Home About Committees North American Classification Committee Current & Prior Proposals 2013 Proposals Comments 2013-B

Comments 2013-B

2013-B-1: Make changes to the linear sequence in the family Mimidae

YES. 5 without comment.

YES. The proposed sequence is the best fit for congruence with the genetic data while maintaining some structure from the prior sequence.

YES. Well-supported, complete phylogeny, and I come up with the same sequence using the usual conventions. However, the proposal needs a brief reference to the conventions we use for the sequence.

YES. Nice work.

2013-B-2: Split Nutting’s Flycatcher into two species: Myiarchus nuttingi and M. flavidior

YES. Nutting’s and Ridgway’s ok for English names.

YES (very weakly).  I’m sure Steve Howell is right about this, but the article presented by him is all pretty anecdotal. I’m just as happy to await a further more detailed paper, especially more carefully delineating the geographic ranges. 

NO. These may be cryptic species, but this is clearly a case where further study is warranted that focuses on genetic, morphologic, and vocal variation among populations within M. nuttingi. I can’t justify the split now based on a sample size of 6 (3 M. n. nuttingi, 3 M. n. flavidior) with limited geographic sampling and only mtDNA. The ML and Bayesian trees don’t agree with regard to monophyly of the two populations, and basal support of those nodes is low. The paper by Sari and Parker (2012) states “Three subspecies are currently recognized for M. nuttingi (Lanyon, 1961), and the lineages found here might [italics mine] represent two of them…” A more complete study would look at all three subspecies and definitively relate different evolutionary lineages to subspecies named on the basis of phenotype, as well as delimit any contact zones and examine genetic introgression (a need mentioned in the paper). Playback experiments would also help to ascertain whether vocally and genetically different populations are likely to be reproductively isolated.

NO. I’m tempted to vote yes but would like to see a bit more done with specimens (morphology, plumage, DNA). Were the specimens used by Sari and Parker from Costa Rica and El Salvador flavidior? If there are vouchers then they should be looked at before making a decision. Only the ML tree  in Sari and Parker has two nuttingi populations as not monophyletic; the Bayesian tree has the two nuttingi populations as sister taxa.

NO. This seems almost certain but according to AOU-CLC policy it should await more fully and carefully developed study and proposal.

NO. The evidence presented does indeed suggest that two species are involved, but with respect to species limits I consider it good preliminary data to precede a more thorough study.

NO. This split may very well be correct (or likely is correct), but the data presented in this paper just don’t quite establish this with certainty. The sound info is just not strong enough, and the genetic data (from an article primarily about another species of Myiarchus) are not firmly tied to the taxa at hand. 

NO, for now. Howell is almost certainly correct on this, and has done a great job of setting the stage for a formal analysis. We need something more rigorous than anecdotes, a few recordings, and genetic samples of uncertain provenance to make a novel split like this one. I suggest that Howell collaborate with someone willing to make and analyze sonograms of recordings, with a reasonable N, and perhaps sort out the identification of the vouchers. Also, if the proposal passes, I strongly recommend a separate proposal on the E names.

2013-B-3: Add Common Moorhen Gallinula chloropus to the AOU Checklist

YES. 1 without comment.

YES. The fact that there is a voucher specimen for this record, and that it’s identification is confirmed by molecular data, provides strong support for this addition.

YES. Molecular data looks solid enough for identification as chloropus. A PCA of skeletal measurements (looks like a partial skel was saved) in a sample of chloropus and galeata would have been a good way to show if the specimen falls within chloropus morphologically.

YES. Great record.

YES. Given that we now have a record for North America of true Gallinula chloropus, I think the continued use of Common Moorhen for the daughter species chloropus from the split of chloropus and galeata opens all sorts of opportunity for confusion (as does the use of Common Gallinule, formerly used by AOU for the entire Gallinula chloropus). Obviously this is not the place to deal with this issue but we really should fix this problem. I personally think that Gallinula galeata is a Moorhen, but even if it is a Gallinule, it needs to be something like American Gallinule, and chloropus should be Eurasian Gallinule or some such.

YES. I agree about the common name issue.

2013-B-4: Merge all North American rosy-finches into Leucosticte tephrocotis

NO. I am not convinced they are conspecific.

NO, but this is a mess. I’m not sure I would have ever voted to re-split the Rosy Finches to start with, what based on an unpublished thesis? I recall Van explaining that the bar for reversing lumps of previously recognized species, especially from the mass lump of 1972 or 1973, was not as high. From my viewpoint all of the North American Rosy-Finches seem more of a group of subspecies rather than separate species. They sound absolutely IDENTICAL to my ear and I see no behavioral or habitat differences. Yes, there are morphological differences, but there ranges are isolated from one another by geography, not all parts of the West, much as we would wish, have alpine habitat above tree line. And how can the justification for splitting Brown-capped and Black from Gray-crowned be justified when the all gray faced littoralis(“Hepburn’s”) is lumped with Gray-crowned, as are the much larger griseonucha (primarily from the Aleutians but west to the Commander Islands and east to the western Alaska Peninsula and the Shumagin and Semidi Islands) and the large and darker umbrina (Pribilofs, St. Matthew and Hall Islands)? I’m not sure I’ve ever seen an intergrade bird except for some intermediate logo-auk-aou.png” border=”0″ width=”240″ height=”146″ littoralis, but worn SY dawsoni Sierra Gray-crowned Rosy Finches in May can look very similar to female Brown-capped, and have even been judged as that by experts in Colorado. And this doesn’t even get us to species limits within Asian Rosy-Finches where all taxa are treated as a single species.

NO. Before lumping them, I would like to see something about the degree of reproductive isolation between the North American forms, including the width and stability of the hybrid zones, and the ratio of pure types to hybrids across the hybrid zone. The molecular data can be interpreted as one species or as a number of very young clades that have not completed lineage sorting.  The genetic data does not contradict that there may be reproductive isolation between the NA forms.

NO. While interesting, the results of Drovetski et al. (2009) in my view did not adequately probe two key attributes of this complex: head plumage and contact zones (the latter with multiple loci). I think further work examining these key aspects will be needed before we change the currently recognized species limits.

NO. The paper is confusingly written and morphological analyses not well-designed to address the issue of species limits.

NO. I think this would put ourselves in the position of possibly changing back to a multi-species treatment again when somebody does a really detailed field study of this group.

NO. I have never been impressed with the differences among the taxa ranked as species in Leucosticte, and we maintain them as separate in part because of the unpublished views in the Johnson dissertation. Drovetski et al. used Johnson’s morphometric data and plumage data, but seem to have interpreted the results differently from Johnson. I don’t have easy access to Johnson (1973), altough he provided some of his rationale in his BNA account of Black Rosy-Finch. Concerning the plumage data, the analysis really is not of overall plumage but only of a single feature, breast color. The problem is that breast color is only useful in distinguishing Black from Gray-crowned, and appears in Ridgway’s (1901) key, for example, only in distinguishing Black from nominate Gray-crowned, and griseonucha (Aleutian) from littoralis (Hepburn’s), that latter two typically treated as conspecific with Gray-crowned. For Brown-capped, Ridgway stated “No distinct or clear gray markings on head” but in a footnote added:

“In very fresh plumage there is a quite well defined area covering exactly the same parts of the pileum as in L. tephrocotis tephrocotis and L. atrata, that is differently colored from the contiguous parts, but instead of this area being clear and perfectly uniform light ash gray the feathers are dusky brownish gray centrally, margined with light brownish gray, producing a more or less squamate or scale-like appearance; furthermore, the brown color which borders this somewhat grayish area is decidedly lighter and duller, or less rufescent, than in L. tephrocotis.”

So, I interpret this to mean that Brown-capped really does have the same head pattern as the others, but it’s just very faint. Nonetheless, I interpret Ridgway’s key to indicate that there are 5 diagnosable phenotypic units with little or no overlap once head color pattern is added to the analysis. If Johnson (1973) interpreted his data to support a 3-species treatment, then I assume that he also found this to be correct, but I am handicapped by lack of access.

Drovetski et al. interpreted their analysis of Johnson’s data as follows: “The variation in breast color purity (F2) accounted for 15.6% of variance in the dataset and represented a taxonomically non-diagnostic, single continuum.” However, it’s not really a geographic continuum, because the geographic distribution of Black is between that of Gray-crowned and Brown-capped. Further, in Fig. 2, Blacks form a discrete, tight cluster, with lower scores on F2 than any other population, as noted by Drovetski et al.: “Although black rosy-finch F2 values did not overlap with the other two species, any combination of groups or taxa along this continuum would produce this lack of overlap in F2 values.” So, this is confusing to me – yes, the F2 scores themselves are distributed continuously, and Brown-capped definitely overlaps with Gray-crowned, but no one has ever claimed to my knowledge that breast color separates those two.  However, the F2 scores for Black do not overlap with those of any other taxon, and depending on the interpretations of the individuals Johnson identified as hybrids, could be interpreted as evidence that atrata is a diagnosable unit. Certainly an analysis that also incorporated head pattern would reveal 5 clusters that are much more discrete than those in Fig. 2, and that it is likely that 5 diagnosable units warrant taxonomic rank, as in traditional classifications. Based on phenotype, one could interpret the data as evidence for 5 PSC species.

Concerning the size data (F1), these are not relevant to species limits and seldom provide ways to diagnose taxa. However, in this case, the Aleutian birds are so much bigger than any others that one could argue for species rank for them, especially if their breast color does differ as described from that of littoralis to the degree described (although not evident in Fig. 2 because littoralis not identified as separate from tephrocotis. The BNA maps don’t really allow me to determine whether littoralis is actually parapatric with griseonucha; if they are, a good case could be made for species rank for Aleutian Rosy-Finch.

Concerning hybridization, unless there is evidence of total breakdown of barriers to gene flow, they do not negate ranking taxa as separate species under the BSC. Otherwise, we would lump Rose-breasted and Black-headed grosbeaks, Eastern and Western meadowlarks, and so on. Given that migratory cardueline finches are notorious wanderers with minimal site fidelity, one could predict a priori that some individuals of one taxon could wander into the breeding range of the adjacent taxon and that at least some low level of hybridization is expected. What counts is what happens where the taxa are parapatric. Here’s where details from Johnson’s dissertation would be nice to have, and he concentrated his efforts at the Black/Gray-crowned contact area in Idaho-Montana (see below). I assume Brown-capped is completely allopatric, but just logo-auk-aou.png” border=”0″ width=”240″ height=”146″ at the BNA maps for the other taxa, the other taxa appear to be potentially parapatric or nearly so, with potential to assay the degree of gene flow. If these taxa were not essentially reproductively isolated, with levels of hybridization at or below the level between, say, Lazuli and Indigo buntings, I would expect there to be entire breeding populations that have intermediate characters. If that is indeed the case, then I would vote to YES, and would change my vote if those data exist.

R. E. Johnson’s BNA account for Black Rosy-Finch, not cited by Drovetski et al., reports the following information on the Black/Gray-crowned contact zone in Idaho-Montana:

“Hybrids between Black Rosy-Finch and L. t. tephrocotis first discovered in Bitterroot Range, along Montana-Idaho border (Mewaldt 1950), and subsequently in Seven Devils Mtns., ID (French 1959a); Little Belt Mtns., MT (Hoffmann 1960); and Cabinet Mtns., MT (Johnson 1972). Analysis of specimens from Bitterroot Range (n = 7) and Seven Devils Mtns. (n = 16) by French (1959a) showed a wide range of color, indicating that hybrids were viable and bred, leading to the conclusion that they were probably conspecific. Further study by Johnson (1972) with larger samples (Bitterroot, n = 33; Seven Devils, n = 59) showed bimodality of color (visual color, colorimetric purity) and of both mensural characters in which the pure forms differ significantly (bill length, toe plus tarsus length), indicating existence of reproductive isolating mechanisms and selection against hybrids between the 2, and indicating separate species status for each. Additional specimens (n = 39) collected since that time also support that conclusion (REJ).”

So these data seem to contradict the findings of Drovetski et al., and should have been addressed specifically by them. Until these findings are reconciled, I cannot see how the current proposal can pass.

Concerning the genetic data, they obviously provide no support for maintaining three species. However, as Drovetski et al. noted, what they have is a single gene tree, with potentially insufficient time for lineage sorting. Low levels of hybridization and the occasional movement of breeding individuals would further complicate lineage sorting. Assuming that the plumage has a genetic basis, however, suggests that there are indeed discrete genetic differences among populations that we cannot yet measure. As an aside, the BNA descriptions of vocalizations, although not written in a comparative way, makes them all sound suspiciously similar.  The BNA accounts indicate or suggest that song in these birds is strictly used for mate attraction, not territorial defense … thus typical of carduelines. Whether playback experiments would be productive is uncertain but worthy of consideration, especially for the allopatric taxa.

Finally, if the proposal passes, I suggest a separate proposal on E names.

2013-B-5: Change the linear sequence of Haemorhous finches

YES. 3 without comment.

YES. This sequence seems justified by the data.

YES, but we need to add that the convention for sequencing is least-diverse branch first in order to justify the change.

YES. An alternative sequence of House, Purple, Cassin’s is equivalent with the data and less disruptive to the existing sequence, and  Purple occurs slightly more NW than Cassin’s. If we split Purple in the future (as is suggested by results in the Smith et al. paper), however, the sequence suggested by the proposal would be better.

NO. If we do this change, we need to explain why. It does not change the interpretation of the relationships among these species to reverse the order. Since I am agnostic (at best) on the value of sequence in providing information on relationships, making a change that doesn’t claim to represent different information regarding relationships seems completely unnecessary. As an aside, I feel like users of our taxonomy are giving up trying to keep up with the annual changes in sequence, that are often based on pretty flimsy support.

ABSTAIN. Insofar as the relationship among the three has not changed and linear presentations are a poor caricature of phylogenetic relationships, this seems like six of one and half a dozen of another to me, though I understand the desire to be consistent in how we linearize taxonomic sequence. We could just approve for consistency and state our convention. Maybe that would be useful for some users.

2013-B-6: Change the citations for nine species described by Thomas Say

YES. 8 without comment.

2013-B-7: Transfer Terenura callinota to the genus Euchrepomis (SACC #557)

YES. 4 without comment.

YES, for reasons given in the proposal and for consistency with the SACC.

YES. callinota is the type of the new genus.

YES, following SACC.

YES. And bravo for making sure there was a morphological basis to the new genus.

2013-B-8a: Split South American endemic Automolus rufipectus from A. rubiginosus (SACC #394)
2013-B-8b: Split South American endemic Dendrocincla turdina from D. fuliginosa (SACC #540)
2013-B-8c: Split South American endemicTroglodytes cobbi fromT. aedon (SACC #526)

YES. 3 without comment.

YES. These are clearly cases where we should defer to the SACC.

YES. I agree with deferring to the SACC.

YES, following SACC.

YES, per SACC comments.

YES. I appreciated the SACC deliberations on these.

2013-B-9: Change the English name of Thamnophilus atrinucha (SACC #570)

YES. 4 without comment.

YES. I am not wild about Black-crowned Antshrike, but I cannot think of a better name that incorporates either geography or plumage. In addition, it would be best to sync with the SACC on this.

YES, following SACC. As an aside, Western Slaty-Antshrike seemed like a particularly bad name anyway when you see them in eastern Costa Rica!

YES, per SACC comments.

ABSTAIN.

2013-B-10a: Split Schiffornis veraepacis from S. turdina
2013-B-10b: Split Schiffornis stenorhyncha s from S. turdina (SACC #505, SACC #543)

YES. 2 without comment.

YES, on the split, but delay on English names until SACC deliberations finished.

YES, on the split, but delay on English names until SACC deliberations finished. At least we have it easier than the SACC. Splitting the northwestern veraepacis from the broad turdina is straightforward given sympatry, vocal and plumage differentiation. Same with splitting stenorhyncha from the remaining South American populations given the elevational parapatry, and vocal differences. These two splits are in line with the molecular data as well. For the extralimital splits, I think we should follow the SACC. The English names of  Western Schiffornis and Rufous-winged Schiffornis seem fine with me, but we need to sync with the SACC.

YES, following SACC.

YES on the split, but delay on English names until SACC deliberations finished.

YES. SACC deliberations were again helpful.

2013-B-11: Split Myrmeciza zeledoni from M. immaculata (SACC #541)

YES. 2 without comment.

YES. Zeldon’s Antibird is fine with me.

YES. No preference on English names. Including the entire SACC proposals and discussions makes these more complicated than necessary.

YES. The vocal data are sufficient for splitting zeledoni/macrorhyncha from immaculata. Zeledon’s Antbird is fine with me for the English name.

YES, following SACC.

YES on both split and English name.

YES. SACC deliberations were again helpful.

2013-B-12: Treat Thalurania fannyi and Thalurania colombica as conspecific (SACC #558)

YES. 4 without comment.

YES. The lump advocated by Donegan and the SACC seems solid as crown color, which was used to split the fannyi from colombica in the 1990s, does not appear to be reproductively isolating those populations.

YES, following SACC.

YES, per SACC comments.

YES. SACC deliberations were again helpful.