This is the sixth installment of Updates and Corrections to the sixth edition of The Clements Checklist of Birds of the World. The entire checklist (including the 2011 Updates and Corrections) is available as a downloadable spreadsheet (in Excel and .csv formats); this year’s spreadsheet version is Clements Checklist 6.6.
The spreadsheet contains 13 fields (data columns); the new column is marked with an asterisk:
Change — a brief note to signal that a change from Clements Checklist 6.5 occurred for that entry. Sometimes only a single change is made per entry; sometimes several changes are made, although only one or two may be noted in the spreadsheet. In all cases, please consult the Updates and Corrections – August 2011 page for a full explanation of these changes.
Change comment – A brief explanation of the change from Clements Checklist 6.5 occurred for that entry. Please consult the Updates and Corrections page for a more complete explanation of these changes.
Sort 6.6 * — reflecting the sequence of species in Clements Checklist 6.6
Category –reflecting whether the entry on that line is a species; a subspecies; a monotypic group (i.e., a group that is equivalent to a single subspecies); or a polytypic group (a group composed of two or more subspecies). So, the total number of subspecies recognized in Clements Checklist is the sum of all entries listed as “subspecies” and as “group (monotypic)”.
Extinct — an entry in this column means that the species or subspecies is extinct
Extinct year — reflects the year the species or subspecies went extinct; “xxxx” is used when the date was not readily accessible.
Sort 6.5 — reflecting the sequence of species in last year’s edition of Clements Checklist
Page 6.0 — reflecting the page number of the species in the last (sixth) print edition
Here is a brief review of the changes that are introduced in Clements Checklist 6.6 (for complete documentation of all changes, please see the Updates and Corrections page.):
Families 227 (with 1 additional, extinct, family)
In this year’s updates, we add 12 new species, that is, species for which there was no entry at all in the previous edition of Clements Checklist. A few of these are species that only recently were discovered and described. Several members of this group, however, are taxa that were described long ago, but which subsequently were lumped into other subspecies, and so were overlooked for decades, until recent taxonomic reviews documented their distinctiveness. Another 74 species are newly recognized in Clements Checklist due to “splits.”
As before, we update the taxonomy and nomenclature of species for North America, based on decisions of the North American Checklist Committee (NACC), through the Fifty-second supplement to the American Ornithologists’ Union Check-list of North American Birds (July 2011). Associated changes include four species added due to splits (Common Moorhen Gallinula chloropus, Snowy Plover Charadrius alexandrinus, Mexican Jay Aphelocoma ultramarina, and Yellow-throated Warbler Setophaga [formerly Dendroica] dominica each are split into two species); a species lost due to a lump (Chestnut-mandibled Toucan Ramphastos swainsonii is merged with Black-mandibled Toucan R. ambiguus); and an overhaul of the family Parulidae (New World Warblers), resulting in changes to the linear sequence of wood-warbler species, and changes to many scientific names.
We also are current with decisions of the South American Classification Committee (SACC) through June 2011. The primary changes resulting from following SACC are the addition of one newly described species (Rock Tapaculo Scytalopus petrophilus), and the split of Stripe-headed Brush-Finch (Arremon torquatus) into eight (!) species.
The remaining changes at the species level, all of which are splits, stem from taxonomic revisions of African and Asian birds. Unlike some other parts of the world, there is no regional checklist authority or authorities responsible for maintaining the taxonomy and nomenclature of birds of these regions. Our reviews of the literature pertaining to the taxonomy and nomenclature of African and Asian birds is an ongoing process, and we anticipate making many further revisions at the species level in future Clements Checklist updates.
Clements Checklist wholeheartedly has adopted the concept of the group, which is borrowed from eBird, the online checklist management system. A “group” is a distinctive (field identifiable) subspecies or group of subspecies. The group is not a formal taxonomic unit, but a group often represents a potential future split (and so groups are a valuable taxonomic tool for the savvy birder).
Groups first were added to Clements Checklist in December 2009 (Clements Checklist 6.5). In Clements Checklist 6.6, we add 564 new groups, but with over 10,000 species to consider, the task of implementing all potential groups still is far from done. This year we compared our taxonomy to other major taxonomies, notably the IOC list, to identify subspecies groups for all the species considered to represent species by other major references. Adoption of these groups will prove useful to our users, especially to help understand differing field guide treatments and alternate names that are in usage elsewhere
With this revision we also standardize the formation of the names of groups. The scientific name of a group should indicate to the user what the scientific name of that unit would be, if it were split as a species. Following the rules of priority of zoological nomenclature, the earliest available name for subspecies or a species has precedence. Our groups are indicated in one of two ways: when two subspecies are involved, we list both names with the earliest name shown first (e.g., Junco hyemalis hyemalis/carolinensis); when three or more subspecies are involved we use just the earliest name (e.g., Junco hyemalis [oreganus Group]). In earlier versions, many of our group names properly took priority into account, but some did not. To the best of our knowledge, we now have revised all group names with respect to priority. (But please let us know if you encounter names that you think still are incorrect.)
Some of our attempts are arranging subspecies into groups are incomplete: one or more distinctive subspecies have been identified as groups, but the remaining subspecies have been left “hanging” – they do not belong to any of the groups we have created in that species, but we have yet to form one or more new groups to accommodate them. These “hanging” subspecies now are highlighted in two ways: 1) the sequence of subspecies and naming of the groups within the species always make it clear that these are not included in a group (i.e., they follow a monotypic group or the species as a whole, so are clearly not a component of the groups above; and 2) in the spreadsheet we have highlighted these “hanging” subspecies in gray to further clarify that their status with respect to groups remains unresolved.
Species with partially formulated groups include the following:
Brown Pelican Pelecanus occidentalis
Roadside Hawk Buteo magnirostris
Red-tailed Hawk Buteo jamaicensis
American Kestrel Falco sparverius
Clapper Rail Rallus longirostris
Dunlin Calidris alpina
Black Noddy Anous minutus
Burrowing Owl Athene cunicularia
Buff-throated Foliage-gleaner Automolus ochrolaemus
Streak-chested Antpitta Hylopezus perspicillatus
Dusky-capped Flycatcher Myiarchus tuberculifer
Brown-crested Flycatcher Myiarchus tyrannulus
Common Raven Corvus corax
Horned Lark Eremophila alpestris
Tropical Parula Setophaga pitiayumi
Bananaquit Coereba flaveola
Red Crossbill Loxia curvirostra
Geographic variation in many of these is quite complex (Red Crossbill in particular!), but we hope to thoroughly review these species and properly formulate groups to accommodate all of their subspecies by the time of next year’s updates. We welcome any help in assigning these “hanging subspecies” to groups, especially if it can be supported by published references.
Some groups are monotypic, that is, they involve only a single subspecies (e.g., “White-winged Junco” Junco hyemalis aikeni), whereas others are polytpic, with two or more subspecies (as in “Oregon Junco,” which includes seven subspecies of Junco hyemalis). We admit that it sometimes is confusing to refer to a single subspecies as a “group” (!). To help make the concept more clear, we now identify all groups as monotypic or polytypic. As mentioned above, this also allows the user to distinguish easily between the groups that contain only multiple subspecies, and those groups that also are a single subspecies. Thus, the entries identified in the spreadsheet as subspecies and as group (monotypic) together comprise the entirety of subspecies in the list, whereas the polytypic groups are a secondary level between subspecies and species.
HIGHER LEVEL TAXONOMY
We substantially revised our treatment at the family level of the passerines in Clements Checklist 6.4, and in Clements Checklist 6.5 we introduced no fewer than six new orders. Research on the higher level taxonomy and nomenclature of birds never ceases, however, and we introduce yet more changes in Clements Checklist 6.6. The most important of these changes are the recognition of six new families, and the loss of another family (Rhabdornithidae), for a net increase of five in the number of families recognized by Clements Checklist. Note that one of these families (Mohoidae) is extinct, however. Therefore, the total number of extant families in Clements Checklist increases to 227, with one additional extinct family included as well.
The 227 families accepted by Clements Checklist are listed below, with the names of newly recognized families in bold), and with an additional extinct family listed in brackets.
[Mohoidae – extinct]
We will continue to release an annual revision that incorporates revisions to the taxonomy and nomenclature of Clements Checklist at the level of the species and higher; as with this year’s release, we anticipate that the annual taxonomic updates will be released in August.
We also have a large backlog of changes that we wish to implement with respect to the nomenclature of subspecies, and to the ranges of species and subspecies. We incorporate a few such changes in Clements Checklist 6.6, but we have many more yet to process. To help us make some headway against this backlog, we will release a second set of updates in early 2012. The second release will include changes only to the nomenclature of subspecies, to the ranges of species and subspecies, and corrections to typographic errors; it will not include changes at the level of the species or higher (so, no splits or lumps, etc.).
Please continue to report potential errors and corrections to Clements Checklist. Many of the errors that you find are ones that we would have taken a long time to notice, so we appreciate your help, and we do want to hear from you. As noted above, we have a backlog of corrections still on hand that await our attention – but please do not let that keep you from suggesting further corrections or revisions. Please keep in mind, of course, that the easiest corrections or proposed revisions are the ones that are accompanied by a supporting reference or citation.
Tom Fredericks logged many hours in checking the list for inaccuracies and inconsistencies. Denis Lepage, who runs Avibase, carefully reviewed our files, compared with other taxonomies, pointed out errors, and helped with many taxonomic issues through this process; we are extremely grateful for his generous assistance. Normand David provided sound advice on some details of nomenclature; we appreciate his assistance. We take full responsibility, of course, for any remaining errors; but we are extremely grateful for the support that we received from Tom, Denis, and Normand.
We also thank the following for their help in pointing out errors in Clements or directing us to important literature for our consideration:
Richard Alcorn, Desmond Allen, Chuck Almdale, Ron Batie, Phillip E. Bedient, Jerry Blinn, Nick Block, Charles Braun, Rick Brown, Ken Burton, Steve Chalmers, Paul Clapham, Andy Cubbon, Theo de Kok, Bruce Deuel, Jim deVries, Stefan Ericsson, Roger Evans, Kieran Fahy, Shawneen Finnegan, Adrian Fisher, Alan Grenon, Alvaro Jaramillo, Peter Kaestner, Peter Kovalik, Niels Larsen, Hans Laue, Jack Levene, Robert Lockett, Murray Lord, Glenn Mahler, Karen McBride, Matthew Medler, Glenn G Mertz, Ellwood Meyers, Michael Nielsen, Steve Olesen, Tommy Pedersen, Kathryn Peiman, Glenn Peterson, Jan Pierson, Diane Porter, Colin Richardson, Duncan Ritchie, Peter Roberts, Philip Rostron, Phil Tizzard, Gordon Tufts, Peter Vercruijsse, Adam Winer, James Yurchenco, and no doubt others whose names we have overlooked but who made suggestions and proposed corrections to the Clements Checklist.
Thanks to all for your support, and we look forward to your feedback.
Thomas S. Schulenberg (Avian Taxonomist); Marshall J. Iliff, Brian L. Sullivan, and Christopher L. Wood (eBird Project Leaders); and Don Roberson.