I have been reading all this discussion with alot of interest and it certainly
has caused alot of emotion to come out.
I have also been trying not to comment as I don't want to add to anyones stress
levels!
However i do find it interesting Ian that you want more scientific data, but
don't want to accept the data already there - instead you would rather trust
your own personal anecdotes/experience?
I think you also attribute too much emotion perhaps to the "pro canon netters".
They have scientific data because they are quite scientific about it rather
than emotional or anecdotal. I think that those in favour of flagging etc would
give it up at the drop of a hat if they found that what they were doing was
causing more harm than good so I'm not sure that attributing an emotional bias
towards them is very accurate.
Personally i can see both sides of the debate and I do think it is a debate
worth having, although i'm really not sure how an independent review into
mortality rates would be any different to the results obtained by the wader
studies groups?
Is any sort of study truly going to be "robust enough" to satisfy the emotions
of those so opposed to leg flagging? Quite honestly i doubt it.
What would be the mechanics of such a study? Would it be to band some and see
if they make it back next year? Isn't that what is being done already?
I am genuinely interested in an answer to this and not just trying to prolong
the debate.
In terms of the birds becoming more skittish; wouldn't it be much easier and
more likely to link this to pressure on lack of habitat and more encroachment
on their feeding grounds by people in general? Surely there is alot more of
that than Canon netting? My own anecdotal evidence would show the ratio of
birds disturbed by people/dogs/raptors at thousands to one compared with
netting/flagging. In the last 10 years I've only witnessed canon netting once
and banding of tern chicks a couple of times but in half a day photographing
waders at Shoalhaven Heads (NSW) i saw the flock put up by raptors or people at
least 10 times.
Cheers
David Stowe
On 27/02/2013, at 7:43 PM, Ian May <> wrote:
> <>Thanks Stephen
>
>
> I also said
>
> "To avoid any possibility that such results could be skewed or biased
> manifests from statistical manipulation and to help put this leg flagging
> debate to rest, at least one if not more, independent scientific studies need
> to be undertaken; " specifically based on project objectives designed to
> test/identify the survival rate, mortality and negative impacts from leg
> flagging/banding/radio tracking/cannon netting on small migratory waders
> (i.e.. birds no larger than Sanderling). " This is what we are asking for
> and if the results were corroborated and verified by a robust field study
> (not just reviewing existing statistics) designed to identify banding
> impacts, that would be a great outcome and we could put the matter to rest
>
> <>My comment "not robust enough" was is in the context of what adequate data
> is required to satisfy the concerns of those who are gravely concerned about
> the impacts of leg flagging migratory waders.
> The statistics are I presume from their existing data base supplied mainly by
> the same pro bird banding group subject to the criticisms. The reply was in
> response to previous discussions and a request to instigate a study into the
> impacts of banding. The results supplied can hardly be accepted as an
> example of unbiased independent review.
>
> Obviously as an individual i do not have access to the same levels of
> information as the pro cannon netters/leg flaggers and I agree, their data
> sets are impressive and would provide a great comparison for verification
> from an independent review into banding impacts. But what I do have however
> is nearly fifty years of field experience watching waders and I have seen
> adverse impacts personally not only in the physical damage caused to some of
> the birds by leg flagging but also from an emerging feeding aversion behavior
> demonstrated in many waders in recent years. This flighty, easily disturbed
> characteristic appears to be developing, probably in response to the
> startling fright and stresses caused by cannon netting and the further stress
> that follows during the subsequent handling.
> Some would argue that more timid behavior could be an advantage to help these
> birds in other places, but what i see are more birds more easily disturbed
> than ever before. When waders are more easily disturbed from their feeding
> and roosting areas when attempting to build their energy reserves and rest
> prior to migration, it could have a hideous effect on success of their
> migration even without the added burden of bands.
>
> Regards
>
>
> Ian
>
> ------------------------------------------------------------------------
>
>
>
>
>
>
> Stephen Ambrose wrote:
>
>> Ian said:
>>
>> " I have studied Clive's response copied below and I thank him for this and
>> fully accept many parts of the reply that are clearly correct, however the
>> stated conclusions about survival rates of small migratory waders after
>> banding are based on statistical data not robust enough to be used
>> adequately for such conclusions, nor collected for the purpose in a project
>> environment designed to test banding impacts."
>>
>>
>> Ian, could you please explain to us why you think the statistical data
>> presented by Clive are not robust. The sample sizes for each treatment
>> (metal bands, metal bands + some flags, metal bands + lots of flags) are
>> very large (5,489 to 11,258), yet calculated annual survival rates
>> associated with each treatment are very similar. Most
>> zoologists/ornithologists/field ecologists/biostatisticians would be envious
>> of such large data sets.
>>
>> How did you reach the conclusion that the data are skewed, biased or
>> statistically manipulated? From reading Clive's response, I don't see any
>> evidence of this. Perhaps I am missing something, so would be delighted to
>> hear your explanation.
>> Kind regards,
>> Stephen
>> Stephen Ambrose
>> Ryde NSW
>>
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