Proposal (392) to South American Classification
Committee
Elevate Dubusia taeniata stictocephala to
species level
The
Buff-breasted Mountain-Tanager (Dubusia taeniata) is a polytypic species
found from the northern end of the Andes south to southern Peru, with an
isolated population in the Colombian Santa Marta mountains (Paynter and Storer
1970, Isler and Isler 1987). The nominate
subspecies (type locality “Santa-Fé-Bogota” Colombia) ranges from western
Venezuela south to northern Peru, north and west of the Marañón low. The
distinctive blue-crowned stictocephala (type locality in Junín, Peru) occurs
from south and east of the Marañón
low to southern Peru (Schulenberg et al. 2007).
The Santa Marta birds, carrikeri, have some blue crowned
streaking, unlike solid, blackish-crowned nominate, with the buff of the breast
extending up to the center of the throat (depicted in Isler and Isler
1989).
As can be readily heard and
visualized spectrographically on both the Xeno-canto America and MLNS
web-sites, the song of nominate consists of 2-3 loud, whistled notes,
“feeeeu-bay” or “feeeeu-feeeu-bay” (Ridgely and Tudor 1989). The first two
notes slur downward in frequency, with the third note (when given) having less
of a frequency change. This song is
consistent throughout the range of nominate (both east and west slopes), and
according to Nick Athanas and Niels Krabbe (pers. comm.) the Santa Marta carrikeri
also has a song similar to nominate.
Birds continue to give this song-type even after playback (Paul Schwartz
recordings from Venezuela; MLNS 70755-70756-70757). In striking contrast, stictocephala’s
song is quite distinct from birds north of the Marañón, and is reminiscent of a Pipreola’s thin,
high-pitched whistle. This song is a single-noted whistle that is sharply
slurred downward in frequency. The single-noted song is continually repeated
and is given at dawn as well as later in the morning and after playback (MLNS
137664).
Because of the dramatic break in
song and plumage across the Peruvian Marañón
low, we recommend that stictocephala be elevated to species status.
Although the specific epithet signifies the crown is spotted, this region and
the nape are actually heavily streaked with cerulean color. To reflect this distinctive plumage
character, we recommend Cerulean-streaked Mountain-Tanager as the English name
for D. stictocephala. As a final
comment, we suspect that genetic data will further corroborate the Marañón break, and may even demonstrate
considerable differentiation among nominate and carrikeri, despite the fact that these latter two taxa reportedly
have similar voices.
Acknowledgments. Nick Athanas
and Niels Krabbe kindly shared their knowledge about the vocalizations of carrikeri. Greg Budney and Jessie Barry at MLNS kindly
made available on-line key cuts of Dubusia.
Literature Cited.
Isler, M. L. and P. R. Isler. 1987.
The tanagers. Natural history,
distribution, and identification.
Smithsonian Institution Press, Washington, D.C.
Meyer de Schauensee, R. 1966. The species of birds of South America and
their distribution. Livingston
Publishing Company, Narbeth, Pennsylvania.
Paynter, R. A., Jr. and R. Storer.
1970. Check-list of birds of the
world. Museum of Comparative Zoology,
Cambridge, Massachusetts.
Ridgely, R. S. and G. Tudor.
1989. The birds of South America. Vol. 1. The oscine passerines. University of Texas Press, Austin.
Schulenberg, T. S., D. F. Stotz, D.
F. Lane, J. P. O’Neill, and T. A. Parker, III.
Birds of Peru. Princeton
University Press, Princeton, New Jersey.
Mark B.
Robbins, Pete A. Hosner, and Dan F. Lane, March 2009
Comments from Cadena: “NO, for a lack of published analyses.”
Comments from Nores: “NO. Yo estoy de acuerdo con Cadena de no
aceptar cambios de este tipo que no estén apoyados por análisis publicados.
Además no veo que haya un “dramatic break in plumage across the Peruvian Marañón low”. Las diferencias para
mi son propias de subespecies.”
Comments from Remsen: “NO, but only on a technicality.
I understand the frustration when vocal differences are known and now
readily assessed by means of online recordings.
However, I favor sticking to our policy of making changes based only on
published analyses and comparisons of those recordings. Note that the above proposal needs only a
little more work to be ready for submitting as a short publication. Just the process of putting together existing
information as a SACC proposal represents the bulk of the work needed to get a
short publication submission-ready. In
other words, a proposal sufficiently detailed and rigorous to pass SACC is also
very close to publishable as a journal note.”
Comments from Zimmer: “NO. My feelings about this proposal are similar
to those of the preceding one (Troglodytes
aedon/cobbi). I think Mark, Pete and
Dan make an excellent case for splitting these birds, and that ultimately, this
will be shown to be the correct course.
But again, given that the SACC has generally maintained a policy of
requiring some sort of published analysis before making a change, I reluctantly
vote NO. If Mark and company could
publish even a short paper with spectrographic examples of the vocal differences,
I would happily change my vote.”
Comments from Jaramillo: “YES –
Although I do think the authors should publish a short note, the vocal
difference seems to clear to me and the data so readily accessible that I feel
more at ease making this change than letting it sit. It seems to me that there
are too few researchers, and even less time for them to do these types of
things than we have open questions. However, I dislike the English name; it
doesn’t quite roll of the tongue.”
Comments from Schulenberg: “YES. I'm with Al on this one. In the past, I've voted against any number
of good-sounding proposals because of the lack of a "published
analysis." But we've let a lot of decent ideas die along the way - many of
which have yet to be written up for publication, years later - and in the
meantime it's becoming easier and easier to assemble the relevant information
online.
“I see some room, in other words, between
"field guide taxonomy" (little or no documentation provided) and a
Kevin Zimmer 30-page exhaustive survey. The point of a published analysis,
after all, is in spreading and sharing data and the conclusions that stem from
them. I think this proposal follows in the vein. If we agree that the authors
convince *us* of the merits of their case, and if the data on which we base our
conclusions are available to others, then we're only hurting ourselves by
voting against it.
“The name "Cerulean-streaked
Mountain-Tanager" is awkward, however. Can't you settle for
"Blue-streaked Mountain-Tanager"? A four-word name (long!) with a
four (!!) syllable opener is too much for me. Simplify, simplify.”
Comments from Stotz: “YES. This looks like a
clear split. I agree with Jaramillo and
Schulenberg that Cerulean-Streaked Mountain-Tanager is a bit too much. Tom’s suggestion of Blue-Streaked
Mountain-Tanager sounds good to me.”
Comments from Stiles: “NO for now, for exactly the same reasons as in the
previous proposal: a peer-reviewed
publication should be required – especially for people like me who are
unfamiliar with the taxa concerned.”
Comments from Pacheco: “YES. Voto sim pelas mesmas razões apresentadas na Proposal
#391. Creio ser mais danoso – mascarando a real diversidade – manter táxons “agrupados”
meramente por tradição/continuísmo do que tratá-los como distintos até que
alguma análise corrobore o contrário.”