Haematopus (1 Viewer)

[Peter Kovalik]

Proposal (931) to SACC

Recognize Haematopus bachmani (Black Oystercatcher) as a subspecies of H. ater (Blackish Oystercatcher)

 

[Mysticete]

Also apparently a NACC proposal, so hopefully the next batch will be passed soon?

Might be jumping the gun on this, as my understanding is that a new study on oystercatcher phylogeny/taxonomy is due out soon.

 

[Paul Clapham]

Might be jumping the gun on this, as my understanding is that a new study on oystercatcher phylogeny/taxonomy is due out soon.

HBW -- BirdLife International has lumped the two since at least 2017. But I gather that splitting and lumping of similar-looking oystercatchers has been going on for a long time, so a new study could be helpful.

 

[Mysticete]

HBW -- BirdLife International has lumped the two since at least 2017. But I gather that splitting and lumping of similar-looking oystercatchers has been going on for a long time, so a new study could be helpful.

The greater significance (IMHO) is that they are fully considering Birdlife taxonomic differences, even when they are a minority (I think the other checklists all recognize this split?). I honestly wasn't sure how much weight they would give to Birdlife, and whether they would be focusing on Clements-IOC differences.

 

[l_raty]

Interesting comment by Alvaro, that Atlantic and Pacific H. palliatus differ in voice. They also differ in mtDNA.

 

[l_raty]

This is what cox1 sequences (genetic barcodes) tell. (Data mainly from BOLD, with a few more from GenBank. No other gene has been sequenced for a large number of taxa. In particular, it may be worth to note that, although Senfeld et al 2020 used a longer alignment in their analysis, with sequences of cox1, cytb and nd2, the only American taxon for which they had more than cox1 was ater : thus the relationships among American taxa in their tree are actually based on cox1 only.)

In this tree, palliatus from Chile and Peru end up forming the sister group of bachmani; the support for this relationship may be a bit less than one might hope, and of course it's only one gene, but it seems in any case clear that these birds form a group distinct from the rest of the species. Note that there is a bird from (Pacific) Panama in the 'Atlantic' group : the separation may not be strictly Atlantic vs. Pacific.

Small distances between closely-related species are the rule rather than the exception in this entire clade. The distance between ater and bachmani may be small for two distinct species in comparison to what is found in many other bird groups, yet it is still larger than the distance between any non-fuliginosus Old World Haematopus spp. It is also larger than the distance between American and Andean Avocet, Pied and Red-necked Avocet, and Pied and Black Stilt.

 

[mb1848]

Thank you for doing this analysis, Laurent. I suppose like all I want to see more data from more places. The oystercatcher in Pacific Panama does not worry me much. Humans dug a big ditch across the smallest part of that isthmus and filled it with water. I know sea birds have used it to get to the wrong ocean. I have never seen H. bachmanni inland but have seen oystercatchers inland in Scotland. I do not know if American Oystercatchers use inland freshwater lakes or river banks or canal banks.



OD of H. bachmani :

v.5 (1839) - Ornithological biography, or an account of the habits of the birds of the United States of America - Biodiversity Heritage Library .



OD of H. townsendi

v.5 (1839) - Ornithological biography, or an account of the habits of the birds of the United States of America - Biodiversity Heritage Library .

Audubon says Townsend did not mention where he got it but assumed California. ?

Plate 427 of Audubon: White-legged oyster-catcher. Slender-billed oyster-catcher .



Oberholser says H. townsendi type area is Falkland. .

https://digitalgems.nus.edu.sg/shared/colls/blsea/files/MutObe1918.pdf .



Townsend:

Narrative of a journey across the Rocky Mountains, to the Columbia River, and a visit to the Sandwich Islands, Chili, &c. - Biodiversity Heritage Library .

Townsend did sail past Juan Fernandez and on to Valparaiso and then to Philadelphia. He never mentioned Falkland Islands or Galapagos or Mexico.

Oystercatchers in California are bachmani all black. In Baja they have frazari which is pied.

Narrative of a journey across the Rocky Mountains, to the Columbia River, and a visit to the Sandwich Islands, Chili, &c. - Biodiversity Heritage Library .

I think H. townsendi Audubon 1838 is a synonym of H. ater 1825 that Townsend collected in Chile?



What is the type area for H. ater? Vieillot mentions Vancouver voyage and isle Curaco which I think is Curaco Valdez on Chiloe Island southern Chile? Buffon edit by Sonnini also mentions Vancouver ? Both mention New Zealand and New Holland???

Page 65 of https://books.google.com/books?id=U2SBevPgUfkC&pg=PA410&lpg=PA410&dq=L+%27huitrier+Noir+Buffon+Sonnini&source=bl&ots=6qmMDNclON&sig=ACfU3U2IWV5uhI0U2M2LHrrkXU7JXCsqXQ&hl=en&sa=X&ved=2ahUKEwif2oTrj-f1AhVtIEQIHdzwCd8Q6AF6BAgFEAM#v=onepage&q=L%20'huitrier%20Noir%20Buffon%20Sonnini&f=false . And is Oudart an author of this name H. ater? He drew the picture.



Vieillot H. ater:

t.2=pt.3-5 (1825) - La galerie des oiseaux - Biodiversity Heritage Library .



Wikipedia says The referred type locality is: " Strait of Magellan "..

The OD of Haematopus leucopodus Garnot, 1826 lists the type area for that bird as Falklandica

 

[Peter Kovalik]

Proposal (931) to SACC

Recognize Haematopus bachmani (Black Oystercatcher) as a subspecies of H. ater (Blackish Oystercatcher)

DID NOT PASS

 

[Jacana]

Coming to a journal near you?

https://twitter.com/x/status/1558849735951269889

 

[Jim LeNomenclatoriste]

Coming to a journal near you?

https://twitter.com/x/status/1558849735951269889

I would be tempted to elevate Haematopus fuliginosus ophthalmicus to the rank of species, as Haematopus ophthalmicus – Spectacled Oystercatcher / Huîtrier à lunettes

 

[jts1882]

Haematopus ostralegus longipipes may need changing as well, unless meadewaldoi is lumped in.


Edit. The lumping of the extinct Canary Island oystercatcher with the Eurasian oystercatcher has been proposed by the same group (see comment and another). The published paper is here.

 

[Xenospiza]

Haematopus ostralegus longipipes may need changing as well, unless meadewaldoi is lumped in.


Edit. The lumping of the extinct Canary Island oystercatcher with the Eurasian oystercatcher has been proposed by the same group (see comment and another). The published paper is here.

Look at those minimal differences between haplotypes in the network... Surely splitting on the basis of DNA makes no sense (esp. in Old World oycs).

meadewaldoi shares its haplotype with ostralegus; chathamensis with unicolor and finschi: the New Zealand oystercatchers appear to be separated only by their choice of breeding ground. Any oystercatcher that resorts to rocks seems to be turning black. Pretty much like many Bananaquits on small islands turn black – and no one has proposed to split all of those yet (but I expect someone to do that shortly).

 

[Markus Lagerqvist]

Kamtjatkastrandskata ["Kamchatka Oystercatcher"] Haematopus osculans was split by the Swedish Taxonomic Committe in 2020, also meadewaldoi was lumped with Haematopus ostralegus.

 

[jurek]

Look at those minimal differences between haplotypes in the network... Surely splitting on the basis of DNA makes no sense (esp. in Old World oycs).

meadewaldoi shares its haplotype with ostralegus; chathamensis with unicolor and finschi: the New Zealand oystercatchers appear to be separated only by their choice of breeding ground. Any oystercatcher that resorts to rocks seems to be turning black. Pretty much like many Bananaquits on small islands turn black – and no one has proposed to split all of those yet (but I expect someone to do that shortly).

The hypothesis that delimiting species in the ornithology in the 21. century is consistent and objective (= scientific) was tested and refuted. The result is consistent with other tests.

 

[comicterns]

Look at those minimal differences between haplotypes in the network... Surely splitting on the basis of DNA makes no sense (esp. in Old World oycs).

meadewaldoi shares its haplotype with ostralegus; chathamensis with unicolor and finschi: the New Zealand oystercatchers appear to be separated only by their choice of breeding ground. Any oystercatcher that resorts to rocks seems to be turning black. Pretty much like many Bananaquits on small islands turn black – and no one has proposed to split all of those yet (but I expect someone to do that shortly).

That haplotype network is almost certainly an indicative illustration based on a single gene, while the phylogeny is based on a suite of genes. Genetic diversity is clearly low in the Old World clade, but the small number of differences evidently stack up to show some level of divergence in the phylogeny.

Also, island melanism is very well documented phenomenon across a wide range of bird taxa - populations on small islands tend to darken eventually. Given the broad morphological similarity of all oystercatcher taxa, and the sheer number of island endemics, plumage is a very poor predictor of evolutionary relationships. Meanwhile niche partitioning, like that shown between the NZ oystercatchers, is significant, which can and has led to some degree of reproductive isolation. Speciation can occur with low levels of ongoing introgression, which may mask the genetic signal at neutral loci, like the ones used in this study. The likelihood is that a full genomic study would reveal much more stark and clear-cut differences between the seemingly closely related taxa in this tree, it may even show the placement of meadewaldoi within ostralegus to be erroneous. Only time will tell.

 

[Xenospiza]

Meanwhile niche partitioning, like that shown between the NZ oystercatchers, is significant, which can and has led to some degree of reproductive isolation.

Thanks for your answer.