The Revised Classification for the Fourth Edition of the A

VoL1926 XLllI] J WETMOREAND MILLER, Classification ofBirds. 337

THE REVISED CLASSIFICATION FOR THE FOURTH EDITION OF THE A. O. U. CHECK-LIST

BY A. WETMORE AND W. DEW. MILLER.

WHEN a new committee,with Dr. Witmer Stone as Chairman, was appointedsubsequent to the Pittsburghmeeting to continue the work of preparationof a fourth editionof the Check-List,the presentwriters were delegatedto draft a revisedclassification in accordancewith presentday ideas. The labors of the subcom- mitteeentrusted with thistask are now complete, and it hasseemed proper to offer a draft of the arrangementas far as sub-families that it may be available in advanceto thoseinterested. In introductionit may be saidthat beforethe first editionof the A. O. U. 'Check-List' was issued in 1886 three individual lists that summarized the bird life of the area that we assume to be North Americanhad been in currentuse. Bairdin 1858published sucha list in quarto form, followingit with an octavoedition in more convenientsize in 1859. Couespublished a check-listin 1873as a synopsisof his'Key to NorthAmerican Birds', and issued a revisededition in 1882to bring the matter downto date. In the meanwhileRidgway in 1881had issueda 'Nomenclatureof North American Birds'. As both Couesand Ridgwaywere members of the committeeof fiveappointed at the first congressof the AmericanOrnithologists' Union to revise the classification and nomenclature of the birds of North America it followed that their ideas were instrumental in moldingthe form of the new work. The committee,until the last moment, was unable to agreeon the classificationto be used and finallyreferred the entirequestion to Dr. L. Stejneger,serving with the committeeby invitation, with instructionsto follow the Coues- Ridgwayarrangement where the two were agreed,and in other casesto use his judgmentas to properprocedure. As through extensivestudies his viewswere already crystallized he was able to completethe work in a singlenight. Listspublished prior to 1886had begunwith what wasconsidered the highestgroup, and had continueddown the llne to end with thoseconsidered the lowest. The arrangementadopted in the 338 Wr,T•UOl• AN•) MI.•.•r•l•, Classification ofBirds. [Auk[July work publishedin 1886 reversedthis order so that the list began with the Grebes as lowest in rank of the families found on this continent and ended with the Thrushes which were held as the highest. This first edition of the ' Check-List' at oncewas adopted as the universal standard for this country. Immediately following its appearancecame the work of Fuerbringer,in 1888, that of Sharpe in 1891, and that of Gadow in 1893, the first and last basedupon profoundanatomical studies that revealedrelationships hitherto unsuspectedwhich indicated radical changes in existingsystems of classification. When the secondedition of the A. O. U. ' Check-List'was pre- paredin 1895,the changesproposed by the authorsmentioned were still too new to have beenuniversally accepted, and no shift was made in the general arrangement. The matter was again con- sideredin 1910, when Mr. Ridgway and Dr. Stejnegerwere asked to draft a new outline. At the last moment, however, the committee, mainly at the instanceof Mr. William Brewster,decided to follow the old orderon the groundsthat proposedschemes differed widely indicating varianceof opinion, and that a shift from the old order would cause confusion in the minds of those familiar with the arrangementin previouseditions. An abstractof Gadow's arrangement,with the A. O. U. equivalentsin brackets,was, however,given in the preface. The arrangementof the 'Check-List' has been followed con- sistentlyin' The Auk,' ' The Condor,'and the many popularworks on ornithologythat have appearedin recentyears. At the same time standard technical works, such as Mr. Ridgway's 'Birds of North and Middle America,' have used a modern schemeso that confusionhas resulted. As relationshipsindicated in the old list are in a numberof caseswholly erroneousit has perpetuatedfalse ideasfrom generation to generation,obviously improper procedure. Changein the presentaccepted order will no doubtoccasion com- plaint but if we are to advancein our sciencewe mustassimilate modem ideas, otherwiseour mechanismwill assumethe general utility of a stagecoach in a time of automobilesand airships. In preparinga revisedclassification we have taken Gadow's work as a basisand have incorporatedin it variouschanges that VoL1920 XLIII] j WETMOREANDMILLER, Classification ofBirds. 339 have been made by later workers. In generalwe have accepted changesfrom the presentorder only when they appearto us def- initely establishedon proper grounds. When doubt seemsto attach to any suggestionwe have followedthe olderclassification. Our aim hasbeen, so far as possible,to presentestablished modern views in a conservative manner. In the few instances where we havenot been in absoluteagreement as to procedurethe matters under dispute have been referred for decisionto Dr. Stone as chairman of the committee as a whole. In summarywe proposeto group North Americanbirds in twenty orders,as againstthe seventeenfound in previouseditions of the' Check-List.' The sequencefollowed is one that seemsbest to illustrate the advance of the different groupsfrom an evolu- tionarystandpoint with due referenceto specializationand adapt- ation for peculiarmodes of llfe. In studyingthe presentarrangement it must be bornein mind alwaysthat the differentgroups do not representmilestones along a directroad leading from highest to lowest,but that they are the modern terminalsof diverginglines of evolutionconnected by commonancestors in a past more or lessremote. It is not difficult to placethem on a planesurface where their relationshipto one anothermay be presentedin termsof two dimensions,but it is anotherthing entirely to rangethem in a singleline. For the last there must be carefulweighing of charactersto determinethose of basic value and an allocation of rank that will not clash with facts. The problemsinvolved are often difficult and in somecases can only be settled arbitrarily. As a final word, thosewho maintain collectionsof eggs,identity of whichis basedon the presentA. O. U. numberpencilled on each specimen,will no doubtfeel a risingantagonism against the pro- poseddrastic changes on the groundof confusionthat seemsimmi- nent if underthe new arrangementnew numbersare assignedto all our birds. Under the presentplans of the Committeesuch con- fusionwill be obviated as in the new edition of the 'Check-List' it is expectedthat eachspecies will bearthe samenumber as now assigned to it, placed in bracketsas at present,and no other. An ap- pendixwill includea concordancewhere the list will be rangedin numericalorder as formerly. This will be so arrangedas to serve FAuk 340 WETMOREAND MILLER, Classification of Birds. [July as an index to the positionof each of the speciesin the present work. The old numbers will thus remain in force. The magnitudeof the task of assemblingsuch a classification asis heregiven will be readilycomprehended when it is remembered that it hasnecessitated consideration of all groupsof birds,living and fossil,at presentknown, sinceour native speciesmust be viewed on a comparative basis with the avifauna of the entire world. In the list that followsfossil groups are omitted. Thoseextra- limital to the A. O. U. list as at presentconstituted are givenin brackets. Class A•rgS Subclass NEORNITHES '[SuperorderPAlr. AEOGNATItAE] [Order 8truthioniformes. Ostriches] [Order Rheiformes. Rheas] [Order Casuariiformes. Cassowaries] [OrderApterygiformes. Apteryxes] [OrderTinamiformes. Tinamous] SuperorderNEOGNATHAE [OrderSphenisciformes. Penguins] Order Gaviiformes. Loons Family Gaviidae Order Colymbiformes. Grebes Family Colymbidae Order Procellariiformes. Tube-nosed Swimmers Family Diomedeidae. Albatrosses Family Hydrobatidae. Fulmars, Shearwatersand Petrels SubfamilyPuffininae Subfamily Hydrobatinae Family Oceanitidae. Long-leggedStorm Petrels Order Pelecaniformes. Totipalmate Swimmers Suborder PhaSthontes Family PhaSthontidae. Tropic-birds Suborder Pelecani SuperfamilyPelecanides Family Pelecanidae. ])elicans Vol.1926 XLIII] J WETMOREANDMILI,•r[, Classificatiou ofBirds. 341

SuperfamilySulides Family Sulidae. Gannetsand Boobies Family Phalacrocoracldae.Cormorants Family Anhingidae. Darters SuborderFregatae Family Fregatidae. Man-o'-war-blrds Order Ci½oniiformes. Herons, Storks, Ibises, etc. Suborder Ardeae Family Ardeidae. Heronsand Bitterns Subfamily Ardeinae SubfamilyBotaurinae Suborder Ciconiae SuperfamilyCiconiides Family Ciconiidae. Storksand Wood Ibises SubfamilyCiconilnae Subfamily Mycteriinae SuperfamilyThreskiornithides Family Threskiornithldae. Ibisesand Spoonbills Subfamily Threskiornithinae Subfamily Plataleinae SuborderPhoenicopteri Family Phoenlcopteridae.Flamingoes Order Anseriforrnes. Screamers,Ducks, etc. ]SuborderAnhimae. Screamers] Suborder Anseres. Ducks, Geeseand Swans Family Anatidae Subfamily Cygnlnae Subfamily Anserinae Subfamily Dendrocygnlnae Subfamily Anatinae SubfamilyFuligulinae SubfamilyErismaturinae SubfamilyMerginae Order Fal½oniformes. Vultures, Hawks and Eagles,etc. Suborder Cathartae. American Vultures Family Cathartidae SuborderFalconi. Falcons,Hawks, Eagles,etc. SuperfamilyFalconldes 342 WETMOREANDMILLER, Classification ofBirds. [.July[Auk

Family Accipitrldae. Hawks, Eagles,etc. Subfamily Elaninae SubfamilyPerninae Subfamily Milvinae SubfamilyAccipitrinae SubfamilyButeonlnae Subfamily Circinae SubfamilyPandioninae Family Falconidae. Falcons,Caracaras, etc. Subfamily Polyborlnae SubfamilyFalconinae Order Galliformes. Gallinaceous Birds Suborder Galli SuperfamilyCracides. Curassows,Chachalacas, etc. Family Cracidae SubfamilyPenelopinae SuperfamilyPhasianides. Pheasants, Grouse, Quails, etc. Family Tetraonidae. Grouse,etc. Family Perdicidae. Quails Subfamily Perdicinae SubfamilyOdontophorinae Family Phasianidae. Pheasants Family Melcagridae. Turkeys [SuborderOpisthocomi. Hoatzins] Order Megalornithiformes. Cranes,Rails, etc: [SuborderMesoenatides. Mesites] [SuborderTurnices. Hemipodes] SuborderMegalornithcs. Cranes,Rails, etc. SuperfamilyMegalomithides Family Megalomithidae. Cranes. SubfamilyMegalornithlnae Family Aramldae. Courlans SuperfamilyRailides Family Railidac. Rails, Cootsand Gallimlles Subfamily Rallinae Subfamily Gallinulinae Subfamily Fulicinae Vol.lO26 XLIII] J Wr.Ta•oRr..•Nv MIL•,r.R, Classification ofBirds. 343

[SuborderHeliornithes, Finfoots] [SuborderEurypygae. Sun Bitterns] [SuborderCariamae. Seriemas] [SuborderOtides, Bustards] Order Charadriiformes. Shore-birds,Gulls, Auks, etc. Suborder Charadrii SuperfamilyJacanides Family Jacanidae. Jacanas SuperfamilyCharadriides Family Haematopodidae. Oystercatchers Family Charadriidae. Plovers,Turnstones, etc. SubfamilyVanellinae SubfamilyCharadriinae SubfamilyAphrizinae Subfamily Arenarlin'ae Family Scolopacidae.Snipes, Sandpipers, etc. SubfamilyScolopacinae SubfamilyNumeniinae Subfamily Canutinae Family Recurvirostridae. Avocets Family Phalaropodldae. Phalaropes Suborder Lari Family Stercorariidae. Skuasand Jaegers Family Laridae. Gulls and Terns Subfamily Larinae SubfamilySterninae Family Rynchopidae. Skimmers Suborder Alcae Family Alcidae. Auks, Murres, etc. Subfamily Plautinae Subfamily Alcinae SubfamilyFraterculinae Order Columbiformes. Pigeons,Doves• etc. [SuborderPterocletes. SandGrouse] [SuborderColumbae] SuperfamilyColumbides Family Columbidae. Pigeonsand Doves Order Psittacifornles. Parrots, Macaws, etc. [ Auk 344 Wr•ogr •N•) MtLLrg, Classificationof Birds. [July

Family Psittacidae. Subfamily Arinae Order Cuculiform0s. Cuckoos,etc. [SuborderMusophagi. Plantain-eaters] Suborder Cuculi Family Cuculldae. Cuckoos,Anis, etc. SubfamilyCuculinae SubfamilyNeomorphinae SubfamilyCrotophaginae Order Strigiformes. Owls Family Tytonidae. Barn Owls Family Strigidae. HornedOwls, etc. Order Caprimulgiformes. Goatsuckers,etc. [SuborderSteatornithes. Oilbirds] SuborderCaprimulgi Family Caprimulgidae. Whippoorwills,Night- hawks, etc. SubfamilyCaprimulginae SubfamilyChordeilinae Order Micropodiiformes. Swifts and Hummingbirds SuborderMicropodii Family Micropodidae. Swifts SubfamilyChaeturinae SubfamilyMicropodinae Suborder Trochili Family Trochilidae. Hummingbirds Sul•familyTrochilinae [Order Coliiformes. Colies] Order Trogoniformes. Trogons Family Trogonidae. Order Coraciiformes. King•shers,Rollers and Hornbills Suborder Aloedines SuperfamilyAlcedinides Family Alcedinidae. Kingfishers SubfamilyCerylinae [SuborderCoracii. Rollers] [SuborderBucerotes, Hornbills] Order Piciformes. Woodpeckersand Jaca•nars vo.•926 J WET•aO•tEAm) Mn, I,mt, Classificationof Birds. 345

[Suborder Galbulae. Jacamars] Suborder Pici Family Picidae. Woodpeckers Subfamily Picinae Order I'•sseriformes. PerchingBirds [SuborderEurylaemi Broadbills] Suborder Tyranni Family Cotingidae. Cotlngas Family Tyrannidae. Tyrant Flycatchers [SuborderMenurae. Lyre Birds] Suborder Oseines Family Alaudidae. Larks Family Hirundinidae. Swallows Family Corvidae. Crowsand Jays Subfamily Garrulinae Subfamily Corvinae Family Paridae. Titmice Subfamily Parinae Subfamily Remizinae SubfamilyPsaltriparinae Family Sittidae. Nuthatches Subfamily Sittinae Family Certhlidae. Creepers SubfamilyCerthiinae Family Chamaeidae. Wren-Tits Family Cinelidae. Dippers Family Troglodytidae. Wrens Family Miraidac. Thrashers,Mockingbirds, etc. Family Turdidae. Thrushes,Bluebirds, etc. Family Sylviidae. Warblers, Kinglets and Gnat- eatchefs Subfamily Sylviinae SubfamilyPolioptilinae SubfamilyRegulinae Family Motaeillidae. Pipitsand Wagtails Family Bombyeillidae. Waxwings Family Ptilogonatidae. Silky Flycatchers Family Laniidae. Shrikes 346 W•TMoR•.z,m) MI•.•.•.R, Classification ofBirds. [July[ Auk

Subfamily Laniinae Family Sturnidae. Starlings Family Vireonidae. Vireos SubfamilyVireoninae Family Coerebidae. Honey Creepers Subfamily Coerebinae Family Mniotiltidae. Wood Warblers Family Ieteridae. Blaekblrds,Orioles, etc. Family Thraupidae. Tanagers SubfamilyThraupinae Family Fringillidae. Finehes,Sparrows, ete. Subfamily Riehmondeninae SubfamilyPasserinae SubfamilyFringillinae SubfamilyCarduelinae Subfamily Emberizinae