Proposal (671) to South American Classification Committee
Change the scientific name of Chapada Flycatcher
Historically, Suiriri consisted of two sets of taxa, white-bellied suiriri (Bolivia, Paraguay, northern Argentina, and Uruguay), and yellow-bellied affinis and bahiae (eastern Bolivia east across Brazil, south of Amazonia). These formerly were recognized as separate species, but now usually are lumped (as per SACC), following discovery of a zone of introgression in Paraguay. In the background to many discussions in the literature on the classification of Suiriri were comments on a small number of specimens that did not match any of the known taxa (see Zimmer et al. 2001 and Kirwan et al. 2014 for a more complete survey of the history of the nomenclature of the genus). As Traylor (1982) noted, the characters of these specimens "ordinarily ... would be strong evidence that we have two sibling species", but that "without field studies of the various taxa, it is useless to speculate".
Zimmer et al. (2001) provided the field studies that Traylor had called for, documenting that two taxa of yellow-bellied Suiriri were broadly sympatric, and locally syntopic. These two taxa differed in morphology (especially bill length), plumage (especially in tail pattern), in vocalizations, and in behavior (with one taxon having a distinctive wing flapping display, lacking in the second taxon). Zimmer et al. (2001) followed all earlier authors in assuming that the widespread member of this pair represented affinis; since the second member of this pair seemed to lack a name, they described it as a new species, Suiriri islerorum Chapada Flycatcher.
More recently, Chapada Flycatcher has been documented at Lagoa Santa, Minas Gerais (Vasconcelos et al. 2006 and references therein). The significance of the presence of Chapada Flycatcher at Lagoa Santa is that this is the type locality of affinis Burmeister 1856. Kirwan et al. (2014) followed up on this point and reviewed the type series of affinis (syntypes), and they found that they all represented the same taxon as islerorum Zimmer et al. 2001. Indeed, Burmeister's original description of affinis (in German) adequately delineates the diagnostic characters of this taxon. Thus, islerorum is a junior synonym of affinis, and the scientific name of Suiriri islerorum should be Suiriri affinis.
This also leaves the taxon traditionally named affinis without a name, for which Kirwan et al. proposed the name burmeisteri.
SACC should revise the scientific name of Chapada Flycatcher to reflect the nomenclatural detective work of Kirwan et al. A "Yes" vote on this proposal, then, is a vote to change the scientific name of Chapada Flycatcher from Suiriri islerorum to Suiriri affinis.
Kirwan, G.M., F.D. Steinheimer, M.A. Raposo, and K.J. Zimmer. 2014. Nomenclatural corrections, neotype designation and new subspecies description in the genus Suiriri (Aves: Passeriformes: Tyrannidae). Zootaxa 3784: 224-240.
Traylor, M.A., Jr. 1982. Notes on tyrant flycatchers (Aves: Tyrannidae). Fieldiana: Zoology, new series 13: 1-22.
Vasconcelos, M.F. de, S. D'Angelo Neto, G.M. Kirwan, M.R. Bornschein, M.G. Diniz, and J.F. da Silva. 2006. Important ornithological records from Minas Gerais state, Brazil. Bulletin of the British Ornithologists’ Club 126: 212-238.
Zimmer, K.J., A. Whittaker, D.C. Oren. 2001. A cryptic new species of flycatcher (Tyrannidae: Suiriri) from the Cerrado region of central South America. Auk 118: 56–78.
Comments from Zimmer: “YES”. Unfortunately, there is no getting around the fact that the entire type series of affinis is unambiguously referable to what we described as “islerorum”. Amazing that none of the previous authors who had commented on a handful of “aberrant” specimens, and who were in agreement on the ways in which those specimens differed from “typical affinis” had ever actually examined the type series of affinis or Burmeister’s written description of the holotype. The fact that the handful of recognized specimens (as of 2001) of the unusual phenotype clustered around Mato Grosso, far removed from the Minas Gerais type locality of affinis, further served to deflect us from considering that the name “affinis” could possibly apply to anything other than the widespread phenotype with which everyone seemed to be familiar.”
Comments from Stiles: “YES. This seems the only way to go – presumably a separate proposal will deal with the English name for affinis.”
Comments from Pacheco: “YES. In nomenclatural terms, a very interesting case, in my opinion, very well solved by Kirwan et al. The participation of Kevin in the original description of islerorum and in this paper is in tune with the "Code of Ethics" of the ICZN.”