Proposal (296) to South American Classification Committee

 

Change the English name of Melanodera melanodera from Canary-winged Finch to White-bridled Finch

 

Effect on SACC: If passed, this proposal would change the SACC (Dickinson 2003) baseline English name of Melanodera melanodera from Canary-winged Finch to White-bridled Finch. The widely used and traditional name Black-throated Finch was considered redundant in proposal #257 which passed to use the name Canary-winged Finch.

 

Background: The genus Melanodera comprises two species: 'Black-throated/Canary-winged/White-bridled' Finch M. melanodera and Yellow-bridled Finch M. xanthogramma. Each species comprises two subspecies. In the case of M. melanodera, one subspecies-M. m. princetoniana-stood at species rank for thirty-three years, while M. xanthogramma has always been considered a polytypic species.

 

As stated by Alvaro Jaramillo in #257, the name Black-throated Finch is already occupied by Poephila cincta of Australia, so we agree that this English name cannot be used for M. melanodera. As an aside-given that it is outside SACC's remit-we note that this name may not be appropriate for P. cincta. Not only do all male Melanodera finches have black throats, but also so do three of the four Poephila finches. Moreover, M. melanodera was described thirteen years prior to P. cincta, but we are not able to comment upon why the name Black-throated Finch has priority for P. cincta.

 

Jaramillo (#257) rejected the alternative name White-bridled Finch on the grounds that "The yellow bridle around the black throat of xanthogramma [Yellow-bridled Finch] is one of the most obvious features of this bird in life. However, with Melanodera melanodera the most obvious feature, and a very distinctive one at that for any South American passerine, is the largely yellow wings. In the bleak grasslands of southernmost Patagonia, these flashes of yellow are hard to miss!". Jaramillo thus proposed the use of Canary-winged Finch for M. melanodera. This name was first coined relatively recently by Sibley & Monroe (1990). 

 

Analysis: In this proposal, we demonstrate that the name Canary-winged Finch is only applicable to the Patagonian subspecies princetoniana of Melanodera melanodera, i.e. the form to which Jaramillo refers. As such, we propose that an alternative name is needed that is applicable to both subspecies. We hereby propose to use the name 'White-bridled Finch'.

 

In his proposal (#257), Jaramillo neglected to mention that M. melanodera, like its congener M. xanthogramma, is a polytypic species. This fact is critical to a determination of an appropriate English name. The two taxa are M. m. melanodera, endemic to the Falkland Islands, an island group of 12,173 km2 (4700 miles2) which are included in the area covered by S.A.C.C. (see Geographical scope, page 2), and M. m. princetoniana of southern Santa Cruz province, Argentina and adjacent Magallanes region, Chile, and northern Tierra del Fuego, Argentina and Chile. The latter was originally described as Phrygilus princetoniana (Scott 1900) and subsequently considered as a subspecies of M. melanodera by Dabbene (1933). 

 

We believe that substantial differences in plumage and abundance levels between the two subspecies means that 'Canary-winged Finch' is an inappropriate and misleading English name for the species as a whole. It is also important to compare M. melanodera with its sister species, Yellow-bridled Finch M. xanthogramma.

 

a) Plumage

Adult males of the two subspecies of M. melanodera differ considerably in plumage. One of the most striking features of male princetoniana is the amount of yellow in its wings. The wing-coverts are mostly bright yellow and the primaries have broad and equally bright yellow fringes. The underwing-coverts and axillaries are also bright yellow and the underside of the remiges is a paler yellow, tipped brown. The mostly yellow wings mean that Canary-winged Finch would be a very appropriate name for this subspecies.

 

In stark contrast, adult males of the nominate melanodera of the Falkland Islands have mostly olive wings. Many birds lack yellow altogether in the wings (pers. obs.). When present, it is (a) substantially less intense than princetoniana and (b) highly restricted in extent, being limited to the outermost lesser wing-coverts, edge of the carpal and very narrow fringes on the outermost primaries. Woods (1988) suggested that yellow was restricted to fringes on the lesser wing-coverts and secondaries (i.e. an even more reduced area), but specimen examination and field experience indicates otherwise. Most of the wing-coverts, remiges and the underwing-coverts are olive, and thus the wings also appear olive in flight.

 

These differences can be clearly seen in published photographs. For example, photograph 841 (page 272) in Couve & Vidal (2003) shows the bright "canary" yellow wings of a male princetoniana. On the same page a male nominate melanodera (photo 845), and a large photograph on page 271 of nominate melanodera, do not show any yellow in the wing. Unfortunately (and confusingly), in this publication, the six photographs captioned "M. m. princetoniana" are actually M. m. melanodera, whereas the three photographs at the top of the page without captions are princetoniana. Conversely, a male nominate melanodera photograph from the Falklands (Shirihai 2002: 267) shows yet another drab winged bird.

 

For a more direct comparison, we also refer the committee to a selection of photographs of all four male Melanodera taxa, which can be viewed at http://picasaweb.google.es/markpearman/OverviewOfMaleMelanoderaFinches and then a single left click on "Presentación de diapositivas".

 

On plumage grounds then, it would be inaccurate to call M. m. melanodera 'Canary-winged Finch'; this name should be exclusive to M. m. princetoniana.

 

b) Relative abundance

In addition, we believe that the comparative abundance of the two M. melanodera taxa is relevant when deciding upon the most representative English name.

 

A breeding bird survey from 1983 - 1993 in the Falklands showed that nominate melanodera was evenly distributed throughout the islands with a population estimate of between 7,000 and 14,000 pairs (Woods & Woods 1997). More than 1,000 pairs were estimated on Sea Lion Island alone, an island of just 905 hectares. Woods (1988) described the species as "resident, common and widespread" and mentioned that the local name is "sparrow", presumably another testimony to its abundance.

 

In contrast, Melanodera m. princetoniana is by far the least known and rarest of the four Melanodera taxa. FjeldsĆ & Krabbe (1990) wrote: "N Isla Grande (where now extinct?) and Sta. Cruz, Arg., vanishing due to overgrazing by sheep, although recently rec. as fairly common at Cabo Vírgenes". Jaramillo (2003) wrote: "A rare finch of Patagonian grasslands which have not been overgrazed" and mapped southern Magallanes and northern Isla Grande. Ridgely & Tudor (1989) wrote: "on the mainland Black-throated Finches have declined precipitously of late" and "particularly numerous on the Falklands, but much less so in mainland portion of range, with few recent records at least from Argentina". Clearly, there is no doubt that princetoniana is a rare bird with a restricted range.

 

With regards to the relative abundance of the two M. melanodera taxa therefore, we find that the name Canary-winged Finch would apply to the numerically small Patagonian population, and not to the large insular population of the Falklands.

 

c) Comparison with M. xanthogramma

The differences between the two forms of M. xanthogramma, are also notable (see #257) and relevant to this proposal. Adult M. x. barrosi has entirely grey wings with an olive shoulder (see individuals in the photo link) which is the reverse of that illustrated in Jaramillo (2003), whereas nominate M. x. xanthogramma has a considerable amount of olive in the wing and the primaries are fringed yellow in fresh plumage (cf. the photo link, completely unlike that illustrated in Jaramillo 2003). In flight, both nominate xanthogramma and nominate melanodera thus have rather similar wing patterns, and the name "Canary-winged Finch" is of no help whatsoever in distinguishing these forms. It is noteworthy that there are BMNH specimens of M. x. xanthogramma from the Falklands and one recent observation from there in 1988 (White & Henry 2001), so the nominate forms of each species do occasionally overlap.

 

This brings us to the single conspicuous and diagnostic feature which easily separates both species and their subspecies, namely the combination of the supercilium, moustachial streak and connecting lines - collectively called "bridles" (because they recall the shape of horse bridles). In M. xanthogramma, these 'bridles' are yellow. In both subspecies of M. melanodera, they are white.

 

Diligent observers will also note that in the polymorphic M. x. xanthogramma and M. x. barrosi, the subocular crescent is white as is the inferior border of the throat, yet these do not detract from the striking aspect of the yellow bridles in the typical grey morph. In the yellow morph, these small areas are pale yellow. In contrast, the bridles of the monomorphic M. melanodera are white in both subspecies.

 

The name "White-bridled Finch" (Mazar Barnett & Pearman 2001, Gill & Wright 2006) for M. melanodera is therefore an accurate name. It has no ambiguity and it is not named after a feature unique to one rare subspecies which is the case with the name "Canary-winged Finch". Both Melanodera species come into direct contact in winter and actually form mixed species flocks in Santa Cruz province, Argentina (Di Giacomo 2005) and presumably also in Tierra del Fuego, and the striking yellow or white "bridles" could provide an isolation mechanism when birds move off and segregate into their different breeding habitats in spring (pers. obs).

 

d) Usage of the two alternative names

The first appearance of the name Canary-winged Finch derives from Sibley & Monroe (1990) and the first appearance of White-bridled Finch from Mazar Barnett & Pearman (2001), thus both are recent names. Jaramillo (#257), also used the number of Google hits for Canary-winged Finch versus White-bridled Finch as an argument for usage of the former. Not surprisingly, given the eleven year gap between the two names, the former was bound to have more hits, yet looking closely one finds that almost all refer to trip reports or websites and none refer to books that are not already mentioned here. The names Yellow-bridled Finch and White-bridled Finch clearly uphold the present taxonomic status of each species, and we suggest that their usage is not intended to form symmetry (a concern expressed by Gary Stiles in #257) but to exemplify the 'only' constant feature which separates the two species.

 

Conclusion: The name Canary-winged Finch is appropriate on plumage grounds to only one of the two subspecies of M. melanodera. Moreover, it is appropriate only to the rarer taxon. The alternative name, White-bridled Finch, is applicable on plumage grounds to both taxa.

 

Recommendation: We propose a "YES" vote to change the name of Melanodera melanodera to White-bridled Finch, or a "NO" vote to retain the name Canary-winged Finch.

 

Literature Cited

Couve, E. & C. Vidal. 2003. Aves de Patagonia, Tierra del Fuego y Peninsula Antarctica (Islas Malvinas y Georgia del Sur). Edit. Fantastico Sur Birding Ltda., Punta Arenas, Chile.

Dabbene, R. 1933. Notas sobre las especies argentinas del género PhrygilusAnal. Soc. Cient. Arg. 115: 169-193.

Dickinson, E.C. (ed.). 2003. The Howard and Moore complete checklist of the birds of the World, Revised and enlarged 3rd Edition. Christopher Helm, London, 1040 pp.

Di Giacomo, A.S. ed. 2005. Áreas de importancia para la conservación de las aves enArgentina. Sitios prioritarios para la conservación de la biodiversidad. Temas de Naturaleza y Conservación 5. Aves Argentinas/Asociación Ornitológica del Plata, Buenos Aires.

FjeldsĆ, J. & N. Krabbe. 1990. Birds of the High Andes. Zool. Mus., Univ. of Copenhagen.

Gill, F. & M. Wright. 2006. Birds of the World: Recommended English Names. Princeton Univ. Press, Princeton NJ. 

Jaramillo, A. 2003. Field Guide to the Birds of Chile including the Antarctic Peninsula, the Falkland Islands and South Georgia. Helm Field Guides, Christopher Helm, London.

Mazar Barnett, J. & M. Pearman. 2001. Annotated Checklist of the Birds of Argentina. Lynx Editions, Barcelona.

Ridgely, R.S. & G. Tudor. 1989. The Birds of South America Volume IThe Oscine Passerines. Oxford Univ. Press.

Scott , W.E.D. 1900. New or undetected species of birds from South America. Bull. Brit. Orn. Club 10: 62-64.

Shirihai, H. 2002. A Complete Guide to Antarctic Wildlife: The Birds and Marine Mammals of the Antarctic Continent and the Southern Ocean. Alula Press Oy, Helsinki, Finland.

Sibley, C.G. & B.L. Monroe, Jr. 1990. Distribution and Taxonomy of the Birds of the World. Yale Univ. Press, New Haven, Connecticut.

White, R. & A. Henry. 2001. Rare & Vagrant Birds In The Falkland Islands 1996-2000. Wildlife Conservation in the Falkland Islands 1: 16-18.

Woods, R.W. 1988. Guide to Birds of the Falkland Islands. Anthony Nelson,  Oswestry, U.K.

Woods, R.W. & A. Woods. 1997. Atlas of Breeding Birds of the Falkland Islands. Anthony Nelson, Oswestry, U.K.

 

Mark Pearman (Buenos Aires), Santiago Imberti (Río Gallegos, Santa Cruz, Argentina), Juan Mazar Barnett (Buenos Aires) and Alan Henry (Stanley, Falkland Islands), July 2007

 

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Additional comment by David Donsker (Taxonomic editor of Gill & Wright 2006): 
"I remember well my disappointment in not being blown away by the yellow wing color in the birds I saw in the Falklands and not realizing at the time that those birds aren't like the one illustrated in Ridgely and Tudor. (Several years later, however, I actually was impressed by the yellow wing color in the individuals seen just north of Punta Delgada). The SACC process is very thorough and appears to stick consistently to its high standards. Hopefully, reason will prevail in the case of M. melanodera."

 

Comments from Stiles: "YES. Given the polytypic nature of M. melanodera, this seems the best for the species as a whole.  Were it to be split, "Canary-winged" would be available for the mainland subspecies."

 

Comments from Stotz: "YES. I am not opposed to an English name that does not apply well across the entire range of a species (examples that come immediately to mind are Olive Oropendola and Great Blue Heron).  However, the issue of relative abundance and range seems to work the opposite direction in this case, unlike the other two cases where the English name is appropriate for the much more widespread taxon."

 

Comments from Jaramillo: "YES - I actually did not "neglect" to mention the issue of melanodera being polytypic, I didn't think it was relevant, as frankly I did not realize the differences between princetoniana and nominate melanodera were so striking. This proposal has been really informative, and it makes me wonder if more species level taxa are present in Melanodera than are currently recognized. Given the issues presented, it does seem clear that Canary-winged is inappropriate, and White-bridled seems quite appropriate. As Gary mentions, Canary-winged is available if princetoniana is ever separated from melanodera."

 

Comments from Robbins: "NO. I vote "no" because what this proposal demonstrates is that mainland princetoniana of Melanodera melanodera deserves species recognition, as apparently was the case when it was described. Indeed, based on what Pearman et al. present, it appears that princetoniana approaches the degree of morphological differentiation from melanodera that is found between melanodera and xanthogramma. As a result, I see no value in changing the name again and then eventually switching it back. I strongly urge Pearman et al. to repackage their proposal into a short paper for Cotinga or another appropriate journal that would formalize species recognition of princetoniana."

 

Comments from Zimmer: "NO. I was all set to vote YES on this one, but Mark's comments are persuasive. It really does sound as if we are dealing with two species-level taxa here, and changing the English names now, only to change back as the result of a split down the line does seem somewhat destabilizing. As nearly everyone has pointed out, "Canary-winged" would be an appropriate name for princetoniana in the event of a split, so we could be looking at going from Black-throated to Canary-winged to White-bridled and back to Canary-winged for princetoniana. If the evidence for a split is as good as it sounds, I also would urge the proposal authors to follow through and straighten out the taxonomy before we further muddle the English name picture. If the evidence for a split is not there, and princetoniana and melanodera are best considered conspecific, then I would vote YES for the English name change to "White-bridled". Meanwhile, I'll hold out for waiting."

 

Further comments from Pearman et al.: Clearly our information has lead to a misunderstanding given the comments by Mark Robbins. If any of the authors of our proposal had suspected that princetoniana had reached species threshold, our proposal would have been submitted after a paper ratifying the taxonomic situation. On the contrary, and with years of experience of the M. melanodera taxa, even daily for some of the authors of this proposal, we have no doubt that the forms are still far from even approaching species threshold. Beyond plumage differences which equate only to distinctions in wing coloration (and hence the misnomer of Canary-winged Finch), we have also conducted a number of playback experiments both in Santa Cruz and on the Falklands, finding 100% immediate response by each taxon to the voice of the other taxon, with direct flights of up to 250 m. directly towards the sound source and vocal contestation usually in the form of extended song bouts which can last for more than an hour. We find this to be a very unusual and even fascinating response among Emberizidae or oscine passerines in general. Due to the similarity of songs, we feel that there is no evidence to treat princetoniana at species level and have no intention to split these forms. Therefore we endorse the current taxonomy, but reiterate the need for an accurate vernacular name as detailed by our proposal.

 

Additional comments from Robbins: "After reading Pearman's comments I change my vote on proposal # 296."

 

Comments from Remsen: "YES. Normally, I would consider the various pros and cons of each name irrelevant because stability is more important, but given that the competing names are both of vey recent origin, I think the arguments of Pearman et al. are persuasive."