species but doesn't hold for
the others. In response to Van's query about vocalizations of pileata versus
the other species currently in Pionopsitta: pileata is quite
different from all the others with which I'm familiar, whereas vulturina,
aurantiocephala, barrabandi and caica all have some
similarities with one another."
Comments from Jaramillo: "YES - Change clear based on
genetic data and morphological data, also unpublished vocal data fide
Zimmer."
Comments from Pacheco: "YES. Os dados disponibilizados por Ribas et al.
(2005) são plenamente convincentes para a adoção do arranjo proposto.
"É oportuno mencionar que um trabalho
independente chegou a conclusões semelhantes:
"Eberhard, J. E. & Bermingham, E. 2005. Phylogeny and
comparative biogeography of Pionopsitta parrots and Pteroglossus toucans.
Mol. Phyl. & Evol. 36: 288304."