Opinions from S. L. Olson and P. C. Rasmussen 2001
- 'Accipitridae belongs to Falconiformes'
- 'Aethiinae belongs to Alcidae'
- 'Alca belongs to Alcinae'
- 'Alca arctica is recombined as Fratercula arctica'
- 'Alca arctica belongs to Alca' according to C. Linnaeus 1758
- 'Alca cirrhata belongs to Alca' according to Pallas 1769
- 'Alca cirrhata is recombined as Fratercula cirrhata'
- 'Alca torda belongs to Alca'
- 'Alcidae belongs to Charadriiformes'
- 'Alcinae belongs to Alcidae'
- 'Alle belongs to Alcinae'
- 'Anabernicula belongs to Anatini'
- 'Anas belongs to Anatini'
- 'Anas acuta belongs to Anas' according to C. Linnaeus 1758
- 'Anas acuta belongs to Anas'
- 'Anas albeola belongs to Anas' according to C. Linnaeus 1758
- 'Anas albeola is recombined as Bucephala albeola'
- 'Anas americana belongs to Anas' according to Gmelin 1789
- 'Anas americana belongs to Anas'
- 'Anas bernicla belongs to Anas' according to C. Linnaeus 1758
- 'Anas bernicla is recombined as Branta bernicla'
- 'Anas clangula belongs to Anas' according to C. Linnaeus 1758
- 'Anas clangula is recombined as Bucephala clangula'
- 'Anas clypeata belongs to Anas' according to C. Linnaeus 1758
- 'Anas clypeata belongs to Anas'
- 'Anas columbianus belongs to Anas' according to Ord 1815
- 'Anas columbianus is recombined as Cygnus columbianus'
- 'Anas discors belongs to Anas'
- 'Anas histrionicus belongs to Anas' according to C. Linnaeus 1758
- 'Anas histrionicus is recombined as Histrionicus histrionicus'
- 'Anas mollissima is recombined as Somateria mollissima'
- 'Anas mollissima belongs to Anas' according to C. Linnaeus 1758
- 'Anas nigra belongs to Anas' according to C. Linnaeus 1758
- 'Anas nigra is recombined as Melanitta nigra'
- 'Anas perspicillata belongs to Anas' according to C. Linnaeus 1758
- 'Anas perspicillata is recombined as Melanitta perspicillata'
- 'Anas platyrhynchos belongs to Anas' according to C. Linnaeus 1758
- 'Anas platyrhynchos belongs to Anas'
- 'Anatidae belongs to Anseriformes'
- 'Anatinae belongs to Anatidae'
- 'Anatini belongs to Anatinae'
- 'Anser belongs to Anserini'
- 'Anser arizonae belongs to Anser' according to Bickart 1990
- 'Anser arizonae belongs to Anser'
- 'Anserinae belongs to Anatidae'
- 'Anserini belongs to Anserinae'
- 'Ardea belongs to Ardeidae'
- 'Ardea americana belongs to Ardea' according to C. Linnaeus 1758
- 'Ardea americana is recombined as Grus americana'
- 'Ardea antigone belongs to Ardea' according to C. Linnaeus 1758
- 'Ardea antigone is recombined as Grus antigone'
- 'Ardea cinerea belongs to Ardea' according to C. Linnaeus 1758
- 'Ardea cinerea belongs to Ardea'
- 'Ardeidae belongs to Ciconiiformes'
- 'Australca is a subjective synonym of Alca'
- 'Australca grandis belongs to Australca' according to Brodkorb 1955
- 'Australca grandis is a subjective synonym of Alca antiqua'
- 'Aythya belongs to Aythyini'
- 'Aythyini belongs to Anatinae'
- 'Balearicinae belongs to Gruidae'
- 'Branta belongs to Anserini'
- 'Branta minuscula is recombined as Anabernicula miniscula'
- 'Bucephala belongs to Mergini'
- 'Bucephala fossilis is a subjective synonym of Bucephala albeola'
- 'Bulweria belongs to Procellariidae'
- 'Buteo belongs to Accipitridae'
- 'Calonectris belongs to Procellariidae'
- 'Calonectris krantzi belongs to Calonectris'
- 'Catarractes affinis is recombined as Uria affinis'
- 'Catarractes antiquus belongs to Catarractes' according to O. C. Marsh 1870
- 'Catarractes antiquus is recombined as Alca antiqua'
- 'Catharacta belongs to Stercorariidae'
- 'Charadriidae belongs to Charadriiformes'
- 'Ciconia belongs to Ciconiidae'
- 'Ciconiidae belongs to Ciconiiformes'
- 'Columba migratorius is recombined as Ectopistes migratorius'
- 'Columbidae belongs to Columbiformes'
- 'Colymboides belongs to Gaviidae'
- 'Colymbus auritus is recombined as Podiceps auritus'
- 'Corvidae belongs to Passeriformes'
- 'Corvus belongs to Corvidae'
- 'Corvus ossifragus belongs to Corvus' according to Wilson 1812
- 'Cracidae belongs to Galliformes'
- 'Diomedea albatrus belongs to Diomedea' according to Pallas 1769
- 'Diomedea albatrus is recombined as Phoebastria albatrus'
- 'Diomedea anglica belongs to Diomedea' according to Lydekker 1891
- 'Diomedea anglica is recombined as Phoebastria anglica'
- 'Diomedea californica is a subjective synonym of Phoebastria anglica'
- 'Diomedea howardae belongs to Diomedea' according to Chandler 1990
- 'Diomedea howardae is a subjective synonym of Phoebastria albatrus'
- 'Diomedea immutabilis belongs to Diomedea' according to Rothschild 1839
- 'Diomedea immutabilis is recombined as Phoebastria immutabilis'
- 'Diomedea nigripes belongs to Diomedea' according to Audubon 1839
- 'Diomedea nigripes is recombined as Phoebastria nigripes'
- 'Diomedeidae belongs to Procellariiformes'
- 'Ectopistes belongs to Columbidae'
- 'Eudocimus belongs to Plataleidae'
- 'Fratercula belongs to Fraterculinae'
- 'Fraterculinae belongs to Alcidae'
- 'Fulica pisana belongs to Fulica' according to Portis 1891
- 'Fulica pisana is a subjective synonym of Podiceps auritus'
- 'Fuligula affinis belongs to Fuligula' according to Eyton 1838
- 'Fuligula affinis is recombined as Aythya affinis'
- 'Gavia belongs to Gaviidae'
- 'Gavia concinna belongs to Gavia'
- 'Gavia egeriana belongs to Gavia' according to Svec 1982
- 'Gavia egeriana belongs to Gavia'
- 'Gavia fortis belongs to Gavia'
- 'Gavia howardae belongs to Gavia' according to Brodkorb 1953
- 'Gavia howardae belongs to Gavia'
- 'Gavia palaeodytes is a subjective synonym of Gavia concinna'
- 'Gaviidae belongs to Gaviiformes'
- 'Gruidae belongs to Gruiformes'
- 'Gruinae belongs to Gruidae'
- 'Grus belongs to Gruinae'
- 'Haematopodidae belongs to Charadriiformes'
- 'Haematopus belongs to Haematopodidae'
- 'Haematopus ostralegus belongs to Haematopus' according to C. Linnaeus 1758
- 'Haematopus ostralegus belongs to Haematopus'
- 'Haematopus palliatus belongs to Haematopus' according to Temminick 1820
- 'Laridae belongs to Charadriiformes'
- 'Larus belongs to Laridae'
- 'Larus argentatus belongs to Larus' according to Pontoppidan 1763
- 'Larus argentatus belongs to Larus'
- 'Larus atricilla belongs to Larus'
- 'Larus delawarensis belongs to Larus' according to Ord 1815
- 'Larus delawarensis belongs to Larus'
- 'Larus minutus belongs to Larus' according to Pallas 1776
- 'Larus minutus belongs to Larus'
- 'Larus parasiticus is recombined as Stercorarius parasiticus'
- 'Larus ridibundus belongs to Larus'
- 'Lestris pomarinus belongs to Lestris' according to Temminck 1815
- 'Lestris pomarinus is recombined as Stercorarius pomarinus'
- 'Melanitta belongs to Mergini'
- 'Melanitta ceruttii is a subjective synonym of Histrionicus histrionicus'
- 'Meleagris belongs to Phasianidae'
- 'Mergini belongs to Anatinae'
- 'Mergus belongs to Mergini'
- 'Mergus serrator belongs to Mergus' according to C. Linnaeus 1758
- 'Miocepphus belongs to Alcinae'
- 'Miocepphus mcclungi belongs to Miocepphus'
- 'Morus belongs to Sulidae'
- 'Morus peninsularis belongs to Morus'
- 'Neophrontops belongs to Accipitridae'
- 'Numenius belongs to Scolopacidae'
- 'Ocyplonessa shotwelli belongs to Ocyplonessa' according to Broadkorb 1961
- 'Ocyplonessa shotwelli is recombined as Histrionicus shotwelli'
- 'Ortalis belongs to Cracidae'
- 'Pachyptila belongs to Procellariidae'
- 'Palostralegus is a subjective synonym of Haematopus'
- 'Palostralegus sulcatus is a subjective synonym of Haematopus palliatus'
- 'Pandion belongs to Pandionidae'
- 'Pandionidae belongs to Falconiformes'
- 'Pelagornis belongs to Pelagornithidae'
- 'Pelagornithidae belongs to Pelecaniformes'
- 'Pelecanidae belongs to Pelecaniformes'
- 'Pelecanus belongs to Pelecanidae'
- 'Pelecanus schreiberi belongs to Pelecanus' according to S. Olson 1999
- 'Pelecanus schreiberi belongs to Pelecanus'
- 'Phalacrocoracidae belongs to Pelecaniformes'
- 'Phalacrocorax wetmorei belongs to Phalacrocorax'
- 'Phasianidae belongs to Galliformes'
- 'Phoebastria rexularum belongs to Phoebastria'
- 'Phoenicopteridae belongs to Ciconiiformes'
- 'Phoenicopterus belongs to Phoenicopteridae'
- 'Phoenicopterus floridanus belongs to Phoenicopterus'
- 'Pinguinus belongs to Alcinae'
- 'Pinguinus alfrednewtoni belongs to Pinguinus' according to Olson 1977
- 'Pinguinus alfrednewtoni belongs to Pinguinus'
- 'Plataleidae belongs to Ciconiiformes'
- 'Plautus alle belongs to Plautus' according to C. Linnaeus 1758
- 'Plautus alle is recombined as Alle alle'
- 'Pliodytes is a subjective synonym of Podiceps'
- 'Pliodytes lanquisti belongs to Pliodytes' according to Brodkorb 1953
- 'Pliodytes lanquisti is a subjective synonym of Podiceps auritus'
- 'Pluvialis belongs to Charadriidae'
- 'Podiceps belongs to Podicipedidae'
- 'Podiceps howardae is a subjective synonym of Podiceps auritus'
- 'Podicipedidae belongs to Podicipediformes'
- 'Procellaria belongs to Procellariidae'
- 'Procellaria aequinoctialis belongs to Procellaria'
- 'Procellaria diomedea belongs to Procellaria' according to Scopoli 1769
- 'Procellaria diomedea is recombined as Calonectris diomedea'
- 'Procellaria gravis belongs to Procellaria' according to O'Reilly 1818
- 'Procellaria gravis is recombined as Puffinus gravis'
- 'Procellaria lessonii belongs to Procellaria' according to Garnot 1826
- 'Procellaria lessonii is recombined as Pterodroma lessonii'
- 'Procellaria parkinsoni belongs to Procellaria' according to Gray 1862
- 'Procellaria parkinsoni belongs to Procellaria'
- 'Procellaria puffinus belongs to Procellaria' according to Brunnich 1764
- 'Procellaria puffinus is recombined as Puffinus puffinus'
- 'Procellaria tenuirostris belongs to Procellaria' according to Temminck 1823
- 'Procellaria tenuirostris is recombined as Puffinus tenuirostris'
- 'Procellariidae belongs to Procellariiformes'
- 'Pterodroma belongs to Procellariidae'
- 'Pterodromoides belongs to Procellariidae'
- 'Pterodromoides minoricensis belongs to Pterodromoides'
- 'Puffinus belongs to Procellariidae'
- 'Puffinus borealis belongs to Puffinus' according to Cory 1891
- 'Puffinus borealis is recombined as Calonectris borealis'
- 'Puffinus lherminieri belongs to Puffinus'
- 'Puffinus pacificoides belongs to Puffinus' according to S. Olson 1975
- 'Puffinus pacificoides belongs to Puffinus'
- 'Rallidae belongs to Gruiformes'
- 'Scolopacidae belongs to Charadriiformes'
- 'Scolopax borealis belongs to Scolopax' according to Forster 1772
- 'Scolopax borealis is recombined as Numenius borealis'
- 'Scolopax media belongs to Scolopax' according to Latham 1787
- 'Scolopax media is recombined as Capella media'
- 'Somateria belongs to Mergini'
- 'Stercorariidae belongs to Charadriiformes'
- 'Stercorarius belongs to Stercorariidae'
- 'Stercorarius longicaudus belongs to Stercorarius' according to Vieillot 1819
- 'Sterna belongs to Laridae'
- 'Sterna maxima belongs to Sterna' according to Boddaert 1783
- 'Sterna maxima belongs to Sterna'
- 'Sterna nilotica belongs to Sterna' according to Gmelin 1789
- 'Sterna nilotica belongs to Sterna'
- 'Sula (Microsula) avita is recombined as Morus avitus'
- 'Sula atlantica is recombined as Morus atlanticus'
- 'Sula atlantica belongs to Sula' according to Shufeldt 1915
- 'Sula loxostyla is recombined as Morus loxostylus'
- 'Sulidae belongs to Pelecaniformes'
- 'Tadorini belongs to Anatinae'
- 'Tadorninae belongs to Anatidae'
- 'Tringa belongs to Scolopacidae'
- 'Tringa melanotos belongs to Tringa' according to Vieillot 1819
- 'Tringa melanotos is recombined as Calidris melanotos'
- 'Tringa ochropus belongs to Tringa' according to C. Linnaeus 1758
- 'Tringa ochropus belongs to Tringa'
- 'Tringa squatarola belongs to Tringa' according to C. Linnaeus 1758
- 'Tringa squatarola is recombined as Pluvialis squatarola'
- 'Turdus migratorius belongs to Turdus' according to C. Linnaeus 1758
- 'Uria ausonia belongs to Uria' according to Portis 1891
- 'Uria ausonia is recombined as Alca ausonia'
- 'Vulturidae belongs to Falconiformes'