American Birding Podcast



2019 AOS Classification Committee Proposals, Part 3

The third and fourth batches of 2019 bird taxonomy proposals submitted to the American Ornithological Society’s North and Middle America Classification Committee have recently been released. For those who might not know, this committee is the volunteer group of ornithologists who make the split, lump, and name-change decisions that influence the ABA Checklist and our field guides.

We suggest the usual caveat that you are undoubtedly familiar with by now, that 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 from year to year.

This post will only mention those changes that affect the ABA Area, but if you’re interested in the whole ball of wax – the committee’s jurisdiction includes all of the North America south to Panama – please refer to the official list of proposals at the AOS’s website.


Transfer subspecies cabanidis from Lesser Violetear Colibri cyanotus to Mexican Violetear C. thalassinus, and delete Lesser Violetear from the North American list

The “Green Violetear” group was split last year into Mexican and Lesser Violetear, which resulted in a name change for the northern group, individuals of which are regularly recorded as vagrants in the ABA Area. This proposal suggests that this split was a little imprecise, with the northernmost population of Lesser Violetear seeming closer to what is now known as Mexican Violetear than the South American populations. Therefore, those violetears of Costa Rica and western Panama should be Mexican rather than Lesser. How does this affect the ABA Checklist? Well, provided the proposal is accepted, Mexican Violetear might need a name change given in light of its newly expanded geographical distribution.


Split extralimital Monteiro’s Storm-Petrel Oceanodroma monteiroi from Band-rumped Storm-Petrel O. castro

Band-rumped Storm-Petrel must be among the most taxonomically vexing species on the planet, which is saying something. At least four subspecies breed in the northeastern Atlantic (plus another four in the Pacific), two of which have been recorded in the ABA Area. Not “Monteiro’s” though, which is an Azores endemic not known to disperse far from its island breeding sites. This subspecies seems to be the most distinct of the four Band-rumped Storm-Petrel populations, and its split appears fairly uncontroversial. Should the AOS adhere to (admittedly frequently defied) convention, however, and rename both sister species of a split, we could see a name change for the species known as Band-rumped Storm-Petrel. Though a future split of the widespread “Grant’s” and “Madeiran” populations down the road might make the whole thing moot.

Band-rumped Storm-Petrels in the Atlantic are overwhelmingly “Grant’s” type, but it’s always worth a closer look just in case its something else. 


Add Thick-billed Warbler Arundinax aedon to the Main List

Add River Warbler Locustella fluviatilis to the Main List

Add European Robin Erithacus rubecula to Main List

Add Pied Wheatear Oenanthe pleschanka to the Main List

Add Mistle Thrush Turdus viscivorus to the Main List

Add Pink-footed Goose Anser brachyrhynchus to U.S. list

Add Nazca Booby Sula granti to the U.S. list

Add Black-backed Oriole Icterus abeillei to the U.S. list

Add Great Black Hawk Buteogallus urubitinga to the U.S. list

These represent the expected “housekeeping” proposals that align the AOS Check-list with the ABA Checklist. Thick-billed Warbler, River Warbler, and Pied Wheatear were all recorded in Alaska in 2018, European Robin was added due to an accepted record from Pennsylvania, and the Mistle Thrush was added due to a bird seen by many in New Brunswick. Nazca Booby, Black-backed Oriole, and Great Black Hawk are added to the US list as they already occur elsewhere in the AOS “Area”, which includes Mexico and Central America. You might be forgiven for not realizing that AOS keeps such a list. It seems the AOS might have forgotten too, if Pink-footed Goose, one of the more regularly occurring Eurasian vagrants to the US, wasn’t already on it. In any case, the oversight is corrected.


Add White-cheeked Starling Spodiopsar cineraceus to the Appendix

Add House Swift Apus nipalensis to the Appendix

Transfer Budgerigar Melopsittacus undulatus from the Main List to the Appendix

I separated out the species added to the Appendix, as the AOS treats these a little different than does the ABA. Both White-cheeked Starling and House Swift were recorded in British Columbia last year. The former was photographed on a golf course in Tofino and the latter was a dessicated specimen found at a shipping terminal at Deltaport. Neither were accepted by the ABA Checklist Committee, and thus neither will be added to the AOS Main List. But it’s nice to have a list of oddities that don’t quite pass records committee muster, and the AOS Appendix is a good place for that.

As for Budgerigar, the formerly robust population on the central Gulf coast of Florida was extirpated in the middle part of this decade. The ABA removed it from our list in 2015 and the AOS seems to be following suit.


Reinstate Nesophlox for Calliphlox evelynae and C. lyrura

The genus Calliphlox consists of tiny hummingbirds found in the Caribbean and throughout the Neotropics. One species, Bahama Woodstar, has been recorded as a vagrant in the ABA Area on several occasions. Research suggests that the two Caribbean species, including Bahama Woodstar, are not as closely related to the mainland species as previously thought, and deserve to be considered a separate genus. If accepted, the scientific name of Bahama Woodstar would be changed.


The full list, including background information and recommendations is available here and here(.pdf). The decisions of the AOS Classification Committee will be published this summer.