Neornithes Gadow, 1893 - living birds
   Neognathae Pycraft 1900 see Cohort Neognathae Pycraft, 1900
     Neoaves Sibley et al. 1988 see Subcohort Neoaves Sibley et al., 1988
       [Order] Strigiformes Wagler, 1830 - owls
         Family Strigidae Vigors, 1825 - owls
           Subfamily Surniinae del Hoyo et al., 2014
             Genus Aegolius Kaup, 1829
               Aegolius funereus (C. Linnaeus, 1758) - boreal owl
                 1 Aegolius funereus richardsoni (Bonaparte, 1838)
                 2 Aegolius funereus funereus (Linnaeus, 1758)
                 3 Aegolius funereus magnus (Buturlin, 1907)
                 4 Aegolius funereus sibiricus (Buturlin, 1910)
                 5 Aegolius funereus pallens (Schalow, 1908)
                 6 Aegolius funereus caucasicus (Buturlin, 1907)
                 7 Aegolius funereus beickianus Stresemann, 1928