"Not all birds can learn to make entirely new sounds. To date, only three groups of distantly related birds have been found to have this ability: songbirds; parrots such as cockatoos and parakeets; and hummingbirds."

Hummingbirds? Now, that I would dearly wish to witness.

Ummm. What about Mynas? They mimic other birds for predatory purposes and they mimic humans.