Split Cinclodes fuscus into three species

Proposal (415) to South American Classification Committee

Effect on South American CL: This proposal would elevate the northern, central and southern populations of Cinclodes fuscus to species level (named as C. albidiventris, C. albiventris and C. fuscus).

Background: Ridgely and Tudor (1994) divided the subspecies of C. fuscus into three groups based on morphology. The first group included only the nominate subspecies, C. f. fuscus; the second group included the forms from the Central Andes (presumably C. f. albiventris, C. f. tucumanus, C. f. yzurietae, C. f. riojanus, and C. f. rufus); and the third group included the forms from the northern Andes (C. f. albidiventris, C. f. oreobates, and C. f. heterurus). Jaramillo (2003) suggested that these groups should likely be recognized as different species, based on morphology, vocalizations, and behavior.

New data and analysis: Sanín et al. (2009; PDF available on http://evolvert.uniandes.edu.co/EVOLVERT/Publicaciones.html) presented an mtDNA-based phylogeographic analysis of C. fuscus with fairly complete sampling of the species’ distribution along the Andes and Patagonia. Three groups congruent with those proposed by Ridgely and Tudor (1994) were found. Analyses including Chesser’s (2004) data revealed that these groups are more closely related to other Cinclodes species than to each other. The nominate subspecies, distributed in southern Argentina and Chile is, as found by Chesser (2004), sister to C. antarcticus, a marine specialist that occurs in southern Chile and Argentina and the Falkland Islands. The populations from the central Andes are closely related to and apparently recently diverged from C. olrogi and C. oustaleti, the latter species even sharing a haplotype with C. f. albiventris (in-depth studies of gene flow and reproductive isolation among these taxa were beyond the scope of the study of Sanín et al 2009). The northern forms are sister to a clade formed by C. comechingonus, C. olrogi, C. oustaleti and the forms of C. fuscus from the central Andes. These topologies, in which C. fuscus was paraphyletic, received strong support and were significantly more likely and parsimonious than topologies enforcing a monophyletic C. fuscus. Although species should not be defined solely based on mtDNA, the results of Sanín et al. (2009) are congruent with the observations made by Jaramillo (2003) and to some extent by Ridgely and Tudor (1994).

Recommendation: I recommend treating C. fuscus, C. albiventris and C. albidiventris as different species and include them in the linear sequence of the genus as follows:

Cinclodes pabsti

Cinclodes antarcticus

Cinclodes fuscus

Cinclodes albidiventris

Cinclodes comechingonus

Cinclodes albiventris

Cinclodes olrogi

Cinclodes oustaleti

Cinclodes aricomae

Cinclodes excelsior

Cinclodes atacamensis

Cinclodes palliatus

Cinclodes patagonicus

Cinclodes nigrofumosus

Cinclodes taczanowskii

The species to be included in the list are highlighted in red. Note that this is the linear sequence suggested in proposal XXX

Literature cited:

Chesser, R.T., 2004. Systematics, evolution and biogeography of the South American ovenbird genus Cinclodes. Auk 121, 752–766

Jaramillo, A., 2003. Birds of Chile. Princeton University Press, Princeton, NJ.

Ridgely, R.S., Tudor, G., 1994. The Birds of South America. Oxford University Press, Oxford.

Sanín, C., Cadena C.D., Maley, J.M., Lijtmaer, D.A., Tubaro P.L., Chesser, R.T., 2009. Paraphyly of Cinclodes fuscus (Aves: Passeriformes: Furnariidae): Implications for taxonomy and biogeography. Molecular Phylogenetics and Evolution. In press. doi:10.1016/j.ympev.2009.06.022

Camilo Sanín, August 2009

Comments from Robbins: “YES. All data sets support the recognition of three species.”

Comments from Stiles: “YES. Again, phylogenetic data effectively mandate the splitting of C. fuscus into three species since, as currently defined, C. fuscus is paraphyletic. The fact that some morphological and behavioral data also tie in with this split is also useful. The only logical alternative would be to lump some accepted and well-defined species into a broad and virtually amorphous fuscus, which I presume would be unacceptable from any point of view.”