Children (16 direct children, 20 direct and indirect children):
Mute swan
Cygnus olor
Whooper swan
Cygnus cygnus
Tundra swan
(tree size 2)
Whistling swan
Black swan
(tree size 2)
Black-necked swan
Cygnus melancoryphus
Trumpeter swan
Cygnus buccinator
Cygnus falconeri
Cygnus herrenthalsi
Cygnus paloregonus
Cygnus equitum
Dwarf maltese swan
Cygnus anatoides
Cygnus atrata
Cygnus bewicki
Cygnus unwini
Cygnus bewickii
Bewick’s swan
Cygnus musicus