Proposal (540) to South American Classification Committee

Elevate Dendrocincla fuliginosa turdina to species rank

Effect of Proposal: This proposal would result in treatment of Plain-winged Woodcreeper Dendrocincla turdina as a separate species from D. fuliginosa (Plain-brown Woodcreeper).

Background: Dendrocincla turdina (Lichtenstein, 1823) is an allopatric, endemic, and well-defined taxon from the Atlantic Forest (southeastern Brazil, adjacent parts of eastern Paraguay, and extreme northeastern Argentina), and is also the type species of the genus Dendrocincla G. R. Gray, 1840.

Peters (1951), without any published justification, considered turdina (together with enalincia) as conspecific with more widespread Dendrocincla fuliginosa (Vieillot, 1818). In fact, the arrangement of Peters for this species follows conclusions of Zimmer (1934) subordinating Middle American and Amazonian taxa rufo-olivacea, atrirostris, phaeochroa, lafresnayei, meruloides, and ridgwayi to fuliginosa. However, the decision for the additional inclusion of two forms of the Atlantic Forest, taunayi, and turdina, within fuliginosa was a decision only of Peters, possibly because Cory & Hellmayr (1925) considered D. atrirostris (at the time only 5 specimens) closed allied to D. turdina enalincia.

It is worth noting that Zimmer did not consider turdina and taunayi as members of polytypic D. fuliginosa (see Zimmer & Mayr 1943).

The trinomial Dendrocincla fuliginosa turdina was adopted without objection by almost forty years in various references (e.g. Meyer de Schauensee 1966, Pinto 1978). Sibley & Monroe (1990) was a first important work to give attention a recommendation by Willis (1983) to treat turdina as distinct species from fuliginosa based on differences of vocal repertoires.

In recent years, various sources (perhaps most) have assumed the independence of Dendrocincla turdina with respect to congeners (e.g. Ridgely & Tudor 1994, Marantz et al. 2003).

New information:  Weir & Place (2011) analyzed mtDNA protein-coding genes (cyt b, ND2 and COI), 16s, RAG 1 and c-myc. of samples belonging to 17 taxa in Dendrocincla to generate a well-supported phylogeny of this genus. Among several results, beyond the scope of this proposal, this work supports the treatment of Dendrocincla turdina (along with taunayi) the sister to the clade that included D. f. fuliginosa, D. f. neglecta, D. f. meruloides, and D. f. ridgwayi, and D. anabatina. They suggested that D. turdina should be considered a separate species – because vocalizations are highly distinct from Amazonian members of the D. fuliginosa – even under Biological species concept.

Recommendation: A fortunate “YES” vote. This recent molecular phylogeny of the genus Dendrocincla allows, finally, recognize as different what ears told us by several years!

References:

CORY, C. B., AND C. E. HELLMAYR. 1925. Catalogue of birds of the Americas. Field Museum Nat. History Publ., Zool. Ser., vol. 13, pt. 4.

MARANTZ, C. A., A. ALEIXO, L. R. BEVIER, AND M. A. PATTEN. 2003. Family Dendrocolaptidae (woodcreepers). Pp. 358-447 in "Handbook of the Birds of the World, Vol. 8. Broadbills to tapaculos." (J. del Hoyo et al., eds.). Lynx Edicions, Barcelona.

MEYER DE SCHAUENSEE, R. 1966. The species of birds of South America and their distribution. Livingston Publishing Co., Narberth, Pennsylvania.

PETERS, J. L. 1951. Check-list of birds of the world, vol. 7. Museum of Comparative Zoology, Cambridge, Massachusetts.

PINTO, O. M. DE O. 1978. Novo catálago das aves do Brasil, parte 1. Emp. Graf. Rev. Tribunais, São Paulo.

RIDGELY, R. S., AND G. TUDOR. 1994. The birds of South America, vol. 2. University Texas Press, Austin.

SIBLEY, C. G., AND B. L. MONROE, JR. 1990. Distribution and taxonomy of birds of the World. Yale University Press, New Haven, Connecticut.

WEIR, J. T. & M. PRICE. 2011. Andean uplift promotes lowland speciation through vicariance and dispersal in Dendrocincla woodcreepers. Molecular Ecology 21: 4550-4563.

WILLIS, E. O. 1983. Three Dendrocincla woodcreepers (Aves; Dendrocolaptidae) as army ant followers. Cienc. Cult. 35: 201-204.

ZIMMER, J. T. 1934. Studies of Peruvian birds, No. 13. The genera, Dendrexetastes, Campylorhamphus, and Dendrocincla. American Museum Novitates 728: 1-20.

ZIMMER, J. T., AND E. MAYR. 1943. New species of birds from 1938 to 1941. Auk 60: 249-262.

José Fernando Pacheco, September 2012

Comments from Zimmer: ““YES”. As Fernando indicates, those who are familiar with turdina have known for some time that its vocalizations are dramatically different from those of other “Plain-brown” Woodcreepers. It is nice indeed to finally have a published, molecular-based phylogeny that we can hang our hats on with respect to this long overdue split. The only surprise in this for me is the revelation that Weir & Place (2011) apparently are treating taunayi of northeastern Brazil as conspecific with turdina. I have recorded several individuals of taunayi, and dozens of turdina, and to my ears, the two are markedly different vocally. If anything, I would have expected that the molecular analysis would have suggested that taunayi was equally distinct from turdina as either was from other Dendrocincla.”

Comments from Stiles: “YES. Vocal and genetic data coincide.”

Comments solicited from Curtis Marantz: “If the Weir-Price results are indeed accurate, it would seem like a bad idea to split turdina and not taunayi out of D. fuliginosa, and for that matter, keeping D. fuliginosa as it is now would be somewhat problematic.  So, one needs either to make some pretty major changes to this complex or question the genetic results.  This said, it seems unlikely to me that D. homochroa is closer to D. fuliginosa than it is to D. merula based on vocalizations, morphology, and its overall biology, but I would be less certain about the placement of D. anabatina within D. fuliginosa, which I suppose is not all that shocking.

“The bottom line, is that splitting one form out of this mess and leaving the others as they are seems like a less than ideal course of action.”

Comments from Pérez-Emán: “A reluctant NO. Although I consider the evidence strongly supports elevating turdina to species rank, I concur with Curtis on the need to evaluate the complete Dendrocincla fuliginosa at once. Although we can recognize paraphyletic species under the Biological Species Concept, the problem here is that D. fuliginosa taunayi is closer to turdina than to the rest of fuliginosa groups. Should we consider taunayi a subspecies of turdina as suggested by Weir & Price (2010)? Biogeographically it makes sense and it is genetically similar. However, it is morphologically and vocally different (though Weir & Price considered them very similar vocally?). The node leading to turdina/taunayi and the rest of species within D. fuliginosa (+ anabatina) is only well-supported by bootstrap values (not posterior probabilities) and the rest of the nodes in D. fuliginosa are not well-supported at all (with the exception of those associated to the meruloides group). Thus, if we consider elevating turdina to species rank together with taunayi, then we will also need to evaluate taxonomic decisions that go from one species, including anabatina (but without a well-supported node associated to it) up to four different species (considering Weir & Price taxon sampling, which was not complete). It would be interesting to bring vocal characters of the complete group to the discussion because it is confusing to know that neither taunayi nor homochroa relationships were the ones expected based on vocalizations (Curtis’ and Kevin’s comments). In summary, the proposal needs to be clear in relation to actions to be taken at least with taunayi, and its consequences for the D. fuliginosa species complex.”

Comments from Jaramillo: “YES. Although a piecemeal way of dealing with Dendrocincla it seems better to me to separate this one out which is uncontroversial as far as I can see, and deal with the rest later.”

Comments from Nores: “YES. The vocalization and molecular analyses clearly show that there are two different species.”

Comments from Remsen: YES. Although I greatly appreciate the concerns of Curtis and Jorge on the need for a complete study, I think we already have enough data to treat turdina as a separate species. As noted by Fernando, there was never any justification published for lumping it in the first place, and doubts have been raised since Willis (1983). As for the problem taxon taunayi, our classification does not deal with subspecies, so we can sneak out of this problem. My instinct, however, is to follow Marantz et al. (2003) in keeping it with D. fuliginosa pending the full analysis we might get one day.”