2020 AOS Classification Committee Proposals, Parts 2 and 3

We got another big batch of new bird taxonomy proposals submitted to the American Ornithological Society’s North and Middle America Classification Committee for 2020. The AOSNMACC 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.

Packets B and C came out together so we’ll throw them all in the same post, which will only mention those changes that affect the ABA Area. If you’re interested in every single one of the proposals– 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 for Part B and Part C (.pdf).


Change the taxonomy of the Phasianidae: (a) eliminate subfamilies and (b) revise the linear sequence of species

We’ll start with a pretty inoffensive re-arrangment of the pheasants and grouses. As researchers have gotten better at digging into the genetics of various bird families, we’ve seen a lot of these re-evaluations of relationships. It’s worth noting that this doesn’t just impact our native grouse and quail, but the many species of introduced pheasants, francolins, and partridges that can be found all over the ABA Area. There’s nothing too surprising here, though turkeys find themselves at the top of the list along with the other native phasianids, with the African and Asian introduced species in their own clumps as well.


Split Aegolius acadicus brooksi from Northern Saw-Whet Owl A. acadicus acadicus

Those who enjoy leafing through field guides for fun may be somewhat familiar with the distinctive brooksi subspecies of Northern Saw-whet Owl found on the island of Haida Gwaii (formerly Queen Charlotte Islands) off the northwest coast of British Columbia. The non-migratory subspecies is unique for a number of reasons, most notably that it is darker and buffier than mainland saw-whet owls, but also that it frequently forages for invertebrates in tidal pools. Recent research suggests that gene flow between the island birds and the mainland birds are almost non-existent and that the Haida Gwaii birds could reasonably be considered to be on different evolutionary trajectories and therefore should be split. The new species could be called Haida Gwaii Saw-whet Owl and would add a new species to the ABA Checklist, additionally giving Canada an endemic bird species.


Remove “Scrub” from the English names of the scrub-jays

Common name changes have become more, er, common in the AOS proposals in recent years, and this one seeks to remove the arguable unnecessary “Scrub” qualifier to the Scrub-Jays in the genus Aphelocoma. The english name “Scrub Jay” was applied to the superspecies consisting of at least five distinct subspecies in 1945. Over the intervening years the group was split, first into Florida, Western, and Island Scrub-Jays, and then again when Western became California and Woodhouse’s Scrub-Jay. The proposal argues that “Scrub” is no longer necessary and for the sake of simplification, not to mention the fact that none of the many species also in the genus Aphelocoma are called “Scrub-Jays”. This isn’t the first time the committee has removed redundant parts of bird common names. It was not that long ago that Nelson’s and Saltmarsh Sparrows still retained the unwieldy “sharp-tailed” as part of their names.


Recognize four species as never established in Hawaii, resulting in (a) transfer of Red-cheeked Cordonbleu Uraeginthus bengalus from the main list to the Appendix, and (b) removal of Helmeted Guineafowl Numida meleagris, Black-rumped Waxbill Estrilda troglodytes, and Tricolored Munia Lonchura malacca from the list of species known to occur in the US

The proposal comes results from the relatively recent decisions by the ABA Checklist committee regarding countable species in Hawaii. Eight non-native species listed by the AOS as established in the US were not accepted to the ABA Checklist by the ABA Checklist Committee (ABACLC), including four species considered previously established in Hawaii. Those species are Helmeted Guineafowl, Red-cheeked Cordonbleu, Black-rumped Waxbill, and Tricolored Munia. The Hawaii Bird Records Committeec onsidered them never to have been established in Hawaii and thus, they would be removed from the AOS US Check-list. Tricolored Munia, however, remains on the AOS North American Check-list by virtue of an established population in Puerto Rico.


(a) Adopt the ABA-CLC criteria for considering species to be established, and (b) reconsider the status of four species currently accepted as established in the US: Japanese Quail Coturnix japonica, Mitred Parakeet Psittacara mitrata, Lavender Waxbill Estrilda caerulescens, and Orange-cheeked Waxbill E. melpoda

For decades, the AOS and the ABA have had differing criteria as to how long a non-native species had to be established to be deemed worthy to be included on their checklists. The AOS criteria looked at a species after 10 years and the ABA after 15 years, having extended from 10 in 1975 after having found the short time period insufficient for some species due to observed boom and bust cycle. Taking this new criteria into account the AOS considers four additional species not accepted by the ABA Checklist Committee: Japanese Quail, Mitred Parakeet, Lavender Waxbill, and Orange-cheeked Waxbill, likely retaining the first three and transferring the last to the Appendix from the Main Checklist.


Revise species limits in the Zosterops japonicus complex

Many Old World Authorities (and eBird) recently split the wide-ranging Japanese White-eye into several species native to east Asia. The species is also an established non-native throughout the Hawaiian Islands and is, indeed, one of the most common landbirds in the archipelago. This newly elevated subspecies is now widely known as Warbling White-eye and the AOS would adopt that name. There is, however, an increasing population of formerly Japanese White-eyes in southern California, assumed to be the subspecies now known as Swinhoe’s White-eye though field identification of these species is difficult. The proposal suggests that the committee adopt this split even if Swinhoe’s is not accepted to the checklist. Both ABA and AOS will keep an eye on that population in the event it becomes established and if those birds are confirmed as Swinhoe’s, that species may see its day on the ABA Checklist.


Transfer Yellow-chevroned Parakeet Brotogeris chiriri from the Appendix to the main list

Yellow-chevroned Parakeet is an established non-native species in southern California, recently added to the California list by the local committee and to the ABA Checklist by the ABA CLC. The AOS would mirror those decisions and add this species as well.


Rectify the linear sequence of Progne spp. (Hirundinidae)

This is another re-evaluation of the taxonomic order of the large swallows of the genus Progne. The most familiar of these to ABA Area birders is the garrulous Purple Martin, but a handful of others have been recorded as vagrants. This proposal would see the order re-arranged slightly.


Split Dusky Thrush Turdus eunomus and Naumann’s Thrush T. naumanni

Dusky Thrush is a rare vagrant to the ABA Area, primarily in western Alaska but is has been recorded in Yukon Territory, British Columbia, and Washington. Some Old World authorities have split the subspecies naumanni, called Naumann’s Thrush. While much rarer, naumanni has also occurred in the ABA Area, notably one well-photographed individual in Gambell (2015). Should the AOS accept this split, the Alaska Bird Records Committee would then consider this individual which would potentially result in a new species on the ABA Checklist.


Treat Northwestern Crow Corvus caurinus as conspecific with American Crow C. brachyrhynchos

Lumps have been out of fashion for some time, but this is one that many birders have been expecting nonetheless. Northwestern Crow has been controversial since it was described in the 19th Century. The crows of the northwest coast differ slightly from American Crows in behavior and vocalization, and the ABA Area birders have tied themselves in knots trying to find a “pure” Northwestern Crow for decades. A recent study that looked at the genetics of crows in northwestern Washington and southwestern British Columbia makes clear what many birders have suspected, that hybridization is extremely common among American Crows and “Northwestern” Crows in moderns times. While the populations may have been diverging thousands of years ago, they have been coming back together for some time now. At least we don’t have to pretend anymore.

Revise species limits within Horned Lark Eremophila alpestris

The species North American birders know as Horned Lark is extremely widespread across the northern hemisphere, with as astonishing 42 named subspecies spread across five continents. The submission proposes a number of different ways to handle this massive superspecies. All of which split the North American subspecies from those in the Old World, with the former retaining the name Horned Lark as Old World birders call their versions Shore Lark anyway.


The full lists, including background information and recommendations are available online, in Parts B and C (.pdf). Stay tuned for the results of the voting this summer. May the splits be with you.

Nate Swick is the editor of the American Birding Association Blog, social media manager for the ABA, and the host of the American Birding Podcast. He lives in Greensboro, North Carolina, with his wife, Danielle, and two young children. He is the author of Birding for the Curious and The ABA Field Guide to Birds of the Carolinas.