Proposal (193) to South American Classification Committee

Recognize Scytalopus stilesi as a valid species

Effect on South American CL: This proposal would add a newly described species to the list.

Background: Cuervo et al. (2005) discovered a new tapaculo from the mid-elevation cloud forests from the Cordillera Central of Colombia that they described as a new species. Their conclusion that this taxa represents a new species is based on a series of 8 specimens along with vocal, genetic, and distributional information. Vocally it is distinct from all other described tapaculos. Morphologically it may not be distinguishable from all taxa but it is distinguishable from the other species that occur in its range. As there is little morphological variation in the genus and vocalizations and ecological separation have been shown to be the key to species limits in the genus, (see Krabbe & Schulenberg 1997,2003) I see no problem in recognizing this as a new species level taxon.

Recommendation: Based on the vocal, genetic, and distributional information, I believe this paper clearly documents a new species level taxon. I recommend a "yes" vote to add this newly described tapaculo to the South American list.

References:

A.M. Cuervo, C.D. Cadena, N. Krabbe and L.M. Renjifo. 2005. Scytalopus stilesi, A New Species Of Tapaculo (Rhinocryptidae) From The Cordillera Central Of Colombia. The Auk 122(2): 445-463.

Krabbe, N., and T.S. Schulenberg. 1997. Species limits and natural history of Scytalopus tapaculos (Rhinocryptidae), with descriptions of the Ecuadorian taxa, including three new species. Pages 47-88 in Studies in Neotropical Ornithology Honoring Ted Parker (J.V. Remsen, Jr., Ed.) Ornithological Monographs no. 48.

Krabbe, N., and T.S. Schulenberg. 2003. Family Rhinocryptidae (tapaculos). Pages 748-787 in Handbook of the Birds of the World, Vol. 8: Broadbills to Tapaculos (J. del Hoyo, A. Elliott, and D. Christie, Eds.) Lynx Edicions, Barcelona, Spain.

Daniel Zimberlin, November 2005

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Comments from Schulenberg: "YES. I have no hesitation in recognizing this species. It is the first of several (many?) newly described Scytalopus taxa that we will be asked to vote on.

"In terms of plumage and morphometrics stilesi is not readily diagnosable, but the same is true for many taxa of Scytalopus. As is discussed in the paper, the vocalizations of stilesi are distinctly different from all sympatric taxa and are not particularly similar to any other member of the genus.

"More importantly, this study incorporates genetic (partial cytochrome b DNA sequences) data, from work that remains in progress to develop a molecular phylogeny for the entire genus (including Brazilian taxa). The preliminary data discussed in this paper show that stilesi is genetically distinct (4-7% percent different from allopatric, closest relatives). I'm not particularly happy with the idea that stilesi is closer to robbinsi (of southwestern Ecuador) than robbinsi is to chocoensis (of northwestern Ecuador and southwestern Colombia). But this could be only the first of many unpredicted revelations from the molecular phylogeny."

Comments from Stiles: "These proposals [193 and 195] are slim as they stand, but the evidence in the papers cited looks solid, incorporating vocal and genetic data as well as morphology (which is often equivocal for birds of this genus. My suggestion would be for the author of these proposals to provide links to the relevant paper(s) (as has John Penhallurick on several occasions), thus saving committee members (especially those outside the USA) possible time and trouble in obtaining them (or alternatively, the author or Van could incorporate a link to a pdf file in the proposal). So, the name of 193 notwithstanding, I will vote YES on both."

Comments from Robbins: "YES. Although the proposal provides minimal information, the Cuervo et al. (2005) data leave no doubt that stilesi should be recognized as a species; hence a YES vote."

Comments from Pacheco: "YES. Os autores suplementaram a decisão de reconhecimento de um novo táxon com dados genéticos e vocais abonadores."

Comments from Zimmer: "YES. Morphology is clearly evolutionarily conservative in this group, with vocal and ecological characters and range disjunction being better indicators of genetic distance. As indicated by Tom, this will be just the tip of the iceberg in the impending recognition of new taxa in this genus."

Comments from Nores: "YES. Aunque denominar nuevas especies por el canto (sin diferencias morfológicas) resulta algo novedoso y si se quiere no del todo convincente, el hecho de que también haya diferencias genéticas resulta fundamental. Bajo este criterio sería interesante analizar también los cantos de las subespecies de Scytalopus superciliaris de Argentina (S. s. santabarbarae de la Sierra de Santa Bárbara, en Jujuy (Nores, M. 1986. Diez nuevas subespecies de aves provenientes de islas ecológicas argentinas. Hornero 12: 263 273) y de la subespecie aún no nominada de El Cantadero, La Rioja) (Nores, M. and Cerana, M. M. 1990. Biogeography of forest relics in the mountains of northwestern Argentina. Rev. Chil. Hist. Nat. 63: 37-48), para ver si se trata de especies y no de subespecies."