英文關鍵字
africa
anatidae
animal
animalia
animals
anseriformes
background
beak
beautiful
bird
chordata
concern
cygnus
cygnus_olor
earth
eurosiberia
family
feathered_creature
feathers
fly
fowl
hansaya
least_concern
member
mute
native
nature
naturel
north
olor
rock
shadows
species
swan
water
waterfowl
white
wild
wildlife