Can you teach a bird to understand a new language?
It turns out you can, scientists have just shown in a fascinating experiment.
Biologists have demonstrated how, with just two days of training, fairy wrens could be taught to flee when they heard an alarm call foreign to them.
This showed that birds could learn to eavesdrop on the calls of other species.
New research, published in the journal Current Biology and led by Australian scientists, suggests that this intriguing approach could be used to help train captive animals to recognise signals of danger before they are released in to the wild.
The first bird tested lived on the campus of the Australian National University in Canberra, near the office of biologist and study leader Professor Robert Magrath.
The biologists trained the fairy-wrens by playing unfamiliar sounds to them, while throwing a model glider of a predatory bird, a currawong or a sparrowhawk, over them.
After only eight playbacks the birds had learned to flee, while they did not flee when played unfamiliar sounds that had not been paired with the gliders.
"There was general disbelief and excitement when the bird learned the task perfectly," Professor Magrath said.
"We had been doing experiments on learning using different methods, but until then with little success.
"So it was exciting to finally crack the practical problems of carrying out this experiment, and get clear results."
While many animals get information about danger by eavesdropping on each other, exactly how they do it has been an ongoing puzzle.
"Recognising other species' calls is a remarkable ability, because there are lots of species in a natural community, and lots of different types of calls," Professor Magrath said.
"It's like understanding multiple foreign languages."
Auckland University biologist Dr Alex Taylor said that, far from the old idea of a "bird brain", many of our feathered friends are much smarter than we think.
Indeed, our understanding of many species -- including New Caledonian crows, which Dr Taylor has watched perform astonishingly complex tasks -- was still in its infancy.
"This study provides more evidence that birds can adapt really well in various situations and learn lots of interesting things about the world as it changes," Dr Taylor said.
"In this case, a predator's new sound is something they've basically learned to avoid."