Proposal (854) to South American Classification Committee
Recognize Scytalopus whitneyi
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, which has long been referred to colloquially as “Ampay Tapaculo” due to its first being recognized as potentially new after a visit by Krabbe and Fjeldså to the Ampay massif in Apurímac dept., Peru, has finally been described. The new species has been given the name Scytalopus whitneyi, honoring Bret Whitney, who is one of the most impressive living field ornithologists working in the Neotropics (Krabbe et al. 2020). The English name suggested for this species is “Ampay Tapaculo”, referring to the type locality, although the species is known to be more widespread.
Scytalopus whitneyi was found to be embedded within a clade that included most of the central and southern members of the S. magellanicus complex (from Peru to Argentina). It is distinctive in minor morphological characters; in particular, it "is readily distinguished from S. frankeae, S. urubambae, and S. simonsi by its overall darker gray plumage and its duller and darker ochraceous brown flanks, rump, and vent, with relatively dense, narrow, and straight barring". More importantly, the primary song of S. whitneyi also differs from that of related species by consisting of a single repeated note; the structure of the notes of the secondary song also differs from the songs of related species (see Krabbe et al. 2020 for details). Its distribution is bound to the north by the Mantaro valley (north of which, it is replaced by S. frankeae) and to the east by the Apurímac valley (east of which, it is replaced by S. urubambensis).
Recommendation: I believe Krabbe et al. (2020) have made a strong case for the recognition of S. whitneyi, and recommend that SACC include it in its list of Scytalopus. The suggested English name Ampay Tapaculo is distinctive in highlighting the type locality. In addition, this English name is the colloquial name that had been used as a placeholder until the taxon was described, and thus is already fairly familiar to many Peru birders. I 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 – good name, and as Dan pointed out, this has been the species’ informal name among leading scytalopologists and their fans.”
Comments from Areta: “A. YES. B. Yes, sounds good and maintains coherence through time.”
Comments from Robbins: “YES, vocal and genetic data support recognition as a species.”
Comments from Bonaccorso: “YES. Differences in genetics and voice are consistent with a new species.”
Comments from Jaramillo: “A. YES. B. YES – See 853, in this case informal name used, in the previous it was not.”
Comments from Zimmer: “A. YES to recognizing whitneyi as a species, as supported by congruent vocal and genetic data sets. B. YES to the suggested name of Ampay Tapaculo, highlighting the type locality for the species.”
Comments from Schulenberg: “YES. It's long been known by that name, and unlike 'Millpo', Ampay is a well-known site, so this name makes sense in that regard.”
Comments from Pacheco: “A. YES. The sequencing of holotypes of the previous names involved in the complex, as happened with the previous proposal, finally allowed the genetic and vocal distinctions (already recognized for decades) to provide the necessary support in the validity of the new species.”