Hello all
In light of the current discussion about wader leg flagging, I have decided to post the following so that others can consider for themselves, if leg
flagging is killing our waders.
On 2nd July 2011, a visit to a local mudflat in northern St Vincent's Gulf,
South Australia, produced 600+ wintering migratory waders. There were at
least 53 Curlew Sandpipers, 23 Bar-tailed Godwit, 8 Red Knots, 3 Greenshank, 1
Mongolian Sandplover, and 500+ Red-necked Stint scattered across about
20 Ha of prime habitat. There were also 40+ Double-banded Plover and 15+
Red-capped Plover.
Not one of these birds was plagued with a leg flag. Is this good or is it bad? Of concern to me was that despite the large numbers of leg flagged
waders in the area just prior to their migration (March/April), what happened to the many flagged birds that were here only three months ago?
People who speak against leg flagging of waders on this forum are frequently advised,
“Unless there is something new, stop now”.
So here is something new.
Not much flagging if any is done in the area of St Vincent’s Gulf, SA. Often about 3% of the thousands of waders that congregate here are seen with
shiny new looking flags just prior to migration (Feb, March). However when birds first return (August and early September), rarely does one see a
flagged bird among them. This indicates that most of the flagged birds previously seen have disappeared, probably died during their post flagging
migration. Occasionally I see a bird with an older faded flag but this is rare.
Considering the observations have been repeated over many years and that "Leg Flaggers" are targeting some of our most vulnerable species, some of
which are possibly declining because of leg flagging impacts, about two years ago I discussed my concerns with one of the flagging organisers.
The conversation was civil and part of it went like this!
I said “there appears to be little or no research into discovering the likely negative
impacts of leg flagging on small waders (Great Knot and smaller).”.
He said “Some effort would be made to analyse previous retrap data in future.
I suggested “Perhaps some of the future trappings of say, Red-necked Stints should not be flagged but instead be fitted with 1 only traditional
small metal band so that survival comparisons can be made with multiple leg flagged birds”
He said “No No, this would not be necessary as current data would show any
variation”
I said “Before leg flagging was introduced, when there was little wader banding activity compared to today, it was not uncommon to see returning
migrating waders in southern Australia wearing a single worn metal band indicating their survival post migration. But now, despite the hundreds of
pre migrating freshly flagged birds that we see at Price each year, rarely does one see any returning with flags in the following season. (This
indicates to me that some numbers of waders do survive after one leg metal banding but few return after leg flagging).
I said. Why not consider fitting to say half of your trapped birds, just one metal band and no leg flag, so that impact comparisons of both
techniques can be made by any field observer. It would soon become obvious if we observe a higher proportion of metal banded birds returning from
migration, that the flagged birds are dying because of leg flags”
He said “This would mess up our statistics and is not necessary. We can get the
same results by analysing existing data”
I said "If there is no problem, what happens to all the leg flagged individuals that I see here at Price just prior to migration? The flagged birds
just do not come back!
He said “These birds are notoriously site unfaithful, mostly returning to the Gulf of
Carpentaria where very few observers see them”.
(But if anyone cares to read the literature, the Global Flyway network states when discussing retrap results, "thankfully, flagged birds are
notoriously site faithful")
Summary
Field observation of wintering waders indicates that leg most of the pre
migration flagged birds are either dying/disappearing/not coming back.
The only reasonable solution is to call for a moratorium on leg flagging in Australia for at least a period of three years. Such a moratorium would
provide circumstances for independent parties to observe and evaluate leg-flagging impacts through normal field observation techniques. In seasons
following a moratorium, Australian flagged waders relocated would clearly indicate the birds that are surviving migration and this result would
finally, prove that leg flagging is of no harm or, is killing our birds.
The results would either confirm or put to rest, the concerns of many who believe based on years of field experience, that leg flagging small waders
is a destructive practice.
Regards
Ian May
PO Box 110
St Helens, Tasmania
0428337956
(To see a flagged bird, see Page 1 of
http://www.globalflywaynetwork.com.au/reports/GFN-Report-NW-Australia-2009.pdf )
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