Proposal (457) to South American Classification Committee

 

Merge Cyanocompsa and Amaurospiza into Cyanoloxia

 

Effect on South American CL: This would merge two genera, Amaurospiza and Cyanocompsa into Cyanoloxia.

Background: Our current Note is as follows:

24. Some authors merge Cyanocompsa into Passerina (e.g., Paynter 1970c). Klicka et al. (2001) found that the two genera are sisters. Klicka et al. (2007), with broader taxon sampling, confirmed that they are sister but that the Cyanocompsa group also included Cyanoloxia and Amaurospiza, and recommended the merger of the three genera (Cyanoloxia has priority). Proposal badly needed

 

New information: Klicka et al. (2007) analyzed two mitochondrial genes (cyt-b, ND2) for about 3/4 of the species in the Cardinalidae as well as several emberizid and thraupid genera to produce a phylogeny of the group.  Below is a part of their maximum-likelihood tree:

 

amaur

Klicka et al. made the following interpretations and taxonomic recommendations:

 

In our topology (Fig. 2), this complex is divided into two clades, although the exact position of Cyanocompsa parellina remains unresolved. Nevertheless, Cyanocompsa as shown is paraphyletic with respect to both Cyanoloxia and Amaurospiza. We favor a taxonomy that recognizes two clades within this group, Passerina, as presently recognized, and a revised Cyanocompsa. The genus Cyanoloxia (Bonaparte, 1850, Consp. Gen. Av., 1 (2), p. 503) has priority over Cyanocompsa and Amaurospiza (both Cabanis, 1861; J.F. Ornith, 9, pp. 3–4); thus, we recommend that these latter two genera be merged into Cyanoloxia. The sister to the Passerina–Cyanocompsa complex is the monotypic form Spiza. Because of its distinctive morphology and behaviors, and its systematic position outside of the core clade, we suggest that it is best retained as monotypic.

Analysis and Recommendation:  With only one of the three Amaurospiza species sampled, one might hesitate on such a merger until taxon sampling is complete.  However, I think most would be surprised if existing Amaurospiza were not a monophyletic group.  All of the males and females in the proposed broader Cyanoloxia share plumage similarities (dull dark-blue males, rich brown females), and a roughly similar bill; they differ primarily in body size, but not by much.  Many or all are birds of dense undergrowth.  Our current Cyanocompsa is already paraphyletic with respect to Cyanoloxia.  So, without personally knowing better their voices or other aspects of their ecology, I see no reason not to merge all into Cyanoloxia.  Without further input, however, I do not make any strong recommendation one way or another – I’ll wait to hear from others.

 

References:

KLICKA, J., K. BURNS, AND G. M. SPELLMAN. 2007. Defining a monophyletic Cardinalini: A molecular perspective. Molecular Phylogenetics and Evolution 45: 1014-1032.

 

Van Remsen, August 2010

 

 

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Comments from Stotz: “YES  On the few occasions when I have seen Amaurospiza, they seemed very much like a Cyanocompsa to me, just in bamboo.  Certainly, Cyanoloxia and Cyanocompsa also seem like they belong together, so I have no problem with this change.  If we wanted to maintain Amaurospiza, we’d need to do something about C. parellina.  The real question this raises is whether a return to the broad Passerina is warranted.  With Amaurospiza included, that treatment would be a monophyletic unit.  Are there any morphological characters to separate Cyanoloxia and Passerina?”

 

Comments from Robbins: “YES, but a tentative yes, given that only one of the three Amaurospiza species has been included in the molecular data.  Doug brings up an interesting point, what is the rationale for maintaining these as separate genera from Passerina?”