- 2013-A-1: Make seven nomenclatural revisions based on Gregory and Dickinson (2012)
- 2013-A-2: Split Guatemalan Pygmy-Owl Glaucidium cobanense from Northern Pygmy-Owl G. gnoma
- 2013-A-3: Recognize Cabot’s Tern Thalasseus acuflavidus as distinct from Sandwich Tern T. sandvicensis
- 2013-A-4: Change the scientific name of the Common Bush-Tanager from Chlorospingus ophthalmicus to C. flavopectus
- 2013-A-5: Move the Hawaiian honeycreepers (Drepanidinae) to subfamily Carduelinae
- 2013-A-6: Split Barolo Shearwater Puffinus baroli
- 2013-A-7: Revise the classification of sandpipers and turnstones
- 2013-A-8: Split Sage Sparrow Artemisiospiza belli into two species
- 2013-A-9: Make changes to generic allocation and linear sequence in family Pipridae
- 2013-A-10: Change the generic placement of Otus flammeolus
- 2013-A-11: Recognize a new generic name for Gymnoglaux lawrencii
- 2013-A-12: Split Melanerpes santacruzi from M. aurifrons
- 2013-A-13: Recognize Hanson’s new species of White-cheeked Geese, Branta spp.
2013-A-1: Make seven nomenclatural revisions based on Gregory and Dickinson (2012)
YES to all. 2 without comment.
YES to all. On the issue of replacing Nyctanassa, I would also support a petition to maintain that generic name over Nyctherodius. With regards to Micropterus and Microptera in 1e, are genera exempt from being considered homonyms when they only differ by the gender suffix (and thus different from species epithets)?
YES to all, but for #6 the spelling should be Lacepède, not Lecepède (although I suppose this name won’t appear in the Supplement anyway).
YES to all. On the issue of replacing Nyctanassa, I would also support a petition to maintain that generic name over Nyctherodius.
YES to all. On the issue of replacing Nyctanassa, I would be willing to support a petition to maintain that generic name over Nyctherodius. With respect to correcting Ptilogonys to Ptiliogonys, we recognize the family Ptilogonatidae so we will need to change the spelling of that family to reflect the change in the spelling of the generic name (i.e., Ptiliogonatidae).
NO on 1a (support petition to keep Nyctanassa). YES to 1b-1g.
NO on 1a, prefer petition for current name. It seems to be well-established & uncontroversial. Recall that the Code says that the purpose is to promote “stability” & universality. This would not do that & seems unnecessary & confusing. YES to 1b-1g.
NO on 1a. Studer’s popular work went through so many editions that this carryover across the magic line of 1899 is probably just reprinting inertia (though I do not have access to editions across this line to see the degree of editorial changes, I see that Gregory and Dickinson surmise the same). Let’s petition the ICZN on this one. Further, if, as Gregory & Dickinson’s paper implies, Stejneger was correctly following the rules at that time (“..this is not now considered a homonym..” implies that it once was legitimately considered so), why would we wish to overturn such a well-established name? YES on 1b: While I have the same sentiment as the previous sentence (above) in this case, it is a subgenus not much used and so represents a small change. YES to 1c-1g.
2013-A-2: Split Guatemalan Pygmy-Owl Glaucidium cobanense from Northern Pygmy-Owl G. gnoma
YES. 2 without comment.
YES, although I wish we also had molecular phylogenetic information on the distinctiveness of these forms.
YES. I think we may want to shorten the suggested Notes section for the new account considerably, in line with other such accounts.
YES. Although the small N for individuals is of concern, the vocal differences appear dramatic – the notes of cobanense are delivered more than 1.5X faster than in gnoma, with no sign of overlap. Given the narrowly defined species limits in the genus based largely on similar vocal differences, treatment of cobanense as a species seems justified.
NO (for now). I believe that there is more then one species in the G. gnoma complex, and vocal differences are clearly an important part of that story, but I would rather wait to see published molecular data to support the song differences.
NO. I am still having difficulties discerning species limits in Glaucidium. Where two taxa overlap (e.g., hardyi and brasilianum in Amazonia) they differ markedly in vocalizations, much more so then do these allopatric populations. Also, in my experience call rates in Glaucidium are pretty variable, depending on how excited the birds are. Have any playbacks been attempted with gnoma and cobanense? I have trouble voting for a proposed split that does not once use the term “reproductive isolation.”
NO. I’m sure this is a valid split, but this is all based on just vocalizations, and that’s the very reason that others have split out other taxa in this group, notably the double noted birds north of the Isthmus of Tehuantepec (slips into the mountains of southeast Arizona and southwest New Mexico), the Mountain Pygmy Owl, and the birds of the Cape District of Baja California (Cape Pygmy Owl). Even the Rocky Mountain birds are different sounding from either the Pacific birds as well as those from Mexico and the southwestern United States (single notes like Pacific birds but with a faster delivery). I’m not aware of any intermingling of any of these populations although haven’t looked carefully to see what happens in the northern Rockies. I should add that I’ve never encountered a Northern Pygmy-Owl in the Rockies, so they must be at least uncommon.
Is the split of cobanense any more compelling than that of the above mentioned other taxa of Northern Pygmy-Owls that have not yet been split? If I can be assured that the answer to that question is yes, then I’ll reconsider. Until then, I’d prefer a more comprehensive decision, rather than selecting just one taxon. Have I missed something here?
NO. Eisermann & Howell (2011) accept Marks et al. (1999) and Konig & Weick (2008) in their treatment of this taxon as a full species, and they provide evidence that six Guatemalan individuals call, on average, at a faster rate than eight Mexican individuals. Unfortunately, it does not appear that degree of character overlap is presented, just the result of a permutation t-test. (This is unacceptable for even subspecies diagnosis. And why no playback experiments?) I am highly skeptical of the bases upon which Marks et al. (1999) and Konig & Weick (2008) elevated this taxon to species level and do not find this treatment of vocalizations to be anything more than showing a promising direction for future research into species limits in this complex.
NO. I believe it very likely that Glaucidium cobanense is a distinct species from gnoma, but I don’t favor splitting it without even considering at least the split between californicum and gnoma, which seems more well-established. I really think we need somebody to look seriously at the whole gnoma complex, not pull one group out at a time.
2013-A-3: Recognize Cabot’s Tern Thalasseus acuflavidus as distinct from Sandwich Tern T. sandvicensis
YES. 3 without comment.
YES, especially given that nominate sandvicensis of the Old World is sister to elegans.
NO. I’d like to see some more information about European birds and how they differ from North American birds apart from genetics. They do certainly seem to tolerate colder waters. Any vocal differences? Is this split more valid than peeling off Cayenne Tern as a separate species? I’m inclined to think the answer is yes, but would like more discussion.
NO. Again, another proposed split that does not once use the term “reproductive isolation.” Vocal, morphological, ecological, and behavioral differences are scant to non-existent. I really do not care if species level taxonomy results in paraphyly (as in Larus argentatus, western populations Corax corax, or Anas crecca). Cabot’s and Elegant are sisters but have some genetic differences (e.g., bill color, crest length, bill shape and length) that result in reproductive isolation (barely?), but Cabots and Old World Sandwich may have greater genetic distance, but those differences (many of which may be genetically neutral, such as third codon positions in transcripted portions of genes) have not resulted in expressed traits that are reproductively isolating.
NO. I think we need better sampling on this one in terms of both data and individuals. Their molecular argument rests largely on the combined data tree, but the number of individuals is small (only 3 sandvicensis, 3 acuflavidus, and 1 elegans; only 3 sandvicensis in the CO1 tree as well) and the geographic sampling is limited (all sandvicensis from the same locality). The authors are not very forthcoming about the nuclear tree, other than the reciprocal monophyly of sandvicensis and eurygnathus/acuflavidus at undisclosed but presumably weak bootstrap levels, making it difficult to assess the value of the nuclear genes as independent data. They evidently were not aware of Elegant X Sandwich tern hybridization, e.g., Charlie Collins’ paper (Western Birds 28: 169–173, 1997), that might complicate interpretations of genetic differences. I would not be surprised that three species should be recognized, but I think stronger data are needed in terms of sampling of genes and individuals. Sangster et al. (2011) cited a paper that outlined plumage differences between sandvicensis and acuflavidus, but these are presumably already part of the basis for designation as separate subspecies. What about voice? As far as I know, there are no closely related species of terns that do not also differ in voice; in fact, this is a major reason why we treated Sternula antillarum as a separate species from S. albifrons, for example. Elegans differs subtly from acuflavidus, and perhaps sandvicensis is at least as or more different? With all appropriate caveats concerning a superficial, qualitative tour through the recordings at xeno-canto (http://www.xeno-canto.org/ species/Thalasseus-sandvicensis), I can’t detect any clear differences between sandvicensis and acuflavidus.
NO. I agree with others that better sampling is needed for the molecular data, especially given the morphological and behavioral similarities.
NO. These two taxa are paraphyletic with respect to elegans, not in different wings of the genus. That is suggestive of species status to me, but not enough by itself. The lack of vocal differences, very limited morphological differences, and essentially identical ecology means that currently I don’t support splitting them.
NO. The evidence presented is very weak for determining species limits; main criteria appear to be mtDNA distance, which is not a useful species limits threshold. Just as monophyly of the genus needs further examination, so too does paraphyly of sandvicensis. The work they cite (unpublished, examining species limits in the New World subspecies) needs to be applied to this proposed split: larger sample sizes and more nuclear data. This has subspecies written all over it and that’s how they are presently treated.
2013-A-4: Change the scientific name of the Common Bush-Tanager from Chlorospingus ophthalmicus to C. flavopectus (SACC #521)
YES. 7 without comment.
YES. Seems clear.
YES. No choice on this one.
YES. “Fifty-year” rule is not applicable given Zimmer’s use of flavopectus in 1947.
2013-A-5: Move the Hawaiian honeycreepers (Drepanidinae) to subfamily Carduelinae
YES. 5 without comment.
YES. There does not appear to be any alternatives that maintain monophyly without creating a bunch more family-level taxa.
YES. The molecular evidence for this grouping is very strong. Isn’t adaptive radiation amazing!
YES. No choice on this one. The “dreps” are just a highly divergent, recent radiation, and if the only survivor were Telespiza, no one would consider them a family, subfamily, or even a tribe.
YES. Good work to Shawn Billerman on this proposal.
2013-A-6: Split Barolo Shearwater Puffinus baroli
YES (option 2).
YES (option 2). I am willing to go along with treating boydi as a subspecies of baroli, i.e., option 2, although I suspect that it will eventually be split. Also, it will fairly soon be proposed for addition to our list, as soon as the pelagic birders finish celebrating our adding Pt. feae and realize there is yet another taxon out there.
YES (option 1). Barolo Shearwater.
YES (option 1). Barolo Shearwater. Baroli definitely does not belong in assimilis. Keeping the morphologically distinct baroli as a monotypic species apart from both boydi and lherminieri makes most sense. Keeping boydi with lherminieri seems okay given their morphological similarities (and is also the status quo). Another option, not presented in the proposal, would be to consider both baroli and boydi at species level distinct from lherminieri.
YES (option 1). The mtDNA corroboration of phenotype helps on this (distance is too much affected by stochastic phenomena).
YES (option 2). Barolo Shearwater, with boydi as a subspecies given that baroli and boydi are sister taxa according to mtDNA (Austin et al. 2004).
YES (option 2). Treat boydi for now as a subspecies, although a species split there too will probably eventually be warranted.
YES (option 2, include boydi as a subspecies); Macaronesian Shearwater. The evidence is overwhelming that baroli has nothing to do with assimilis, and fairly convincing that it merits species rank rather than being treated as a subspecies of lherminieri. The only question for me is how to rank boydi. As outlined in the proposal, boydi seems as distinctive as are several species-level taxa in this group of birds, but I am reluctant to vote for this without a formal presentation, analysis, and published summary of the evidence in a technical journal, preferably by an objective expert on shearwaters.
YES, but only by the barest of margins as I am uneasy about the low mtDNA divergence and lack of other molecular information. Species limits in these disjunct island-breeding seabirds are among the hardest to evaluate. Of the options I might prefer Option 2 (Split Puffinus baroli including P. boydi from P. assimilis), but mostly just to be consistent with the BOU treatment, as both Options 1 and 2 seem reasonable given the limited available information.
YES. Definitely split and consider as a separate species from both assimilis and lherminieri. I vote weakly for option 1 using Barolo Shearwater for this bird.
YES. I suggest that we give the two species (if split accepted) new common names.
2013-A-7: Revise the classification of sandpipers and turnstones
YES. 2 without comment.
YES, although I also have reservations about the linear sequence given the short branch lengths at the deeper nodes within the ‘Calidris‘ clade.
YES, with the correction of the author’s name Horsefield to Horsfield, an error pointed out to me by Dan Gibson. Dan also pointed out an error in one of the dates which must be corrected before publication of the Supplement.
YES. I hope that Black-bellied Turnstone is a typo. If not a vote NO for that change in the English name. Are we sure that Calidris has priority over Philomachus? They are described on same page/plate of same publication. I think that the one enlarged genus conveys the great morphological evolution that has occurred in this clade, while splitting it up piecemeal would not reflect this.
YES. The decision here is largely subjective. Losing distinctive Philomachus and Tryngites is “uncomfortable”, but the alternative, namely splitting broad Calidris into a multitude of genera, is even more so. To keep Tryngites, for example, one would have to recognize at least 7 other genera, by my count, including naming a new one for C. bairdii, and the “peeps” would be scattered in at least three genera. To keep just Philomachus would be less painful but would require placing Sharp-tailed Sandpiper in monotypic Limnocinclus or merging it Limicola with Broad-billed Sandpiper (ugh). Trying to be objective as possible, the branching pattern in Gibson & Baker (2012) has the look of a very twiggy bush with short branches connecting most of the deep nodes, i.e., an explosive radiation. I recognize that an even broader-than-present Calidris would be unusually heterogeneous, but I see no better solution in terms of generic limits. As an aside, sinking Eurynorhynchus is long overdue; yes, we are all impressed with the bizarre bill tip, but otherwise it’s very similar plumage-wise to the species now revealed as its sister, Calidris ruficollis.
YES. At least we get to use Calidris, and while I don’t like a genus with such extreme morphological variation in it, I don’t see a ready morphological solution to a finer-scale, multi-genus answer at this time, and actually would like to see more nuclear data thrown at the phylogeny to better understand relationships in an expanded Calidris.
NO, but YES to fixing the classification to be consistent with Gibson and Baker’s results. This approach of lumping everybody into Calidris is at odds with what we have done in most other groups. I do agree that we can’t realistically rescue all of the current genera, Tryngites being the most difficult. But I think that lumping everything into Calidris obscures more than it helps. My suggestion would be the 4 genus solution. That would be Calidris for the knots plus surfbird, Philomachus for Ruff, Limicola for Broad-billed + Sharp-tailed, and Ereunetes (looks to be the oldest name) for all the rest. I recognize that Limicola for those 2 species is both novel and not intuitive. I think though that because of that, we might get more attention paid to these birds. I suspect Calidris for everybody might very well end the discussion.
NO. This is all pretty radical. I can accept the various merging of genera without a problem, but it’s the linear sequence I’m worried about, especially within Calidris. I’ve always thought of Sharp-tailed and Pectoral Sandpipers as being closely related, although I grant their vocalizations are quite different. Likewise White-rumped and Baird’s are not together and structurally they look very similar, though here the vocalizations are at opposite ends of the range. Surely, Least Sandpiper and Long-toed Stint must be close as they are so similar in plumage and behavior and vocally are somewhat close. And Western and Least are separated from the Old World stints and Red-necked and Little Stints (again very similar in appearance and pretty similar in vocalizations) are not near each other in the linear sequence. I can accept Surfbird just being an odd Calidris, but why isn’t it next to Great Knot, a species it closely resembles in alternate plumage? And Great Knot has hybridized with Surfbird on at least one occasion. I’m inclined to accept the proposal, but don’t like the linear sequence within Calidris. So, the question is how strongly is the linear sequence supported within Calidris in this new proposed scheme?
NO. I’m not in favor of such broad genera. This doesn’t square with other recent generic-level changes we’ve made. The solution will not be straightforward in this case, however.
2013-A-8: Split Sage Sparrow Artemisiospiza belli into two species
YES. 1 without comment.
YES, but why not Bell’s Sparrow and Sage Sparrow?
YES. I am fine with Bell’s and Sage Sparrow, but what would we call canescens if/when it gets split off from belli? Grinnell (1905) used the name California Sage Sparrow when describing this taxon as a new subspecies, so if we eventually split canescens from belli, would the names be: Sage Sparrow (nevadensis), Bell’s Sparrow (belli + clementae and cinerea), California Sage Sparrow (canescens) – or come up with a new name for canescens? Bell’s Sparrow (including canescens) is essentially restricted to California – if you include Baja California – with the exception of a disjunct population in extreme western Nevada at Palmetto Wash. I would like to come up with names that consider what we would call canescens if that split happens in the future. I realize that people don’t like compound names, but I like the geographic contrast between Great Basin Sage Sparrow and California Sage Sparrow – although that still leaves us with a problem if canescens and belli are split (California and Bell’s Sage Sparrow?).
YES, although I share concerns about canescens. And, I too favor keeping the English name of Sage Sparrow for nevadensis and Bell’s Sparrow for the other taxa. I’ve always liked patronyms and keeping the name Sage Sparrow fits the habitat well of the Great Basin bird. That’s where they are. The situation gets muddled with canescens with salt bush and creosote, etc. Most recently, my sightings of coastal Bell’s are from dense thickets of chamise. They seem so different to me from interior birds in that I hardly I ever see them in situations where they run around with tails up in the air. I can’t see into the chamise, so views are invariably after I’ve coaxed them up to bush tops with play-back. And they don’t seem to do much tail twitching either. Songs of coastal birds are certainly very different from nevadensis, the former sounding more like a Rufous-crowned Sparrow to my ear witha loose jumbled pattern. Great Basin birds have a pulsing rhythum to them. They don’t sound close. I’m less familiar of late with the songs of canescens and birds here in Round Valley, northwest of Bishop, don’t really sound like either coastal birds or nevadensis to my ear, and they seem to respond to play-back of both! But then I’m just a few miles and a few thousand feet away from nevadensis. The proposal doesn’t include vocal information, no doubt coming in a forthcoming publication. Anything on contact notes?
YES. Split belli and nevadensis as distinct species. I much prefer Bell’s Sparrow and Great Basin Sparrow for English names.
YES. I prefer the two species split, as proposed.
YES. All data point toward restriction of gene flow in the contact zone and essential reproductive isolation. If these two were freely interbreeding, then the distribution of phenotypes and genotypes at the contact zone would be quite different, and there would be no hint of sympatry. Normally, I’d also like to see data on vocalizations, but because the effort has been concentrated directly on the secondary contact, they aren’t required like they would be in less rigorous examinations of population interaction.
We do need, in my opinion, however, to discuss the English names separately. Rather than create a couple of new, compound names, I think this is a case in which we could consider breaking the usual rule and retaining two, simpler, traditional names, Sage Sparrow and Bell’s Sparrow, as in much of the earlier literature. In fact, this is not the usual case of a split of two species not previously recognized as distinct – this is an de-lumping of two species that formerly those two separate names, with Bell’s disappearing into a more broadly defined Sage Sparrow. Ridgway (1901) treated them as conspecific but still used “Bell’s Sparrow” for A. b. belli and “Sage Sparrow” for A. b. nevadensis. This would also have the advantage of retaining “Sage” for the species whose habitat is predominately “the” sage for most of us, i.e. Artemisia tridentata, Big Sagebrush, and would also emphasize the importance of conservation of Big Sagebrush. (I recognize that there are other sages in the habitat of Bell’s, of course, but most of us think first of Artemisia tridentata whenever we hear “sage.” The problem with this English name scheme is that canescens has usually been associated with nevadensis, not the coastal belli group; in fact, Ridgway called canescens “Gray Sage Sparrow.” Nonetheless, I think this alternative should be discussed separately before adopting the two novel, compound names (which would require a hyphenated Sage-Sparrow, by the way).
YES. I accept the split of belli and nevadensis as distinct species. I think we need to think about the English names. Great Basin Sage Sparrow and California Sage Sparrow are pretty clunky. This is akin the initial names given to the Sharp-tailed Sparrows when split, which we have now abandoned. If we are going to retain Sage in these names, I think that they should be hyphenated, as a group name so Great Basin Sage-Sparrow and California Sage-Sparrow. I would be okay with Bell’s Sparrow and Great Basin Sparrow as better alternate and shorter English names.
YES. But in addition to the evidence developed I would like to see estimates of gene flow using nuclear markers.
YES. I would prefer a 3-way split.
2013-A-9: Make changes to generic allocation and linear sequence in family Pipridae
YES. 3 without comment.
YES on the sequence which incorporates the rest.
YES. It makes sense to keep in line with the SACC.
YES. Move mentalis and erythrocephala to Ceratopipra and pipra to Dixiphia.
YES. SACC already did this and implemented the changes. See discussion there.
YES to taxonomic and sequence changes.
YES (including lumping Chloropipo with Xenopipo and sequence of Pipridae). While I am leery of this kind of among-study meta-analysis, especially when taxon sampling is so weak (especially in overlap), this seems to be a useful solution based on what we can construe to be solid.
NO, but only because waiting a little while might give us much better information on which to base these changes, given that the taxon sampling in the published studies is sparse. I believe that I know of 4 different, independent research groups that have more extensive phylogenetic projects near completion on the manakins.
2013-A-10: Change the generic placement of Otus flammeolus
YES. 4 without comment.
YES. Place flammulatus in the monotypic genus Pslioscops.
YES. Place flammulatus in the genus Psiloscops.
YES. No question on removal from Otus, so the only decision, as the proposal notes, is whether to resurrect Psiloscops or to merge into Megascops. This is essentially a subjective decision, and I favor monotypic genus treatment here to highlight the several distinctive features of this species.
YES. Place flammulatus in the genus Psiloscops.
YES. I think Psiloscops is warranted here.
2013-A-11: Recognize a new generic name for Gymnoglaux lawrencii
YES. 7 without comment.
YES, but an objection has been raised that I do not currently have at hand.
YES, for reasons given in the proposal.
YES, for nomenclature reasons only. I gather that there is no phylogenetic information that bears on the placement of this lineage among related genera.
2013-A-12: Split Melanerpes santacruzi from M. aurifrons
YES. 5 without comment.
NO. I’ve looked at Howell and Webb (1995) in their Mexican guide and see the following statements: “Complex geographic variation: Three groups, all with linking, variably intermediate populations.” And referring to the northern group states that it integrades with dubius from southern Tamulipas to to the Isthmus. The proposal focuses on the vocalizations which I think are important, but the hybrid issue (frequency) is not addressed.
NO. I agree with others about the need for more data (nuclear genes, contact zones).
NO. I think there may be more going on than what we can assess with this proposal.
NO. Although this information is promising, more is needed to define species limits in this case, particularly in contact areas and using nuclear DNA as well as mitochondrial.
NO, tentatively, with reservations, and open to changing the vote depending on the opinion of others. The García-Trejo et al. (2009) data consists of 872 bp of mtDNA, a small N for base pairs by recent standards. From this, they concluded that M. aurifrons as currently constituted is not monophyletic. Although this paper is only 4 years old, there is no discussion in the paper of the possibility that an mtDNA gene tree might not reflect accurately the true species tree or that nuclear loci might give a different tree. The problem is that if Red-bellied Woodpecker, a recent derivative at the northern end of this group’s range, did not exist, we would have a monophyletic (with respect to mtDNA) Golden-fronted Woodpecker. That said, it strikes me that given that the contact zone between Red-bellied and Golden-fronted shows little evidence of hybridization, as the authors noted, and that those two differ in the same sorts of ways, plumage-wise, as do many of the subspecies of the santacruzi group, I would have expect at least as much structure among the Middle American populations; yet the García-Trejo et al. tree shows clearly that there is little genetic structure among those populations, at least in terms of mtDNA. As the authors stated, the santacruzi group contains subspecies that are redder than Red-bellied Woodpecker, including the center of the belly, as well as populations with bellies darker than are those of either northern Golden-fronted or Red-bellied, but also includes a subspecies, polygrammus, of Pacific SW Mexico, that is pale and yellow, much like distant northern aurifrons, as noted astutely by García-Trejo et al. The degree of red vs. yellow pigmentation is roughly associated with humidity gradients, with the yellowest populations with the palest breasts in the driest areas.
What concerns me is the contact zone between northern and tropical Golden-fronteds, in coastal eastern Mexico. Although the authors describe the santacruzi group as being discretely different from the northern group, Selander & Giller (1963) found evidence for intergradation between the two based on plumage characters, and their figures showing distribution of character scores are fairly convincing in their absence of abrupt shifts, with populations in central Mexico, where nominate aurifrons contacts the northernmost taxon of the santacruzi group, grateloupensis. There are signs throughout the ranges of the santacruzi group of intergradation among fairly distinctive taxa, in accord with the mtDNA data. From Selander & Giller (1963):
“Our studies fully support the view that all populations of the aurifrons complex belong to a single species, since even the most highly differentiated forms have been shown to intergrade in zones of contact. We have already discussed in detail the complete and gradual transition from C. a. aurifrons of the Mexican plateau to C. a. dubius of the Yucatan Peninsula through populations assigned to C. a grateloupensis [which would include veraecrucis, considered a synonym by Selander & Giller].”
I looked at our large series of specimens from these taxa in Mexico and have to agree with Selander & Giller, whose conclusions and taxonomy were followed subsequently also by Short in his woodpecker monograph. So, there seems to be a mismatch between the signal from phenotype and the mtDNA signal. García-Trejo et al. had multiple individuals from the critical region, namely Tamaulipas south to Tabasco, so weak sampling from the region is not a problem. Thus although grateloupensis is indeed intermediate in color, and thus naturally seems to reflect gene flow, this is not the case genetically.
The potential call note difference nicely outlined by Pieplow is interesting; the tropical birds do indeed sound different, with that double-noted call. As Pieplow noted, however, the N is small and the geographic distribution is fairly limited. What we really need is a series of points strategically placed to cross the contact zone. In roaming around other recordings available online, I note (with all appropriate caveats concerning a superficial tour) that the santacruzi group, to my ear, sounds virtually identical to Red-bellied in terms of the rolling churrrr call – listen to the Macaulay recordings:
Overall, I feel uneasy about the split without a more detailed description of the contact zone. The two groups are evidently parapatric, so a transect through these readily accessible areas would show immediate whether there is an abrupt shift from northern to tropical groups with essential reproductive isolation. With the growing army of recordists out there, a highly feasible and very informative project would be to gather data on call types through that transect zone to see if there is abrupt shift and whether it corresponds with the named taxa; Pieplow has set the stage for such a project. A minor correction to the proposal: Peters (1948) lumped the santacruzi group with aurifrons, not Selander & Giller (1963).
2013-A-13: Recognize Hanson’s new species of White-cheeked Geese, Branta spp.
NO. 5 without comment.
NO. Unfortunate that so much work went into such an impossible a mess of nomenclature and taxonomy.
NO. A firm No on this, and as an aside, continuing mild hesitation about the Cackling versus Canada split.
NO. I don’t think folks still have a handle on separating taverneri (a Cackling Canada) from parvipes (a Canada Canada) and don’t advocate further muddling the waters with goose droppings or further separations. There’s been lots of moaning too on both sides of the Atlantic with the Bean Goose split, with the Dutch (of course!) further splitting off middendorffii as its own species and the British (in a recent BB paper moaning about the entire split). There have been a number of sightings from Alaska and one from CA where the ID to species has been uncertain, and in correspondence concerning the CA bird the Japanese refer to a population of wintering Taiga Bean-Geese (breeding at the Kolyma Delta) that are smaller and quite unlike their cousins breeding farther east and south and winter elsewhere in Japan. Photos of a Bean Goose from the Philippines, their first, have been published in various publications as both species! Despite those concerns, I’ve begun to wonder that within Greater White-fronted Geese, the taxonelgasi is distinct in a number of ways and perhaps merits species status.
NO, for all the reasons in the proposal and the published reviews.
NO (to both and beyond). Notwithstanding Hanson’s enthusiastic work and Anderson’s efforts to bring it to light, this is frankly a mess. Geographic variation, unless put into a populational context, represents just so many different colored marbles without evolutionary or taxonomic relevance. I have seen hundreds if not thousands of specimens taken in migration or on wintering grounds that suggest that we do not yet have a full grasp of the variation occurring within or in some cases among breeding populations (or perhaps of hybridization between them), but to name all of these variants without that crucial reference back to breeding populations and their relationships is not an advance. I do not support the species or subspecies in these works. I do note a silver lining, however: they are all vouchered, and with today’s and tomorrow’s technology “Branta canadensis” enthusiasts can reap sufficient molecular markers to reconcile and link this abundance of described phenotypic diversity with populations using genomic methods.