RE Waders, Dowitchers, etc

Subject: RE Waders, Dowitchers, etc
From: "Rory O'Brien" <>
Date: Fri, 23 Jun 1995 22:56:31 +1000 (EET)
Does anything useful come out of cannon netting and does it help in their 
conservation???  In my experience the answer is YES - very definitely.  
Wader banding gives the INFORMATION you quote on the size of populations 
(along with counts of course), it provides info on the structure of the 
populations (% juveniles etc) and the LONG TERM trends in populations.
All of this information is essential for their conservation.  For 
instance, even common waders (E.g. Red-necked Stint) appear to be in 
decline.  Such information has probably influenced ANCA in their 
decisions to now employ people such as Doug Watkins to work with the 
Asian Wetland Bureau (AWB) on wader conservation throughout the flyway.  
This appointment (for at least 1 year from now) will be of great benefit 
to waders who are far more at risk on their migration through Asia than 
they ever could be through waderbanding (figures such as 50,000 (or was 
it 500,000?) Oriental Pratincoles being caught for food on just ONE 
island in the flyway spring to mind).

In case anyone is interested the mortality rate from cannon netting is 
generally around 0.5 - 2 %, from memory.  I also have memories of *VERY* 
nasty incidents (e.g. oystercatchers being cut in half by cannon-nets) 
and these are obviously difficult to deal with and almost impossible to 
justify.  However although they tend to be dramatic and memorable, and to 
be the first thing that comes to mind about cannon netting, there is much 
more to it.  For instance, the number of waders banded each year in 
Victoria alone is well over 2000, usually 5000, and the recovery rate 
(live retraps) is up to 25% in some catches.  This sort of recovery rate 
is EXTREMELY high and provides invaluable data about population trends, 
etc - more to the point, for each bird banded there is a high probability 
that it will provide useful information.  This contrasts with some 
species of bush birds, which usually disappear without trace after 

Just one other point for the record (although I wasn't there) the 
Long-billed Dowitcher was not recognised as such until it was netted by 
the VWSG, and it was identified in the field and photos taken.  
Subsequently these photos were brought into the RAOU and discussed by 
resident and non-resident experts (e.g. Bob Swindley, Kevin Bartram, 
David Eades etc etc)) who after some debate agreed it is most likely to 
be a long billed.  Bill length was in the ranges of both spp, the wing 
and tarsus very close to the upper limit for short billed.  The tail had 
very narrow bands of white in the centre but 50/50 on the outer tail 
feathers, and the grey on the breast had no visible spotting but did 
break up a little in the lower parts.  The bird was in winter plumage and 
had no moult on the wing.  The consensus was ~90% probability that it is 
a long billed.


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