Neornithes Gadow, 1893 - living birds
   Neognathae Pycraft 1900 see Cohort Neognathae Pycraft, 1900
     Galloanserae Sibley, Ahlquist & Monroe Jr., 1988 see Subcohort Galloanserae Sibley, Ahlquist & Monroe Jr., 1988
       [Order] Anseriformes Wagler, 1831 - waterfowl and screamers
         Family Anatidae Vigors, 1825 - ducks, geese, swans
           Subfamily Anatinae Vigors, 1825 - pond ducks
             Genus Anas Linnaeus, 1758 - Pacific black duck
               Anas strepera Linnaeus, 1758 - gadwall
                 ‡Anas strepera couesi (Streets, 1876) - Coues's gadwall