Are birdwatching ‘playbacks’ bad for birds?

Birdwatchers seem like a bird’s best friend. They help promote bird conservation, and as citizen scientists, they often collect avian population data.

But birdwatchers also frequently play recordings of bird calls in the wild to attract their quarry. On some birdwatching tours, guides repeat these “playbacks” for rare birds for more than an hour in order to satisfy their curious customers. Does the constant chatter end up harming the birds?

Researchers argue in PLOS ONE that this question hasn’t been adequately answered. It’s possible that responding to the recorded calls could sap the birds’ energy, distract them from looking for food, or place them in the path of a predator, the authors say. Results of previous research have been mixed: Some scientists found that playbacks didn’t affect the songs of male finches, while others reported that playbacks influenced female chickadees’ mating decisions. Some studies even suggest that recorded calls could benefit birds by prompting them to move to new territory or spend more time building nests.

J. Berton C. Harris, a researcher now at Princeton University in New Jersey, decided to investigate the question in Ecuador. First, he scouted for the locations of two species, plain-tailed wrens and rufous antpittas. Then Harris played bird calls for five minutes to 36 groups of wrens or antpittas and recorded their responses. He also monitored how they responded to recordings of background noise, such as the sounds of insects and wind.

After the playbacks, the wrens sang more duets and the antpittas sang more songs than they did after hearing background noise, Harris and a colleague report. The birds also tended to repeat these songs more often. “[P]layback could negatively affect species if they become stressed, expend energy, or take time away from other activities to respond to playback,” the team writes.

But another experiment suggested that the birds might become used to the extra noise. Harris played call recordings to five groups of wrens for five minutes per day over about three weeks. He monitored behavior such as how close the birds came to the speaker and how long it took them to respond to the playback. By the twelfth day, “wrens showed little or no response,” according to the study. So if playbacks are frequent, birds might eventually stop paying attention. Roberta Kwok | 14 October 2013

Source: Harris, J.B.C. and D.G. Haskell. 2013. Simulated birdwatchers’ playback affects the behavior of two tropical birds. PLOS ONE doi: 10.1371/journal.pone.0077902.

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