Home About Committees North American Classification Committee Current & Prior Proposals 2014 Proposals Comments 2014-B

Comments 2014-B

2014-B-1: Split the Cuban Parrot (Amazona leucocephala) complex into multiple species

YES, but I think this is very marginal. Even though the variation is concordant, the differences are merely adaptations to their islands. I think these are primarily “conservation species.”

NO for now. This is a thorough proposal, and the data are certainly suggestive of divergence between populations. However, like others, I question whether these should be considered biological species.

NO. It’s interesting that the Great Abaco birds nest in limestone holes, but given the lack of vocal differences and only slight visual differences I’d maintain the status quo. The Bahamas and Cuba share many affinities. How separate are the Great Inagua birds from the Cuban birds?

NO. I am closer to accepting this than the last proposal regarding this group, but I still think subspecies are the best way to characterize the diversity. Although multiple species of Amazona may be sympatric or even occur on one Greater Antillean island  (i.e., collaria and agilis on Jamaica), they tend to be from disparate clades within the genus. Even though we treat other members of this clade as species (vittata, collaria, ventralis, and leucocephala), and some may differ genetically only as much as some subspecies within leucocephala, they are much more different in plumage than the subspecies in leucocephala. It would be interesting to see if they differ as much in vocalizations, breeding, and habitat use.

NO. This is a well-crafted proposal, but the data suggest to me that these parrot populations are not likely to be reproductively isolated were they to come into contact, and levels of differentiation are modest.

NO (as it is). I think that a better approach based in the evidence is to recognize only three species: A. leucocephala, A. bahamensis and A. caymanensis.

NO, at least not as formulated in the proposal. However, I do favor splitting caymanensis which is morphologically and genetically the most divergent. The Bahamas clade could also be considered a full species but the case is less compelling.

NO. This is an excellent proposal that reflects a lot of synthesis of research data and natural history information, and I hope that the author will publish this. However, the evidence in my opinion is insufficient for species rank for these taxa. Concerning morphology, this alone is insufficient evidence for anything but subspecies rank, and perhaps even removal of subspecies names. Going back to the thorough quantitative analyses in the original Reynolds-Hayes paper, they were unable to find a single plumage or morphological character that diagnoses any of the named populations. In fact, Dickinson & Remsen (2013) did not recognize newly described abacoensis or inaguensis because they used a strict subspecies definition that required one or more diagnostic characters to define a taxon. Reynolds & Hayes had to use 2-4 characters in a DFA analysis to get significant discrimination, and even then did not get 100% correct assignment of any of the island populations. On that basis, Dickinson & Remsen (2013) should probably have synonymized all the subspecies. This geographic variation is interesting and important to quantify, but not all geographic variation merits named taxa. Just logo-auk-aou.png” border=”0″ width=”240″ height=”146″ at specimens of all these populations, I can see why – individual variation in the amount of red in the belly throat, and amount of white on head, shows lots of individual variation within each island, and using an illustration of just one individual from each population would be misleading. This pattern of strong individual variation in degree of red pigmentation is widespread in Amazona, Psittacara, and other parrot genera.

As for the genetic differences, the % sequence differences are not impressive and actually fall well within the range of typical values for sedentary tropical populations ranked as subspecies or not given names. The use of comparative genetic distance in taxonomy is highly controversial, and certainly must be constrained to within-group comparisons to at least control for some of the variables. For example, it has been known for decades that the degree of genetic differentiation among tropical, sedentary bird populations is much greater than that between migratory or highly dispersive higher latitude taxa. Further, the use of arbitrary breaks in continuous variation in degree of differentiation in an extraordinarily minute fraction of the genome, especially the non-recombining mtDNA portion, as a measuring stick for taxon rank has presents severe conceptual problems.

As for vocalizations, the slight differences in call notes among some populations are intriguing. Perhaps some field experiments could shed light on their significance.

As for the nest site differences (Abaco vs. the rest), secondary cavity nesters are typically flexible in nest site choice, and it’s not clear to me from the proposal that the Abaco population does not also nest in trees.  As for the differences in timing of breeding, this is a notoriously variable feature among populations currently treated as conspecific.

In summary, the biological differences among these populations are interesting and important in their own right, and it is easy to see how one would be frustrated that these are not reflected in taxonomy. These separate populations merit individual conservation concern, regardless of taxonomic rank.

NO, for now, at least.

NO. Very interesting and informative work, but I just don’t see how the data merits treatment of these generally weakly defined subspecies as distinct biological species.

NO. Overall, this is a well furnished proposal. What is missing, however is the biological relevance of differences found. All the results are predicted for subspecific divergence of allopatric populations; would the birds not successfully interbreed if they had the opportunity? The answer to this seems to be unaddressed. This goes back to one of the most difficult aspects of the BSC – determining the status of allopatric populations. The most commonly used method is to contrast the differences in allopatric populations like these with the same characteristics in sympatrically breeding species that are closely related, e.g., in the same genus, or family if necessary. But not in different orders. Genetic distances or population genetic diagnosability alone are not very useful indicators of species limits, especially when these neutral characters are so strongly affected by small population size, as is likely in several of these populations.

2014-B-2: Add Maguari Stork (Ciconia maguari) to the main list

YES. 7 without comment.

YES. Plumage, pattern of head feathering, and bill size eliminate other species. Although storks are fairly common in captivity (I am not sure about Maguari), I would not expect an escapee at that location.

YES. Evidence is good.

YES. Published photo, migratory species, accepted by national committee = doesn’t get any more straightforward than that.

YES. Straightforward identification based on photo.

2014-B-3: Add Lined Seedeater Sporophila lineola to the main list

YES. 6 without comment.

YES. Adult male distinctive. Not mentioned in the proposal is that this species is strongly migratory, and an overshoot or reverse migrant to Costa Rica (or even further north) is not that strange. A wild origin seems much more likely than an escape from captivity, for which there is no evidence for this individual, even though seedeaters are commonly kept in aviculture.

YES. Evidence is good.

YES, although it is difficult to rule out a captive origin.

YES. Published photo, migratory species, accepted by national committee = doesn’t get any more straightforward than that.

YES. Straightforward identification based on photo. Timing is reasonable. This species is migratory from SE South America into western Amazonia and large numbers are present still in October. I think the likelihood of an escapee of a South American species of Sporophila in Costa Rica is very low given its presence in appropriate habitat and consorting with other species of Sporophila.

2014-B-4: Transfer Azure Gallinule (Porphyrio flavirostris) from the main list to the Appendix

NO. 1 without comment.

YES. 1 without comment.

YES, to Appendix. The cited American Ornithological Union should also remove it.

NO. This is a strange story, but it seems like the conservative approach is to keep the status quo for now, until it can be confirmed that the bird actually was held in captivity and escaped a few days before the specimen was found.

NO. I do believe that the bird should be placed in the Appendix, but that motion failed 4-4 years ago. I see no new evidence presented why that vote should be essentially invalidated, except perhaps a change of Committee membership. This is the only species where the ABA and AOU differ, but there will be another I suppose eventually. 

NO. I still find Remsen and Parker’s argument more compelling than some second hand information that this species was kept in captivity nearby and escaped. It seems such an unlikely species to have in captivity in New York. The ABA-CLC vote to remove barely passed (5-3 to remove, Birding 31:518, 1999). I am trying to figure out if the AOU-CLC voted on this already (post 1999) but I don’t seem to have all proposal sets from that era and they are not on our online site.

YES. No information warrants its permanence in the main list.

NO. Although we generally defer to ABA on matter of origin, as far as I can tell, the ABA acted on hearsay on this, namely third-hand knowledge from someone who did not want to be identified because … the bird might have been illegal? If/when the facts can be verified that an Azure Gallinule escaped from a nearby aviary just before the sighting, then I’ll be the first to vote against this record. Until then, I would object to dismissing an extralimital record of a migratory bird based on hearsay from a potentially shady character. Although details are now fuzzy, I recall that we were unable to find any records of this species in captivity in North America, even in zoos.

The proposal does not do justice to the potential for this species to occur as an extralimital vagrant. First, the Rallidae in general are perhaps the most amazing dispersers on the planet, certainly relative to their morphology. Perhaps if human colonists of oceanic islands had not wiped out hundreds, perhaps thousands, of species, this would be more generally appreciated. Second, within the Rallidae, the species in the former genus Porphyrula are arguably the best of all. The track record of our Purple Gallinule in terms of vagrant records within and beyond the W. Hemisphere is truly astonishing. The Allen’s Gallinule of tropical Africa has perhaps an even more impressive track record given that it breeds entirely within the tropics, yet has been recorded in several European countries as well as Ascension, St. Helena, and Rodriguez islands far out in the Atlantic and Indian oceans.

Remsen and Parker (1990) showed that Azure Gallinule is likely an intratropical migrant, like Allen’s, and that the Dec. occurrence of the individual in New York falls in that migration period. As of 1990, there were five extralimital records Azure Gallinule: 1 from 3000 m in the Venezuelan Andes, two that had crossed the eastern Andes to Bogotá, one on a granite outcrop in Venezuela, and one in extreme s. Brazil, 800 km from nearest known breeding population. No other records from North America, but it’s only a matter of time. The problem is that Azure is similar enough to Purple that an individual is likely to be dismissed as the latter.

A more general comment is that I have become less militant over the last two decades in demanding a pattern of vagrancy when evaluating the likelihood of a record pertaining to an escape. First (although not directly relevant to this proposal), I have become impressed by the growing collection of extralimital records of nonmigratory species – I think we have underestimated the dispersal abilities of sedentary birds. The pivotal example for me was the Red-cockaded Woodpecker in the Chicago area many years ago. Second, I am actually impressed with how FEW obvious escapees I see (other than waterfowl) during my extensive fieldwork. Given how many cockatiels, budgies, and various estrildids get loose every year, I wonder why I don’t see more or hear of more, especially since they would likely be drawn to feeders? Given their proportional representation in the aviary world, it seems to me there ought to be hundreds of thousands of sightings of these species for every Azure Gallinule-type sighting. If I’d spent more time in S. California, south Florida, or various border towns, my impressions would certainly be very different.

Continuing to ramble … although we all know how small the odds are at detecting a single lost vagrant, at least we’re dealing with source populations that are likely on the order of 105–107 individuals. In contrast, species that are scarce in captivity (such as Azure Gallinule) likely have source pools of just 10-100 individuals. So, the probability of detection of these individuals, all else being equal, is at least 3-4 orders of magnitude lower, and that’s not even taking into account the likely lower rate of survival of escaped aviary birds. Therefore, which is really “the” conservative approach?

NO. For the most part, I think that we should try to go along with the ABA, but I still vote no on this one, but that is not a strong no.

NO. I think the odds favor this being a wild bird and wouldn’t want to make a change based on undocumented hearsay.

NO. I have to begin by saying that this is a completely inadequate proposal. It does not reference the relevant literature, namely Remsen and Parker 1990, which provided the evidence and rationale for the original listing of the species. The links provided in the proposal go to the original publication where the species was accepted to the ABA list, and a brief summary of the disagreement between the current ABA treatment and the treatment by the AOU. The proposal contains no new information of any type relating to the issue of the whether the Azure Gallinule was wild or not. Even if this proposal didn’t have controversy associated with it, I wouldn’t vote for it because of how poor the proposal is.

The committee has previously considered this issue, probably a decade ago, and it did not pass. I remain convinced that Azure Gallinule should remain on the AOU North American checklist based on the specimen. The proposal states that “some people were told it was an escaped bird…Whether true or not, it is enough to remove the record.” I disagree with this strongly.

What I see is a published paper (Remsen and Parker 1990) which provides evidence of large-scale migratory movements within South America of Azure Gallinule, other vagrant records of the species (although admittedly within South America), evidence of vagrancy to North America of other Neotropical Rallids (Paint-billed Crake, and Spotted Rail), which are not known to be migratory, and the massive level of vagrancy at the same geographic scale by Purple Gallinule and Allen’s Gallinule, close relatives of Azure Gallinule.  A pdf of Remsen and Parker 1990 is available here: http://www.museum.lsu.edu/~Remsen/1990WBPorph.pdf

In contrast, the evidence to support the removal of Azure Gallinule from the main list consists of anonymous hearsay of a series of unsubstantiated claims that we have no way to evaluate.  According to an ornithologist, this other person claims to have had an Azure Gallinule in captivity (recognize that Azure Gallinule is extremely rare in captivity; I personally have never seen it in captivity). He claims that it escaped from him. He further claims it escaped at a geographic locality relevant to the specimen record. He also claims that it escaped at a time prior to the specimen being found. Each of those statements could be true, but we have absolutely no evidence to support any of those claims. In order to remove Azure Gallinule based on these claims, all of them must be considered true. I would also note that the information claiming a captive origin of the bird became known to the ornithological community a decade after the record, which further limits my willingness to accept the argument for a captive origin of this bird.  I personally can’t see how we can remove Azure Gallinule based on these claims. In my view the story is so flimsy that it cannot possibly undermine the reasoning that placed Azure Gallinule on the main list in the first place.

2014-B-5: Transfer Yellow-winged Cacique (Cacicus melanicterus) to Cassiculus

YES. 4 without comment.

YES. The proposal provides good justification for this treatment.

YES. Clearly, melanicterus falls outside of Cacicus, despite some plumage similarities, which may be pleisiomorphic. Although they only used one sample of melanicterus  (and only have mt DNA markers from that sample), if it was mis-IDed than I would expect it to closely ally with another taxon, not be outgroup to all other caciques and oropendolas (minus Amblycercus).

YES. Phylogenetic evidence is strong.

YES. Clearly does not belong to Cacicus.

YES. New genetic data require the resurrection of Cassiculus. Once again, the authors of the Peters CL series got carried away in lumping bird genera, and as in so many cases, the classification of Ridgway, and in this case also Hellmayr, more accurately represented biodiversity.

YES. Genetic data seem clear.

YES. Resurrecting the monotypic genus Cassiculus does seem warranted given the data.

2014-B-6: Split Gymnopithys leucaspis into two species (SACC #587)

YES. 4 without comment.

YES. The genetic data strongly support this, although it would be nice to see a quantitative analysis of the song differences.

NO. It seems this split is being accepted by both the SACC and our committee based on hunches about song differences that have not been published or analyzed. I listened to 10+ cuts of each species on Xeno-canto and I hear a lot of variability in both species that did not really sort out into dramatic differences between bicolor and leucapsis. The written descriptions (from HBW) in the proposal are not much help. Plumage and morphological differences are minimal. That rufigula may be closer to leucapsis than bicolor does not mean that reproductive isolation has arisen between leucapsis and bicolor.

YES, following SACC, but with reservations. This is a tough one because there are no obvious consistent vocal differences between these two and the very different-logo-auk-aou.png” border=”0″ width=”240″ height=”146″ rufigula. For consistency, one would either have to lump rufigula with these two or split all three, and I prefer the latter option.

YES. The alternative of expanding Gymnopithys is unacceptable.

YES. Go along with SACC.

YES. I have mixed feelings here. It is  not a requirement that a biological species be monophyletic, so the weakness of the characters that distinguish leucaspis and bicolor could argue against splitting them.  rufigula is so distinct morphologically that I don’t think that lumping all 3 together makes any sense. So the options are splitting all 3 or the status quo. I guess I go weakly for the split.

YES (reluctantly). I could imagine a scenario in which leucaspis-bicolor is a paraphyletic biological species and am thus troubled by the weak phenotypic case for splitting them. But, then the Andes are a big barrier. Further work on the population genetics and vocalizations of the two is warranted.

2014-B-7: Split Pyrrhura roseifrons, lucianii, and amazonum from P. picta (SACC #306, SACC #403)

YES. 5 without comment.

YES. We should follow the SACC in this case.

YES. Does not affect taxa in our area, expect by constraining what is included in picta outside the NACC area. Therefore, I think we should follow the SACC.

YES, in part for consistency with SACC which has already considered this complicated situation in detail.

YES, following SACC.

YES. There will probably eventually be further splitting in this group, and the Central American taxon will no longer be picta, but for now following the SACC treatment makes the most sense.

YES. This seems like a reasonable approach.

2014-B-8: Revise the linear sequence of species in the genus Saltator (SACC #593)

YES. 6 without comment.

YES (including English name change).

YES (including English name change).

YES. Pretty straightforward. I also vote to change the English name of Saltator grossus to Slate-colored Saltator.

YES, both to the change in linear sequence and to the name change to Slate-colored Saltator.

YES. This sequence needs to be changed.

2014-B-9: Revise the linear sequence of species in the genus Dendrocincla (SACC #597)

YES. 7 without comment.

YES. This change makes sense given the data, and is consistent with the SACC.

YES. Straightforward change to reflect phylogeny.

YES. However, it would be good to see the issue of paraphyly of fuliginosa with respect to anabatina clarified.

NO. I can’t really see the value in this change. There is no new information regarding relationships in this new sequence. Rather it is based on criteria for sequencing that are entirely arbitrary.  To be fair, I am tired of fiddling with sequence changes that provide little or know information about relationships (even ones that do, because there is so little relationship info in sequences).

2014-B-10: Revise the classification of Automolus and relatives (SACC #601)

YES. 8 without comment.

YES. The genetic data strongly support this change.

YES. Not surprising that the “foliage-gleaner” genera were not monophyletic. I am okay to keep the great English name for subulatus (Striped Woodhauner) even though other species in the genus (sensu strictu) are called foliage-gleaners.

YES. Finally getting clarity regarding relationships within the Furnariidae. This is a well-defined group an dclear results that make sense to me.

2014-B-11: Split Siberian Stonechat (Saxicola maurus) from Common Stonechat (S. torquatus)

YES (option 2). 3 without comment.

YES (option 2, no on 2a).  Follow recommendations of proposal.

NO (option 1). I think more data in terms of taxon sampling and nuclear markers are needed before making any changes here.

NO. This is a real problem, but one that I think we can sit on the sidelines and await further developments. With all of the molecular work being done with most of the taxa of the Common Stonechat, I’m surprised that more has been done with the vocalizations. Urquhart (2002) said this was being worked on, but had nothing to offer then. I have to be skeptical of Zink’s molecular study showing strong divergence between maurus and stejnegeri. I am aware of no consistent plumage features (only average differences as detailed by Urquhart) which separate them, and are there bio-geographical differences? What about the distinctly different (by plumage) przewalskii which is well isolated by geography (and altitude?) that remains unstudied? This species remains highly peripheral to North America,  and without clear guidance I don’t see why it remains for AOU to get into the weeds.

YES (option 2, 3-way split). This seems like a very complex issue, and it would be difficult to pursue this more fully without a lot of time, especially for a taxon that is only a vagrant to our area. I therefore trust the proposal’s recommendation, which also follows the BOU’s action. For the same reason  I vote NO on options 2A.

YES (option 2), as being the best relatively conservative approach and for being generally consistent with other authorities. Nice proposal on a complicated situation with imperfect data and conflicting interpretations thereof.

NO (option 1). I am by nature skeptical of mtDNA being the sole criterion upon which species limits are based, as Zink et al. (2009) rely, and I would argue that we expect paraphyly at shallow levels of evolutionary divergence. With important haplotype sharing occurring at AST (Zink et al. 2009: Fig. 1 and p.771) and also it looks like at CHI (yes: Fig. 2) and maybe DOR (Fig. 1), and (p.771) “Geographic overlap of some clades was observed, suggesting the possibility of introgression at zones of contact.”, there is insufficient evidence here to split these out as biological species. The group is a mess, and I am confident that soon someone will take it on with nuclear markers and obtain some better resolution.

NO. It is clear that that there is potential for multiple species to be recognized in S. torquatus given sympatry of indicus with S. leucurus. However, we have no business dealing with this complex situation from afar given the shortage of critical data, just because we have a single North American specimen. It would be one thing if there were a solid analysis of species limits in this complex that we could follow, but all we have is a bunch of gene trees based on short sequences of mtDNA. Thus, it’s alarming that the BOU and IOC would make taxonomic decisions based on these data alone. Empirical demonstrations of the dangers of reliance on gene trees based on a single locus have been around for many years, and labeling taxa as paraphyletic based on a single gene tree is misleading.

Are vocal differences among members of the torquata complex comparable to those between the two for-certain separate species, S. t. indicus and S. leucurus?

NO (option 1). I think it is premature to split maurus from torquata based on a single gene tree. There is no evidence regarding voice provided, and there are a number of taxa involved. First off, this isn’t really our fight and secondly, it seems like more work needs to be done to understand the relationships. I don’t think anything would require us to accept that if we leave maurus in torquata that we have to bring in these other taxa, although I can’t rule out that making sense.  Finally, the identity of North American examples of this group seem to have a lack of clarity that this split will just highlight. I think we are better off waiting for more definitive analysis of the entire group.

2014-B-12: Revise the generic assignments of several introduced estrildids

YES (all three proposals). 6 without comment.

NO. Of the two data sets cited in the proposal, only one (Arnaiz-Villena et al. 2009) breaks the phylogeny down to the level of species. While these data are suggestive, they are based soley on cytochrome-b from mostly blood samples. I would like to see better data before making these changes.

NO. It seems these changes are based on incomplete and poorly resolved phylogenies. Certainly a better phylogeny cannot be far off for this rather important family. I would rather live with some inapt names temporarily then make changes now only to make more changes just a few more years down the road.

YES on all three sub proposals (with some reservations about doing this on the basis of one mtDNA-based study). I would also be comfortable putting this on temporary hold, awaiting Sorenson et al. in prep…

YES. The genetic data require changes in classification, and Payne in Handbook of the Birds of the World has adopted these changes.

MIXED. YES on transferring oryzivora to Lonchura. With the two published studies conflicting on where Euodice goes, I guess I would be conservative and await an better-supported outcome concerning generic limits with Lonchura before changing that (so NO on 2). I vote YES on 3 because Spermestes seems to clearly not belong to the same clade.

2014-B-13: Eliminate Trogoninae (New World Trogons) as a subfamily of the Trogonidae

YES. 1 without comment.

NO. Hold off.

NO. I prefer to wait until the additional data (per Addendum in the proposal) are published.

YES. No good options, but not good to be misleading which is where we are at present.

YES. Although the evidence is equivocal, it seems best to not have subfamilies given what we know about relationships within the family. It’s not necessarily the most stable action we can take, but keep the subfamilies implies relationships that are not known.

YES. Eliminate subfamily structure until more clarifying information is available.

NO. Await publication of Cracraft group’s analysis.

NO. To avoid a flip-flop, let’s wait until the new data are published. I have a hard time believing that the New World trogons are not a monophyletic group on biogeographic grounds.

NO. Seems premature.

NO. I think that the inconsistency of the results across studies argues for the status quo. I suspect that New World Trogons will likely prove to be a monophyletic unit in the end.

NO. Let’s wait until relationships are better resolved before we eliminate the subfamily concept from our taxonomy of this interesting group.

2014-B-14: Remove hyphens from English names of the “Black-Hawks” (SACC #515)

YES. 6 without comment.

YES. I’ve never been fond of hyphens and the more we can rid of the better. Our use of hyphens certainly differs from most of the rest of the English speaking ornithological world.  It is confusing, at best.

YES. Straightforward regarding our usage of hyphens and group names. 

YES. Required deletion with new data that indicate that “Black-Hawk” is not a monophyletic group.

YES. Long overdue crucial change.

YES. While it is too late to make English names reflect monophyletic groups, we might do our bit to eliminate confusion when we can and it’s not very disruptive.