The dodo bird.
The Dodo Bird
Rhea.
kiwi rhea dodo
ostrich, emu, penguin, road runner
Xeme
'Wren'
erne
Some sea birds with four letters are: - Erne - Tern - Gull
lark, coot, dodo, wren
A duck and a swan are both water birds with four letters.
Ibis
Starts with a