Opinions from K. J. Bickart 1990
- 'Accipitridae belongs to Accipitriformes'
- 'Anabernicula belongs to Anatini'
- 'Anas belongs to Anatini'
- 'Anatidae belongs to Anseriformes'
- 'Anatinae belongs to Anatidae'
- 'Anatini belongs to Anatinae'
- 'Anser belongs to Anserini'
- 'Anser arenosus belongs to Anser'
- 'Anserinae belongs to Anatidae'
- 'Anserini belongs to Anserinae'
- 'Aquila belongs to Buteoninae'
- 'Branta belongs to Anatini'
- 'Branta woolfendeni belongs to Branta'
- 'Buteo belongs to Buteoninae'
- 'Buteoninae belongs to Accipitridae'
- 'Ciconia belongs to Ciconiidae'
- 'Ciconiidae belongs to Ciconiiformes'
- 'Circinae belongs to Accipitridae'
- 'Circus belongs to Circinae'
- 'Cygnus belongs to Anserini'
- 'Cygnus (Olor) belongs to Cygnus'
- 'Cygnus (Olor) belongs to Cygnus' according to Wagler 1832
- 'Cygnus (Olor) mariae belongs to Cygnus (Olor)'
- 'Gruidae belongs to Gruiformes'
- 'Grus belongs to Gruiformes'
- 'Grus haydeni belongs to Grus'
- 'Gypaetinae belongs to Accipitridae'
- 'Neophrontops belongs to Gypaetinae'
- 'Podiceps belongs to Podicipedini'
- 'Podicipedidae belongs to Podicipediformes'
- 'Podicipedini belongs to Podicipedidae'
- 'Podilymbini belongs to Podicipedidae'
- 'Podilymbus belongs to Podilymbini'