CANBERRA, Aug. 3 (Xinhua) -- An Australian species of bird eavesdrops on other species' alarm calls warning of predators, researchers have found.
The study, released by the Australian National University (ANU) on Friday, found that birds belonging to the Australasian wren family endemic to Australia and New Guinea have the capacity to learn the alarm calls of other species.
Robert Magrath, the lead author of the study from the ANU's Research School of Biology, discovered that the birds can learn the meaning of an alarm call without seeing a predator.
"We knew that fairy-wrens learn to recognize alarm calls if they repeatedly see a hawk at the same time as hearing an unfamiliar call, but we suspected they could learn just by listening to familiar alarm calls, without having to see a predator at all," he said in a media release on Friday.
"Theoretically they could learn with their eyes closed."
Magrath's team, including ANU's Domenique Potvin and Chaminda Ratnayake as well as Andrew Radford from the University of Bristol, played sounds to fairy-wrens in Canberra's National Botanic Gardens.
"We made the experiment as realistic as possible by using stereo speakers to simulate a natural chorus of alarm calls from birds common in the Gardens. But we also snuck in an unfamiliar sound, to see if they could learn about it," Potvin said.
In the early stages of the study, the fairy-wrens ignored the unfamiliar call but after just two days, they identified it as an alarm call and fled to cover upon hearing it.
Magrath said the finding could play a major role in protecting rare species.
"When threatened species are released into the wild after captive breeding, they often make easy pickings for predators," he said.
"Our work suggests a way of teaching them to recognize alarm calls at the release site. Captive breeding programs are expensive, so any extra chance for survival is worth investigating."
