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.
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: 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, 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.”