Proposal (213) to South American Classification Committee

Change linear sequence of species in Gypopsitta/Pionopsitta

Background: Our current linear sequence of species in Gypopsitta/Pionopsitta (see Proposal 212) is:

aurantiocephala
vulturina
haematotis
pulchra
barrabandi
pyrilia
caica

New information: Ribas et al. (2005) found, using mtDNA sequence data, the flowing sister-species relationships, which are largely consistent with predictions from biogeography:

(1) aurantiocephala + vulturina (with caica the sister to this pair)

(2) barrabandi + pyrilia

(3) haematotis + pulchra

Support for those relationships was reasonably strong in both maximum parsimony and maximum likelihood analyses.

However, when plumage characters were added and combined with the genetic data, the topology shifts slightly in that caica becomes the sister to a group formed by two Amazonian pairs: (aurantiocephala + vulturina) + (barrabandi + pyrilia); however, support for the “basal” position of caica is weak. Ribas et al. provided rationale for why they had more confidence in the topology generated by the molecular data.

We can tinker with our linear sequence slightly to reflect the phylogenetic hypothesis of Ribas et al. (2005) as follows, starting by convention with northernmost species first,:

haematotis
pulchra
pyrilia
barrabandi
caica
aurantiocephala
vulturina

Various other permutations are possible with respect to placement of caica, but this reflects the authors' best estimate of relationships among the species.

Recommendation: YES. Our current sequence does not reflect phylogenetic hypotheses. Although linear sequences are a poor way to portray relationships, for consistency we should make those sequences as consistent as possible with available data.

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.

Van Remsen, March 2006

Note added by Remsen 20 June 06: Tavares et al.'s (2006; Syst. Biol. 55: 454-470; see SACC Biblio) phylogeny independently indicates that Gypopsitta spp. and Pionopsitta pileata do not form a monophyletic group.

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Comments from Stiles: "YES. Insofar as possible, this arrangement seems the best fit that a linear sequence can offer given the more complex relationships indicated by the phylogeny."

Comments from Nores: "YES. A esta propuesta la encuentro también coherente, ya que refleja lo que Ribas et al. (2005) han analizado mediante dos diferentes formas: (i) secuencias de genes mitocondriales cyt b y ND2 y (ii) 26 caracteres de plumaje. Lo único que no me parece bien es que por convención se pongan primero las especies de más del norte, porque esto puede crear problemas de relación con el género anterior y con el siguiente. En este caso, la especies más emparentada con Pionites leucogaster sería G. haematotis y con Hapalopsittaca amazonina y Pionopsitta pileata, G. vulturina, siendo que la relación es aparentemente al revés."

Comments from Jaramillo: "YES - Looks like the logical step based on the published information."

Comments from Pacheco: "Yes. Em consonância com o voto na proposta precedente."