Wrens eavesdrop on the neighbors
Superb fairy-wrens eavesdrop, learn to understand and react to the danger calls of other bird species that live nearby, according to new research published today in the Proceedings of the Royal Society B.
Associate Professor Robert Magrath and Thomas Bennett from the Research School of Biology at The Australian National University made the discovery by playing recordings of miner-bird danger calls to fairy-wrens and observed the wrens fleeing to safety.
The ability of superb fairy-wrens to eavesdrop on other species is remarkable, because alarm calls sound different for each different species, Associate Professor Magrath said.
We found that the fairy-wrens have to learn what the other species calls mean so that they know when they need to take action to avoid danger.
Superb fairy-wrens are small blue wrens, common in the south-east corner of Australia.
The behaviour we observed was particularly interesting because the fairy-wrens only reacted to the danger call recordings if miner birds were common in the immediate area, Associate Professor Magrath explained.
For example, fairy-wrens living on one side of a road where miners were present fled when noisy miner alarms were played back to them, while those over the road did not react.
This supports the notion that fairy-wrens have to learn to understand other local bird calls, rather than simply reacting because danger calls are loud or rapid.
Learning to listen to other species danger signals allows the fairy-wrens to react quickly to danger, whether it is spotted by fellow wrens or by other species in the local area.
The research suggests that birds can cope with a new environment by learning about the local community, and provides a valuable insight into how species like the superb fairy-wren will adapt to the rapidly changing world.