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 Picae Linnaeus, 1758 see Parvclass Picae (C. Linnaeus, 1758)
             Genus Cuculus Linnaeus, 1758
               1 Cuculus canorus Linnaeus, 1758 - common cuckoo
               2 Cuculus persa Linnaeus, 1758 see Tauraco persa (C. Linnaeus, 1758)
               3 Cuculus vetula Linnaeus, 1758 see Saurothera vetula (C. Linnaeus, 1758)
               4 Cuculus glandarius Linnaeus, 1758 see Clamator glandarius (C. Linnaeus, 1758)
               5 Cuculus scolopaceus Linnaeus, 1758 see Eudynamys scolopaceus (C. Linnaeus, 1758)
               6 Cuculus niger Linnaeus, 1758
               7 Cuculus americanus Linnaeus, 1758 see Coccyzus americanus (C. Linnaeus, 1758)
               8 Cuculus auratus Linnaeus, 1758 see Colaptes auratus (C. Linnaeus, 1758)