Clements Checklist

August 2021

Overview

This is the 15th installment of The Clements Checklist of Birds of the World following the publication, in 2007, of the 6th edition of The Clements Checklist of Birds of the World. Although we typically update the checklist annually, we did not have a release in 2020, due to a database upgrade. Because the Clements Checklist has become tightly interwoven with eBird, the checklist now is referred to as the eBird/Clements Checklist. The entire checklist (including documentation of all revisions) is available as a downloadable spreadsheet (in Excel and .csv formats). This year’s spreadsheet version is eBird/Clements Checklist v2021, and was released on 24 August 2021.

As usual, we will post a list of the major 2021 Updates & Corrections (e.g., new species, splits, lumps, and name changes) here at a later date. As noted above, however, full documentation of all changes is incorporated into the spreadsheet itself; and eBird also has a very useful summary of the major changes as well.

The spreadsheet contains 13 fields (data columns):

sort v2021 ‚Äď Reflects the sequence of species, groups, and subspecies in eBird/Clements v2021

Clements v2021 change ‚Äď A brief note to signal that a change from eBird/Clements Checklist v2019 occurred for that entry. Sometimes only a single change is made per entry; in other cases several changes are made.

text for website v2021 ‚Äď Provides a fuller explanation of the change(s) from Clements Checklist v2019 that occurred for that entry.

category ‚Äď 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). Thus, the total number of subspecies recognized in the eBird/Clements Checklist is the sum of all entries listed as “subspecies” and as “group (monotypic).”

English name

scientific name

range

order

family

extinct ‚Äď an entry (1) in this column means that the species or subspecies is extinct

extinct year ‚Äď Reflects the year the species or subspecies went extinct (or, since the extinction date rarely is known with certainty, an approximation of the last year in which it was reported); ‚Äúxxxx‚ÄĚ is used when the date of extinction is not readily accessible.

sort v2019 ‚Äď Reflecting the sequence of species in eBird/Clements Checklist v2019

page 6.0 ‚Äď Reflecting the page number of the species in the last (sixth) print edition (2007)

 

SUMMARY STATISTICS

Species             10824
Subspecies       20458

Groups               3761

Families         248 (with 1 additional, extinct, family)

 

SPECIES

In this year’s updates, we add a remarkable total of 17 newly described species, which come from three different regions. As so often is the case, South America contributes the greatest number of new species (nine), although all of these result from taxonomic revisions of just two (but speciose!) genera: Oxapampa Antpitta Grallaria centralis, Ayacucho Antpitta Grallaria ayacuchensis, Puno Antpitta Grallaria sinaensis, Chami Antpitta Grallaria alvarezi, Chachapoyas Antpitta Grallaria gravesi, and Panao Antpitta Grallaria oneilli, which are distributed in the northern Andes, in Colombia, Peru, and Bolivia; and White-winged Tapaculo Scytalopus krabbei, Ampay Tapaculo Scytalopus whitneyi, and Jalca Tapaculo Scytalopus frankeae, all of which are endemic to the Andes of Peru. The next largest set of additions are from tropical Asia (six), with one from New Guinea – Satin Berrypecker Melanocharis citreola – and five from Indonesia and insular Malaysia: Alor Myzomela Myzomela prawiradilagae, Taliabu Myzomela Myzomela wahe, Peleng Fantail Rhipidura habibiei, Taliabu Bush Warbler Locustella portenta, and Spectacled Flowerpecker Dicaeum dayakorum. Finally, there two newly described species from Africa, Kilombero Cisticola Cisticola bakerorum and White-tailed Cisticola Cisticola anderseni, both of which occur in southern Tanzania.

GROUPS

eBird/Clements Checklist has adopted the concept of the group, which initially was developed by eBird, a free, global online system to manage your bird records and bird lists. A “group” is a distinctive (field identifiable) subspecies or group of subspecies. The group is not a formal taxonomic unit, but 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 the eBird/Clements Checklist v2021, we have a net loss of 39 groups, as many of this year’s splits represent groups that were upgraded to a species.

HIGHER LEVEL TAXONOMY

No new families are added or lost this year, and so the total number of extant families in the eBird/Clements Checklist remains 248, with an additional extinct family (Mohoidae Hawaiian Honeyeaters), for a total of 249 families. The nomenclature and sequence of species and genera were revised in several families, however, most notably in Phasianidae (Pheasants, Grouse, Quail, and Allies); Trochilidae (Hummingbirds);Phalacrocoracidae (Cormorants and Shags); the lorikeets (Psittaculidae Old World Parrots, in part); Meliphagidae (Honeyeaters); Locustellidae (Grassbirds and Allies); Sylviidae (Sylviid Warblers, Parrotbills, and Allies); Zosteropidae (White-eyes, Yuhinas, and Allies); Timaliidae (Tree-Babblers, Scimitar-Babblers, and Allies); Pellorneidae (Ground Babblers and Allies); and Leiothrichidae (Laughingthrushes and Allies).

The 248 extant families accepted by Clements Checklist are listed below, with the names of orders in bold CAPITAL lettering, and with an additional extinct family listed in brackets. We also provide the number of families in each order (in parentheses, after the name of each order), and the number of species in each family (in parentheses, after the name of each family).

 

STRUTHIONIFORMES  (1)          

 

1           Struthionidae                                       Ostriches  (2)

 

RHEIFORMES  (1)                         

 

2           Rheidae                                               Rheas  (2)

 

TINAMIFORMES  (1)                    

 

3           Tinamidae                                           Tinamous  (46)

 

CASUARIIFORMES  (1)                

 

4           Casuariidae                                         Cassowaries and Emu  (4)

 

APTERYGIFORMES  (1)              

 

5           Apterygidae                                         Kiwis  (5)

 

ANSERIFORMES  (3)                    

 

6           Anhimidae                                           Screamers  (3)

 

7           Anseranatidae                                     Magpie Goose  (1)

 

8           Anatidae                                              Ducks, Geese, and Waterfowl  (174)

 

GALLIFORMES  (5)                       

 

9           Megapodiidae                                     Megapodes  (22)

 

10         Cracidae                                              Guans, Chachalacas, and Curassows  (56)

 

11         Numididae                                           Guineafowl  (6)

 

12         Odontophoridae                                  New World Quail  (33)

 

13         Phasianidae                                         Pheasants, Grouse, and Allies  (181)

 

PHOENICOPTERIFORMES  (1)          

 

14         Phoenicopteridae                                 Flamingos  (6)

 

PODICIPEDIFORMES  (1)            

 

15         Podicipedidae                                      Grebes  (22)

 

COLUMBIFORMES  (1)                

 

16         Columbidae                                         Pigeons and Doves  (348)

 

MESITORNITHIFORMES  (1)     

 

17         Mesitornithidae                                   Mesites  (3)

 

PTEROCLIFORMES  (1)               

 

18         Pteroclidae                                          Sandgrouse  (16)

 

OTIDIFORMES  (1)                        

 

19         Otididae                                               Bustards  (26)

 

MUSOPHAGIFORMES  (1)          

 

20         Musophagidae                                     Turacos  (23)

 

CUCULIFORMES  (1)                    

 

21         Cuculidae                                            Cuckoos  (147)

 

CAPRIMULGIFORMES  (8)         

 

22         Podargidae                                          Frogmouths  (16)

 

23         Caprimulgidae                                     Nightjars and Allies  (97)

 

24         Nyctibiidae                                          Potoos  (7)

 

25         Steatornithidae                                    Oilbird  (1)

 

26         Aegothelidae                                       Owlet-nightjars  (10)

 

27         Apodidae                                             Swifts  (112)

 

28         Hemiprocnidae                                    Treeswifts  (4)

 

29         Trochilidae                                          Hummingbirds  (352)

 

OPISTHOCOMIFORMES  (1)      

 

30         Opisthocomidae                                  Hoatzin  (1)

 

GRUIFORMES  (6)                         

 

31         Sarothruridae                                       Flufftails  (11)

 

32         Rallidae                                               Rails, Gallinules, and Coots  (159)

 

33         Heliornithidae                                     Finfoots  (3)

 

34         Aramidae                                             Limpkin  (1)

 

35         Psophiidae                                           Trumpeters  (3)

 

36         Gruidae                                               Cranes  (15)

 

CHARADRIIFORMES  (19)          

 

37         Chionidae                                            Sheathbills  (2)

 

38         Pluvianellidae                                     Magellanic Plover  (1)

 

39         Burhinidae                                           Thick-knees  (10)

 

40         Pluvianidae                                         Egyptian Plover  (1)

 

41         Recurvirostridae                                  Stilts and Avocets  (9)

 

42         Ibidorhynchidae                                  Ibisbill  (1)

 

43         Haematopodidae                                 Oystercatchers  (12)

 

44         Charadriidae                                        Plovers and Lapwings  (68)

 

45         Pedionomidae                                     Plains-wanderer  (1)

 

46         Thinocoridae                                       Seedsnipes  (4)

 

47         Rostratulidae                                       Painted-Snipes  (3)

 

48         Jacanidae                                             Jacanas  (8)

 

49         Scolopacidae                                       Sandpipers and Allies  (97)

 

50         Turnicidae                                           Buttonquail  (17)

 

51         Dromadidae                                         Crab Plover  (1)

 

52         Glareolidae                                          Pratincoles and Coursers  (17)

 

53         Stercorariidae                                      Skuas and Jaegers  (7)

 

54         Alcidae                                                Auks, Murres, and Puffins  (25)

 

55         Laridae                                                Gulls, Terns, and Skimmers  (99)

 

EURYPYGIFORMES  (2)              

 

56         Rhynochetidae                                    Kagu  (1)

 

57         Eurypygidae                                        Sunbittern  (1)

 

PHAETHONTIFORMES  (1)        

 

58         Phaethontidae                                      Tropicbirds  (3)

 

GAVIIFORMES  (1)                        

 

59         Gaviidae                                              Loons  (5)

 

SPHENISCIFORMES  (1)              

 

60         Spheniscidae                                       Penguins  (18)

 

PROCELLARIIFORMES  (4)       

 

61         Diomedeidae                                       Albatrosses  (15)

 

62         Oceanitidae                                         Southern Storm-Petrels  (9)

 

63         Hydrobatidae                                       Northern Storm-Petrels  (18)

 

64         Procellariidae                                      Shearwaters and Petrels  (96)

 

CICONIIFORMES  (1)                   

 

65         Ciconiidae                                           Storks  (19)

 

SULIFORMES  (4)                          

 

66         Fregatidae                                           Frigatebirds  (5)

 

67         Sulidae                                                Boobies and Gannets  (10)

 

68         Anhingidae                                          Anhingas  (4)

 

69         Phalacrocoracidae                               Cormorants and Shags  (40)

 

PELECANIFORMES  (5)               

 

70         Pelecanidae                                         Pelicans  (8)

 

71         Balaenicipitidae                                  Shoebill  (1)

 

72         Scopidae                                              Hamerkop  (1)

 

73         Ardeidae                                              Herons, Egrets, and Bitterns  (68)

 

74         Threskiornithidae                                Ibises and Spoonbills  (36)

 

CATHARTIFORMES (1)               

 

75         Cathartidae                                          New World Vultures  (7)

 

ACCIPITRIFORMES  (3)              

 

76         Sagittariidae                                        Secretarybird  (1)

 

77         Pandionidae                                         Osprey  (1)

 

78         Accipitridae                                         Hawks, Eagles, and Kites  (250)

 

STRIGIFORMES  (2)                      

 

79         Tytonidae                                            Barn-Owls  (18)

 

80         Strigidae                                              Owls  (225)

 

COLIIFORMES  (1)                        

 

81         Coliidae                                               Mousebirds  (6)

 

LEPTOSOMIFORMES (1)

 

82         Leptosomidae                                      Cuckoo-Roller  (1)

 

TROGONIFORMES  (1)                

 

83         Trogonidae                                          Trogons  (43)

 

BUCEROTIFORMES (4)

 

84         Upupidae                                             Hoopoes  (3)

 

85         Phoeniculidae                                      Woodhoopoes and Scimitarbills  (8)

 

86         Bucorvidae                                          Ground-Hornbills  (2)

 

87         Bucerotidae                                         Hornbills  (59)

 

CORACIIFORMES  (6)                  

 

88         Todidae                                               Todies  (5)

 

89         Momotidae                                          Motmots  (14)

 

90         Alcedinidae                                         Kingfishers  (118)

 

91         Meropidae                                           Bee-eaters  (28)

 

92         Coraciidae                                           Rollers  (13)

 

93         Brachypteraciidae                               Ground-Rollers  (5)

 

GALBULIFORMES  (2)                   

 

94         Bucconidae                                         Puffbirds  (36)

 

95         Galbulidae                                           Jacamars  (18)

 

PICIFORMES  (7)                           

 

96         Lybiidae                                              African Barbets  (41)

 

97         Megalaimidae                                     Asian Barbets  (34)

 

98         Capitonidae                                         New World Barbets  (14)

 

99         Semnornithidae                                   Toucan-Barbets  (2)

 

100       Ramphastidae                                      Toucans  (36)

 

101       Indicatoridae                                       Honeyguides  (17)

 

102       Picidae                                                 Woodpeckers  (233)

 

CARIAMIFORMES  (1)                 

 

103       Cariamidae                                          Seriemas  (2)

 

FALCONIFORMES  (1)                 

 

104       Falconidae                                           Falcons and Caracaras  (65)

 

PSITTACIFORMES  (4)                 

 

105       Strigopidae                                          New Zealand Parrots  (4)

 

106       Cacatuidae                                           Cockatoos  (21)

 

107       Psittaculidae                                        Old World Parrots  (190)

 

108       Psittacidae                                           New World and African Parrots  (175)

 

PASSERIFORMES  (142)               

 

109       Acanthisittidae                                    New Zealand Wrens  (4)

 

110       Calyptomenidae                                  African and Green Broadbills  (6)

 

111¬†¬†¬†¬†¬†¬† Eurylaimidae¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬† ¬†¬†¬†¬† Asian and Grauer’s Broadbills¬† (9)

 

112       Sapayoidae                                          Sapayoa  (1)

 

113       Philepittidae                                        Asities  (4)

 

114       Pittidae                                                Pittas  (46)

 

115       Thamnophilidae                                  Typical Antbirds  (237)

 

116       Melanopareiidae                                 Crescentchests  (4)

 

117       Conopophagidae                                 Gnateaters  (11)

 

118       Grallariidae                                         Antpittas  (68)

 

119       Rhinocryptidae                                    Tapaculos  (65)

 

120       Formicariidae                                      Antthrushes  (12)

 

121       Furnariidae                                          Ovenbirds and Woodcreepers  (306)

 

122       Pipridae                                               Manakins  (53)

 

123       Cotingidae                                           Cotingas  (65)

 

124       Tityridae                                              Tityras and Allies  (33)

 

125       Oxyruncidae                                        Sharpbill, Royal Flycatcher, and Allies (7)

 

126       Tyrannidae                                          Tyrant Flycatchers  (425)

 

127       Menuridae                                           Lyrebirds  (2)

 

128       Atrichornithidae                                  Scrub-birds  (2)

 

129       Ptilonorhynchidae                               Bowerbirds  (27)

 

130       Climacteridae                                      Australasian Treecreepers  (7)

 

131       Maluridae                                            Fairywrens  (32)

 

132       Meliphagidae                                      Honeyeaters  (190)

 

133       Dasyornithidae                                    Bristlebirds  (3)

 

134       Pardalotidae                                        Pardalotes  (4)

 

135       Acanthizidae                                       Thornbills and Allies  (65)

 

136       Pomatostomidae                                  Pseudo-Babblers  (5)

 

137       Orthonychidae                                     Logrunners  (3)

 

138       Cinclosomatidae                                 Quail-thrushes and Jewel-babblers  (12)

 

139       Campephagidae                                   Cuckooshrikes  (89)

 

140       Mohouidae                                          Whiteheads  (3)

 

141       Neosittidae                                          Sittellas  (3)

 

142       Psophodidae                                        Whipbirds and Wedgebills  (5)

 

143       Eulacestomatidae                                Ploughbill  (1)

 

144       Oreoicidae                                           Australo-Papuan Bellbirds  (3)

 

145       Falcunculidae                                      Shrike-tit  (1)

 

146       Paramythiidae                                     Tit Berrypecker and Crested Berrypecker  (2)

 

147       Vireonidae                                           Vireos, Shrike-Babblers, and Erpornis  (63)

 

148       Pachycephalidae                                 Whistlers and Allies  (63)

 

149       Oriolidae                                             Old World Orioles  (38)

 

150       Machaerirhynchidae                           Boatbills  (2)

 

151       Artamidae                                           Woodswallows, Bellmagpies, and Allies  (24)

 

152       Rhagologidae                                      Mottled Berryhunter  (1)

 

153       Platysteiridae                                       Wattle-eyes and Batises  (31)

 

154       Vangidae                                             Vangas, Helmetshrikes, and Allies  (39)

 

155       Pityriasidae                                         Bristlehead  (1)

 

156       Aegithinidae                                        Ioras  (4)

 

157       Malaconotidae                                     Bushshrikes and Allies  (50)

 

158       Rhipiduridae                                       Fantails  (54)

 

159       Dicruridae                                           Drongos  (29)

 

160       Paradisaeidae                                      Birds-of-Paradise  (42)

 

161       Ifritidae                                               Ifrita  (1)

 

162       Monarchidae                                       Monarch Flycatchers  (100)

 

163       Corcoracidae                                       White-winged Chough and Apostlebird  (2)

 

164       Melampittidae                                     Melampittas  (2)

 

165       Platylophidae                                      Crested Shrikejay  (1)

 

166       Laniidae                                              Shrikes  (34)

 

167       Corvidae                                              Crows, Jays, and Magpies  (128)

 

168       Cnemophilidae                                    Satinbirds  (3)

 

169       Melanocharitidae                                Berrypeckers and Longbills  (11)

 

170       Callaeidae                                           Wattlebirds  (5)

 

171       Notiomystidae                                     Stitchbird  (1)

 

172       Petroicidae                                          Australasian Robins  (49)

 

173       Picathartidae                                       Rockfowl  (2)

 

174       Chaetopidae                                        Rockjumpers  (2)

 

175       Eupetidae                                            Rail-babbler  (1)

 

176       Hyliotidae                                           Hyliotas  (4)

 

177       Stenostiridae                                       Fairy Flycatchers  (9)

 

178       Paridae                                                Tits, Chickadees, and Titmice  (63)

 

179       Remizidae                                           Penduline-Tits  (11)

 

180       Alaudidae                                            Larks  (99)

 

181       Panuridae                                            Bearded Reedling  (1)

 

182       Nicatoridae                                          Nicators  (3)

 

183       Macrosphenidae                                  African Warblers  (21)

 

184       Cisticolidae                                         Cisticolas and Allies  (161)

 

185       Acrocephalidae                                   Reed Warblers and Allies  (61)

 

186       Locustellidae                                       Grassbirds and Allies  (66)

 

187       Donacobiidae                                      Donacobius  (1)

 

188       Bernieridae                                          Malagasy Warblers  (11)

 

189       Pnoepygidae                                        Cupwings  (5)

 

190       Hirundinidae                                       Swallows  (86)

 

191       Pycnonotidae                                       Bulbuls  (151)

 

192       Phylloscopidae                                    Leaf Warblers  (79)

 

193       Scotocercidae                                      Bush Warblers and Allies  (36)

 

194       Aegithalidae                                        Long-tailed Tits  (11)

 

195       Sylviidae                                             Sylviid Warblers, Parrobtills, and Allies  (69)

 

196       Zosteropidae                                       White-eyes, Yuhinas, and Allies  (142)

 

197       Timaliidae                                           Tree-Babblers, Scimitar-Babblers, and Allies  (54)

 

198       Pellorneidae                                        Ground Babblers and Allies  (62)

 

199       Leiothrichidae                                     Laughingthrushes and Allies  (143)

 

200       Regulidae                                            Kinglets  (6)

 

201       Tichodromidae                                    Wallcreeper  (1)

 

202       Sittidae                                                Nuthatches  (28)

 

203       Certhiidae                                            Treecreepers  (11)

 

204       Polioptilidae                                        Gnatcatchers  (21)

 

205       Troglodytidae                                      Wrens  (86)

 

206       Elachuridae                                         Spotted Elachura  (1)

 

207       Cinclidae                                             Dippers  (5)

 

208       Buphagidae                                         Oxpeckers  (2)

 

209       Sturnidae                                             Starlings  (123)

 

210       Mimidae                                              Mockingbirds and Thrashers  (34)

 

211       Turdidae                                              Thrushes and Allies  (174)

 

212       Muscicapidae                                      Old World Flycatchers  (327)

 

213       Bombycillidae                                     Waxwings  (3)

 

214       Mohoidae                                            Hawaiian Honeyeaters  (5)                        [extinct]

 

215       Ptiliogonatidae                                    Silky-flycatchers  (4)

 

216       Dulidae                                                Palmchat  (1)

 

217       Hylocitreidae                                       Hylocitrea  (1)

 

218       Hypocoliidae                                       Hypocolius  (1)

 

219       Promeropidae                                      Sugarbirds  (2)

 

220       Modulatricidae                                    Dapple-throat and Allies  (3)

 

221       Dicaeidae                                            Flowerpeckers  (48)

 

222       Nectariniidae                                       Sunbirds and Spiderhunters  (143)

 

223       Irenidae                                               Fairy-bluebirds  (2)

 

224       Chloropseidae                                     Leafbirds  (11)

 

225       Peucedramidae                                    Olive Warbler  (1)

 

226¬†¬†¬†¬†¬†¬† Urocynchramidae¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬†¬† ¬†¬†¬†¬† Przevalski’s Pinktail¬† (1)

 

227       Ploceidae                                             Weavers and Allies  (118)

 

228       Estrildidae                                           Waxbills and Allies  (140)

 

229       Viduidae                                              Indigobirds  (20)

 

230       Prunellidae                                          Accentors  (13)

 

231       Passeridae                                           Old World Sparrows  (43)

 

232       Motacillidae                                        Wagtails and Pipits  (67)

 

233       Fringillidae                                          Finches, Euphonias, and Allies  (229)

 

234       Calcariidae                                          Longspurs and Snow Buntings  (6)

 

235       Rhodinocichlidae                                Thrush-Tanager  (1)

 

236       Emberizidae                                        Old World Buntings  (44)

 

237       Passerellidae                                       New World Sparrows  (132)

 

238       Calyptophilidae                                   Chat-Tanagers  (2)

 

239       Phaenicophilidae                                 Hispaniolan Tanagers  (4)

 

240       Nesospingidae                                     Puerto Rican Tanager  (1)

 

241       Spindalidae                                         Spindalises  (4)

 

242       Zeledoniidae                                       Wrenthrush  (1)

 

243       Teretistridae                                        Cuban Warblers  (2)

 

244       Icteriidae                                             Yellow-breasted Chat  (1)

 

245       Icteridae                                              Troupials and Allies  (105)

 

246       Parulidae                                             New World Warblers  (111)

 

247       Mitrospingidae                                    Mitrospingid Tanagers  (4)

 

248       Cardinalidae                                        Cardinals and Allies  (49)

 

249       Thraupidae                                          Tanagers and Allies  (381)

 

FUTURE UPDATES

The next annual revision that incorporates revisions to the taxonomy and nomenclature of the eBird/Clements Checklist will be released in August 2022.

ACKNOWLEDGEMENTS

Please continue to report potential errors, corrections, and suggestions for improvement of the eBird/Clements Checklist to cornellbirds@cornell.edu). Many of the errors that you find are ones that would have taken a long time to notice, so we appreciate your help, and we do want to hear from you. Please keep in mind, of course, that the easiest corrections or proposed revisions are ones that are accompanied by a supporting reference or citation.

We are excited to be working with a team of representatives from other global checklists to minimize differences between the lists and to coordinate on taxonomic revisions and nomenclatural issues. As part of these efforts, we especially wish to thank Nigel Collar, Paul Donald, David Donsker, and Pam Rasmussen, each of whom contributed valuable insights and served as a sounding board on many issues related to taxonomy and nomenclature. We take full responsibility, of course, for any remaining errors. We are grateful to Terry Chesser for providing advance copies of works in progress, and to both Terry and to Van Remsen for their too-little appreciated roles in chairing regional classification committees.

We also thank the following for their help in providing helpful comments on the eBird/Clements Checklist or for directing us to important literature for our consideration:

Gary Allport, Ernesto Alvarado Reyes, Dave Bakewell, Avery Bartels, Ned Brinkley, Ken Burton, Paul Clapham, Karen D’Alessandri, Paul Donald, Andy Elliott, Garry George, Mat and Cathy Gilfedder, Doug Gochfeld, Alan Grenon, Piotr Hass-Sandej, Praveen J, Lee Jones, Peter Kaestner, Peter Kennerley, Max Kirsch, Peter Kovalik, Niels Larsen, Jack Levene, Robert Lockett, Jay McGowan, Glenn Mertz, Shai Mitra, Joe Morlan, Thane Pratt, Hugo Rainey, Colin Richardson, Don Roberson, Craig Robson, Steve Rose, Daan Sandee, Fabrice Schmitt, Fred Sheldon, David Slager, Andrew Spencer, Zack Weber, Wich’yanan Limparungpatthanakij, Johnny Wilson, and Adam Winer, as well as the wider community of eBird users, the always astute members of the Taxonomy and Nomenclature group on BirdForum, and no doubt others who we inadvertently may have overlooked.

Thanks to all for your support, and we look forward to your feedback.

Thomas S. Schulenberg, Marshall J. Iliff, Shawn M. Billerman, Thomas A. Fredericks, Jeff Gerbracht, Denis LePage, Brian L. Sullivan, and Christopher L. Wood.