Birds of a feather talk together
Pet parrots, such as cockatoos, that are let loose in the wild are teaching native birds to talk.
NO NEED TO THINK you're going bird-brained if you hear mysterious voices from the trees - it's likely just a curious cockatoo wanting a chat. 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."
Birds mimic each other
As well as learning from humans directly, "the birds will mimic each other," says Jaynia Sladek, from the Museum's ornithology department. "There's no reason why, if one comes into the flock with words, [then] another member of the flock wouldn't pick it up as well."
'Hello cockie' is the most common phrase, though there have been a few cases of foul-mouthed feathered friends using expletives which we can't repeat here.
The evolution of language could well be passed on through the generations, says Martyn. "If the parents are talkers and they produce chicks, their chicks are likely to pick up some of that," he says. This phenomenon is not unique; some lyrebirds in southern Australia still reproduce the sounds of axes and old shutter-box cameras their ancestors once learnt.
Related gallery: birds of paradise
Birds of a feather chat together
In rural areas talking parrots will probably begin to lose their language abilities, says Martyn, with some words "likely to just disintegrate a bit and become part of that particular flock's repertoire."
However, in Australia's big cities like Sydney, Melbourne and Brisbane, cockatoos will probably maintain and improve their vocabulary due to regular contact with humans. "That's certainly the case in the Botanic Gardens [in Sydney]," says Martyn. "If you say 'hello' or 'hello cockie' to the cockatoos, and if they're interested in you and not just picking around for food, you may well trigger a response."
Check out this video of a cockatoo who's been taught to talk: