Rare is the birder who doesn’t use sound to attract his quarry. Pishing, tape recordings and now iPhones are often considered the tools of the trade. But a new study published in PLOS One warns that sound, particularly taped playbacks, could be harming birds by stressing them out and interrupting their normal routines.
A Princeton University researcher examined the effects of playbacks on 24 groups of plain-tailed wrens and 12 groups of rufous antipittas in the forests of Ecuador. He played a five-minute recorded song, then monitored the birds for one hour afterwards. Both species would sing more often after hearing the recording and repeated the songs more often. He deduced from these observations that the increasing singing might be wasting the birds time and zapping their energy by causing them to respond to non-existent intruders. The distractions the playbacks create for the birds could prevent them from caring for their nests, foraging or looking for mates.
“Birdwatchers are ardent conservationists and they want to minimize their impact while observing secretive birds,” Harris said in a prepared statement. “Unfortunately, as evidenced by this research, birdwatchers may also have negative effects on ecosystems.”
He also conducted a second trial on the wrens to monitor the effect of prolonged exposure to the recordings. They sung more for the first 12 days, then eventually got used to the constant recordings and stopped responding.
Harris said that further research would be needed to better understand the long-term impacts of the recordings on specific behavior, such as mating.
“Studies of the effects of playback on bird reproductive success have not yet been done,” said Harris. “And until such studies are available, it’d be wise for birdwatchers to be cautious of the negative effects.”