Proposal (953) to South American Classification Committee

Recognize Sporophila iberaensis as a valid species

Background: Sporophila iberaensis was described almost 7 years ago (Di Giacomo & Kopuchian 2016), amid a controversial dispute with another name proposed in home-made PDF preprint distributed in advance of publication. By then, SACC evaluated only the recognition of the unavailable (sensu ICZN) name “Sporophila digiacomoi” (sic), leaving the recognition of Sporophila iberaensis once an “extended paper by Di Giacomo and Kopuchian is published”.

Unfortunately such an extended paper has not been published (it is available only as a preprint at biorxiv.org), yet several recent papers brought up much data that easily allow to evaluate the validity of the species.

In short, the works by Galluppi-Selich et al. (2018), Turbek et al. (2019), and Browne et al. (2021) confirmed the unique breeding habitat of the species compared to other sympatric capuchinos seedeaters, such as S. ruficollis, S. palustris, S. cinnamomea and S. hypoxantha. Most interestingly, Turbek et al. (2021) showed that the distinct song and plumage of Sporophila iberaensis indeed work as a premating barrier to hybridization with the largely syntopic S. hypoxantha, whereas the genomic data shows it has a unique genetic profile among all southern capuchinos species. All these add to the distinct plumage pattern and voice presented in the original description (Di Giacomo & Kopuchian 2016) and song collections (Lopes-Lanús 2013), despite being also available on unpublished sources (Xeno-Canto, the preprint in bioRxiv, the one by Lopes-Lanús, etc.).

Recommendation: it is clear that Sporophila iberaensis is as distinct from congeners as any other species of southern capuchinos seedeaters recognized currently, so I recommend a yes vote. In fact, virtually any author dealing with the group, including IUCN/Birdlife, IOC, CBRO, etc, already recognizes the species as valid. SACC/Clements seems to be the only major source that has not yet recognized it.

Literature Cited:

Browne, M., Turbek, S. P., Pasian, C., & Di Giacomo, A. S. (2021). Low reproductive success of the endangered Iberá Seedeater in its only known breeding site, the Iberá Wetlands, Argentina. Ornithological Applications, 123(2).

Di Giacomo, A. S, & C. Kopuchian 2016. Una nueva especie de capuchino (Sporophila: Thraupidae) de los Esteros del Iberá, Corrientes, Argentina. Nuestras Aves 61: 3-5.

Galluppi-Selich, T., Cabral, H., & Clay, R. (2018). Status of the Ibera Seedeater Sporophila iberaensis. Revista Brasileira de Ornitologia, 26(4), 234-239.

López-Lanús B (2013) Sonidos de aves de pastizal en pampas y campos del cono sur. Anexo 8 apéndice auditivo del inventario focal de fauna para los sitios piloto... En Marino GD, Miñarro F, Zaccagnini ME & López-Lanús B (eds.) Pastizales y sabanas del cono sur de Sudamérica: iniciativas para su conservación en la Argentina. Temas de Naturaleza y Conservación 9. Aves Argentinas/AOP, Fundación Vida Silvestre Argentina e Instituto Nacional de Tecnología Agropecuaria, Buenos Aires

Turbek, S. P., Browne, M., Pasian, C., & Giacomo, A. S. D. (2019). First nest description of the Iberá Seedeater (Sporophila iberaensis). The Wilson Journal of Ornithology, 131(1), 156-160.

Turbek, S. P., Browne, M., Di Giacomo, A. S., Kopuchian, C., Hochachka, W. M., Estalles, C., ... & Campagna, L. (2021). Rapid speciation via the evolution of pre-mating isolation in the Iberá Seedeater. Science, 371.

Vitor Q. Piacentini, December 2022

Comments from Robbins: “YES. I vote yes for recognizing iberaensis as a species.”

Comments from Stiles: “YES. Given the amount of recent data assembled by Vitor, I vote YES on the recognition of S. iberaensis.”

Comments from Pacheco: “YES, for prompt recognition of the specific taxon.”

Comments from Lane: “YES. This seems pretty cut and dried.”

Comments from Claramunt: “YES. I think that the distinctiveness of its plumage and voice, combined with the genetic evidence of lack of inbreeding, at least with S. hypoxantha, is sufficient evidence.”

Comments from Areta: “NO. The current SACC note relevant to this issue reads:

"Sporophila melanops (Pelzeln, 1870). "Hooded Seedeater": known from the type specimen from Goias, Brazil; treated as a valid species by Hellmayr (1938) and Pinto (1944), but usually treated as species of uncertain status (Meyer de Schauensee 1970, Sibley & Monroe 1990); Ridgely & Tudor (1989) considered it more likely a variant of S. nigricollis or a hybrid than a valid species.  Meyer de Schauensee (1952) examined a specimen from Goias that he considered possibly this species and different from S. nigricollis.  Treated as a valid species by Dickinson et al. (2003).  Areta et al. (2016) examined and sequenced the type specimen and determined that it pertains to the "capuchinos" clade, whereas the female specimen examined by Meyer de Schauensee (1952) pertains to S. nigricollis or S. caerulescens, and that application of the name melanops is unsettled, but it could be a junior synonym of S. ruficollis or apply to a local population of seedeaters known to breed in the Esteros del Iberá, Corrientes, Argentina, to which the name S. ruficollis might instead be applicable, whereas the name S. plumbeiceps might be available for what is currently known as S. ruficollis; a hybrid origin was not ruled out, but as considered unlikely."

“We have not had time to publish our findings, but there are now photographs and sightings of birds looking like the type of S. melanops and giving "Iberá Seedeater" songs (no recordings yet) in both Argentina and Paraguay. This suggests that S. melanops should be the name for this species, as proposed as a possibility in Areta et al. (2016). The original description and all the cited subsequent works have not dealt with the nomenclatural aspect of the proposition of a new name; therefore, of course, without an attempt to look for older names, anyone can coin a new one.

“Pearman & Areta (2020) wrote the following:

“I therefore vote NO to the usage of the name S. iberaensis given that its usage has not been well researched or justified.

“Cited literature

ARETA, J. I. , V. DE Q. PIACENTINI, E. HARING, A. GAMAUF, L. F. SILVEIRA, E. MACHADO, AND G. M. KIRWAN. 2016. Tiny bird, huge mystery—the possibly extinct Hooded Seedeater (Sporophila melanops) is a capuchino with a melanistic cap. PLoS ONE 11(5): e0154231. doi:10.1371/journal.pone.0154231

PEARMAN, M., AND J.I. ARETA. 2020. Birds of Argentina and the South-west Atlantic. Field Guide. Helm, London.”

Additional comments from Claramunt: “I continue to vote YES. I think that the distinctiveness of its plumage and voice, combined with the genetic evidence of lack of inbreeding, at least with S. hypoxantha, is sufficient evidence, at least in the context of our current understanding of seedeater taxonomy. The situation is very complex in general, but within that context, S. iberaensis seems to be a good species.

“Regarding the potential application of the name melanops to this species, as suggested by Nacho, I don’t see a compelling case. The type of melanops is very different from any iberaensis that I’ve seen so far. In particular:

Bill: light in melanops versus black in iberaensis.

Crown: black vs. gray

Dorsal parts including upper tail coverts: uniformly light brown vs. a mix of shades of sand to grayish brown (blotched, similar to S. pileata).

Also, the borders of the wing coverts seem much lighter in iberaensis, more contrasting with the brown centers and remiges.

“The type specimen of melanops is still a big mystery. After two centuries of its discovery (exactly two centuries this year!), nobody has collected or photographed another capuchino quite like it. Because of the black throat, it has been suggested that it may be an aberrant plumage of S. ruficollis or S. iberaensis (Areta et al. 2016) with a mutation that turned the gray cap into black. But the rest of the body doesn’t match. Areta et al. (2016) suggested that it may be a young male in an intermediate plumage, with an adult-looking head but a juvenile-looking body. This intermediate pattern seems common among capuchinos. I like that idea, I’ve seen many capuchinos with such patterns.

“If this is the case, then the type of melanops would be in an intermediate juvenile plumage plus a rare melanistic mutation. But in this case, other species may also be good candidates for a match with the melanops type. In particular, S. nigrorufa, S. bouvreuil, and S. pileata would require only a black neck mutation (they already have a black cap). Basically, any other capuchino that experienced a complete black-head mutation can potentially match the S. melanops type. And then, there is the possibility for the type to be of hybrid origin, potentially involving ruficollis or iberaensis as one of the parental forms (providing the black throat genes), and S. nigrorufa or S. pileata as the other (providing the black cap genes).

“In sum, the affinities of the type of melanops are still wildly speculative. I don’t see any compelling evidence suggesting that it is closer to iberaensis in particular. Therefore, it would be unjustifiable to delay the recognition of S. iberaensis, or use Sporophila sp. for it, because of speculations about the type of the mysterious S. melanops.”

Additional comments from Lane: “Wow, this has been a wild ride... but Nacho's comments are based on largely *unpublished anecdotal evidence* at this point. The name "iberaensis" is available and therefore it makes sense to use it until we can be certain that melanops is the correct name. That, however, will require a well-defended, published work that makes crystal clear that melanops is, indeed, the proper name. Right now, that conclusion simply not founded on more than a lot of leaps of logic by Nacho et al. To leave the population as "Sporophila sp." when a perfectly good name is available is nonsensical. So I stick with YES for recognizing the name S. iberaensis for the entity we are discussing.”

Comments from Remsen: “YES. Nacho may have some valid points, but I think these need to be reinforced and published; as is, I think burden-of-proof falls on showing that iberaensis is a synonym of melanops.”

Comments from Bonaccorso: “YES. I understand Nacho´s reservations, but there are good reasons to recognize this species as separate from the mysterious S. melanops. If a compelling case can be made to merge it into S. melanops, we will have to deal with it.”

Comments from Jaramillo: “YES. We can change the situation when Nacho's data are published. But for the time being, it is a Yes on this proposal.”