For those who are not biologist or never taken Ornithology (study of birds) this video is really amazon on how complex birds vocalization are. They can do thing beyond what humans can do. I would suggest go to 1:30:00. http://www.wimp.com/lyrebirdsounds/
Growing up in Victoria Australia these guys will blow your mind with the stuff they can imitate.
When I first saw the video about a year ago I assumed it was a fake comedy video, however, after reading up on it I was amazed that this is true. Those birds are incredible.
Do they immitate the Stuka siren while bombing the cleanest car they can find?