On 1/14/07, David Stowe <> wrote:
Also no-one has scientifically explained why call playback is a no no.
( I ask this not as an argument but to learn!)
I had a look and found the subject is much discussed and little
researched. Also, research would ideally be based on a specific bird
or group of birds. For a PDF of a thread relating to playback and
neotropical birds, see:
http://www.science.uwaterloo.ca/~smithsm/playback.pdf
In that thread, Alvaro Jaramillo (author of "Birds of Chile" and
oth"New World Blackbirds") comments that there is very little real
research on the subject. Sounds like an excellent research subject for
an ornithology student.
I do remember that in the US, some threatened/endangered birds have
been so harassed by tape playback that conservation area management
plans have had to address the issue. I remember a case of a rare owl
species that was constantly being pulled out with territorial
challenge recordings. The birds were getting so exhausted 'defending'
their territories, reproductive rates crashed. Tape playback was
banned. Unfortunately, I can't find the details on this. However,
there's a similar story regarding the Rose-throated Becard. Here's a
link to the management plan:
http://www.gf.state.az.us/w_c/edits/documents/Pachagla.d.pdf
With that in mind, I'd say that if a conservation department has any
suspicion that birders are harming birds through playback, habitat
destruction, pishing, etc., the department should err on the side of
caution.
[Digression: The legal situation with bird conservation in the US is
fairly complex and different than in Australia. Ultimately, agencies
have a legal obligation to protect animals deemed threatened or
endangered. Of course, they often don't. This leads to lawsuits, the
primary instrument of direct democratic action in the US. The various
state and federal fish, wildlife, forest, and environmental management
authorities can be sued to do their jobs. In Hawaii, for example,
lawsuits seems to be pretty much the only way to get any action out of
the federal or state governments. The species/subspecies question is
quite significant in this context, too. For example, the Elepaio, a
Hawaiian endemic that looks and acts like a Fantail, was previously
one species. Now, it's three species divided by island. By splitting
the species, the individual island-specific species should receive
greater protective rights than when they were mere subspecies.]
Some research has been done on stress hormone levels in birds from
various stressors, including playback:
http://www.princeton.edu/~hau/VirginieCanoine.htm
For people that haven't birded in very crowded settings, such a
Florida or on a twitch in the US or Europe, it can be hard to imagine
the impact birders can have. I don't leave the house without
binoculars and deliberately bird as often as possible. How often do I
run into a birder in Australia? Never, or close to it...and then only
at some of the very best-know locations in the country. In the US or
Europe well-know spots are often crowded.
If any of the scientists on the list know of more research, I'd love
to hear more about it!
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David Adams
Wallaga Lake 2546 NSW
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