Hi Tony,
Your points and Richard's observations seem reasonable. The concern
expressed on the NEOORN discussion was a fairly extreme case looking at
multiple playback sessions every single day. A useful measure of stress in
birds is adrenocorticosteroids in blood and body condition, as I mentioned
in my previous email. One of the papers I linked found that indeed once
birds had habituated to people they suffered less from stress, and in fact
it was birds with moderate to low visitation that suffered the most, because
they still had semi-regular disturbance, but never developed a coping
mechanism. Their recommendation was to have a "sacrificial" area for
tourists and keep the rest of the area free from all visitors. Of course
this was just effects of visitors, doesn't help with the playback
discussion, particularly if birds become desensitised to playback.
Essentially how I read all this is: 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.
I don't use playback either, and I do pish occasionally (with little success
mostly). I don't mind so much if others do use it ethically, as long as
they respect my request not to do it while they bird with me. I much prefer
the challenge of seeking birds out myself rather than abusing a pavlovian
response in their psyche. But then I'm not really a twitcher so don't mind
missing the occasional species on a trip.
And to answer Alistair's question, I'm at roughly 630 birds on my Australian
list (including Lewin's Rail several times) without having used tapes for
any of them. There was one species (Marbled Frogmouth) that I had seen and
wasn't on my list because it was through playback, but I subsequently
tracked one down without it. I'm resigned to maybe never seeing Rufous
Scrub-bird, but I will keep trying.
Regards,
Chris
On Tue, Sep 16, 2008 at 12:25 PM, Tony Russell <>wrote:
> At last a bit of balance ! Thank you Rich for your contribution. I must
> say I have to agree with your comments, essentially on the following
> counts:
> 1) The amount of energy a bird might expend in chasing a playback call
> for a few minutes has to be insignificant in relation to it's whole
> day's output in following it's normal activities, so I don't go along
> with the notion that playback tires a bird.
>
> 2) The observation that some bird species appear to tolerate
> "interference" less than others is interesting, but is more annoying to
> the observer than it is "stressful" for the bird. Is there any useful
> accurate measure of stress in birds ? I think it's the hopeful observer
> who gets stressed out.
>
> 3) The other observation that some bird species seem to habituate to the
> playback (and thus fail to respond to it) is no different to them
> habituating to any other sound or visible intrusion that comes their
> way, ie, vehicular sound and motion. Surely this habituation must save
> energy rather than expend it. It's often only when a vehicle stops
> rather than passing by as usual that birds take fright and fly for
> cover. Again, annoying for the hopeful observer, but hardly any more
> stressful for the birds than if some normal predator approaches.
>
> Tony.
>
> BTW, I don't ever use playback to attract birds, but I do sometimes
> mimic their calls if I can.
>
> -----Original Message-----
> From:
> On Behalf Of Richard Hoyer
> Sent: Tuesday, September 16, 2008 10:10 AM
> To:
> Subject: Re: [Birding-Aus] Effects of call playback on birds
>
>
> Hi All,
>
> I've already chipped in here, so I probably shouldn't say too much
> more. And thanks to Andrew Taylor for finding the summary from Neoorn,
> it's a good review. But it seems that the best argument, and the one
> that would seem to have the most scientific consideration, would be
> the "excessive spent energy" one.
>
> But how much energy exactly, quantified, is a bird expending when it
> reacts to tape, pishing, or mobbing? And how much does that compare to
> the energy the bird has available to expend on such behaviors?
>
> Those are very hard questions to answer well, but that's where the
> answer lies. But if you watch birds do perfectly normal, every day
> things without playing tape, pishing and mimicking owls, and then
> watch their responses to those stimuli, you can get an idea.
>
> I watch a bird pursue a small insect in an amazing burst of energy,
> chasing it for a full 30 seconds in nonstop flight. I see a
> territorial bird go after an intruder for 5 minutes without pause. I
> watch a group of birds mob a cat, snake or owl for 10 minutes without
> pause. And it would surprise me if any amount of tape playing,
> pishing, etc. I have ever done (and I've done quite a bit) measures up
> to the normal, daily energy expenditures that I witness. I think if a
> bird is short on energy, they will spend it looking for food rather
> than responding. In fact, I frequently watch birds responding to
> pishing and owl imitations forage along the way, while chipping and
> coming in for close views.
>
> I might mention that 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 (few recordings really have no background
> noise). And the response you get is uninteresting and sometimes even
> makes the bird harder to see than if you had just waited a bit. A bird
> responding territorially has to be concerned about physical contact
> with the supposed intruder as well as aware of the presence of
> predators. So the response is usually of a very wary bird, moving
> fast, reacting to your smallest movements by fleeing, and going into
> what a friend has called "satellite mode" - encircling you with
> frustrating speed. On the other hand, there are some species that are
> best (and sometimes only) seen with smart use of playback.
>
> I suspect the actual effect varies from species to species, and I hope
> that a controlled study would include birds from several different
> groups. Some birds will abandon the nest with any sort of disturbance
> (I've been told that Swainson's Hawk is this way). With others, you
> can barge in for 10 minutes, take the eggs out of the nest, replace a
> parasite-ridden nest with one saved from last year, replace the eggs,
> and see no problem at all.
>
> Good Birding,
>
> Rich
> ---
> Rich Hoyer
> Tucson, Arizona
>
> Senior Leader for WINGS
> http://wingsbirds.com
> ---
>
> On Sep 15, 2008, at 4:51 PM, Douglas Carver wrote:
>
> > 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 them sparingly (one had a rule of
> > thumb that
> > if the bird did not appear after the second playing of the call or
> > song, he
> > would not try a third time). While neither had hard empirical data
> > (or at
> > least, no data they shared with the class), they both said that a bird
> > responding to a call is expending energy needlessly, which puts
> > unnecessary
> > stress on the bird. The bird's well-being is more important than our
> > twitch.
> >
> > Cheers,
> >
> > Douglas Carver
> > Albuquerque, NM
> > USA
>
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