Planet of the Apes may have focused on the wrong species:
Native parrots, especially cockatoos, seem to be learning the art of conversation from their previously domesticated friends.
The Australian Museum’s Search and Discover desk, which offers a free service to identify species, has received numerous reports of encounters with talkative birds in the wild from mystified citizens who thought they were hearing voices.
Martyn Robinson, a naturalist who works at the desk, explains that occasionally a pet cockatoo escapes or is let loose, and “if it manages to survive long enough to join a wild flock, [other birds] will learn from it.” (Australian Geographic via Slashdot.)
Perhaps it’s time to add skyward-pointing cameras to the banks of video surveillance near the borders. This might also be a good time to get a cat. (That’s a good idea even if the parrots never get their act together.)