Thanks Ian. I have been misinformed (and unfortunately in turn have
misinformed others).
I was led to believe that the band was acquired with adult plumage and was
then permanent. Clearly this is not correct.
You of course are correct. I have (somewhat too late) now read the relevant
plumage information in HANZAB which confirms that non-breeding adult
plumage, while variable, shows lesser degrees of completeness and brightness
of the band compared with breeding-plumaged birds. And as you say, the
presence of grey legs is the key feature for identifying juveniles.
I must now modify/retract my recent posting re the proportion of juvenile
birds in the flocks of Banded Stilt seen at Rottnest Island and the Western
Treatment Plant. Having not taken particular note of their leg-colour I am
unable to make any informed comment about the proportion of juveniles
present in those flocks and hence my enquiry becomes inappropriate.
Thanks again. I have learned what I really should have known.
Regards. Richard
From: Ian May
Sent: Monday, 10 November 2014 3:33 PM
To: Richard Nowotny
Cc:
Subject: Banded Stilt breeding information
Hello Richard
The most reliable feature to field ID juvenile Banded Stilt is "Grey legs"
(not pink as in adult birds) with no visible breast band. Adult birds lose
their breast band in non breeding condition and attain a full rich chestnut
breast band in breeding plumage. When suitable flood events occur, birds
will quickly molt into breeding plumage over several weeks. Partially
banded birds are mostly in the process of molting their breeding garb;
however the situation is confused because some birds (probably older
individuals) retain their chestnut breast band permanently.
See also
http://bioacoustics.cse.unsw.edu.au/birding-aus/2002-07/msg00022.html
Regards
Ian May
St Helens, Tasmania 7216
0428337956
_____
Richard Nowotny wrote:
I have recently seen large aggregations of Banded Stilt, firstly at Rottnest
Island off Perth (I estimated the total number of birds on the Rottnest salt
lakes to be in the many thousands) and then at the Western Treatment Plant,
Werribee, Victoria (where the numbers are less but still many hundreds to a
thousand). What is of interest apart from the uncommonly large numbers is
the high proportion of juvenile birds present, as evidenced by the number of
birds with no or incomplete chestnut bands. I presume that this reflects a
recent major breeding event on some inland lake (probably in Western
Australia). However, I have not read or heard any report/s of any such
breeding event this year.
Does anyone have any information about Banded Stilt breeding events this
year?
Regards. Richard
Richard NOWOTNY
Port Melbourne, Victoria
M: 0438 224 456
<HR>
<BR> Birding-Aus mailing list
<BR>
<BR> To change settings or unsubscribe visit:
<BR> http://birding-aus.org/mailman/listinfo/birding-aus_birding-aus.org
</HR>
|
