TO BE(GIN PLAYBACK) OR NOT TO BE(GIN PLAYBACK), THAT IS THE QUESTION!
Whether 'tis nobler in the mind to conform to the wishes of outraged
birders, and to cease using recorded playback, or to take arms against these
purists, and by blatantly using playback, silence them.
By Bill Gilbert, Ph.D.
As an avid birder in the eastern United States, your goal each spring
is to see all of over thirty wood warbler species that regularly pass
through your state. Thus one morning late in May you stand by the old canal
bed, binoculars and tape recorder in hand, trying to sight the uncommon and
secretive Connecticut Warbler, your last unchecked species. The
long-abandoned canal, filled with burdock, poison hemlock, poison ivy,
blackberries, nettle, and every other brand of scratching and urticating
plant known to man, is a perfect haunt for your elusive prey. Impatiently
you roll a tape of the Connecticut's song. No response! For over an hour
you work the canal's edge. No response! Finally, from deep in the dark
tangles, a response! The bird is shy, however, and comes no closer. So you
plunge into the brush. Thorns tear your ankles and nettles numb your hands,
but you press on. Now, just beyond a huge black willow, your quarry
answers. Peering around the trunk you finally spot it: another birder with
a tape recorder!
This vignette, showing how birders can fool each other, highlights just
one possible problem of using recorded playback in birding, nature
recording, and science. Perhaps because I am a birder, a recordist, and a
scientist all in one, Nature Sounds Editor Sharon Perry asked me to write an
authoritative article on this controversial issue. Little did she realize
that I didn't know beans about the subject.
But I am resourceful! I could draw on two decades of using playback in
the field for bird banding and research, I knew the ornithological
literature, and I knew how to use the library. I quickly went there to find
an authoritative article. In Current Contents, under keywords "playback"
and "recorded playback," I found title after title on neat ways scientists
use playback to solve taxonomic, acoustic, and behavioral problems, mostly
with birds. Unfortunately, there was nothing about playback's dark
underbelly. I
then turned to my personal memory of the bird song and behavior literature
dating back several decades. Unfortunately, my data banks came up empty.
Back to square one and clueless, I contacted Sharon. I told her I had
lots of great information on playback, but did she possibly know of any
additional sources (just to cover my bases, of course). Sharon suggested
that I check out the Nature Recordists' Website. I did this, and downloaded
relevent material from a discussion thread on the ethics of using recorded
playback. I was off and running (or at least I thought).
Reviewing the interchanges of the playback ethics thread, I was struck
by the thoughtfulness and sophistication of the discussion. Seven
participants, including Doug Von Gausig (coordinator of the Website) and
Bernie Krause came down on the side of using little if any playback for
recreational/commercial purposes (e.g., attracting birds for viewing or
stimulating them to sing for recordings). Four participants, including Dave
Lauten from Oregon and J. R. Fletcher (a former birding guide in the
tropics) saw no harm with moderate use of recreational/commercial playback.
Interestingly, participants on both sides of the issue condoned moderate
playback use for scientific/management purposes, such as for separating
"sibling" species of birds, documenting range extensions, or broadcasting
distress calls to deter agricultural pests.
So the controversy lay with recreational/commercial use, and democracy
would declare the "purists" (those against playback use) the winners. But
this article isn't about democracy, so let's review the arguments. Those
against recreational playback said it greatly disturbs birds, makes their
behavior and vocalizations abnormal, and can harm their nesting and
viability. Syd Curtis, an eloquent Aussie, admitted to having caused a rare
Albert's Lyrebird "extreme distress" many years ago by bombarding it with
its own song. Doug Von Gausig stated that playback elicits "---fear and
defensive reactions, and other uncommon, unnatural responses." and that "---
we (don't) have the right to inject these influences ---." Jim Morgan
cited two Western Kingbirds that "--- became extremely agitated --- and then
promptly left the area (after hearing playback)." Finally, Marty Michener
expressed his views with "I have watched poor birders, repeatedly playing
the same cuts to birds in the field, never even noticing the male (bird) has
responded, but they are too yang-adrenaline-testosterone poisoned to even
see." Obviously, playback raises the hackles on some people's necks.
On the other side of the aisle, Dave Lauten argued that response to
playback is "quite natural" He also suggested that man-made problems, from
habitat loss to oil spills, put much more pressure on birds than does
occasional playback. J. R. Fletcher (the former bird guide in Ecuador) said
he saw no adverse effects among tropical birds from using recorded playback
over many years. J. R. tested his thesis of no lasting effects by
subjecting territorial males of seven temperate-zone species to playback.
He found birds attracted to temporary playback usually took less than a
minute to return to normal behavior. The extreme was a Hutton Vireo which
gave an altered call for 30 minutes. On the other hand, individuals of five
other
species gave no response at all to playback.
So what is the answer? Is playback harmful or not? Dave Lauten, T.
Stephenson, and Alvin Cearley asked if anyone could cite an actual published
study on the subject. J. R. Fletcher said he knew of none, Jim Morgan said
"I'm sure they can be found," and Doug Von Gausig suggested that such
studies might be located where playback had been used to control pests (such
as driving Starlings from airports). Aside from these inconclusive
responses, however, the silence on actual studies was deafening.
Now I had done a literature search, consulted my memory banks, and
assimilated the opinions of some the best and brightest in the recording
world, and to a great extent I still was back at square one. My last hope
to make better sense of the issue lay in reviewing my own experiences as a
researcher, bander, recordist, and watcher of birds.
Initially let me say there are circumstances where I personally believe
recreational/commercial playback should not be used. For example, recorded
playback is banned on the breeding grounds of the endangered Kirtland's
Warbler in Michigan, and I would concur for three reasons. The ban might
preclude the possibility that a birder (they flock to the area for guided
tours) might place the Kirtland's on his or her life list based on hearing
some other birder's Sony. The ban also might shield Fish and Wildlife
Service bureaucrats from possible criticism that they were endangering
Kirtland's Warbler reproduction or viability. Finally, since the Kirtland's
is endangered, if there is any possibility that lots of tourists with tape
recorders could disrupt normal breeding, then we should err on the side of
caution. I also understand that playback of a certain owl species (possibly
the Whiskered Screech) is banned from a heavily touristed area of southern
Arizona. Again, I would concur with what possibly is more of a courtesy to
the birder than to the bird. In general (as my opening vignette might
suggest) we should practice utmost courtesy in using playback where other
birders abound (minimally, yell "fore" before pressing the button).
Courtesy to birders is one thing, but what about possible effects of
playback on the birds themselves? We have established that opinions on this
are divided, and that there likely are few if any published studies on the
matter. The fact that no such studies can be readily found might give us a
clue, however. Scientists, like investors, seek the most return for their
investment, and thus choose research projects that prior knowledge suggests
will give good results. For example, few scientists would search for the
Sasquatch. If DNA testing on a recovered hair sample indicated an unknown
species of ape, however, scientists likely would take up the search.
Perhaps few if any scientists have tested long-term playback effects on
birds because they have little a-priori evidence that such effects exist.
During many years of field research with Wilson's and Orange-crowned
Warblers I have seen no evidence for ill effects from playback. The birds
responding to playback mainly are males (a fact also pointed out in the
ethics thread), and those males tend to respond most strongly before mating
(and thus before nesting begins). Therefore, even if playback did cause
adverse behavior in a male before mating, it likely would minimally affect
the actual nesting process. Also, as Walt Knapp of the ethics thread
pointed
out, even if a bird does respond strongly to playback, we cannot assume that
the response necessarily is detrimental. Speaking anthropomorphically, I
agree with Walt that a strongly responsive male may just be getting practice
and confidence in driving away intruders. I back his view with
observations. My older male warblers tend to hang back, responding to
playback only with song, if at all. It seems they have been through it all
before, and can deal with any rival. New territorial birds, however, often
show strong playback response. Until they have a few encounters and
victories under their belts, they tend to appear frantic (which tends to
make them great subjects for mist netting). So experience in dealing with
intruder song (even playback) may be a good thing for a male bird.
Another observation that has molded my opinion on playback is that rival
male birds tend to have a hierarchy of response toward each other. Initial
response tends to be with song. If song does not settle a dispute (e.g.,
the location of a territorial border), then the conflicting males often stop
singing and confront each other with chip notes and aggressive displays
(conflicting Wilson's Warbler males often circle each other while flipping
their wings). If things get real serious, males can end up in
"claw-to-claw" combat, and I occasionally see two "locked" males flutter to
the ground and continue pecking at each other even while lying in the duff.
The point here is that, while inexperienced males may get their adrenalin up
in responding aggressively to song, established males seem to regard song as
just a first stage of aggression, and something they easily can deal with.
Finally, the thing that most leads me to believe that hearing temporary
playback likely has little lasting effect on birds is that, in addition to
being a recordist, I also am a bird bander. Banding is an essential
operation for many, perhaps most, avian field studies; only through color
banding can one tell individual birds apart. Banding often means capturing
one's subjects in a mist net. I hope I do not offend those acutely attuned
to the feelings of birds by revealing the details of an average netting and
banding operation. Elliot McClure, the Dean of American bird banding,
expressed it bluntly in writing: "From the standpoint of the bird, the net
is an abominable creation. Birds do not like to be netted." * Imagine
being
snagged from mid air by a giant cobweb, having a massive predator descend on
you, capture you, carry you off in a bag, then capture you again and tweak
your every extremity before finally letting you go. If the pecking on one's
hand doesn't suggest the bird is unhappy, then the struggling in the net,
the bag, and in the hand should. This struggling sometimes leads to
exhaustion, and good banders are trained to see its first signs. When a
bird's eyelids begin to flutter, measurements cease and the bird is held
softly in the hand as it "falls asleep." Within about 15 minutes the bird
recovers, looks around, and flies away. Although likely confused, it is
unhurt.
Even though the process of netting and banding is stressful for a bird,
only once have I seen a lasting behavioral effect. A female orange crown I
netted while building her nest subsequently stopped building and abandoned
her mate (never since have I netted a nest-building female). Otherwise, I
have netted and banded hundreds of Orange-crowned and Wilson's Warblers and
not one male has abandoned its territory, and not one female has abandoned
her eggs, following the process. Males resume singing, sometimes within the
hour but certainly by the next day, and females always return to their eggs
within the hour. I also have seen no evidence that breeding success (e.g.,
hatching rate, fledging rate) is harmed in any way.
It is possible that the behavioral responses of some bird species are
different from those of my warblers. However, I know of no official
restrictions on banding any species based on known adverse behavioral
responses (such as likely territorial abandonment). My master banding
permit allows for capture of "all species except waterfowl, eagles or
endangered/threatened species."
The reason I have gone on and on about netting and banding is to
emphasize how temporarily traumatic the experience is for a bird. However,
if birds typically can survive netting and banding with no continuing
effects, then hearing playback may be way down on a list of things that
could cause a bird lasting problems. I believe other field ornithologists
who mist net and band would think similarly. This familiarity with the
process of netting and banding, plus a general knowledge of bird behavior,
may partially explain why scientists have been reluctant to study possible
adverse playback effects. To quote J. R. Fletcher from the ethics thread:
"(I) firmly believe them (birds) to be resilient scrappy beings quite able
to take in stride far greater upset than an occasional spurious voice
followed by a brief search
for an intruder that turns out not to be there."
Even though little if any research has been directed toward the
supposed dark side of playback, could such studies be designed to settle the
playback controversy? There would be many complicating factors, as was
pointed out by Marty Michener in the ethics thread. Also, a direct test
using normal playback conditions probably would not work. What might work
is to test extreme conditions of playback. One might start by issuing
playback continually from dawn until dusk to territorial males of a given
bird
species. Control territories would receive no playback. If effects were
evident (e.g., if playback males abandoned their territories or did not
attract mates), then in the next series of tests one might reduce playback
by 50% (perhaps one hour on and one hour off during the day). Over a series
of tests one might reduce playback frequency until there was no measurable
effect on the birds. One might presume playback frequencies below that
level to be "safe." Of course, to conduct such a lengthy, loud experiment
one
might need a large private wooded estate for a study area, preferably one
patrolled by bloodthirsty Dobermans so playback equipment would not be
vandalized. Your local park probably would not do.
So that's the skinny on use of recorded playback, at least as I
interpret it. Most concerned with this issue seem to support playback for
scientific/management purposes, but not for recreational/commercial uses in
heavily touristed areas (especially where there are rare target species). A
fairly even split of opinion exists, however, for the general use of
recreational/commercial playback, and for whether that playback might
compromise target species' reproduction, survival, and behavior. Efforts to
locate published studies on the topic have come up empty. This apparent
paucity of controlled research might seem surprising until viewed from the
perspective of scientists best situated to carry out the studies. That such
scientists apparently have minimal enthusiasm for the studies might suggest
minimal concern for the "problem."
This discourse likely will not settle the recorded playback debate. I
really have only entered my opinion into the mix, and given my reasons.
Even counting my vote in favor of moderate recreational/commercial playback
use would still leave the tally at seven to five in favor of the "purists."
Only after someone does a definitive study might the debate reasonably end.
In case you want to apply for a grant to study this thing, don't forget to
include funding for the Doberman kibble.
*McClure, Elliott. 1988. Bird Banding. Pacific Grove, CA: The Boxwood Press
(p. 189).
________________________________________________________________________
________________________________________________________________________
|