2024-A-1: Reconsider the generic placements of Haplospiza rustica and Acanthidops
bairdi2024-A-2: Make changes to our classification of the herons (Ardeidae): (a) Modify thelinear sequence and existing taxonomic structure within the family; and (b) Revise thegenus-level taxonomy of the bitterns (Ixobrychus, Botaurus); (c) Revise the genus-leveltaxonomy of Bubulcus ibis (Cattle Egret) and related species; and (d) Remove thehyphen from the group name Night-Heron
2024-A-3: Revise the sub-family and genus-level classification of the Charadriidae
2024-A-4: Recognize extralimital Puffinus bailloni, P. bannermani, and P. persicus as
species distinct from Audubon’s Shearwater P. lherminieri2024-A-5: Treat extralimital Puffinus boydi as a separate species from Audubon’s
Shearwater P. lherminieri2024-A-6: Treat Cory's Shearwater as two species, Calonectris diomedea and C.
borealis2024-A-7: Treat Jamaican Petrel Pterodroma caribbaea as a separate species fromBlack-capped Petrel P. hasitata2024-A-8: Treat Coccyzus bahamensis as a separate species from Great Lizard-Cuckoo
C. merlini
2024-A-9: Treat Piaya mexicana and P. “circe” as separate species from Squirrel Cuckoo
P. cayana2024-A-10: Treat Stelgidopteryx ridgwayi as a separate species from Northern
Rough-winged Swallow S. serripennis
2024-A-11: Treat Larus smithsonianus and L. vegae as separate species from Herring
Gull L. argentatus
2024-A-12: Transfer Coccothraustes abeillei and C. vespertinus to Hesperiphona2024-A-1
Reconsider the generic placements of Haplospiza rustica and Acanthidops bairdi
NO (Option 4). For all the cogent reasons outlined in detail in the proposal, leave
everything as is until we have additional genetic data to confirm the topology of the tree.
These are the kind of things best mentioned in footnotes until additional data require achange that might cause major instability in nomenclature. I think that combining allthese genera in a single genus is the way to go given their genetic and morphologicalsimilarities (other than bill shape), but this has to be done in a publication that proposesa replacement name for Phrygilus unicolor.
NO (Option 4). Given the uncertainty in the nodes supporting relationships among the
taxa in question, I agree with the proposal that it is best to leave the taxonomy as is until
we have more information.
NO (Option 4). Maintain rustica in Haplospiza and bairdi in Acanthidops until
phylogenetic relationships are fully resolved for the clade that includes the genera
Geospizopsis, Haplospiza, and Acanthidops.

NO (Option 4). I agree with the proposal, I suggest that we wait for more or different
data and a clearer analysis about the relationship between Haplospiza rustica andAcanthidops bairdi, and among the three genera Geospizopsis, Haplospiza, andAcanthidops.
NO (Option 4). Although this arrangement will likely be incorrect at some point in the
future, I would rather wait with the imperfect status quo than to change it now, only tohave to change it again soon thereafter. The low support values for parts of the tree,inconsistent results with different analyses, and promise of better results with moregenetic data all should make us wait. Three monotypic genera is inconceivable with suchclosely related taxa.
NO (Option 4). The proposal lays out the arguments for different options and why it
makes sense to wait for additional data before changing these generic treatments.
NO (Option 4). As the proposal lays out a very strong argument, this seems to be theleast disruptive option for the time being, until the relationships among these 5 species
can be clarified. I would strongly prefer to avoid any move that would create additionalmonotypic genera, especially for species that all seem quite similar. While bill shape isindeed distinct, as the proposal notes, this is something that is very plastic in
Thraupidae, and there are several genera in the family that have quite a range of bill
shapes and sizes (notably Geospiza).
NO (Option 4). I have little familiarity with these species, other than Acanthidops bairdi,
but I prefer stability until the genetic evidence is more convincing and uniform inagreement as to how to rearrange these similar appearing species.
NO (Option 4). What an interesting puzzle. The discord between limited genetic data
(dominated by mtDNA) and morphology causes what seems to be best treated as a
yet-unresolved phylogeny with respect to generic limits. I agree that each of the first
three options are undesirable and that the best course is to hold the status quo until amore trustworthy understanding of relationships is reconstructed.
NO (Option 4). This seems like the only viable option given the published phylogenetic
data. If the unpublished UCE topology holds up, I would favor option 1 with an expanded
3-species Haplospiza. H. unicolor, rustica, and bairdi seem a phenotypically cohesive
group, with similar plumage, vocalizations, and bamboo specialization. The different billmorphologies don’t bother me, given the plasticity in this trait within the Thraupidae.
NO (Option 4). Option 3 or 4, probably a preference for 4. My thoughts on the various
options:
Option 1: Given the existing data, there isn't justification for this option at this time, since
the support for this relationship is so low. The proposal is correct in its dissection ofindividual gene support for the relationships, given the data in Burns et al. 2014 - there islittle published support for the clade containing unicolor, rustica, and bairdi. However,there is an unpublished UCE tree that supports the topology of the Burns et al. 2014 tree
(G. plebejus, G. unicolor)(H. unicolor (A. bairdi, S. rusticus)). But this tree is too
preliminary to base a decision on, so I’m not yet going to recommend option 1. But
hopefully, we can eventually go with option 1 - three species Haplospiza.
Finally, I would never recommend the alternative where there would be the requiredname change of unicolor species - what a nightmare. At the end of the day, I'm morepersuaded by stability than making the genera make "sense”.
Option 2: I can't remember if we considered putting rustica into Acanthidops (option 2),
but this is not as preferable as option 3 since option 3 has already been proposed andused.
Option 3: This is what is recommended in the Zootaxa paper (Burns et al. 2016) where
the generic classification was revised. That paper reverted to Spodiornis for consistency
with the “rule" of having no genera that didn't have strong support for monophyly, sosomething had to be done with Haplospiza. Looks like Clements/eBird is following thiswith Spodiornis used for Slaty Finch (rusticus). This option is fine with me.
Option 4: This option seems the least disruptive, especially given that there will likely be
an opportunity to have all three in Haplospiza in the future.

2024-A-2
Make changes to our classification of the herons (Ardeidae): (a) Modify the linear
sequence and existing taxonomic structure within the family
YES. 1 with no comment.
YES. This looks like the correct linear sequence based on the available phylogenetic
data.
YES. This classification is based on topologies that showed up repeatedly.
YES. The revised classification appears to be well-supported by different data sets.
YES. Adopt the new linear sequence and subfamily classification based on Hruska et al.
(2023).
YES. A tentative vote in favor.
YES. The Hruska et al. (2023) study is a great advance in our knowledge of relationships
in this group.
YES. Yes to the sequence and to the subfamilies, but with some reluctance. In my
opinion, until we have a time-calibrated tree of the Ardeidae, maintaining the subfamily

category in the family is based mainly on tradition (as opposed to other families withdeep internal divisions for which no subfamilies are designated. We need to have atleast a somewhat objective reason for maintaining that category in some families and notothers, e.g. rough criteria based on divergence times.
YES. Reasons are stated in the proposal.
YES. Makes sense based on the UCE species tree.
Make changes to our classification of the herons (Ardeidae): (b) Revise thegenus-level taxonomy of the bitterns (Ixobrychus, Botaurus)
YES (Option B). I checked the seven listed synonyms for Ixobrychus and none of thetype species listed on zoonomen are exilis or involucris, so it seems like there’s noavailable genus name for exilis (if we wanted to transfer it to a monotypic genus). Of thealternatives, I prefer expanding Botaurus to include all of Ixobrychus for a few reasons:1) the crown age of an expanded Botaurus is roughly comparable to that of other heron
genera when accounting for the branch length inflation mentioned by the Hruska study,and 2) it negates the issue of not having sampled the type of Ixobrychus in the UCE
sampling. Also, for some of the same reasons as I’m voting to merge Bubulcus into
Ardea, I think one of the really cool things that the phylogenetic data from the Hruska
study shows is that body size is extremely labile in herons. So, even though an
expanded Botaurus is highly variable in size, they all essentially do the same thing(marsh skulkers) and the various Old World Ixobrychus span the range in size between
our large and small New World taxa. I understand the issues with transferring somelargely Old World taxa to Botaurus when it’s not really within our purview, but I am
absolutely opposed to the idea of exilis being in a different genus than the extremely
morphologically similar sinensis and minutus. I would prefer to leave exilis where it is ifthat is our other option. The mitochondrial data at least does place minutus with the restof the Ixobrychus, so we do have some evidence that minutus and exilis are not sisters.
If that were to hold up with genomic data (which I would imagine is not forthcoming), I
really can’t see any option other than transferring all of Ixobrychus to Botaurus. If weneed to wait until a global checklist such as WGAC votes on this and then re-voteourselves, that’s fine by me.
YES (Option B). I vote for revising the genus-level taxonomy of Ixobrychus andBotaurus, with a preference for the option of subsuming Ixobrychus into a broader
Botaurus. I originally voted yes to transferring Ixobrychus exilis to Botarus based on the
UCE data, but other committee member arguments swayed me to prefer an expanded
Botaurus.
YES (Option A). According to the most recent multilocus phylogeny, Ixobrychus exilis
should be transferred to Botaurus. As recommended in the proposal, I think thattransferring the species endemic to the Americas is the best option, in addition to being
more consistent with the depth of nodes. I agree to re-vote if a global body such as
WGAC endorses a different treatment.

Update on 2024-A-2b: Now that WGAC has endorsed merging all Ixobrychus into a
broader Botaurus, I change my vote and support the decision made by global
authorities.
YES (Option B). When I look at Ixobrychus exilis in specimen trays alongside five other
Ixobrychus species, it would be a challenge to tell them apart if the labels were covered(i.e., Hruska et al. fig. 3 is no surprise). If Botaurus really does encompass this degree ofphenotypic variation, it makes more sense to have a broad Botaurus that contains it all
rather than ignore phenotype and split exilis out of Ixobrychus. (Unless there are someother traits clearly shared between exilis and Botaurus that are not present in the rest of
Ixobrychus.) The node uncertainties here in their fig. 4 also suggest a single-genus
treatment for now.
YES (Option B). This one is exasperating because the authors of the paper (including 5
friends) and the reviewers did not even mention the obvious alternative hypothesis, i.e.
subsuming Ixobrychus in Botaurus. In disbelief, I just re-read relevant sections of Hruska
et al., an otherwise excellent paper, to confirm that there is no mention of this obvious
alternative.
First and foremost, any changes based on this paper should be DOA because the typespecies of Ixobrychus is minutus (Ardea minuta Linnaeus 1766). But minutus was not
sampled by Hruska et al. The only mention of minutus in the text (as revealed by the
Find function) is its initial mention as a member of traditional Ixobrychus and its inclusion
in Ixobrychus sensu lato in the classification table. Huang et al. (2016) sampled minutus
but not exilis. Päckert et al. sampled minutus, sinensis, and exilis, but not dubius. So, theonly data relevant to the relationship between exilis and the type species of Ixobrychus
is Päckert et al.’s mtDNA barcode tree, which indeed found exilis as sister to Botaurus,
not minutus. But that same tree placed cinnamomea and eurhythmus as sister toeverything else, including minutus and flavicollis, the latter sometimes placed in themonotypic genus Zupetor.
This absence in the analysis of the type species for the genus should be sufficientgrounds for voting NO on the proposal. Proper taxonomic procedure requires
assessment of the type species of the genera involved. How can we revise the limitsof Ixobrychus without its type species being included in the analysis? How can weput exilis and minutus in separate genera based on this paper when one of them was not
sampled? Step 1 of any valid taxonomic revision is analysis of the type taxa.
But let’s just pretend that exilis and minutus are not closely related, as suggested by thebarcode papers. Then, there would be no question that a change needs to be made inclassification given these data. Here’s the problem. The four Ixobrychus species exilis,
minutus, dubius, and sinensis are so similar that they have always been considered partof a species complex. Mayr & Short (1970) officially designated them as a superspecies(parapatric replacements of monophyletic lineage). This was followed subsequently bybasically all authorities to one degree or another. This is not to say that Mayr & Short
didn’t make mistakes in their superspecies designations, but they usually got it right(because recently diverged species typically remain morphologically similar andparapatric or allopatric), and in this case no one that I know of familiar with the groupwould fault them for having made this designation based on their parapatric replacement
pattern and similar plumage and morphology, despite Hruska et al.’s possible falsificationof it being a monophyletic group.
Note the extreme similarity between our I. exilis and the Australian taxon dubius (treatedas a subspecies of minutus or as its own species depending on classification). They areso similar that I suspect without doing some advance studying, all of us would misidentify
dubius in the field as our familiar exilis (and on a just a quick view would likely pass off
male minutus as exilis also). See other comments on the similarities among these taxa
from direct field experience and on covering up specimen labels. Note that Hruska etal.’s three sentence discussion of the issue includes no mention of this extreme
phenotypic similarity, yet they want to put these remarkably similar taxa in different
genera.
I can think of no analogous case in birds. Of course DNA has revealed some big
surprises that have violated our world view of the value of plumage as a phylogenetic
character. But this is different. Exilis, minutus, dubius, and to some degree sinensis areamong the most ornamented of herons, with a suite of shared plumage patterncharacters not found elsewhere in the group or even the family. If they were a cluster ofpattern-less dull birds, then that they weren’t each other’s closest relatives might justhave been hidden by an absence of characters – no big deal. But this is the opposite, atleast within heron phenotypes. Add to this their parapatric replacement pattern andperhaps even vocal similarities (see other comments), and placement in separate
genera, when a reasonable phylogenetic alternative that maintains them as congeners isavailable, will likely draw eyerolls, head shakes, and snickers from many ornithologists.
I can think of a recent case in which we expanded one genus to include another despite
morphological discontinuity: Catoptrophorus into Tringa. The Willet really differs
phenotypically from typical Tringa, which are fairly homogeneous, but when faced withthe genetic results, we had no problem expanding Tringa to include morphologicallydisparate Catoptrophorus.
Why not just expand Botaurus to include Ixobrychus? At least Terry’s proposal broughtup this possibility, but he argued that broad Botaurus would be too heterogeneous
phenotypically. Here’s my counter-argument. Structurally, one could make a case that
Botaurus look superficially like giant juvenal-plumaged Ixobrychus. (This is the oppositeof the Bubulcus-Ardea case, which many of you are in favor as treating as congeners.).
Check out Jutglar’s plate. One could also make a case that involucris is intermediate
between Ixobrychus and Botaurus in plumage (and thus no surprise that it is on the
branch Botaurus sensu stricto, as the recent genetic data suggest). From theillustrations, female cinnamomeus looks like a miniature Botaurus, as does female
eurhythmus … in my opinion. The oddball flavicollis closes the size gap to some extent
between big Botaurus and small Ixobrychus; body weights in HBW (1992, v. 1) show
overlap between flavicollis and the low end of our American Bittern. My point is that once
you look at the diversity of bitterns, beyond just our familiar Least and American, a single
genus is palatable in my opinion, certainly much more so than placing phenotypicallysimilar allotaxa in different genera.

I would change my mind (as long as minutus is also included in the analysis) if atime-calibrated tree indicated that the split between Hruska et al.’s broad Botaurus andconstricted Ixobrychus was ancient, e.g. early Miocene as in many groups labeled as
genera in birds.
YES (Option B). I agree to transfer Ixobrychus exilis to Botaurus, the evidence from
UCE is clear.
YES (Option B). I think expanding Botaurus to include the Eurasian, African, andAustralian taxa is the better solution. While there is a clear divide genetically,morphologically between the two main clades of bittern, all of the small bitterns are very
similar, and it would make more sense if Botaurus just included all the bitterns, with thegenus just being polymorphic.
YES (Option B). This is pretty subjective, but I prefer a larger Botaurus and for thebitterns that includes the Eastern Hemisphere taxa.
NO. Even though the topologies seem rather solid, the exclusion of the type species in
the analyses is a critical lapse and makes it difficult to do any restructuring at this time.
NO. I’ve thought about this for weeks and just can’t wrap my head around transferring I.
exilis and presumably I. involucris (SACC decision) to Botarus, yet leave the rest of the
Old World Ixobrychus as is. When I first went to Europe in the spring of 1977 and saw
and studied a number of I. minutus everything about them (morphology and behavior)suggested Least Bittern (I. exilis) to me, so much so that I initially thought that they were
the same species until I checked the scientific names. Recently I went to Xeno-Cantoand checked vocalizations of Little Bittern and the single note of the song is certainly
different from the coo-cu-cu-cu song of Least Bittern, but then I found an entry for callnotes on Little Bittern and the chatter series of harsh kek notes (see the entry on
Xeno-Canto recorded on 15 August 2019 at Campo de Moro Verde, Spain) sounds tomy ear identical to the comparable call of Least Bittern. This call of Least Bittern was notwell known, but once learned, you realize how common this species can be inappropriate habitat. In looking at the rest of the Old World Ixobrychus I see Cinnamon
Bittern (I. cinnamomeus) fairly regularly in Southeast Asia and have once seen the muchscarcer Schrenk’s Bittern (I. eurhythmus). By far the commonest species in eastern Asia
is Yellow Bittern (I. sinensis) and I’ve watched many over four decades of visits. They
certainly resemble Least Bitterns on structure and somewhat on morphology, but again
behaviorally they seem very similar and collectively quite different from the three speciesof Botaurus I’ve seen. The calls of Yellow Bitterns I’ve perused on Xeno-Canto seem
similar enough in type to Least and Yellow Bitterns, but didn’t find the harsh and rapid
series of notes. I guess overall, I would prefer to do nothing on this for now and await
further genetic studies than do something that seems pretty radical to me which will laterneed to be changed. I am also left despairing that just because there is no available
name for a combined genus of I. exillis and I. involucris doesn’t necessitate getting themthrown into Botarus as the only solution.

Update on 4 June 2024: Now that this has passed and we have an enlarged andexpanded Botarus, we now have a linear sequence that is B. exilis, B. lentiginosus, B.
pinnatus, B. minutus, and B. sinensis. We are asked to believe that exilis is closer tolentiginosus (and pinnatus). This is despite the very close phenotypic similarity between
exilis and minutus and to a slightly lesser extent sinensis. This is also despite theyear-round contact call (a quick series of harsh squawking notes) is to my ear identicalbetween exilis and minutus. Really? I invite anyone to listen to the available recordingson Xeno-Canto and do their own evaluation.
I remember not too long ago we were asked to believe that Lazuli Bunting (Passerinaamoena) was closer to Blue Grosbeak (now P. caerulea) than to Indigo Bunting (P.
cyanea). This was based on two independent (I think) mtDNA studies. Given theconcerns the linear sequence was slightly modified to P. caerulea, P. amoena, and P.
cyanea. After this finesse and after the Supplement was published along came anotherpaper based on nuclear DNA that showed that in fact P. amoena and P. cyanea weresisters, as expected, given their very similar songs, including all call notes which soundidentical to one another, and somewhat frequent interbreeding. So here why not startwith the large species of Botarus, then go to the small species, thus, B. lentiginosus (orB. pinnatus), then B. exilis, B. minutus and B. sinensis? Further genetic studies with anevaluation of all species (per Van’s comments) would be the most desirable outcome for
now at least we still have the small Botarus together and still next to the large ones
rather than exilis isolated at the beginning of the linear sequence. Convergent evolution
despite, very close phenotypic appearance, is one thing, but when you combine that withidentical or nearly identical contact calls, I feel it more likely that something here isamiss.

Make changes to our classification of the herons (Ardeidae): (c) Revise thegenus-level taxonomy of Bubulcus ibis (Cattle Egret) and related species
YES (Option A). 2 with no comment.
YES (Option A). According to the most recent multilocus phylogeny, Bubulcus ibis
should be transferred to Ardea. I agree to re-vote if a global body such as WGAC
endorses a different treatment.
YES (Option A). I’m opposed to placing Bubulcus into Ardea for the reasons others
have raised, namely morphology, but especially behavior. When one watches theforaging gait of a flock of Cattle Egrets moving through a grassy field, one is notreminded particularly of any species of Ardea. Yes, Intermediate Egret (A. intermedia)
does cause some confusion visually in the field with Cattle Egret, particularly with theeastern subspecies of Cattle (coromandus), perhaps best treated as a separate species.
Also, Cattle Egrets have a distinct alternate plumage which involves much of theplumage while in Ardea and for that matter Egretta the alternate plumage mainlyinvolves head and neck (and elsewhere) plumes and the change of soft part colors. I’m
intrigued by the preference in another comment for transferring some species toCasmerodias, although I’m always struck by how similar the calls of Ardea alba and A.
herodias (and presumably A. cinerea) are.
YES (Option A). I think we have to go with the UCE data, i.e. Bubulcus is embedded inbroad Ardea. So, the decision is arbitrary. Sink Bubulcus or resurrect Casmerodius? I
see good points for both treatments. However, the biggest difference between Cattle
Egret and the others is size – if Cattle Egret were the size of a typical Ardea, I suspect
we wouldn’t balk at the decision. Size alone is not a criterion for a separate genus (thinkof Chloroceryle as just one of many examples). Also, I think two Old World taxa, withwhich we are less familiar, intermedius and purpurea, close the size gap somewhat.
Cattle Egret is obviously a highly specialized feeder that has “broken out” of the standard
Ardea morphology, and the smaller size likely is a benefit to its agile pursuit of flushedarthropods and small vertebrates. I will point out that Cattle Egret holds its own with the
big Ardea in terms of voraciousness: for entertainment for anyone who read this far,here’s my video of one swallowing a snake that is longer than the bird:
https://www.youtube.com/watch?v=fMqjKbuDDUY&t=29s. Also, we’ve all seen Great
Egret and Great Blue Heron regularly feeding facultatively in terrestrial situations. One
final point: how would one diagnose resurrected Casmerodius other than by tree
typology? Distinguishing Great White Heron from Great Egret takes a little practice, forexample: https://www.youtube.com/watch?v=p0B4fOUDQWI.
YES (Option A). Transferring Bubulcus ibis to Ardea would involve the least change. In
these cases, I also generally prefer to avoid successively splitting genera when it is not
explicitly necessary; to me, fewer larger genera are more informative to relationships
than a bunch of small and monotypic genera.
YES (Option A). For Ardea, I think that we need to make a change of some kind basedon the phylogenetic data. I’m more confident in the UCE topology than the otherphylogenetic data, and transferring ibis to Ardea is less disruptive than resurrecting
Casmerodius. Also, as with the bitterns, we now know that body size is very labile inherons. Despite its unique behavior, I don’t think it’s too much of a stretch to include ibis
in Ardea, as the various (former) A. intermedia species look quite similar to ibis and fill inthe size gap between ibis and the larger Ardea.
YES (Option B). The Cattle Egret is so behaviorally and morphologically separate fromother species in Ardea, that it does not make sense to place it in that genus. I muchprefer to split off alba, intermedia (and pacifica) into Casmerodius.
YES (Option B). I see arguments for both options, and am slightly in favor of transferring
alba, intermedia, and pacifica to Casmerodius rather than transferring Bubuculus ibis to
Ardea for the reasons given by others. However, I could go either way on this issue.
YES (Option B). Similarly here, I tend to like decisions regarding genus limits thatincorporate phenotypic traits and not just genetic ones. Huruska et al. (2023) focus only

on the latter. The gene tree uncertainties in Hruska et al. (2023: fig. 4) make placementof Bubulcus uncertain with respect to its Ardea relatives. They are correct to note that “itsbehavioral and morphological distinctiveness have prevented a generic name change inthe major bird checklists…” Those traits are so distinctive that I think recognition of amonotypic genus is warranted. Rather than lump it into Ardea, I support we splitting thatclade into Ardea, Bubulcus, and Casmerodius (fig. 4), which would fit their fig. 3 as well.

Make changes to our classification of the herons (Ardeidae): (d) Remove thehyphen from the group name Night-Heron
YES. 1 without comment.
YES. The phylogenetic data show that the Night Herons are not monophyletic.
YES. Sequence looks good, unless either part of A2-b does not pass.
YES. Non-monophyly of the night herons based on UCE data mandate this change.
YES. Remove hyphen from Night-Heron group name. Phylogenetic analysis in Hruska etal. (2023) does not support monophyly for species currently considered “Night-Heron”.
YES. Remove hyphen based on established policy.
YES. Changing Night-Heron to Night Heron is warranted given their findings.
YES. The UCE data do not support the monophyly for the species.
YES. Mandatory change required by our policy.
YES. Remove the hyphen from “night-heron” based on the naming guidelines.

2024-A-3
Revise the sub-family and genus-level classification of the Charadriidae
YES. I agree with all the recommendations in this excellent proposal (Yes to A,,D,E,F,G;
No on B,C,H). I think this proposed classification balances changes where needed(some Charadrius to Anarhynchus) with stability to where change is less sure (species
level sequence in larger genera)
YES. I agree with the proposal, it is valuable to review the classification of Charadriidae
taking into account the published phylogenies. (a) YES. Several phylogenies
consistently place morinellus on a long branch closely related to Charadrius sensu

stricto, time since divergence supports genus-level divergence. (b) NO. Keep dubius
within Charadrius until further research (with more species/samples and molecularmarkers) clarify the relationships. Consider recommendations from global authorities
since it is a mainly extralimital species. (c) NO and (d) YES. Since support is low formany internal nodes in that clade, it will be best to leave all members of the group aspart of the same genus. (e) YES. Adopt the new linear sequence. (f) YES. Pluvialis isconsistently a separate group in available phylogenies. (g) YES and (h) NO. Vanellus isembedded within Charadriinae in phylogenies; keep Anarhynchus within Charadriinae.
YES. (a) YES. The data consistently place morinellus on a long branch that suggests
generic-level divergence; thus, placement in the genus Eudromias makes sense. (b) NO.
I agree with the proposal’s recommendation not to transfer Charadrius dubius toThinornis, given that this species is largely extralimital to the NACC area and global
authorities have not yet adopted this treatment. (c) NO. Agree with the proposal’s
recommendation. (d) YES. (e) YES. (f) YES. Pluvialis is clearly on a long branch, thus
placement in a separate subfamily makes sense. (g) YES. (h) NO. It seems preferable tomerge Vanellinae into Charadriinae rather than recognize three subfamilies dominatedby a single genus.
YES. Excellent proposal. (a) YES. I agree and when one spends time with morinellus
they behaviorally are pretty different, starting with that you can often approach to withinseemingly ten feet or so to them. (b) NO, but it would not surprise me if additional
studies confirm that Charadrius dubius is pretty different and a change will be necessary.
Their soft and plaintive vocalizations strike me as really quite different from other
Charadrius along with the lack of a white wing stripe. (c ) NO, as outlined in the proposal.
(d) YES, (e) YES (f) YES. This one seems long overdue. (g) a reluctant YES. I’m on thefence on this, but am left with the feeling that the species in the dominant genus,
Vanellus, are strikingly so similar collectively and so different from other groups thatmaintaining a separate designation is hard to resist. (h) YES.
YES. (a) NO. I’d rather wait for more data on this one. Long branches on a tree
reconstructed with ~69% missing data are of questionable utility, so I’d rather be
conservative for now and retain morinellus in Charadrius. While this might leave aparaphyletic Charadrius, filling in those large gaps in the data matrix could change that
relationship quite a bit. And for example, we could even now simply broaden Charadrius
to include Thinornis and morinellus and it would be roughly equivalent to the genus
Vanellus in the same red-arrowed figure (I am ignoring morphology here, though
Thinornis has a history of being considered a somewhat sketchy genus). (b) NO, forreasons outlined. Again, the Thinornis/Charadrius (sensu stricto) relationship could use
some additional data to provide more confidence on this relationship.When I cursorily
look at specimens, Eudromias looks more like a genus-level split than Thinornis, but ourholdings of Thinornis and Charadrius are a bit spotty. (c) NO. D is a much better option.
(d) YES. I agree this is not core Charadrius and this seems like a good taxonomic
solution. (e-g) YES. All seem appropriate. On G, I do recognize that this makes for amore heterogeneous Charadriinae and that given more data and a clearer

understanding of relationships we might break this into three subfamilies. (h) NO.
YES. I agree with the excellent proposal. (a) YES. (b) NO. (c) NO. (d) YES. The data arequite clear. (e) YES. (f) YES. (g) YES. (h) NO
YES. Yes to (a)(d)(e)(f)(g). NO (b), (c) (h). Reasons are given in the proposal.
YES. Kudos for extracting the reliable signal out of all that messy data, and all the
proposal recommendations are cautious and wise in my opinion. That the banded
plovers fall in two different genera is another example of plumage characters notnecessarily providing reliable phylogenetic signal. However, that morinellus is on a long
branch that argues for restoration of Eudromias is subjectively pleasing to those of us
who never understood its inclusion in Charadrius. Another committee member made agood point on what we can/can’t make of a long branch when there are so many missing
data, but I think the new data shifted the balance in what is an arbitrary decision in termsof strict typology.
Mini-rant: That the gene-based tree was not published as a figure in the Černý-Natale
paper is yet another of dozens of examples in the last decade that make me wonder
sometimes if MPE is actually a peer-reviewed journal. Evidently, the message is notwidely appreciated that phenotypic data have a difficult time eliminating convergence orstrong divergence, as “proven” by the Livezey-Zusi monograph that produced a couple
dozen conspicuous and indisputable examples of this (e.g., loons and grebes
maintained as sisters, and diving-petrels and phalaropes restored to family rank). That
was way back in 2007 with the world’s largest-ever matrix of phenotypic data (2K+
characters).
YES. (a) YES to transfer morinellus to Eudromias for the reasons outlined in the
proposal. (b) NO to transfer dubius to Thinornis, as I agree that the support is not strong
and in this case it makes more sense to maintain it and the other species in this clade in
Charadrius sensu stricto. (c) NO on recognizing the genus Ochthodromus, and instead(d) YES on moving these taxa to the genus Anarhynchus. It is very clear that these taxa
are not part of Charadrius, and are supported as a well-supported clade in multiple
studies, but subdivision within this clade does not have strong support, and I agree withthe proposal that all of these taxa together should be transferred to Anarhynchus and notdivided between Anarhynchus and Ochthodromus. (e) YES on adopting the new linear
sequence for the plovers, for the reasons stated in the proposal. I also agree with thedecision not to alter the sequence within each main clade for the time being, since thenode support within clades is low. (f) YES on recognizing Pluvialinae given thelong-branch length involved here; I do not support treating this as a separate family,
given the many shared similarities between Pluvialis and the other plovers, they fit muchbetter within Charadriidae. (g) YES on transferring Vanellus into Charadriinae, given theparaphyly of Charadrius sensu lato by the Vanellus lapwings, I think it is appropriate toinclude them in Charadriinae, rather than further recognize another smaller plover
subfamily that is for all intents and purposes identical to the other, and all almost
comprised entirely of a single genus. Single genera subfamilies describe nothingdifferent from the subfamily itself, and are not useful for classification purposes if they
can be avoided. (h) NO.
YES. Nice job on the proposal. I agree with all of their recommendations: YES on(a)(d)(e)(f)(g). NO on (b)(c)(h).
YES. Appreciate the work on this proposal to distill the strongly supported informationfrom the trees. I agree with all the recommendations.

2024-A-4
Recognize extralimital Puffinus bailloni, P. bannermani, and P. persicus as species
distinct from Audubon’s Shearwater P. lherminieri
YES. This seems long overdue. Clearly there is a lot more work that needs to be done inthis group but really this seems more like housekeeping given that everyone else haslong treated these as specifically distinct, and the only ramification to our list is the range
statement.
YES. This splits off three non-Atlantic subspecies from lherminieri, which makes
biogeographic sense. This group has a subtle but confusing amount of variation inmorphology and plumage, but restricting the long-tailed, but short-winged lherminieri toAtlantic populations makes lots of sense.
FYI: our current classification is:
Puffinus subalaris Galapagos Shearwater.
Puffinus puffinus Manx Shearwater.
Puffinus auricularis Townsend’s Shearwater.
Puffinus newelli Newell’s Shearwater
Puffinus bryani Bryan’s Shearwater. (H, A)
Puffinus opisthomelas Black-vented Shearwater.
Puffinus lherminieri Audubon’s Shearwater.
Puffinus baroli Barolo Shearwater. (A)YES. Although heavily reliant on mitochondrial DNA, the genetic data do indicate thatbailloni, bannermani, and persicus are unrelated to lherminieri. Based on the data ofAustin et al. (2004) I’m less convinced that persicus should be considered separate frombailloni, but given that these are well outside our area I think we should follow global
authorities that recognize the two as species. The node support for the sister relationshipof bannermani and the newelli complex is rather weak, but at the very least bannermani
seems to be unrelated to lherminieri.
Given the many different taxonomic treatments applied to the name “Audubon’s
Shearwater”, ranging from a pantropical, to a North Atlantic, or western Atlantic species,
I am in favor of abandoning the name Audubon’s for lherminieri. Especially if proposal

2024-A-5 passes, the breeding range would be largely restricted to the Caribbean, so I
would be in favor of the name Caribbean Shearwater for lherminieri, which is also thecommon name given by McAtee for nominate lherminieri. However, I was a bit confused
as to why “Audubon’s” was applied to lherminieri given that he was neither the collector
nor the describer, and turned up a paper by Palmer (1931) who gave the reasons for thename. Palmer (1931) says that Audubon was in fact the first to collect the species, in
1826, but called the specimens P. obscurus Gmelin, a name now generally disregarded
due to uncertainty about which taxon it applies to (Murphy 1927), but at the time applied
to small black-and-white shearwaters from the Pacific and Indian oceans (= P. bailloni?).
The confusion is understandable, given that we’re still sorting out the identification andtaxonomy of these birds! Lesson’s name lherminieri from 1839 was overlooked by someauthors, or at least his diagnosis was unavailable. Finsch, in 1872, named P. auduboni
based on a specimen from Florida, which gives us the source for the common name,
although auduboni is now a synonym of lherminieri. So, the common name “Audubon’s”
was originally applied to the Caribbean taxon, despite Audubon not realizing that he hadcollected a new species. The expansion of the name “Audubon’s Shearwater” to a
globally-distributed species was perhaps a poor choice, and could be a good reason for
not changing the name of lherminieri now, as we are basically reverting to the original
common name for lherminieri. A name change may also not be required, given that thisis not a parent-daughter split. However, given the many subsequent taxonomic
circumscriptions of the name “Audubon’s Shearwater” I think it would be better to adopt
a new name for the modern treatment of lherminieri.
Murphy, R.C. 1927. On certain forms of Puffinus assimilis and its allies. American
Museum Novitates 276: 1-15.
Palmer, T.S. 1931. Audubon’s Shearwater in the United States. The Auk 48(2): 198-206.
https://www.jstor.org/stable/4076787
YES. It would be nice to see this corroborated with non-mtDNA data, but these changes
make sense given the combination of genetics and biogeography. It also puts the NACC
list in line with global lists.
YES. The UCE-ddRAD phylogeny from Ferrer Obiol et al. (2021) and previous mtDNA
phylogenies support that P. bailloni and P. lherminieri are separate taxa, they do noteven represent sister species, therefore recognizing the split of P. bailloni from P.
lherminieri is long overdue. Recognizing P. bannermani and P. persicus as separate
species from P. lherminieri is supported by mtDNA phylogenies and biogeography.
YES. I vote in favor for all of the reasons given, but particularly given the trend for
splitting these island-breeding or island-group isolates as separate species makes it
untenable that the Caribbean breeding taxon with distinct structural differences bemaintained with other taxa found thousands of miles away.
I agree fully that we should consider changing the English name of Audubon’s
Shearwater to Caribbean Shearwater which well describes the range of the speciesacknowledging that they range into the western Atlantic. I note too (Howell and Zufelt(2019) that there is a small population of this taxon in Espirito Santo, Brazil. Given the
drastic overhaul of these small shearwaters, English name changes can be justified.
Retaining the English name of Audubon’s Shearwater would be decidedly unhelpful.
Howell, S.N.G. and K. Zufelt. 2019. Oceanic Birds of the World, a Photo Guide.
Princeton University Press.
YES. While I am reluctant to rely so much on mtDNA for species limits, it is clear that
there are multiple species here and these are extralimital for us so going with theprevailing other authorities seems warranted.
YES. I agree with the proposal, based on the morphology, biogeography and genetic
differences that supported the split of the three extralimital species.
NO. This is basically a protest vote. I think the proposal makes the best of a badsituation, but one could also state that genetics, biogeography, and morphology also
support treatment of all of these taxa as subspecies. In some ways I see the advantagesof following other world classifications, but I can also see a disadvantage: the conformity
implies that data convincingly support that classification, and thus no further work isneeded, when in fact this is far from the case. I think it is actually beneficial when thedata can be interpreted in more than one way: if world classifications differ, then the
problem is emphasized, not pushed under the rug. The section in Ferrer Obiol et al.
“Considerations of shearwater taxonomic classification” is worth reading for its catalog ofwhat data are missing and what data are need to produce a well-supportedclassification, with the following quote near the end:
“As a final consideration, our analyses based on genomic data and the ongoingtaxonomic debate suggest that the species status of these taxa should be
re-evaluated. Future studies should use species delimitation approaches under an
integrative taxonomic framework, combining genomic data with a thoroughmorphological re-evaluation including a detailed evaluation of vocalisations.”
I’m in favor of waiting for those data and a “do no harm” approach until then.
YES. I vote in favor for the reasons outlined in the proposal, and to bring us in alignment
with other global checklist authorities .
YES. While not a slam dunk due to heavy reliance on mtDNA, this seems the best
course of action given the data and circumstances at hand.
YES. Although more data are needed, I think there is enough here to make this split andbring us into conformance with other lists. But I agree that this push to have one global
world list will obscure taxonomic problems that need more work.

2024-A-5
Treat extralimital Puffinus boydi as a separate species from Audubon’s
Shearwater P. lherminieri
YES. I vote in favor, but with reservations. Puffinus boydi seems as distinct fromlherminieri in morphometrics and genetics as is baroli, but there is limited divergence
between boydi and lherminieri in plumage or vocalizations. I’m swayed by the nuclear
DNA data showing that boydi+baroli is very divergent from lherminieri, with the ~1 Ma
divergence time estimate. The Flood and van der Vliet 2019 paper mentioned in the
proposal does an excellent job of sorting out the morphological differences between
boydi and baroli, but does not analyze lherminieri. However, what strikes me from thepaper is the extensive overlap in plumage between boydi and baroli, with sharedmorphometrics (just a slightly longer tail in boydi), in contrast to the larger andlonger-tailed lherminieri, which mirrors the closer relationship between boydi and baroli
shown in the genetic data.
The D-statistic introgression data are interesting, but tell us about ancient, not ongoinggene flow, which is not especially relevant to current species limits under a biological
species concept. The proposal does note that this introgression between boydi andlherminieri was estimated to occur in the Pleistocene, but it seems that the paper authors
did not do any demographic modeling to estimate recent gene flow.
What gives me pause is the vocalizations. As is mentioned in the proposal, there are few
vocalizations available for any of these taxa, but it appears that at least some biologists
are working at the breeding colonies of both boydi and baroli, but most recordings are
not on the public repositories. The Sound Approach website has some interesting
information on vocalizations (https://soundapproach.co.uk/species/boyds-shearwater/)as does this post documenting a boydi in a barolo breeding colony(https://subalpinebirding.com/blog/a-boyds-shearwater-in-a-barolo-colony). What strikes
me is the very different (higher pitched / more notes) calls of barolo in comparison to
boydi. However, the few recordings of lherminieri on ML (especially
https://macaulaylibrary.org/asset/42998 andhttps://macaulaylibrary.org/asset/151481441) sound extremely similar to those of boydi.
A formal analysis of these vocal differences, if any, would be very informative.
Although boydi is extralimital based on current knowledge, the movement data from
Ramos et al. (2020) suggest that individuals could show up near the coast of northern
South America, or even in the Lesser Antilles, where they would be near colonies oflherminieri in the Lesser Antilles and Fernando de Noronha.
YES. Recent phylogenetic analysis considering genomic data support that P. baroli and
P. boydi represent sister taxa, and both are sister to P. lherminieri. Maintaining boydi aspart of P. lherminieri results in a classification with paraphyletic groups. Several lines ofevidence (vocalizations, morphology, and lack of evidence of hybridization) support P.
baroli as a separate species from boydi, so lumping boydi with P. baroli is not an option(and it would be outside of the NACC jurisdiction). I agree with the proposed
recommendation to consider the extralimital boydi as a separate species from P.
lherminieri.
YES. I vote in favor, but I’m uneasy after reading other comments. There are 2-3
subspecies within the newly configured P. lherminieri. Perhaps boydi is another? For
now, I think it is best to adopt European taxonomy for boydi which I believe pretty
uniformly recognize it as a separate species.
YES. I agree with the proposal. Puffinus boydi and P. ihermineri have differences ingenetics, distributional area, morphology, size, and foot color. And in most of thephylogenetic trees P. boydi is closely related to P. baroli, and not to P. lherminieri.
YES. Reasons are outlined in the proposal.
YES. I generally defer to global taxonomies on extralimital taxa and it seems there are
multiple lines of evidence to support the split—although it does seem a very recent one.
YES. I vote in favor, but with reservations. I have gone back and forth on this one.
Multiple independent studies show that Puffinus boydi is separate from P. ihermineri andmore closely related to P. baroli; thus, it makes sense to separate boydi from ihermineri
which is the basis of the proposal. The proposal specifically does not include an option
to recognize boydi as a subspecies of baroli, so we can’t vote on that. Factors that areswaying me in favor of elevating boydi to species include: (1) a combination of genetic,
phenotypic, and at least subtle vocal differences; (2) my inclination to defer to global lists
for extralimital taxa. However, my reservations are two-fold: (1) lack of a formal study of
vocal differences; (2) uncertainty about current gene flow and what is maintaining
reproductive isolation between baroli and boydi, given that there is movement between
colonies (the proposal mentions “lack of evidence of hybridization despite occurrences at
each other’s colonies” but does not provide details).
YES. I vote in favor based on monophyly and phylogenetic position to other relevant
taxa. Also agrees with biogeography and to some extent morphology, and makes it
concordant with decisions on other taxa outside our purview.
NO. P. baroli and boydi are clearly closely related, and the evidence seems morecommensurate with subspecies-level divergence. With divergence being just ~120 Kyr(Ferrer Obiol et al. 2023), a D-value indicating gene flow of unknown timing and extent (Iam unclear on “lack of evidence of hybridization”), the Ferrer Obiol et al. (2022)
observation of subspecies-level genetic divergence mentioned, and phenotypic
differences being “subtle,” the elevation to full species seems unwarranted.

NO. Although I would rather not buck the more global list, given that this taxon is outside
the NACC area, I just do not see any evidence that boydi is reproductively isolated frombaroli. Yes, it is quite divergent genetically, but what are the morphological, phenological,
or vocal differences that could maintain reproductive isolation?

2024-A-6
Treat Cory's Shearwater as two species, Calonectris diomedea and C. borealis
YES. These two taxa breed sympatrically and differ in several traits (morphology, voice
including differential response to playbacks, genetics, chemical profiles of uropygial
secretions), with limited evidence of hybridization where they breed sympatrically. Thus,
they appear to be reproductively isolated. Very interesting proposal that will put the
NACC list in line with other global checklists.
YES. Both diomedea and borealis breed in sympatry with limited gene flow. They show
genetic and phenotypic (vocalizations, uropygial secretions) differences. I agree withretaining the English names already in general use for these Old World species, evenmore so given that they are found in the NACC area as non-breeders.
YES. All the evidence supports these as biological species. The birds are clearlyrecognizing each other as different, even if we struggle to identify them based on
plumage. To my ear, the vocalizations do sound quite distinct, and consistently different
between the two taxa. This will certainly make east coast pelagic trips more interesting.
Although it goes against our common name guidelines, I think it’s better to follow the
global checklists and use the English names suggested in the proposal.
YES. I looked at the recent edition of Birds of Europe, 3rd edition (2023) which I justpurchased. Here, the two taxa are still treated as subspecies. Svensson’s text in part:“Frequently more difficult to separate from Cory’s than many imagine: the two are often
inseparable due to individual or age-related variation, or to field conditions (light,
distance)....” Under voice, “calls [of Scopoli’s] very similar to those of Cory’s Shearwater
but said to differ in being slightly less coarse and guttural.”Svensson, L., K. Mullaney and D. Zetterstrom (2023). Birds of Europe (3rd edition).
Princeton University Press.
YES. It's a good proposal. The almost allopatric distribution of borealis and diomedea,
there isn´t any hybridization between them. I agree with the English name: Cory´s
Shearwater for C. borealis and Scopoli´s Shearwater for C. diomedea.
YES. I vote in favor for the reasons outlined in the proposal. All of the publishedevidence strongly advocates for species status of these two taxa.
YES. Although I have previously argued that the preponderance of intermediatephenotypes casts doubts on whether diomedea (ss) and borealis are reproductively
isolated, I think I have been using the wrong characters for assigning the taxa.
Separating diomedea (ss) and borealis has long been primarily determined by the extent
of white on the underside of the primaries, with size, especially of the bill, being
secondary. A few other characters are rather subjective and variable (amount of dark on
the outer primary coverts, darkness of cap). In contrast, Zidat et al assigned subspecies
by seven mensural characters, five bill measurements, wing length, and tarsus length,and did not use extent of white on the underside of the primaries.They found strong
evidence that, based on these characters, the individuals assigned to diomedea werereproductively isolated from borealis on the Chafarinas Islands, where they breed insympatry. Despite ample evidence that the extent of white on the underside of the
primaries shows a great deal of intermediates (my unpublished data; also see othercomments), this character continues to be used in the field as the main criterion to
identify these taxa. Although using the extent of white on the underside of the primaries
to identify will be problematic for birders, the birds on the Chafarinas Islands are likely
not using this character to identify mates.
YES. Reasons are stated in the proposal.
YES. I voted yes to this proposal in 2018: “based on the published information (genetics,
vocalizations, morphology, and chemical differences)” and continue to support the split. I
agree with the proposal that it’s best to act on the evidence we have on hand instead ofcontinuing to wait for (potentially) conflicting data.
NO. We know of unpublished evidence for intermediates, perhaps substantial numbersof them, and while there is “almost no evidence of hybridization on islands where both
occur,” you’ll see below that I don’t think that’s an accurate summary. We have anunresolved issue of just how much gene flow is occurring. I’m not convinced that
following the fashion of other lists is compelling enough to make this split. Finally, I go
back to my 2018 vote and comments:“No. The Zidat et al. (2017) study shows what appear to me to be rates of introgressionthat are too high for these to be full biological species (1 of 14 pairs mixed; otherevidence of hybridization). They are differentiated to a small degree, but they have notachieved sufficient levels of reproductive isolation (disassortative mating still too high).
This, with Andy’s comments, leads me to consider that these are good subspecies.”
Note that that is a 7% hybridization rate. The presence of assortative mating is not aneffective species-limits criterion, because its effectiveness needs to be very high to pushhybridization and gene flow to the low levels required for the “essentially reproductively
isolated” criterion of the BSC. It is possible that there are additional postmating isolating
mechanisms, although the unpublished evidence of substantial numbers of intergradessuggests that those are not highly effective either.

2024-A-7
Treat Jamaican Petrel Pterodroma caribbaea as a separate species fromBlack-capped Petrel P. hasitata
YES. The plumage differences, combined with differences in morphology and feather
lice, lend support to recognizing the putatively extinct Jamaican Petrel as a separate
species. It would be interesting to sequence the old museum skins for comparison withBlack-capped Petrel.
YES. Most (all?) other Pterodroma that show dark and light morphs also show a wide
range of intermediates (e.g. neglecta, arminjoniana, and heraldica), while extreme darkmorphs are typically separate species (e.g. atrata). Given the lack of intermediatemorphs, I would be surprised if hasitata and caribbaea were a case of intraspecificplumage variation. The feather lice differences also point to species status, as does thepossibility of hasitata breeding on Jamaica, at least in modern times (Simons et al. 2013,
p. 19). It would certainly be nice to have ancient DNA data to support this, but I think theweight of the evidence points towards species status for caribbaea.
Simons, T.R., D.S. Lee, and J.C. Haney. 2013. Diablotin Pterodroma hasitata: A
biography of the endangered Black-capped Petrel. Marine Ornithology 41(Special
issue): S3–S43.
YES. The variation that exists between Pterodroma caribbaea and P. hasitata does notcorrespond to intraspecific polymorphisms as evidenced by other species of petrels that
present polymorphisms. Feather lice diversity also supports the differentiation between
caribbaea and hasitata. I agree with the English names Black-capped Petrel (P. hasitata)and Jamaican Petrel (P. caribbaea).
YES. Reasons are outlined in the proposal. Surely, P. caribbaea is extinct?
YES. The morphometrics are a good indicator but the feather lice tip it for me.
YES. There is sufficient morphological (plumage) evidence for the separation of
Pterodroma caribbaea from P. hasitata. I agree with the proposal about English names.
YES. Reasons are outlined in the proposal.
YES. Reasons are outlined in the proposal.
YES. Reasons are stated in the proposal.
YES. Plumage differences and lice differences are convincing. Let’s hope a population
still survives.

2024-A-8
Treat Coccyzus bahamensis as a separate species from Great Lizard-Cuckoo C.
merlini
NO. I agree with the proposal’s recommendation that the current evidence for splittingthese taxa is weak. As noted in the proposal, more data are needed on genetic andvocal variation along with a formal analysis of morphological and color differences.
NO. We need more genetic, vocal, morphological and color data, as well as analyses ofthese data to clarify the relationships between these species.
NO. The evidence currently available does not support the split. As mentioned in therecommendation of the proposal, analyses of vocalizations, plumage coloration, andmorphometry are needed, in addition to analysis of intraspecific genetic variation andphylogenetic relationships of the different subspecies.
NO. These are subspecies-level characteristics, and as we know from the large-scale
review of Hudson & Price (2014, Journal of Heredity, 105:821–833) island birds are
already oversplit.
NO. Not on the basis of presently available data. Of course a genetic study might upend
this but thus far this seems a weak case for a split.
NO. Comprehensive analyses would be desirable, but these seem like subspecies-level
differences. With its rich brown plumage, nominate merlini seems to me the mostphenotypically distinctive of the group, rather than bahamensis. A quick search of photosof bahamensis available online seems to show some variation in the amount of rufous on
the outer vane of the primaries, with some individuals showing quite a bit of rufous atleast at the proximal end of the primaries. However, none of the plumage differencesamong taxa in this group seem to approach those of other Lizard-Cuckoos currently
recognized as species. Given the many other shared species between Cuba and the
Bahamas, it does not seem surprising that these would be a single species.
The long call of bahamensis does sound slightly higher pitched to my ear (but the
sample size is very small), but this is only in comparison to merlini, as it doesn’t appear
that any recordings are available for decolor or santamariae.
NO. The only data supporting separation are plumage characters, and these seem slightand not well supported. I am intrigued, however, by the large geographic distance in therange of these two taxa. Would be interesting to see genetic data.
NO. The current evidence for splitting seems very weak. The plumage/morphologicaldifferences seem well within the range of variation for subspecies. Given there do notappear to be any vocal differences, until there is more evidence in this case, thesegroups definitely seem best treated as subspecies of a single species.

NO. I agree with the proposal that the limited phenotypic differences alone are notsufficient to recognize bahamensis as a separate species from merlini. We need a morecomprehensive data set.
NO. The rather subtle differences have not been put in the context of reproductive
isolation, which is paramount in discussing whether they should be split.
NO. Reasons are given in the proposal. Without data on vocalizations, this split is DOA.
This BLI split is an indictment of their methodology. Can someone point out an exampleof two species that differ only in extent of rufous in wing and in tail tip color?
NO. The island subspecies isolates off Cuba, decolor (Isla de Juventud) andsantamariae (a dozen plus cays off the north coast) would seem to bridge some of theplumage differences between nominate merlini and bahamensis. And, these islandisolates are largely unstudied. I think too that there isn’t an appreciation as to how the
Bahamas and Cuba are so similar in terms of a shared fauna. Within landbirds most of
the shared species are either treated as subspecies or in the case of the Olive-capped
Warbler (Setophaga pityophyla), the species is treated as monotypic with separate
populations in west and east Cuba and the northern Bahamas (Grand Bahama and Little
and Great Abaco). Only with the former Greater Antillean Oriole was there a decision totreat Cuban (I. melanopsis) and Bahaman (I. northropi) as separate species. These two
showed (in adults) distinct morphological differences, largely black in the former,
black-and-yellow in the latter, but were genetically closely related. I recall a split vote onwhether to treat them as separate species. This for me heightens the importance ofseeing firm evidence as to why the Bahamas and the three Cuba subspecies should betreated as separate species, and at the moment there is very little evidence to persuade
me why the status quo (by almost all authorities) should not continue. I’ll only add that I
have rather extensive experience with nominate merlini and have seen and heard
bahamensis a number of times on Andros and twice on New Providence; the latter
population is now extirpated. I have seen santamariae a few times on Cayo Coco. I havenot been to Isla de Juventud off the south coast of Cuba. At no time did I notice anything
vocally different between the two “groups” and I have heard no discussion from anyone
suggesting the two should be regarded as separate species. I’m perfectly willing to be
persuaded otherwise once additional studies are undertaken.

2024-A-9
Treat Piaya mexicana and P. “circe” as separate species from Squirrel Cuckoo P.
cayana: (a) Treat Piaya mexicana as a separate species from P. cayana; (b) Treat
Piaya “circe” as a separate species from P. cayana
YES (a and b). Of course there is a lot more that needs to be done to sort out thedetails, as is normally the case with widespread complexes like this. But it seems to me
there is sufficient evidence that mexicana is reproductively isolated despite essentiallybeing parapatric, indicating it is better treated as a separate species, so I think we should
adopt this improved understanding of species limits. There is also good evidence in theform of orbital skin turnover zones, supplemented by a deep mtDNA break found by bothstudies, that there are two separate species in South America. Again, there are plenty ofissues to be worked out, including nomenclatural ones, but I don’t think it is an
improvement to do nothing when we have pretty convincing evidence.
YES (a and b). Reasons are given in the proposal. My primary concern is thenomenclatural issue with circe/mehleri. Perhaps it would be better to wait to adopt thissplit until a publication sorts this out with a first reviser action.
YES (a and b). I agree with the proposal. The problem is the nomenclatural issue.
YES (a and b). As noted in the proposal and others, this is indeed a very borderline
case, and more information would be ideal, but the available information does suggestthat the different taxa in question are either sympatric or parapatric with limited to no
introgression on a scale that is similar to what we see in other classic hybrid zones
where we consider the hybridizing taxa to be separate species. While detailed,population-level genetic analyses that includes more nuclear loci would be ideal for boththe contact zone between mexicana and thermophila and between “circe” and cayana,
the available evidence, particularly the abrupt turnover in orbital skin color, as well as therelatively deep mtDNA divergence, seems pretty strong that introgression is very limited.
YES (a), NO (b). Borderline cases, but at this point, there is more evidence arguing to
split P. mexicana than to not split (narrow contact zone, genetics, morphology). I'm lessconvinced by the case for P. “circe”. It’s probably best to defer to SACC anyway.
YES (a), NO (b). From evidence presented in this and the 2022 proposal, it seems highly
likely that mexicana and thermophila approach one another with little or no gene flow.
The eyeskin, plumage, and morphometric differences are quite dramatic and would likely
serve as reproductively isolating. The rudimentary genetic data are indicative of little
gene flow. Yes, it would be nice to have better data, but I think we have already reached
the point where conclusions from the present data lean very heavily to separate species
status. Even though the case to split circe and cayana is just as strong,I think we should
defer to the SACC, or at least wait until they have voted.
NO (a and b). As noted in this thorough and complex proposal, this is a borderline caseand the data are intriguing, but it still seems like more study is needed - in particular,
formal analysis of vocal and plumage variation within and between
populations/subspecies as well as a comprehensive study of what is happening incontact zones.
NO (a and b). Highly conflicted on this one. Borderline indeed. If the data assembled in
the proposal were in the form of a peer-reviewed publication, I would vote YES because
I think it more closely approximates species limits than does the current broadly defined,Peters-based single species. A thorough study that sampled all taxa might reveal someconflicts with a three-species taxonomy, and it is always easy to require more data
before making splits in a complex like this one. But a “do no harm” conservative
approach might be the wisest thing to do in a case like this given the data gaps. We
already know that basing taxonomy on mtDNA gene trees is unwise, so I don’t trust thebasics of the tree typology. And the contact zones outside of the mexicana-thermophila
one are poorly characterized. And then there’s the circe-mehleri nomenclature problem.
Given the absence of any sign of free gene flow between mexicana and thermophila, I
personally would consider that sufficient evidence for a species split. Given the orbitalring color differences outlined in the proposal, I think it also might be safe to extrapolate
from the mexicana-thermophila situation to the South American situation. If all this weresummarized in a publication rather than NACC + WGAC proposals, I would be strongly
in favor of a YES vote, especially because that would also provide the first revisor
opportunity. If the proposal passes, then I highly recommend a separate one on English
names rather than rush names through at this point.
NO (a and b). (a) Definitely a borderline case. Clear differences in the undertail color
between mexicana and thermophila, in addition to differences in tail length. To date,there is only one study that has analyzed DNA and that has included mexicana
representation (Sánchez-González et al. 2023). This study analyzed mitochondrial DNA
and did not detect the presence of gene flow between mexicana and thermophila.
However, the presence of individuals with an intermediate phenotype has been reported
in a narrow contact zone between both forms, which is located in the state of Oaxaca(Binford 1989; photographs in proposal 2022-B-11). Mitochondrial DNA provides a partial
history of the organisms under study and, furthermore, selection of mitochondrial DNA
may impede detection of gene flow. Nuclear DNA needs to be analyzed to demonstrate
the presence/absence of gene flow, quantify gene flow if present, and determine whether
individuals with an intermediate phenotype represent (or not) hybrids. Although there
appear to be differences in songs, quantitative vocal analysis and playback experiments
are recommended. I notice that the geographic ranges of mexicana and thermophila
seem to abut over a longer extent than the narrow hybrid zone mentioned (involving thestates of Puebla and Veracruz, as shown on Figure 1 of Sánchez-González et al. 2023).
It would be valuable to report how the two lineages behave there. (b) Detailed studies
needed in the potential contact zones. It is an interesting idea to propose the orbital color
as an indicator trait of two separate groups, an idea that should be explored in moredetail (e.g., how does orbital color change through life?).
NO (a and b). Good proposal. I am going to be conservative on this one. These are bothpotentially good biological species, but at present the evidence is not compelling enoughto show they are not subspecies, as they are currently treated. We’ve seen too manycases where mtDNA is not a reliable indicator of species limits, and "diagnosabledifferences across a small contact zone" is also not a reliable indicator, especially whenintermediates are present. Earlier considerations of mexicanus and cayana as separate
species (e.g., Ridgway 1916) used a different species concept than the BSC.
Hybridization appears to be present, and it would be good to know what those levels are
and whether only a few loci are involved in the phenotypic differences. There are even

more unanswered questions between “circe” and mexicana, and mtDNA is notoriously
unreliable as a species limits (and species tree) indicator.
NO (a and b). There is compelling evidence here to believe that there very well may be
multiple species within the complex. However, I prefer to wait for more data, specificallya more thorough analysis of both contact zones. The PCA differences in morphometrics
between mexicana and thermophila are slight and overlapping—I don’t think these arestrong evidence of reproductive isolation. In contrast, the lack of shared mtDNA
haplotypes is compelling evidence for separate species, but I would like to see thisbolstered with more sampling and nuDNA as well. We know very little about the contact
zone between the circe and cayana groups. They are about a similar level of divergencebased on mtDNA, so a three way split in the future seems a likely outcome. However,acting conservatively, I’d prefer to wait until we have a more complete analysis ofputative hybrid zones.
NO (a and b). A weak NO to (a) and a stronger NO to (b). I’m sort of thinking after
reading the proposal that this might be the ‘cart before the horse’ syndrome, or at least
the majority of the issues fortunately lie outside of our area. Regarding part B, thatmatter should be left for the SACC to deal with, although the information is helpful forcontext. Regarding (a), I agree with others that mexicana is likely best treated as aseparate species from cayana given the apparent parapatry in Oaxaca in the Isthmus of
Tehuantepec, but I would prefer additional vocal studies and hopefully additional fieldwork in the overlap zone. That said, the proposal is well-crafted and pretty convincing. I
agree that the orbital ring colors are potentially significant. I’m left feeling there isn’t thatmuch new information since the last time we reviewed this proposal. I agree that apublished peer-reviewed paper outlining the issues would be ideal.

2024-A-10
Treat Stelgidopteryx ridgwayi as a separate species from Northern Rough-winged
Swallow S. serripennis
NO. A more thorough population-level study of known breeding birds with bettersampling for genetic and vocal data are needed, especially to better understand areas ofpotential contact or sympatry.
NO. We voted this one down a few decades ago for all the reasons indicated in the
proposal, and nothing meaningful has been produced since. The newer genetic data areessentially useless because of the absence of samples of breeding birds from anywhere
near contact. As for nest-site differences, hole-nesters in general are notoriously flexible,
so I don’t put much stock in that. The proposal correctly outlines all the additional datathat are needed to make an informed decision on this one, one way or another.
Additional data may indeed show that ridgwayi is a valid BSC species, but I think it isprudent to wait for actual data rather than a compilation of anecdotes.
NO. I agree with the proposal that there are potential species-level differences here, but,again, the evidence is not sufficiently compelling to show they are not just subspecies,
as we currently treat them.
NO. A better understanding of the distribution areas of the different subspecies and theirpotential overlap in the Yucatan Peninsula is needed. Evidence is also needed todemonstrate that nesting sites are different between serripennis and ridgwayi. Genetic
studies with geographical representation of the contact zones are necessary to rule out
the presence of extensive gene flow. Given the annual migratory cycle that some
populations of these swallows present, all analysis must explicitly consider the time ofyear.
NO. The proposal makes abundantly clear that no line of evidence is really bulletproof interms of establishing species status for ridgwayi. I won’t be surprised if they turn out tobe better treated as separate species, but for now there is way too much uncertainty inall respects.
NO. More data are needed that specifically links to localities near potential contact zone.
Genetic and vocalization data would be particularly helpful. However, I am intrigued by
the UCE data and the depth of the split between ridgwayi samples andnorthern/southern clade samples.
NO. These do seem like species but there are too many unanswered questions. It’s noteven clear to me which taxa would go with ridgwayi if it were split. The distribution
statements in the proposal seem to indicate that both burleighi and stuarti occur in
Belize, but the type locality of the former is in northern Belize and the latter is in central
Guatemala. So, it seems more likely that burleighi, rather than stuarti, would be thetaxon breeding in most of that country and therefore be part of the split species (i.e. S.
ridgwayi with burleighi as a subspecies). Even photos and sound recordings frombreeding colonies would go a long way towards sorting out the questions about
distribution, breeding site characteristics, and potential sympatry. The genetic data are
intriguing, but needs a focused study that incorporates all taxa and vouchered samples
from known breeding sites, or at least from times when migratory taxa are absent.
NO. I agree with the proposal. We need a study that includes a broad sampling andincludes molecular and vocalization data.
NO. This seems like a particularly messy system which needs much more work to figureout what’s going on. The current available evidence seems contradictory in whether
ridgwayi is a valid species, so it is clear that a more thorough analysis of genetics,
vocalizations, and breeding behavior is needed to understand the species limits of theseswallows.
NO. I agree with the proposal that there is a strong chance of multiple species within thiscomplex, but we need more data before we can decide one way or another.

NO. I agree with the recommendation in the proposal that key information to make thiscall is lacking in several areas. Most importantly, are lack of samples in areas of close
contact. It seems unclear how the subspecies would be divided up if split.
NO. I have heard ridgwayi a few times in the Yucatan, and maybe an allied subspecies(stuarti) in Belize too. I thought about the issue in view of the Howell and Webb (1995)
split. I thought the calls sounded rather different, thus the split interested me. But as
noted by all, much more research is needed. Looking at the ranges of ridgwayi and allied
subspecies there may be a rather extensive area of sympatry or parapatry where studies
could be done and maybe we could get some more detail on the calls of ridgwayi otherthan “harder than Northern Rough-winged Swallow” (Howell and Webb 1995). I note thatin their description of the juvenal plumage, the wingbars and tertials are edged withcinnamon. This is shared with Northern Rough-winged and I find those characters thebest way to age the latter species.

2024-A-11
Treat Larus smithsonianus and L. vegae as separate species from Herring Gull L.
argentatus
YES (Option A). Great proposal! It seems clear that smithsonianus and argentatus are
simply superficially similar, and their different-looking juveniles provide additional
evidence of this. As mentioned in the proposal, the treatment of vegae+mongolicus
could go either way but separate species status seems marginally like abetter-supported option.
YES (Option A). Genetic evidence suggests that the species Larus argentatus, as
currently considered by AOS, represents multiple taxa. Although the phylogeny from
Sonthagen et al. (2016) is not fully resolved, with polytomies and low node support, andincluded only one sample from argentatus smithsonianus, in conjunction with othergenetic studies (Sternkopf et al. 2010, Linklater et al. 2021) there is agreement thatsmithsonianus is a separate group from argentatus/argenteus. Although not of
reproductive individuals, plumage differentiation of juveniles supports the split ofsmithsonianus from argentatus/argenteus. Additional information is needed to better
understand vegae and mongolicus, but current evidence does not support them as partof smithsonianus or argentatus/argenteus.
YES (Option A). As noted in the proposal, there appears to be fairly good evidence torecognize smithsonianus as a separate species based on genetics, differences injuvenal plumage, and lack of response to at least feeding calls. Regarding vegae, I’mslightly swayed to also splitting that taxon (including mongolicus) based on theSonthagen et al. (2016) study that included nuclear data in addition to mtDNA (versus
Liebers et al. 2004). Note that there is currently a large genomic study of white-headed
gulls underway, so hopefully that will help to further clarify relationships in the futureonce those data are published.
YES (Option A). A somewhat reluctant YES to Option A. I am more supportive ofsplitting smithsonianus apart from nominate argentatus and argenteus than I am for
splitting off vegae. The one thing missing though is any analysis of the long display callsof the two groups, something that has helped sort out species status with other large
white-headed gulls. Given the abundance and close proximity to urban areas ofbreeders, this would seemingly be fairly easy to do. As for vegae (more western birulai
now not recognized by most as a valid subspecies), I’m even more uneasy, particularly
with the inclusion of more poorly known mongolicus with this species. The subspecies
vegae differs in adult plumage more from smithsonianus than either argentatus orargenteus does, mainly by its darker mantle. Juveniles differ from smithsonianus in thesame way that argentatus/argenteus do (tail patterns and overall lighter and morespeckled plumage though perhaps closer to smithsonianus and much individual
variation). Subspecies vegae does nest on St. Lawrence Island, Alaska, where it istermed a fairly common and widespread breeder and is perhaps increasing (Lehman2019). As with smithsonianus and argentatus/argenteus there is no ‘long call’ analysis. I
note that Dickinson and Remsen (2013) treat American Herring Gull (L. smithsonianus)
as consisting of three subspecies: smithsonianus, vegae, and mongolicus. That English
name seems about as appropriate as American Pipit, although if japonicus is split as its
own species, it would be more appropriate for the pipit.
As for English names, I’m fine with American Herring, European Herring and Vega gulls.
I do wonder why everything has to be American this and American that. Mostsmithsonianus breed in Canada. East Siberian Gull rather than Vega Gull is a
non-starter. It is cumbersome and while they do breed in the eastern portion of Siberia,
the great majority breed in the Russian Far East with some breeding on St. Lawrence
Island, Alaska. Mongolian Gull is fine, but again I oppose us making this split at this time.
YES (Option A). I’ve been going back and forth on this a lot. I think another committee
member is spot-on in saying this is as close as we have to a syngameon in birds, whichof course makes taxonomic decisions terribly difficult, in what is arguably one of the mostproblematic groups in avian taxonomy. The data we’re dealing with is incomplete, and it
sure would be nice to wait until the whole genome data are published.
I think the data in the Linklater thesis are problematic. There is clearly extensive geneflow here, but all of the argentatus samples are from Iceland, a place where argentatusarrived just ~100 years ago, and where based on phenotypic data we know thathybridation is rampant (as high as 55% of birds in some colonies; Ingolfsson 1970). So,
are those argentatus samples in Linklater actually representative of the genetic patterns
in that taxon? I don’t think so. There is also some nuclear AFLP data in the Sternkopf etal. (2010) paper, which shows a very different pattern, and which I suspect is closer tothe true evolutionary history. Using 43 highly differentiated loci (their Figure 7), theyfound smithsonianus was closer to hyperboreus, while argentatus was closer to fuscus(compare colors in K 5-7), and did not recover the polyphyletic patterns shown in the
mitochondrial data.

There are also some odd things going on in the Linklater (2021) structure plots. The pale
blue and dark blue colors are reversed in Figure 3a versus 3b/3c, so the proportions ofancestry in 3a vs 3b are actually essentially identical, which tells me that the species
prior actually adds little or no information to population assignments. 3c is simply a
population assignment based on allele frequencies (which population does an individual
most closely resemble), so we shouldn’t read too much into it in terms of gene flow. I
was intrigued, though, by the one argentatus/argenteus and the three hyperboreus
samples that genetically cluster with smithsonianus. Looking at Figure 3.4a and theirsampling table, it looks like the three hyperboreus samples are from Nunavut, and given
their clustering with smithsonianus I would hazard a guess that all three aresmithsonianus x hyperboreus hybrids or misidentified smithsonianus. The oneargentatus/argenteus that is genetically smithsonianus is from Iceland, and I wonder
about the possibility of a smithsonianus showing up at a breeding colony there.
Smithsonianus is known to occur in Iceland, although most detected there are juveniles
in the non-breeding season. I don’t think there’s enough to be certain that these are
hybrids, and to infer rates of hybridization from the structure plot. The BayesAss
migration rate data seem to suggest minimal ongoing hybridization, which I findsurprising given the known hybridization between many of these taxa based on
phenotypes. However, I went and read Linklater (2021) and she notes that BayesAss did
not converge for any runs involving argentatus, so those estimates are unreliable.
We also know that hybridization is rampant (or at least occurs) between basically every
possible pairwise combination of Herring x another large Larus, and is often common incases where the two parental species look nothing alike, even with drastically different
back color or wing tip color. This is reflected in the rampant allele sharing in Figure 7 ofSternkopf et al. (2010). Marinus x smithsonianus is common in the northeast.
Hyperboreus hybridizes extensively with smithsonianus, argenteus/argentatus, and at
least some with vegae. Smithsonianus x glaucescens hybrids are common in southern
Alaska. So, I’m not sure what the presence or absence of hybridization amongsmithsonianus, vegae, and argentatus would really tell us about species limits, even in a
BSC framework. And I don’t think anyone is suggesting we lump all the large Larus. That
multiple species show up in multiple parts of the tree (hyperboreus, californicus, and ofcourse argentatus sensu lato) also suggests that hybridization has been going on forquite a long time.
The nuclear data, especially, seem to indicate that smithsonianus and argentatus are notespecially closely related within the large Larus, which tips the scales towards splitting
for me. Yes, they are extremely similar phenotypically, but there are some differences inwingtip pattern of adults that differentiates most individuals. The juveniles are quite
different, too, as others have noted.
Although it would be good to see more genetic data on vegae/mongolicus, thephylogeny in Sonthagen et al. (2016) seems to suggest that vegae at least is closer tocachinnans than to smithsonianus, again suggesting that the phenotype is misleading.
Having seen a fair number of vegae, including as vagrants among smithsonianus, it
strikes me as the most phenotypically distinct of the group, often quite strikingly so. The
combination of the darker mantle, red orbital ring, fine head streaking (in basic plumage),dark eye, “string of pearls” in the primaries, and slimmer structure, all suggest to me that
it is a different species than smithsonianus. Smaller individuals can look closer tocalifornicus and some can look quite dark-backed.
The playback data from Fring is intriguing, but I would want to experiments with the longcall, rather than just the feeding calls. Although the proposal suggests that nothing has
been published, I was interested in whether recordings of the long call available online
might indicate differences among the taxa. Surprisingly, long calls of all taxa are
available on Macaulay. In listening to recordings, it sounds to me like smithsonianus has
harsher introductory notes, while vegae gives a slower series. The differences are not as
drastic as in comparison to cachinnans or fuscus, though.
smithsonianus:
https://macaulaylibrary.org/asset/355718271
https://macaulaylibrary.org/asset/224708
mongolicus:
https://macaulaylibrary.org/asset/591678611
vegae:
https://macaulaylibrary.org/asset/64404891
https://macaulaylibrary.org/asset/64404891
argentatus:
https://macaulaylibrary.org/asset/203898201
https://macaulaylibrary.org/asset/203905841
argenteus:
https://macaulaylibrary.org/asset/167776321
https://macaulaylibrary.org/asset/167774571
Olsen (2018) also has descriptions of the long calls that suggest some differences
between the taxa. He lists vegae being drier / higher pitched than argentatus andhoarser than smithsonianus, and smithsonianus being “similar to argentatus, butsomewhat dryer and deeper with quicker series: ci-auww, often combined with deep,
cackling gag-ag-ag-ag.”
Ingolfsson, A. (1970). Hybridization of Glaucous Gulls Larus hyperboreus and Herring
Gulls L. argentatus in Iceland. Ibis, 112: 340-362.
Olsen, K. M. (2018). Gulls of the World: A Photographic Guide. Princeton University
Press.
YES (Option A). As one would expect from any Larus gulls, the Herring Gull taxonomy
and classification complex is very complicated, and there are no perfect choices
available for us. More information would definitely be preferable, but the available
evidence argues fairly strongly for species status, especially for North American andEuropean populations. The split of these two populations is at least as strong as anyother recognized gull species. The situation with vegae and mongolicus is definitely
much different, but based on available evidence, I think it is best to treat them as aseparate species together, although the placement of mongolicus may prove different

with additional research (however, this should not prevent us from acting now on othersplits in the complex that we feel are warranted).
YES (Option A). Good genetic and phylogenetic evidence for smithsonianus andargentatus to be considered separate species. The other taxa are more uncertain, but tome there is more evidence to not treat them as part of smithsonianus. More data ofcourse are needed, but if we always wait for more data, nothing will ever change. To me,
there is better evidence at this point to go ahead and treat as 3 species.
NO (Option C). Status quo: No change. This is a good proposal on a difficult group. But
I think subspecies rank best fits our current understanding of these birds. Genetic
distinctiveness and cladistic preferences for monophyly and sister relationships are ofless utility in groups where gene flow is common. Phenotypic distinctiveness is also an
attribute of subspecies and in this group I think that is a far better taxonomic fit. We have
unpublished UCE data from our group that show extensive gene flow between
smithsonianus and vegae, so under the BSC that part of the proposal does not fit theBeringian situation.
Most evidence suggests incomplete reproductive isolation and substantial levels of geneflow in members in contact; so sister relationships I don’t think are particularly important– historic refugia are just that. The formerly isolated populations are out of refugia now
and mixing quite a bit to create the ongoing confusion that their taxonomy has been.
Northern hemisphere white-headed gulls are perhaps the best example of a syngameon
in birds. We’d have to adopt a botanist-like species concept to recognize them as
species, and that is unlikely (compare Barraclough 2019:6, The Evolutionary Biology ofSpecies, Oxford, with the working BSC in ornithology).
Linklater’s (2021) results look to me like substantial levels of gene flow (3a) enable more
distinctive groups to emerge only when priors like phenotypic-based ID (i.e., taxon) areadded to the model. If the results had been clean without priors, I’d be more inclined tosee that these genetic differences might reflect species-level taxa. (Even with the priors,
it looks like there is substantial gene flow.) Rather than split off smithsonianus, theseresults could be viewed to provide stronger support for lumping hyperboreus andargentatus (see also the PCA figures) or providing some confirmation that hyperboreus
could be a species distinct from “smithsonianus” (though see fig. 3.3c and its three likely
hybrids). Overinterpretation of STRUCTURE results is common, and the software isdesigned for population genetics, not species limits. In reading Linklater (2021), it looks
like the results were not examined critically in terms of biological species limits, butrather interpreted wholly in the framework of the IOC (i.e., split) taxonomic framework. A
problem with using Linklater to inform us about species limits between argentatus andsmithsonianus is very limited sampling. All of her 6 samples of the former are from
Iceland and, given the genomic results, likely have a lot of admixture from hyperboreus.
However, and this is informative, 1/6 of the argentatus looks like a hybrid withsmithsonianus (figs. 3.4 and 3.5; text results p.30). That’s a 17% hybridization rate inthis small sample. In fact, her fig. 3.5 PCA indicates substantial hybridization among all
4 of the “species” in the study. Finally, her analyses of migration rates are likely wrong,being far lower than both STRUCTURE and PCA analyses show.
I think we’ll eventually find levels of ongoing gene flow that would require lumping these
all under the BSC. There is some genomic work in progress that should shed additional
light, but for now I don’t see that the isolating mechanisms that are present are
particularly effective among our current concept of Larus argentatus sensu lato.
NO (Option C). I feel that using the genetics results presented in the proposal are a poormeans to understand reproductive isolation in this group. With current range expansions,
LWH gulls have been shown to hybridize with little regard to genetics, or even plumage.
There is no reason to think that such hybridization also did not occur in the past, as
environments changed throughout the Pleistocene. In my view, current genetic
similarities are as likely to be related to geography as they are to ancestry. In suchsituations it is imperative to use traditional means of assessing actual or potential
reproductive isolation. Adult smithsonianus and argenteus/argentatus show negligible
differences in plumage, soft parts, and morphometrics. Immature plumages have no
bearing on reproductive isolation. Long call displays have not been studied in any sort ofdetail. I do not see any means by which smithsonianus and argenteus/argentatus wuld
be reproductively isolated if they were in contact, especially since LWH gulls areespecially prone to hybridize.
NO (Option C). A very difficult case, and I appreciate the quality of the proposal and thework done on the group thus far. Hybridization rates still seem quite high to me forseparate species under the BSC, so I’m going to opt for the status quo in this instanceand retain these as subspecies.
NO (Option C). It is a very complicated taxonomic group, the information in the proposal
provides some information about the species limits between smithsonianus, vegae andmongolicus, but the results are weak and contradictory. Although there is a little light on
the group, I think we should wait to have more information to make a change.
NO (Option C). As noted, the extent of gene flow among all these taxa suggests that thedichotomous branching pattern we’re used to thinking of does not apply, Therefore,
which taxa are each other’s closest relatives may not be the appropriate conceptual
framework and may obscured by gene flow, particularly the mtDNA that dominate current
analyses. So, smithsonianus and argentatus may not appear to be each other’s closest
relatives in the analyses based on currently sampled variable loci only because they do
not share an active contact zone. That said, I have no solution to this problem other thanmaking the usual lame appeals for more data, particularly genomic data, as well assome solid data on whether eye ring color, bill spot color, long calls, or other things are
involved in mate selection. I thank the proposal author for taking on this tough case andsynthesizing the data for us – excellent proposal.

2024-A-12

Transfer Coccothraustes abeillei and C. vespertinus to Hesperiphona
YES. This seems to me the better option than maintaining what appears to be
non-monophyly or to lumping all these disparate taxa into one genus. And, theHesperiphona species differ obviously from Coccothraustes, and there was apparently
never any published rationale for the lump.
YES. The species vespertina and abeillei were transferred from Hesperiphona to
Coccothraustes without rationale. The phylogenetic relationships of grosbeaks in thegenera Hesperiphona, Coccothraustes, Eophona, and Mycerobas are not resolved, aphylogeny including representatives of all the species in that grosbeak clade does notexist; therefore it is not clear whether vespertina and abeillei (Hesperiphona) are moreclosely related to Coccothraustes or to Eophona or Mycerobas. The phylogeny inZuccon et al. (2012) provides some evidence that Hesperiphona and Coccothraustes
might not represent sister groups. Moreover, Sushkin (1925), based on his anatomical
research (mainly osteological), mentioned that Perissospiza [currently within Mycerobas]
is extremely similar to Hesperiphona in the shape of the bill, and concluded that
Perissospiza is the nearest relative to Hesperiphona. I think that transferring backvespertina and abeillei to Hesperiphona is the best approach until the phylogenetic
relationships of the four genera of grosbeaks are better understood.
YES. I vote in favor, mainly because there was no published rationale for the lump. The
relationships of these finches were uncertain when Hesperiphona was merged into
Coccothraustes. Little clarification has emerged since. Viscerally, I have wondered about
Evening Grosbeak, the species of Hesperiphona I know best, being with Hawfinch, a
species I know fairly well in Asia (Japan) and also from multiple birds in western Alaska.
The waddling gait of Hawfinches strikes me as pretty different from the foraging gait of
Evening Grosbeaks, and their calls (contra Oscar) sound pretty different. Hawfinches
calls on Xeno-Canto sound like the calls of a number of species of Emberiza buntings, oreven like Northern Cardinals, not the loud and shrill Evening Grosbeak calls. I can easily
hear the latter, less so the former, particularly when high overhead. Despite their similar
shape, Hawfinches look larger headed and they are much less strongly sexuallydimorphic. I believe that Hawfinches have a much more strongly undulating flight. I
guess this is a philosophical matter, but I’m unhappy about maintaining a fiat decision for
decades when there was no initial rationale, particularly when I think it may have been
the wrong decision. For what it is worth, I see that Svensson et al. (2023) continue torecognize Hesperiphona.
Svensson, L., K. Mullarney, and D. Zetterstrom. 2023. Birds of Europe (3rd edition).
Princeton University Press.
YES. I vote in favor, but without strong conviction. I wish we had some definitive
evidence for these relationships. This solution prolongs our oversplitting of oscines at thegenus level.

YES. Reasons are stated in the proposal.
NO. I could be swayed to change my vote, but the available molecular data do notprovide strong resolution to phylogenetic relationships and Coccothraustes abeillei was
not sampled. Although the original AOU decision to lump vespertina and abeillei into
Coccothraustes was made without comment, I’d prefer to see stronger evidence formoving them back into Hesperiphona.
NO. The genetic data are inconclusive and do not require a change in genus limits. I
would like to see more loci and taxa sampled before making a change, especially to becertain that abeillei and vespertinus are actually sister taxa. Vocally, abeillei andvespertinus are fairly similar, but abeillei bears more than passing plumage resemblance
to some species of Mycerobas. If abeillei + vespertinus do turn out to be sister to
Coccothraustes (thus not requiring a change), I would actually be inclined to resurrect
Hesperiphona based solely on plumage dissimilarity, but I would prefer to be certain that
abeillei and vespertinus form a clade. For now, I think we need more data and would
prefer to stick with the status quo before making a change.
NO. Not for now, the molecular data presented are contradictory. I prefer to wait for moredata and a robust and clear analysis.
NO. I definitely follow a philosophy of more inclusive genera as being more informative
about the taxonomy and relationships of species rather than many smaller ones. While
the relationships of these grosbeaks are clearly unresolved, the evidence for removing
abeillei and vespertinus from Coccothraustes is not compelling to me; further, while notpart of the proposal and outside the scope of the NACC, to overcome the potential
paraphyly of identified in Zuccon et al. (2012), perhaps a better move would be to merge
both Eophona and Mycerobas into Coccothraustes, as they share many similarities tothe taxa we currently recognize in Coccothraustes (the Mycerobas grosbeaks being very
similar to abeillei, and the Eophona grosbeaks being similar in respects tococcothraustes).
NO. I would rather not make a change based on an assumption (abeillei and vespertinus
are sisters). This can easily be resolved with additional taxon sampling and analyses.
NO. The molecular phylogeny does not provide strong evidence for the non-monophylyof Coccothraustes and Hesperiphona. Only the nuclear tree in Fig. 2 of the proposalshows this relationship, and it’s not strongly supported. Therefore, changing the genera
is not necessarily. There may be other reasons (morphology, vocal, etc.), but these are
not presented in the proposal. I understand that the switch was made in the 6th edition
without comment, but that doesn’t necessarily mean there wasn’t a reason.