Well I lack knowledge in making things like this happen.
Birds could really bring a marvelous atmosphere to the game, Isnt it possible to make the bird, as if it was an actual unit, then when your in the editor, then define its way points and cycle it, just the way you can any other unit? dunno maybe its impossible and I just dont have a clue
The only think that doesnt sound right is your men shouting BIRDY! at D3D4 and stuff like that.