Proposal (622) to South American Classification Committee

 

Recognize newly described Hylopezus whittakeri and split Hylopezus macularius into two species

 

Effect on South American CL: If adopted, this proposal would add a newly described species of Hylopezus to the list and elevate to full species status one current subspecies of H. macularius (paraensis).

 

Background: Currently, H. macularius is treated as a polytypic species with three recognized subspecies: H. m. macularius, H. m. paraensis, and H. m. diversus (Krabbe and Schulenberg 2003). This taxonomic treatment began with Snethlage (1907) who described paraensis as a subspecies of H. macularius and was later consolidated by Zimmer (1934), who lumped macularius, paraensis, and the new taxon he described, diversus, into a single biological species because plumage differences separating them were very subtle, suggesting only subspecific differentiation.  In addition to the subspecies above, a fourth taxon, H. m. dilutus, was described by Hellmayr (1910), but later synonymized with paraensis by Cory and Hellmayr (1924). More recently, Maijer (1998) showed that H. auricularis (until then regarded as a subspecies of H. macularius) was vocally very distinct from any other taxa grouped under the Spotted Antpitta and thus deserved full species status, a recommendation which has been followed ever since (Krabbe and Schulenberg 2003, Remsen et al. 2013).  Other similar examples of cryptic undescribed variation still persist in the polytypic H. macularius complex, suggesting that further splits are warranted (Krabbe and Schulenberg 2003, Remsen et al.  2013).

 

New information: Carneiro et al. (2012) conducted a systematic revision of the polytypic H. macularius based on morphometric, plumage, vocal, and molecular characters. Reconstructed phylogenies recovered with overall strong support the reciprocal monophyly among four main lineages of the Spotted Antpitta, three corresponding to already named taxa (dilutus, macularius, and paraensis), and one, to a newly described taxon, H. whittakeri, endemic to the Madeira–Xingu interfluvium, and which proved to be the vocally most divergent taxon in the complex (Carneiro et al. 2012).

 

Analysis/Recommendation: The statistically well supported reciprocal monophyly recovered for the four lineages of the Spotted Antpitta identified in Carneiro et al. (2012), added to their vocal mutual diagnoses, which remain constant within each clade, are indicative of species level status either under the Phylogenetic Species Concept (PSC) or the Biological Species Concept (BSC). Under the PSC, their reciprocal combined molecular, vocal, and morphological diagnoses provide the basis for considering macularius, dilutus, whittakeri, and paraensis as separate species, whereas under the BSC the concerted evolution between genetic and vocal characters, added to the absence of genetically/vocally intermediate individuals, are also indicative of species level status for these lineages. However, given the poor sampling of dilutus, it seems premature to infer reproductive isolation between dilutus and macularius given the results of the loudsong diagnosability tests, and the uncertain phylogenetic affinities of the former, whose recovered sister relationship to H. paraensis and H. whittakeri lacked significant statistical support, therefore not allowing the rejection of a putative monophyly involving macularius and dilutus.  Therefore, the combined results support the recognition of at least three biological species in the Spotted Antpitta complex, as follows:

 

Hylopezus macularius - Spotted Antpitta. Distributed in southern Venezuela (Amazonas), southern Colombia (Amazonas), northern Peru west of the Ucayali river through the western banks of the Negro and Branco rivers in the Brazilian state of Amazonas (dilutus); the Guianan shield from the eastern bank of the Negro and Branco rivers eastward through eastern Venezuela (Bolívar), Guyana, Suriname, French Guiana, and the state of Amapá in Brazil (macularius).

 

Hylopezus paraensis - Snethlageęs Antpitta. Distributed south of the Amazon in Brazil from the Xingu River eastward in the state of Pará to the western part of the state of Maranhčo, and southward to southern Pará.

 

Hylopezus whittakeri- Alta Floresta Antpitta. Endemic to the Madeira–Xingu interfluve in Brazilian south-central Amazonia.

 

Literature Cited

 

Carneiro, L. S., Gonzaga, L. P., Rźgo, P. S., Sampaio, I., Schneider, H., and Aleixo, A. 2012. Systematic revision of the Spotted Antpitta (Grallariidae: Hylopezus macularius), with description of a cryptic new species from Brazilian Amazonia. Auk 129: 338-351.

 

Cory, C. B. and C. E. Hellmayr (1925). Catalogue of birds of the Americas, part 4. Field Museum of Natural History Zoological Series 13: 1- 390.

 

Hellmayr, C. E. 1910. The birds of the Rio Madeira. Novitates Zoologicae 17:257– 428.

 

Krabbe, N., and T. S. Schulenberg. 2003. Family Formicariidae (ground-antbirds). Pages. 682-731 in Handbook of the Birds of the World, Vol. 8. Broadbills to tapaculos. (J. del Hoyo et al., Eds.). Lynx Edicions, Barcelona.

 

Maijer, S. 1998. Rediscovery of Hylopezus (macularius) auricularis: distinctive song and habitat indicate species rank. Auk 115:1072-1073.

 

Remsen, J. V., Jr., C. D. Cadena, A. Jaramillo, M. Nores, J. F. Pacheco, J. Pérez-Emán, M. B. Robbins, F. G. Stiles, D. F. Stotz, and K. J. Zimmer. 2013 [Version: 31 October 2013]. A classification of the bird species of South America. American Ornithologists’ Union. [Online] Available at http://www.museum.lsu.edu/~Remsen/SACCBaseline.html.

 

Snethlage, E. 1907. Neue Vogelarten aus Südamerika. Ornithologische Monatsberichte 15:193–196.

 

Zimmer, J. T. 1934. Studies on Peruvian birds. XII. Notes on Hylophylax, Myrmothera, and Grallaria. American Museum Novitates 703: 1-21.

 

Lincoln Carneiro and Alexandre Aleixo, December 2013

 

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Comments from Stiles: “YES.  A very well-crafted study, with good sample sizes and morphometric, vocal and genetic data clearly presented and analyzed, with representative specimens of all forms photographed; I agree with the authors’ conclusions regarding recognition of H. whittakeri and the resultant rearrangements and splits (a nice change from the recent descriptions in the HBW volume!).”

 

Comments from Remsen:  “YES.  The Auk paper presents strong vocal evidence for species rank of these taxa, with excellent N (27-45 individuals of the three taxa) and quantitative assessment of differences.

 

”As for English names, not that the ones proposed in the proposal break the usual rule of having a new names for each of the daughter species to prevent confusion.  Thus, “Spotted” would refer to the new H. macularius sensu stricto, whereas for many decades it referred to the broadly defined species.”

 

Comments from Nores: “YES. The Auk paper presents clearly analyzed vocal and genetic data, which is good evidence for species rank of these taxa.”

 

Comments from Zimmer: “YES.  The Auk paper presents strong evidence (vocal, genetic and morphological) for the proposed split of H. macularius and the recognition of H. whittakeri.  Interestingly, the vocal distinctions between whittakeri and the other members of the macularius complex (which, as noted, are the most divergent of any pairwise comparison in the complex) have been recognized for a long time, at least since 1989 when Ted Parker first visited the Alta Floresta region.  The problem was that those birds (= whittakeri) were assumed to belong to south bank paraensis, and the thinking was that the dramatic vocal differences represented a north bank versus south bank difference between macularius and paraensis.  It was only much more recently that field recordings from near the type locality of paraensis have confirmed that it is vocally more similar to north bank macularius than either taxon is to south bank whittakeri.”

 

Comments from Robbins: “YES. Carneiro et al. provide multiple lines of evidence that clearly indicate that whittakeri and paraensis should be recognized as species; what a thorough piece of work!”

 

Comments from Pacheco: “YES. O artigo que fundamenta a proposićčo apresenta dados vocais e moleculares que apoiam fortemente o tratamento em duas espécies.”