Proposal (853) to South American Classification Committee
Recognize Scytalopus frankeae
Effect on AOU SACC classification: The addition of a new, Peruvian endemic, member of the Scytalopus magellanicus complex.
Background: The tapaculo genus Scytalopus has become the poster child for unrecognized diversity in the Neotropics. In the early 20th century (e.g., Cory and Hellmayr 1924) only 16 species were recognized, this was reduced to only 9 (10, counting S. indigoticus, which is now in genus Eleoscytalopus) by Zimmer (1939) and Peters (1951). Now, nearly a century after Cory and Hellmayr, SACC recognizes 43 spp., and new species are being described nearly annually. The tropical Andes seem to be home of the highest species richness within the genus, with strongly elevational stratification among species—as many as seven species can share a slope from about 1000 m to treeline (usually around 3500 m); along a slope, seldom do two closely related species occur, rather, each elevational replacement is sister to an allopatric form, usually separated by an intermontane valley. This pattern of allopatric replacements is, as one might predict, most pronounced among the highest-elevation species, the members of the S. magellanicus complex. This complex stretches from Colombia to Tierra del Fuego, and comprises at least 16 well-defined genetic clades (and probably more, with more sampling). In addition to genetic differentiation, these clades are defined by vocal differentiation, something that aligns with the general application among birds of the Biological Species Concept (perhaps the most conservative of present-day favored species concepts), as has been applied by recent suboscine work (e.g., Isler et al. 1998). Thus, specialists studying the family have been churning out descriptions of new taxa with regularity. The most recent publication to tackle the group is Krabbe et al. (2020), which described three new species, all endemic to Peru.
Analysis: Of the three new taxa described in Krabbe et al. (2020), two have been long suspected to be likely new species (e.g., Fjeldså and Krabbe 1990), but confounding nomenclatural issues prevented much forward motion in the description. Between the construction of a well-sampled molecular phylogeny, and the sequencing of a few key holotypes, these questions have been sufficiently resolved to allow the description and naming of these species. One has long been referred to colloquially as “Millpo Tapaculo” due to its first being recognized as potentially new after an LSU expedition to a locality called “Millpo” (in Huánuco, Peru, near the border with Pasco). It has finally been described and given the name Scytalopus frankeae, honoring Dra. Irma Franke, former curator of the ornithological collection at the Museo de Historia Natural de la Universidad Mayor de San Marcos in Lima, Peru (Krabbe et al. 2020). The English name suggested for this species is Jalca Tapaculo, invoking a Peruvian name (probably of Quechua origin), jalca, for the semi-humid brushy treeline habitat in which small shrubs grow amid ichu bunchgrass, much like the humid paramo habitat farther north—the typical habitat for this species.
Scytalopus frankeae was found to be embedded within a clade that included most of the central and southern members of the S. magellanicus complex. It is morphologically very similar to many other members of the clade, a common enough reality within the genus, and it is best distinguished from these genetically and vocally, and on the basis of geographic range. Regarding voice distinctions, its typical churr notes of the song are simple, without the distinct introductory stroke of its sister species S. altirostris, and are composed of fewer and slower-paced strokes (no overlap); the frequency range of its churrs are greater than in any other species in the S. magellanicus complex (see Krabbe et al 2020 for spectrograms). The species’ distribution is bound to the north by the Huallaga valley (north of which, it is replaced by S. altirostris) and to the south by the Mantaro valley (south of which, it is replaced by S. whitneyi).
Recommendation: I believe Krabbe et al. (2020) have made a strong case for the recognition of S. frankeae, and recommend that SACC include it in its list of Scytalopus. The suggested English name Jalca (pronounced “HAL-ka” in American English) is not particularly descriptive of the bird, nor is the habitat exclusively inhabited by this species (most Peruvian and Bolivian members of the S. magellanicus complex live in jalca). However, it is a unique name and should prevent confusion with other tapaculos. Given that the species in the genus present few distinctive features to allow for memorable English names, I think that Jalca Tapaculo is about as good as it gets here, and suggest that it also be adopted by SACC.
Cory, C. B., and C. E. Hellmayr. 1924. Catalogue of birds of the Americas., Part III. Field Museum of Natural History Zoological Series, Volume XIII, Part 3.
Fjeldså, J., and N. Krabbe. 1990. Birds of the high Andes. Apollo Books, Svendborg, Denmark.
Isler, M. L., P. R. Isler, and B. M. Whitney. 1998. Use of vocalizations to establish species limits in antbirds (Passeriformes: Thamnophilidae). Auk 115: 577-59.
Krabbe, N.K., T.S. Schulenberg, P.A. Hosner, K.V. Rosenberg, T.J. Davis, G.H. Rosenberg, D.F. LANE, M.J. Andersen, M.B. Robbins, C.D. Cadena, T. Valqui, J.F. Salter, A.J. Spencer, F. Angulo, and J. Fjeldså. 2020. Untangling cryptic diversity in the High Andes: Revision of the Scytalopus [magellanicus] complex (Rhinocryptidae) in Peru reveals three new species. Auk 137: xxx. https://doi.org/10.1093/auk/ukaa003
Peters, J. L. 1951. Check-list of birds of the world. Volume VII. Museum of Comparative Zoology, Cambridge, Massachusetts.
Zimmer, J. T. 1939. Studies of Peruvian birds. No. XXXII. The genus Scytalopus. American Museum Novitates number 1044.
Daniel Lane, April 2020
Comments from Remsen: “A. YES. Vocal and genetic data are consistent with recognizing this as a new species. B. YES, for the reasons outlined by Dan.”
Comments from Areta: “A. YES. B. It seems strange to use Jalca Tapaculo for a bird that has been known for ages as Millpo Tapaculo, but if Jalca shall be, Jalca be.”
Comments from Robbins: “YES. It has long been appreciated that birds collected in Huánuco represented a new species, the voice coupled with the new genetic data confirm this as a species.”
Comments from Bonaccorso: “YES. Differences in genetics and voice are (almost) as good as it can get for species in this group.”
Comments from Jaramillo: “A. YES – solid data to separate as biological species. B. YES. Sounds like a good enough rationale, apply a name that is more informative, as opposed to one that has been around informally.”
Comments from Zimmer: “A. YES” to recognizing frankeae as a species, due to congruence between vocal and genetic data sets. B. YES to Jalca Tapaculo as the English name, given that it accurately reflects the habitat occupied by the species, and, that “Millpo Tapaculo” although long in informal use, reflects not the broader distribution of the species, but merely the locale where the taxon was first recognized as possibly distinct.”
Comments from Schulenberg: “YES. It's long been known as Millpo Tapaculo, but no one's ever been back to Millpo (nor is anyone likely to return any time soon), and the site otherwise is barely known at all; so, retaining Millpo in the name makes no real sense.”
Comments from Pacheco: “A. YES. The sequencing of holotypes involved in the complex finally allowed the genetic and vocal distinctions (already informally recognized) to support the validity of the new species.”