Proposal (613) to South American Classification Committee
Recognize newly described genus Anumara
Effect on SACC: This would add a newly described genus to the list to replace Curaeus for C. forbesi.
Background: The genus Curaeus has typically consisted of two species, C. curaeus of Patagonia etc., and endangered C. forbesi, known from of E Brazil (Alagoas + Pernambuco; Minas Gerais). Actually, forbesi was placed more in broadly defined Agelaius by Hellmayr and Meyer de Schauensee, but Blake (in Peters CL) and Short & Parkes in a 1979 paper in the Auk placed it in Curaeus.
New information: Powell et al. (2014) published an impressively comprehensive phylogeny of the Icteridae (100% species sampled; up to 5200 bp nDNA and up to 16K bp mtDNA for taxa). It is unlikely that there will be a better phylogeny any time soon using current sequencing technology.
Among their many important findings was that the genus Curaeus is not monophyletic. Here is the critical section of their combined tree:
As you can see, C. curaeus was found to be the sister taxon to Amblyramphus holosericeus with strong support, whereas C. forbesi was found to be part of the more diverse lineage that is sister to that pair. (By the way, all species in the combined lineage are found primarily south or east of Amazonia, so there is a strong biogeographic theme in this group of birds.) Curaeus was not found to be monophyletic in any of their analyses. Rather than combine all nine genera, Powell et al. named a new genus, Anumara, for forbesi. See their paper for details.
Analysis and Recommendation: This is a straightforward move required to keep Curaeus monophyletic. It creates yet another monophyletic genus in a group that already has a number of them, but the lineages all appear to be fairly old and strongly differentiated genetically. The alternative, combining all into a single, exceptionally heterogeneous genus, is likely unacceptable by the subjective standards of how genera are delimited in terms of morphology. Certainly in terms of relative lineage age, forbesi deserves its own genus. Therefore, I recommend a YES on this one.
BLAKE, E. R. 1968b. Family Icteridae. Pp. 138-202 in "Check-list of birds of the World, Vol. 14" (Paynter R. A., Jr., ed.). Museum of Comparative Zoology, Cambridge, Massachusetts.
POWELL, A. F. L. A., F. K. BARKER, S. M. LANYON, K. J. BURNS, J. KLICKA, AND I. J. LOVETTE. 2014. A comprehensive species-level molecular phylogeny of the New World blackbirds (Icteridae). Molecular Phylogenetics and Evolution 71: 94-212.
Van Remsen, December 2013
Comments from Stiles: “YES, as the genetic data are well supported and the long branch length to forbesi indicates that its divergence is relatively old.”
Comments from Pacheco: “YES. I fully support this proposal. For purely vocal reasons, the late Jaques Vielliard proposed in 1991 the genus “Omarornis”. However, this name is not available according to ICZN (Piacentini & Pacheco, in prep.).”
Comments from Zimmer: “YES. This seems to be the only solution for keeping Curaeus monophyletic, and it does square with the genetic data and the long branch-length to forbesi.”
Comments from Jaramillo: “YES. These birds were incorrectly considered part of the same genus (Curaeus) based on the fact that they were black, and had longer bills than the other all black species. Yet vocally and biogeographically this never made much sense. Moving forbesi to Anumara clarifies a longstanding problem.”
Comments from Robbins: “YES, given that everything that doesn’t have a short branch is given monophyletic generic status in this clade; therefore to be consistent, the long branch of forbesi merits a genus.”
Comments from Stotz: “YES seems straightforward given that the alternative would be to lump none genera, including some pretty distinctive blackbird groups.”