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. Being neither a scientist
nor an ornithologist, I have refrained from
drawing conclusions on either the ethics or the science and have
instead left it to the readers to form their own opinion
on the subject. But this time based on some
available inputs of relevance. My own bias
is to refrain from using playback on any species that is
‘Endangered’ and to regulate playback in all
protected places. However, I hope to limit the
impact of my views only to the choice of illustrations which accompany this
article.
♫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/orcoming 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. To be effective the sound system used as
an audio lure should produce 90-110 dB of sound. TheResources Inventory Committee of
British Columbia's guideline
for woodpecker inventory suggests that the “machine should be able to
broadcast sounds over a distance of 400 meters; one technical
description of a recommended player has a frequency of about 40 Hz to
12 kHz and power output of 1.2 watts at 1 kHz”[32]. The same guidelines
also recommend playback of three series of
20second calls
followed by a 30second
break for a total of 2.5 minutes. However, the
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. A field-experiment conducted in the Ebro
Delta in
1993 showed that “Mist-net with tape lures were on
average twice as effective as nets without tape lures”
in attracting Curlew Sandpipers[48]. 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, throws up
a bewildering mix of reactions and responses. There
appears to be a paucity of any empirical research on the possible
effects of the use of playback to attract birds, though scientists
seem to use playback regularly. Many of the more
descriptive inputs are
from people who use playback for their own purposes,
and are usually subjective or anecdotal.
However, they are often the most qualified to speak on the subject as
they have meaningful experiences.
On the flip side are those who voice
opinion without any experience and are often theones who oppose playback on ethical grounds.
There is a 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.
Exposure to call playback may have associated energy costs
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. Many technically qualified
individuals have made personal comments on the subject, based on their
experiences and some research organizations have relied on scientific
inputs to frame guidelines. These are not always backed by any
published literature on the subject.
Scientific
studies:The available
writings suggest that responding to call-playback may incur energy
costs, disrupt social systems, lead to pair break-ups and cause
stress. Some of the more relevant are extracted below:
♪
A study conducted by Professor Martin Wikelski of the University of
Illinois on Spotted Antbirds in Panama
found that male antbirds increased their testosterone levels and
became more aggressive, even in a sexually inactive period, when
confronted by a prolonged (2 hrs) playback of recorded sounds made by
potential enemies. Professor Wikelski goes on to say “it makes
sense for birds to maintain a baseline level of aggression without
testosterone, because testosterone has costs, such as higher mortality
rates”.[19, 25]
[Similar studies on bush warblers (Cettia diphone) in
Japan[21] suggest that adrenocorticosteroid
responses to stress may vary according to location (tropics vs
temperate regions) and territorial and parental behaviour
and results of such experiments may not be generalized.]
There is also "evidence that prolonged high
levels of circulating testosterone may incur costs that may
potentially reduce lifetime fitness"
~
Avoiding the 'Costs' of
Testosterone: Ecological Bases of Hormone-Behavior Interactions
by John C Wingfield & others.[18]
♪ Daniel J. Mennill of the
University of Illinois led a team that conducted a study on 'female
eavesdropping on male song contests in songbirds'[15]
using call playback. The results showed that female Black-capped
Chickadees eavesdrop on male song contests to make extra-pair mating
decisions following simulated playback defeats of their partner. Dr.
Mennill also found that “... high-ranking
males who lost song contests also lost paternity in their nests.”
and “ Finally, our results show that short playback sessions can
have long lasting and far-reaching effects on individual fitness.”[15,
22]
Paul McDonald comments on the same study in
the Birding Aus forum “The point is that with only a very
short playback period (...), the authors
triggered females to drastically
change their reproductive behaviour.
Likewise, it has been shown in many species that other males
also eavesdrop on these interactions, and the 'loser' may be prone to
more intrusions from adjacent males, as his quality may be inferred to
be lower than it actually is following an experimental defeat. Thus,
by continually playing calls in the one territory, I suspect birders
are effectively simulating the resident bird 'losing' to the
tape/mp3 player that it fails to evict from its territory.”[27]
Similar results were obtained by Dr. Jeffrey R. Lucas, Professor,
Dept. of Biological Sciences, Purdue University on studies conducted
on Carolina Chickadees. He found that it was “very common for us to
instigate territory disputes”.. “because responses that we
elicit from one neighbor are usually reacted to by other neighbors”.
He believes that these increased interactions may potentially have a
disruptive effect on social systems. Dr.
Lucas's comments were shared on the NEOORN discussion board[6].
♪Paulo Gama Mota, Director, Museum
of Science, University of Coimbra, Portugal conducted a 'test of the
effect of male song on female nesting behavior in the Serin (Serinus
serinus)' in a field playback experiment. He found that that females
who listened daily to playbacks of male songs, during the
nest-building stage, spent about 30% more time nest building than
females that were not thus exposed. Incidentally, male song is known
to “stimulate female reproductive activity, affecting their
behavior and physiology, such as follicular growth, nest building
and egg laying”.[49]
Several field studies have shown that playback of songs are
sufficient stimuli to evoke behavior which normally occurs in
response to the singing of another bird (e.g., Weeden and Falls,
1959; Stein, 1963).
♪Playback experiments
conducted by Dr. K. Yasukawa and others on Red-winged Blackbirds
showed that territorial males can discriminate between neighbours,
strangers and self songs and react differently to each and “stranger
song elicited significantly more intense Song Spread displays than
did self song”.[16]
(Tape-luring depends heavily on playback of 'stranger' songs/calls –
Ed.)
♪Studies conducted by Dr.Shallin D. Busch of the University of Washington, Seattle on
the reproductive endocrinology of the song wren (Cyphorhinus
phaeocephalus) using conspecific playback to simulate a territorial
intrusion showed that such use resulted in an increase in
Luteinizing hormone and testosterone in the territorial male.[20]
♪Playback of colony sound tests in
Zebra Finch (Taeniopygia guttata) colonies conducted by Dr. Joseph
R. Waas of the Department of Biology, Queen’s University, Ontario
and others to test the hypothesis that “social stimulation,
derived from the presence and activities of conspecifics, can hasten
and synchronize breeding in colonies of birds” [24] found that such stimulation
influenced the breeding schedule and clutch sizes positively.
♪Speaker-replacement studies by
Krebs (1977) showed that song playback affected space use in
free-living birds. [We
have been unable to access this paper
- Ed].
Comments by Scientists:
Many scientists and ornithologists have made personal comments on
various forums. There are also comments attributed to those who
study birds. Many of these comments were contributed to an
enlightening discussion on the subject entitled “Audio
playback: impact on Neotropical birds?”[6]
initiated by Stephen M Smith of the Department of Biology,
University of Waterloo, Canada on the NEOORN[26]
discussion board. Another meaningful discussion
took place on the Birding Aus mailing list which was a source of
additional inputs.
Appended are a selective extract of
comments/remarks:
♦
Paul G. McDonald, Lecturer and Macquarie University Research
Fellow (Birds AUS post,16 Sep 2008)[27]
: According to Dr. McDonald playback affects bird
behaviour subtly, though energy wastage “as a direct result of
playback is probably not very important....”. It is the
possibility of long-lasting negative effects of limited playback
that are more a cause for concern. These effects may include loss of
clutch paternity for resident males and energy expenditure to defend
territory even after the playback ceases. He is “not aware of any
papers that test this directly, and this is unlikely to lead to any
conservation issues. However, it does raise ethical concerns, as the
results from the playback may continue well beyond the point birders
have left the area”.
♦Bruce W. Miller, Associate
Conservation Zoologist, Wildlife Conservation Society, Gallon,
Belize (NEOORN post[6], 22
March 2005): Dr. Miller states that “.... many bird species
formerly common are no longer to be found in the same locations
where some guides ...... play tapes for 15–20 min without stop”.
The birds, however, continue to be found in similar undisturbed
habitats. His observations are based on records kept over a period
of 14+ years.
♦
Alvaro Jaramillo, Senior Biologist, San Francisco Bay Bird
Observatory and professional tour guide leader (NEOORN post[6],
22 March 2005): Mr. Jaramillo has used playback on tours as well as
in scientific contexts. He believes that “tape playback is
harmless” and the territory holding male emerges the victor in
the duel There is an impact on behaviour, “but then it is much
better than people trampling vegetation or trying to sneak up on
birds...”.
♦
Bridget Stutchbury, Professor and Canada Research Chair, York
University, Toronto. Author of 'Silence of the Songbirds' (NEOORN
post[6], 28 March 2005): Dr. Stutchbury agrees that playback is to be generally discouraged
unless it is used specifically for formal data collection and/or
research. According to her, “Recreational playbacks for birding
can be harmful if done repeatedly to the same pairs of birds; and
it’s unnecessary”.
♦
Bruce Falls, Ornithologist and Professor of Zoology,
University of Toronto (NEOORN post[6] , 31 March 2005):According to Dr.
Falls, playback is a valuable tool for both research and counting
and its use in moderation is justified with the gains outweighing
any
downsides. His field experiences with White-throated Sparrows
and Meadowlarks showed that effect of playback was 'negligible'
and the birds "habituated”. Dr.
Falls goes on to add that “However, I do have concern for rare
birds that are repeatedly assaulted by playback from a succession of
groups at the same site. Habituation may limit the damage but I
would prefer to err on the side of caution”.
♦
Phil Taylor, Professor, Acadia Biology Department Chair,
ACWERN, Nova Scotia (NEOORN post[6],
24 March 2005): Dr. Taylor does not consider careful use of playback
to be a “big issue”. He is, however, concerned about the “disruptive”
or possible “detrimental” impact of excessive playback or
repeated playback aimed at individuals or pairs.
♦
Kathryn E. Sieving, Professor, Wildlife Ecology and
Conservation, University of Florida (NEOORN post[6],
25 March 2005): According to Dr. Sieving, audio playback has an
impact on (neotropical?) birds. The impact she is aware of is the “increased
risk of predation on individuals responding to playbacks”. She
gives an example of playback-research studies in Chile, where
predatory birds attacked birds responding to conspecific territorial
calls. Dr. Sieving goes on to add that “More and more people will
be using this technology, and we have to moderate it at some point.”
♦
Jeffrey R. Lucas, Professor, Dept of Biological Sciences,
Purdue University (NEOORN post[6],
25 March 2005): Dr. Lucas's comments on the potentially disruption
of bird social systems by the use of playback has been described
above. He also goes on to say that “The point is that there are
lots of ways to disrupt a social system through playbacks, and to do
this in order to let some people see a rare bird seems a bit much.”
♫Birdwatchers and like:
Bird lovers, birders, bird photographers are the one's who often use
call playback or have been around to see the effects of lures. They
have expressed opinion in various forums based on their own feelings
on the subject. 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.
Presented below
is a cross-section of some representative
opinions culled from the Web:
♣ Dennis Rogers, 22 March 2005, NEOORN[6]:
“No matter the conservation value of the area in question or the
science available to judge impact of playback use, the fact is a
tiny proportion of the local or global population is likely to be
affected. So the conservation importance is negligible.”
♣ Rasmus Boegh, 18th April 2005,
Birdforum[7]: “Special
caution should be taken when dealing with rare birds or birds during
the breeding season, and regularly a complete "no" to playback may
be the best approach in those situations. In areas where playback is
used more or less continuously, it has been observed that birds get
"played out". The fact that their behaviour is significantly altered
should be enough to ban it completely in those cases.”
♣ Ian, 20th April 2005, Birdforum[7]:
“I think using playback reduces disturbance on habitat and bird
populations as a whole, since birders head for a stake out and focus
their attentions on one area/pair of birds.”
♣ Alf King, 20th April 2005, Birdforum[7]:
“In my personal opinion I don't like to see tapes being used,
especially just for a "quick tick" for which I believe some (not
all) visiting birders may be guilty.”
♣ Nigel Blake,18th April 2005,
Birdforum[7]: “While I
personally would not use taping I don't really see that taped calls
would have any different effect than that of a rival bird singing in
the area.”
♣ Jos Stratford, 20th April 2005,
Birdforum[7]: “I agree with
the general consensus - an isolated, one-off use of a tape lure
probably is of little consequence to an individual bird, but
repeated use is more likely to be an issue.” ♣ SheffieldPete, 28th Jan 2008, Wild
About Britain[10]: “Tape
luring is a pretty frowned upon practice, as it stresses birds
something rotten and can seriously disrupt breeding.”
♣
KnockerNorton, 4th February 2008,
Birdforum[8]: “ If you stand
there for half an hour, blasting out a tape, it's not a good idea. But
used for a few minutes to check presence / get an i.d. isn't going to
do any harm in most cases. Calling down migrants to unsuitable areas
is questionable, or harassing migrants at the coast.”
♣
J Moore,14th
February 2008, Birdforum[8]: “I
think the big problem comes in heavily birded areas, or where a bird
difficult to see is known to be in a particular area. Those
situations present the potential for multiple birders to be playing
recordings of the same bird on a frequent basis over an extended
period. If that happens, the playing of recordings may seriously
disrupt the bird's natural behavior."
♣
Richard Klim, 17th February 2008,
Birdforum[8]: “I have seen
examples where birders who are totally against the use of tapes will
instead spend many hours wandering repeatedly through fragile
habitat, ..., causing untold damage and seriously disrupting the
normal routines of countless birds.”
♣ gyrfalcon, UK, 17th February 2008,
Birdforum[8]: "Is the birder
seeing the bird more important than the perceived stress and
disturbance to the bird?".
♣ Graham, 21st May 2008, Birdforum[9]:
“....it's just cheating, isn't it? Where's the satisfaction in
luring birds when it achieves nothing a bit of fieldcraft and
patience won't also deliver? .... I can't understand how people are
pleased with sightings achieved this way.”
♣ Sancho, 22nd May 2008, Birdforum[9]:
“On the tape-lures issue, I'm no expert but I'm uncomfortable
with it. We don't know what bird-song really means. Playing a
recording to a nesting bird especially could affect its behaviour,..”.
♣ Hanno, 23rd May 2008, Birdforum[9]:
“I have no qualms using a recorder here in Vietnam. There are
hardly any birders, I use it only for a short time each time, and
without playback there is little chance of seeing some of the
skulkers.” ♣ KnockerNorton, 21st May 2008, Birdforum[9]: “, ...but
playback in itself is neither unethical nor unacceptable.”
♣
Chris Sanderson,16th September 2008,
Birding-Aus[11]: “..in
situations where playback still works it is likely you are causing
the birds stress. How much stress, and whether that has long-term
survival impacts needs research.”
♣ Douglas Carver, USA, 15th September
2008, Birding-Aus[11]: “I
have taken courses with two different ornithologists at the
Smithsonian Institution. Both cautioned against using playbacks,
except in rare instances, and even then using then sparingly (...).
While neither had hard empirical data (...), they both said that a
bird responding to a call is expending energy needlessly, which puts
unnecessary stress on the bird.”
♣ Rich Hoyer, USA, 15th September 2008,
Birding-Aus[11]: “... though
I have years of tape playing experience, and I'm pretty convinced it
doesn't have much of an effect on birds, it's not something I
recommend very highly. Often birds don't respond, so you've wasted
time you could have spent looking for other birds. It's distracting
and noisy (...). And the response you get is uninteresting and
sometimes even makes the bird harder to see than if you had just
waited a bit."
♣ Dan Bieker, who’s been teaching Field
Ornithology at Piedmont Virginia Community College, on a live
broadcast on the 'Birding Ethics'[30]
conducted by Nancy King on August 17, 2007 (VFH Radio), had this to
say to the question 'is (playback) so good for the bird?': “no”.
“It disrupts the birds. A lot of these birds are right on the
edge of survival. And to disturb them like that, um, raises some
ethical questions.” John Spahr,
Former Virginia Society of Ornithology president, had this to say in
the same programme: “If one is cautious and limits the use of
audio recordings, I think that’s perfectly acceptable.”[30]
♣ A blog post dated 4th June 2009 by Ruth K. quotes
Mike Burrell, an experienced birder and
researcher thus: “As far as bird song playback goes. It certainly
stresses a bird. But, so does pishing, squeaking, etc. ....”[37]
♣ Dr. Peter May in a 'Screech Owling'
article written for Nature Photographers relates his experience of
playback of owl tapes attracting predatory birds to the mobbing
flock due to the concentration of prey. In his opinion “Overuse
of tape playback to attract birds can be detrimental to the survival
and reproduction of some species by preventing them from devoting
full attention to other biological demands, such as feeding their
offspring.”[36]
Forest owlets are on the
edge of survival
♫Lawmakers, Regulators & Conservation
bodies:
There are no blanket prohibition or sweeping restrictions, in any
country, on the use of call playback to lure birds – at least I did
not find any after searching widely. 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. The regulations that apply to National Parks
prohibits playback exceeding 60 decibels. In the United Kingdom, it
is considered a offence to disturb, intentionally or recklessly, at
or near the nest, a species listed on Schedule1 of the Wildlife &
Countryside Act 1981. Disturbance could include playback of songs
and calls. Other than these, 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-playbackfor any species of crake or rail is not permitted.
Appended
below is a list of some of these restrictions/prohibitions:
♠ United States Fish and Wildlife Service. Department of the
Interior. Subchapter C: The National Wildlife Refuge System. Part
27-Prohibited Acts. Subpart G—Disturbing Violations: Light and Sound
Equipment: § 27.72 Audio equipment: “The operation or use of audio
devices including radios, recording and playback devices,
loudspeakers, television sets, public address systems and musical
instruments so as to cause unreasonable disturbance to others in the
vicinity is prohibited.”[1]
♠ Code of Federal Regulations; Title 36 -- Parks, Forests, and
Public Property; Chapter I – National Park Service, Department of
the Interior; Part § 2.12 Audio disturbances: “(a) The following are
prohibited:
(1) Operating motorized equipment or machinery such as an electric
generating plant, motor vehicle, motorized toy, or an audio device,
such as a radio, television set, tape deck or musical instrument, in
a manner: (i) That exceeds a noise level of 60 decibels measured on
the A-weighted scale at 50 feet; or, if below that level,
nevertheless; (ii) makes noise which is unreasonable, considering
the nature and purpose of the actor's conduct, location, time of day
or night, purpose for which the area was established, impact on park
users, and other factors that would govern the conduct of a
reasonably prudent person under the circumstances.”[2]
♠ "In England, Scotland and Wales, it is a
criminal offence to disturb, intentionally or recklessly, at or near
the nest, a species listed on Schedule 1 of the Wildlife &
Countryside Act 1981. Disturbance could include playback of songs
and calls. The courts can impose fines of up to £5,000 and/or a
prison sentence of up to six months for each offence."[3]
♠ The Royal Society for the Protection of Birds (RSPB)'s own
guidelines go thus: “Repeatedly playing a recording of birdsong or
calls to encourage a bird to respond can divert a territorial bird
from other important duties, such as feeding its young. Never use
playback to attract a species during its breeding season.”[4]
♠ The American Birding Association's (ABA) Code of Birding Ethics
recommends the following: 1(b) “.... Limit the use of recordings and
other methods of attracting birds, and never use such methods in
heavily birded areas. or for attracting any species that is
Threatened, Endangered, or of Special Concern, or is rare in your
local area.”[5]
♠ Bird Observation & Conservation Australia's (BOCA) policies
include: “Do not harass birds by repeated disturbance. Excessive
spotlighting, or repeated playback or imitation of calls can cause
stress.”[28]
♠ Arizona Game and Fish Department's pages on the Elegant Trogon
Trogon elegans states that “of tape recorders and other call-back
mechanisms to entice a trogon into better view, can effect nesting
success. (Johnson 2000).”[38]
and conservation measures introduced include restrictions on
'tape-recorded trogon calls used to lure the birds into view'.[29]
♠ At the Great Dismal Swamp National Wildlife Refuge, USA
“Playback recorders or devices are prohibited because they adversely
affect wildlife behavior”.[40]
♠ The Matagorda National Wildlife Refuge, USA website requests that:
“Please help us protect the natural avian communities in our parks
by refraining from using playback tapes of bird songs. Frequent use
of these tapes disrupts normal avian activity patterns, disrupts
essential territorial behavior and may lead to nest failure.”[41]
♠ Big Woods area, USA : “Playback tapes or any method of producing
Ivory-billed Woodpecker vocalizations and double knock sounds
are not permitted on any of the federal, state, and non-government
organization lands in the Big Woods. Producing these sounds could
affect Ivory-bill behavior and alter the findings of the ongoing
research.”[42]
♠ Galapagos National Park bans use of tape lures.[39]
♠ Sinharaja Wilderness Area prohibits tape playback: “A new
threat that has an adverse effect on the avifauna is the
“commercialization of bird watching”. The use of tape lures to
attract rare and elusive birds (mostly endemics) to be shown to
foreign visitors by using breeding or communication calls has
clearly had its impact. The practice, on the merit of clear
evidence, resulted in prohibiting tape lures within Sinharaja
Wilderness Area.”[34]
♠ Queensland's 'Nature Conservation (Protected Areas Management)
Regulation 2006 – Sect139' states: “A person must not use a radio,
tape recorder or other sound or amplifier system in a way that may
cause unreasonable disturbance to a person or animal in a protected
area.”[46]
♠ Byron Bay Integrated Water Management Reserve, Australia requires
that “Permit holders are not to employ call-playback for any species
on site without Councils permission.”
♠ “Permit holders are not use ‘call-playback’ for any species of
crake or rail at the Western Treatment Plant. This condition arises
from expert advice provided to Melbourne Water”[47]
♠ The British Trust for Ornithology - Guidelines for Constant Effort
ringing in Europe: “Tape lures are not permitted on constant effort
sites at any time during a visit because they may disrupt normal
bird activity.”[12]
♠ The Ornithological Council, Washington in their ' Guidelines to
the Use of Wild Birds in Research* ' state that: “Playback of
tape-recorded vocalizations to free-living birds causes little
disturbance or trauma if the duration of the playback is kept within
reasonable bounds (normally less than 30 minutes). More prolonged
playback may distract subjects from activities that are essential to
reproductive success. Unless required for the experiment,
speakers should not be placed close to the nest, etc. ....”[13]. [* Note: A major revision
of the Guidelines is expected to be posted by the end of 2010; TOC -
pers comm 25/12/10]
♠ British Columbia’s Ministry of Environment Lands, and Parks
protocol for woodpecker inventory states that “Playback surveys are
suitable for species that respond readily to recordings, occupy
relatively large home ranges and/or are otherwise difficult to
detect.”[32]
♠ Guidelines for Nocturnal Owl Monitoring in North America. Beaverhill Bird Observatory and Bird Studies Canada, by D. Lisa
Takats and others recommend that playback protocol for survey is
optional and “Playback can also potentially be disruptive to owls
(may increase risk of predation, disrupt foraging and courtship,
and/or draw females off nests). In addition, playing calls can pull
owls off their territories giving inaccurate information on their
habitat use (Holroyd and Takats 1997).”[31]
♫Published notes /
reports / articles:
♥
TRAFFIC's bulletin on 'The Illegal
Trade in Wild Birds for Food' highlights the ill-effects of playback
use: “Hunters targeting small birds for the food trade often use
illegal hunting methods to maximise the number of birds killed in
each attempt. Illegal methods include
the use of recordings to
attract birds – ‘tape lures’, .....”.
“38,000 Common Quail Coturnix coturnix were shot in Serbia during
two months in 2004 – more than the entire breeding population of
Serbia. It is estimated that over 90% were shot illegally, using
tape lures and semi-automatic shotguns.”[35]
♥In Tamil
Nadu, India trappers around Nagapattinam have been known to use
speakers attached on trees to trap wild birds for food.[43]
♥
BirdJam, a bird song identification
tool maker for the Apple iPod® provide recommendations to
birders for responsible use of BirdJam iPod's. Written by Sharon
Stiteler, the recommendations stress against repeated playback to
elicit response and warn against continuous playback “during the
breeding season when you might get both male and female birds
agitated and away from the nest. That's when predators, competitors
and cowbirds would have an opportunity to find the nest unguarded.”[44]
♥Cornell Lab
of Ornithology's 'Birds in Forested Landscapes'
program provide a protocol for 'Playback use and responses'. These
include recommendations on duration of call playback - 'two
one-minute segments for playback or five minutes for the mobbing
call' and state that the playback protocol “'must be standardized,
and it is important not to stress territorial birds.” The protocol
concludes that “The birds might appear agitated in response to the
mobbing calls, but we feel that this five-minute mobbing sequence
will be less invasive than searching the forest for nests.”[45]
♫Summary[ A 'Summary page'
is provided here
] Call
playback has wide usage in drawing response from birds. There
appears to be no published empirical study to determine the effects
of playback. This has led to the
absence of uniform guidelines
to explain the impact and regulate the use. Call playback is a source of disturbance and
affects birds in different degrees.However, such impact may be marginal and
may not be of significance. Continuous
playback and playback targeted at rare and endangered birds should
be avoided till we understand the effects better.
This is
what we know. In the end it is for you to
judge for yourself!
♫Some
Comments received: §12th
November 2009: "The call play back should not be
allowed at all. It is certainly harmful for territorial birds and
breeding birds". Dr. Girish Jathar §19th
November 2009: A helpful summary of the diversity of
information and views to date. This should stimulate some serious
research into the subject, without which we are simply speculating. § 21st
December 2009: Wonderful unbiased article... Human footprint on bird
habitat can actually be made smaller with the judicious use of
technology..........
____________________________
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.
What do we know about it?
1993
On the flip side are those who voice
opinion without any experience 
change their reproductive behaviour.
Likewise, it has been shown in many species that other males
also eavesdrop on these interactions, and the 'loser' may be prone to
more intrusions from adjacent males, as his quality may be inferred to
be lower than it actually is following an experimental defeat. Thus,
by continually playing calls in the one territory, I suspect birders
are effectively simulating the resident bird 'losing' to the
tape/mp3 player that it fails to evict from its territory.”
downsides. His field experiences with White-throated Sparrows
and Meadowlarks showed that effect of playback was 'negligible'
and the birds 
♣ SheffieldPete, 28th Jan 2008, Wild
About Britain
♣ KnockerNorton, 21st May 2008, Birdforum
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. The regulations that apply to National Parks
prohibits playback exceeding 60 decibels. In the United Kingdom, it
is considered a offence to disturb, intentionally or recklessly, at
or near the nest, a species listed on Schedule1 of the Wildlife &
Countryside Act 1981. Disturbance could include playback of songs
and calls. Other than these, various countries/locations have
imposed need
the use of recordings to
attract birds – ‘tape lures’, 
