Split and lump season is coming early this year, and the first document containing the proposed taxonomic updates to the AOU North American Check-list, which in turn are incorporated into the ABA Checklist, has been released, a full two month earlier than last year. This first batch contains 12 proposals that have been submitted in 2014, not all of which involve ABA-Area birds as the AOU’s North American jurisdiction includes Mexico and Central America to Panama’s southern border.
As usual, it’s important to note that these are just proposals and the committee has yet to vote on them formally. There are some that are unlikely to make the cut for whatever reason, but in my opinion the proposals are often more interesting than the actual results anyway as we get a peek into the wild world of bird taxonomy as it exists in 2014.
This post will only mention those changes that affect the ABA Area and Hawaii, but if you’re interested in the whole ball of wax please refer to the official list of proposals at the AOU’s website (.pdf).
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Revise the classification of the Psittaciformes
We’ve come to expect the rearrangement of at least one family every year in the AOU proposals, and the first of the year comes in Psitticiformes, the parrots. New research attempts to get to the bottom of the order’s remarkable homogeneity in form across families in both the Old and New Worlds, which indicates that the parrots are a very old family. New World parrots, currently in the family Psiitacidae, appear to have split from their Old World counterparts 30-35 million years ago, which at least would seem to justify their own family separate from Old World species which would go into a new family called Psittaculidae.
Psittaciformes are represented in the ABA Area by 9 species – 6 from the New World, 2 from the Old World, and 1 now extinct. The two Old World Species, Budgerigar and Rosy-faced Lovebird, would be moved into Psitticulidae.
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Split Pterodroma heraldica and P. atrata from Herald Petrel P. arminjoniana
A proposal offering clarification of tubenose taxonomy is as predictable as as a family re-ordering, and in a move long-expected by east coast pelagic birders Trindade Petrel, Pterodroma arminjoniana, would finally see recognition as a full species. These “Herald” Petrels have long been known from the Gulf Stream. Most records are from North Carolina, but a number of other states and provinces have seen records of this flashy multi-morphed Pterodroma in recent year.
Herald Petrel is a south Pacific species, not yet recorded in the ABA Area but a vagrant in Hawaiian waters. It has a broad breeding range, and breeds on islands in the Coral Sea east to Easter Island. Trindade Petrel, conversely, nests on a few islands off the south coast of Brazil. Aside from the wide discrepancy in breeding locations, the species differ also in size, with heraldica being smaller than arminjoniana, and in their all important mtDNA.
There is an interesting side-discussion regarding Round Island in the Indian Ocean where arminjoniana and heraldica nest side by side, along with the similar Kermedec Petrel, P. neglecta and the proposed “Henderson” Petrel, P. atrata. What that means for the whole group isn’t immediately clear, and birds there show characteristics of some or all of the four species which calls into question whether the Round Island birds aren’t just a giant hybrid swarm. But that’s outside of the ABA Area, and a question for another day.
Intermediate-ish phase “Trindade” Petrel, July 2013, off Hatteras, NC. Photo by Nate Swick
Transfer American Tree Sparrow Spizella arborea to Spizelloides
Birders in North America know the widespread Spizella genus, which includes familiar species like Chipping and Clay-colored Sparrows, quite well. Though it doesn’t take much field experience to realize that American Tree Sparrow, nestled in Spizella for nearly 100 years, is sort of an odd-bird out. They’re fatter and shorter-tailed, with a sweet, warbling song rather unlike the repetitive trills of their co-geners. The genetic evidence bears this out, too, putting the American Tree Sparrow closer to Juncos and pot-bellied Zonotrichias in the sparrow family tree.The proposal places American Tree Sparrow in its own genus, Spizelloides, and slots it between Fox Sparrow (Passerella) and the Zonotrichia sparrows on the official list.
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Split Passerina pallidior from Painted Bunting P. ciris
This split was covered in more detail by David Ringer at 10,000 Birds, but the gist is that the two populations of Painted Buntings, those on the east coast and those in the southern Great Plains show some genetic distance despite being difficult or impossible to identify in the field. The authors of the study informing this proposal calls the two populations “incipient” species based on the aforementioned genetics, differences in wintering range, and some issues with molt timing. While they do not go so far as to suggest the split – that’s solely the opinion of the individual making the proposal – they do advocate treating the populations as distinct so as to better manage conservation of the two populations, particularly the declining eastern birds. In the event of a split, the species would go by the uninspired Eastern and Western Painted Bunting.
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Split Toxostoma arenicola from LeConte’s Thrasher T. lecontei
Filling this year’s thrasher split quota, it is proposed that a unique population of Le Conte’s Thrasher, Toxostoma lecontei arenicola of Baja California Sur, be split off as it’s own endemic species, to be called Rosalia Thrasher. Evidence suggests it differs from nominate Le Conte’s not only in its genetics, but also in plumage and habitat preference. The former being darker and preferring a more arid landscape. The proposed Rosalia Thrasher has not occurred in the ABA Area, and Le Conte’s Thrasher north of the border would remain unchanged in name.
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Split Laysan Honeycreeper from Apapane Himatione sanguinea and change its specific epithet to fraithii
Hawaii is not in the ABA Area (yet?), but it’s avifauna remains fascinating and worth discussing here. Laysan Honeycreeper, now extinct, was endemic to Laysan Island in the northwestern islands. In 1950 it was lumped with the similar and more widespread Apapane. This proposal returns the Laysan bird to full species status and retains its English name rather than borrowing one from Hawaiian.
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Split Newell’s Shearwater Puffinus newelli from Townsend’s Shearwater P. auricularis
Townsend’s Shearwater is a poly-typic species with a population that breeds on islands off of western Mexico and a population that breeds in Hawaii (called Newell’s Shearwater by many authorities). It is one of several species of small, black and white shearwaters in what is called the “Manx Shearwater complex”, by virtue of the fact that all were considered subspecies of that prototypical small, black and white shearwater.
As with much reevaluation of tubenose taxonomy in recent years, it turns out that those that were once considered conspecific are not even that closely related. Townsend’s Shearwater doesn’t seem to travel far beyond immediate west Mexico waters, but Newell’s disperses widely, with records from American Samoa, Marianas, and California (2007).
Townsend’s Shearwater is represented on the ABA Checklist by that single 2007 record from California which was of the Hawaii breeding population. This proposal’s acceptance would see Newell’s Shearwater replace Townsend’s Shearwater on the ABA Checklist
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Correct the citation for Pterodroma solandri
Pterodroma solandri, called Providence Petrel on the ABA Checklist, is an enigmatic seabird off North America’s Pacific coast. There are a handful of records from Alaska through California, but only a few are substantiated owing to the difficulty in identification of this bird compared to other dark Pacific Pterodromas, namely Murphy’s Petrel.This proposal clarifies the citation of the species’s type location, the location where the first specimen was obtained.
Currently, the type locality references a September 1844 description of the then new species in Proceedings of the Zoological Society of London, placing the type location at Bass Strait. In a bit of 19th century subterfuge (I imagine), this however was not the first published reference of the species, and the proposal notes a May 1844 description of P. solandri in Annals and Magazine of Natural History. In fact, the PZSL paper did not include the type locality, instead taking it from the latter publication without proper citation. In fact, the locality was in fact Bass’s Strait, rather than Bass Strait. This proposal seeks to clarify all that.
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The full list, including background information and recommendations, is available here (.pdf). We’ll have a look at subsequent proposals as they’re released.