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.
Literature
cited:
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
Note on voting from
Remsen: Although I anticipate no problems, let’s formally
break this into “A” for species rank and “B” for adoption of the proposed name.
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.”