Bird Call Playback
Summary

 
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                                What do we know about it?

 

 
Summary by Sumit K. Sen

Main Article

Call Playback is widely used to evoke response from birds


Little is known about the hotly debated subject of the effect or impact of luring birds with the aid of audio devices. What is available is scattered knowledge, often anecdotal, spread across literature and discussion groups on the Internet. There is no single-point reference or compilation of these diverse, polarized and often complicated, opinions at one place, making it even more difficult for those interested to make an informed decision on the subject.

The purpose of this article is to present - in one place - available opinion, scientific results, and laws and regulations concerning the impact of call playback on birds.

Call Playback:
Call playback to attract birds is variously referred to as 'tape-lure', 'tape playback', 'audio playback' etc. This is a technique of playing back a sound to which a (most often unseen) bird responds by calling back and/or coming close to the the source of the sound. It can be achieved by playing back pre-recorded calls, or recording of a bird call in the field and playing it back, or by playing back a hostile call which can be a predator call or a mobbing sound. The equipment used can be tape recorders, Walkmans, mini-disc players, compact-disc players, iPod's or similar. These devices are often coupled with external speakers to boost the signal and can include the use of portable megaphones.
T
he length/duration of playback is one of the more contentious issues surrounding the whole topic and there are as many opinions as people who comment on this aspect.

Scientists, researchers, ornithologists, bird-ringers, poachers, tour-guides and amateur birders widely and regularly use call-playback. It is known to be a particularly effective tool for bird surveys, field-experiments, migration study, bird trapping for science and for food, and often to show ‘sought-after’ and skulking endemics to paying birdwatchers.

Audio playback has been proved to have an impact on bird behaviour. Many species respond to the stimulus of conspecific activity by calling back in response, and very often coming close to the source of the sound.  
However, call playback is noted to have degrees of effectiveness and success is often influenced by variables like season, species, time, appropriateness, experience of the user, impact of overuse, and technical issues. Territorial response is often the most commonly elicited behaviour, though fear, hunger, and attraction of safe resting places can also be some of the factors that draw reactions to call playback.

A study of all available references, pertaining to the subject. There appears to be a paucity of any empirical research on the possible effects of the use of playback to attract birds. Many of the more descriptive inputs are from people who use playback for their own purposes, and are usually subjective or anecdotal. On the flip side are those who oppose playback on ethical grounds. There is common ground though as no one seems to support endless playback at a single site and almost everyone seems to agree that playback should be avoided wherever species of conservation concern are involved. This does seem to suggest that, in the absence of scientifically evaluated knowledge, most feel that it is pragmatic to err on the side of caution and use common sense instead. Everyone seems to agree that good or bad, playback does indeed affect bird behaviour and is surely an intrusion.

The Science and Scientists:
As mentioned, it was not possible to trace any reviewed literature dealing specifically with the scientific study of the effects of the use of playback to attract birds. Most of the available scientific literature covers behaviour studies and adrenocortical responses using call-playback as one of the tools.
The available writings suggest that responding to call-playback may incur energy costs, disrupt social systems, lead to pair break-ups and cause stress.

Birdwatchers:
Bird lovers, birders, bird photographers are the one's who often use call playback or have been around to see the effects of lures. Many have expressed surprise at the lack of any scientific study which would have enabled them to take an informed decision on the subject. Some felt that it was unethical to intrude but some others felt that birdwatching itself is an intrusion and call playback is only an extension of it and, therefore, as acceptable as any other process of disturbing birds.

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Lawmakers, Regulators & Conservation bodies:
There appear to be no blanket prohibition or sweeping restrictions, in any country, on the use of call playback to lure birds. There are location specific, playback volume, season, time of day, and species risk based bans. Use of restrictions to control call playback is more widespread and prevails in many areas and locations. The most sweeping is the law in the United States of America which prohibits the use of playback devices which cause unreasonable disturbance at all National Wildlife Refuges. Various countries/locations have imposed need-based restrictions which can be blanket - like in Sri Lanka, where playback is prohibited in the Sinharaja Wilderness Area, or be species based like the one in Water Treatment Plant in Australia where call-playback for any species of crake or rail is not permitted.


Published notes / reports / articles:
 
In Tamil Nadu, India trappers around Nagapattinam have been known to use speakers attached on trees to trap wild birds for food.
BirdJam, a bird song identification tool maker for the Apple iPod®  recommend against repeated playback to elicit response and warn against continuous playback during the breeding season.

This is what we know. In the end it is for you to
judge for yourself!
____________________________

Sumit Sen
Kolkata, India
November, 2009

I make no claims that my views are those of the 'Birds of India' website or those associated with it.

END

 

   
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