Another bivalve victim (moderated)

To: Ian May <>
Subject: Another bivalve victim (moderated)
From: David Stowe <>
Date: Wed, 27 Feb 2013 22:48:21 +1100
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 

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.

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 
>> ===============================
>> To unsubscribe from this mailing list,
>> send the message:
>> unsubscribe
>> (in the body of the message, with no Subject line)
>> to: 
>> ===============================
> ===============================
> To unsubscribe from this mailing list,
> send the message:
> unsubscribe
> (in the body of the message, with no Subject line)
> to: 
> ===============================


To unsubscribe from this mailing list,
send the message:
(in the body of the message, with no Subject line)

<Prev in Thread] Current Thread [Next in Thread>

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the birding-aus mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU