Imperium naturæ C. Linnaeus, 1758 - nature
   Mundus Plinius - physical world
     naturalia - natural bodies
       Regnum Animale C. Linnaeus, 1758 - animal kingdom see Kingdom Animalia Linnaeus, 1758
         Class Aves Linnaeus, 1758 - birds see Subclass Aves Linnaeus, 1758
           Order Accipitres Linnaeus, 1758 see Suborder Accipitres (C. Linnaeus, 1758)
             Genus Falco Linnaeus, 1758
               01 Falco melanaetus Linnaeus, 1758
               02 Falco chrysaëtos Linnaeus, 1758 see Aquila chrysaetos (Linnaeus, 1758)
               03 Falco fulvus Linnaeus, 1758
               04 Falco canadensis Linnaeus, 1758
               05 Falco rusticolus Linnaeus, 1758 - gyrfalcon
               06 Falco barbarus Linnaeus, 1758
               07 Falco caerulescens Linnaeus, 1758 see Microhierax caerulescens (Linnaeus, 1758)
               08 Falco albicilla Linnaeus, 1758 see Haliaeetus albicilla (Linnaeus, 1758)
               09 Falco pygargus Linnaeus, 1758 see Circus pygargus (Linnaeus, 1758)
               10 Falco milvus Linnaeus, 1758 see Milvus milvus (Linnaeus, 1758)
               11 Falco forficatus Linnaeus, 1758 see Elanoides forficatus (Linnaeus, 1758)
               12 Falco gentilis Linnaeus, 1758 see Accipiter gentilis (Linnaeus, 1758)
               13 Falco subbuteo Linnaeus, 1758 - Eurasian hobby
               14 Falco buteo Linnaeus, 1758 see Buteo buteo (Linnaeus, 1758)
               15 Falco tinnunculus Linnaeus, 1758 - common kestrel
               16 Falco sufflator Linnaeus, 1758
               17 Falco cachinnans Linnaeus, 1758 see Herpetotheres cachinnans (Linnaeus, 1758)
               18 Falco sparverius Linnaeus, 1758 - American kestrel
               19 Falco columbarius Linnaeus, 1758 - merlin
               20 Falco lanarius Linnaeus, 1758
               21 Falco haliaetus Linnaeus, 1758 see Pandion haliaetus (Linnaeus, 1758)
               22 Falco gyrfalco Linnaeus, 1758
               23 Falco apivorus Linnaeus, 1758 see Pernis apivorus (Linnaeus, 1758)
               24 Falco aeruginosus Linnaeus, 1758 see Circus aeruginosus (Linnaeus, 1758)
               25 Falco palumbarius Linnaeus, 1758
               26 Falco nisus Linnaeus, 1758 see Accipiter nisus (Linnaeus, 1758)