Proposal
(322) to South American
Classification Committee
Remove Saltatricula from
Emberizidae
Effect on SACC: This would transfer a monotypic genus from
Emberizidae to Incertae Sedis.
Background: SACC classification currently places Saltatricula
in the Emberizidae, with the following footnote:
58b. Saltatricula
is one of many "emberizine" genera for which genetic data (Burns et
al. 2003) suggest a closer relationship to the Thraupidae.
I think that many have suspected that this monotypic genus was one
of many colorful South American emberizines that was not part of that family,
as suggested by the only genetic analysis in which it has been included (above).
The genus name (diminutive for Saltator) reflects the plumage similarity
to species in that genus, especially aurantiirostris.
New information: Klicka et al.'s (2007) analysis
included 102 genera of tanagers, emberizines, and cardinalines. The genetic sampling
consisted of 2281 bp of two mitochondrial genes, ND2 and cyt-b ... a nice
sample. Not only does Saltatricula fail to cluster with the emberizine
genera sampled, but it is also embedded in Saltator (see also
Proposal 321). The critical node (in their Fig. 1) for that placement has
strong support (> 95% Bayesian), as does the node that supports a sister
relationship to Saltator atricollis.
Analysis and Recommendation: mtDNA is widely
considered a reliable predictor of phylogeny at these levels of taxonomy, and
certainly these data sets represent the first truly scientific estimates of the
phylogeny and classification of this group. There is no support for retaining
this genus in Emberizidae, and I am unaware of whatever rationale was used
originally for its placement there other than being roughly sparrow size with a
seed-crusher bill.
See Proposal 321 for rationale for removal of Saltator
from Cardinalidae and its presumably temporary placement as Incertae Sedis. For
now, I recommend that Saltatricula follow Saltator into this
category and be placed next to it, with a footnote pointing out that it is
almost certainly embedded within Saltator. I am tempted to propose a
merger directly into Saltator, and both Kevin and John think this is the
way to go. Nonetheless, I suggest waiting for a more-detailed analysis of the
genus that generates additional information on exact placement with additional
taxon-sampling; in other words, a 2-step process: first removing it from Emberizidae
(this proposal, for which I recommend a YES), and then placing it within Saltator.
References:
KLICKA, J.,
K. BURNS, AND G. M. SPELLMAN. 2007. Defining a monophyletic Cardinalini: A
molecular perspective. Molecular Phylogenetics and Evolution 45: 10141032.
[See SACC
Literature Cited for others]
Van Remsen
(in consultation with Kevin Burns and John Klicka), December 2007
______________________________________________________________________________________________________
Comments from Cadena: "YES. The genetic data leave
no doubt that Saltatricula does not belong in the Emberizidae. In fact,
the Klicka et al. 2007 study actually demonstrates quite convincingly that this
taxon should be merged into Saltator: both the node that demonstrates
the monophyly of the Saltator-Saltatricula clade (excluding S.
rufiventris) and the node showing a sister relationship between Saltatricula
and S. atricollis are strongly supported, so I don't see how denser
taxon sampling could change the picture."
Comments from Stiles: "YES. The genetic data
support moving this genus out of Cardinalidae and also the merging of it with Saltator,
so I would support this move as well."
Comments from Stotz: "YES. We should definitely move out of Emberizidae,
but I can't see any reason for not going ahead with the next step and lumping
it into Saltator, except perhaps for some slight issue regarding order within
Saltator."
Comments from Robbins: "YES. I concur with Doug in
that we should not only move Saltatricula out of Emberizidae, but
place it in Saltator."
Comments from Pacheco: "YES. Por coerência, o meu voto acompanha os demais colegas."
Comments from Nores: "YES, por las razones dadas en la propuesta 321. También considero que, si
Burns y Klicka están de acuerdo, habría que ponerlo directamente en Saltator
y no esperar otra propuesta."