Great work, Martin. I hope others will follow that link.
I shall not imitate the cracked record and repeat my position on
the use of ‘migrant’. However I revoice my protest
against the use of the suggested opposite, ‘stayer’, for a bird
seen in Canberra in Winter that for all anyone knows might have been in
Tasmania the week before.
The summer/winter maps in the BA 98/02 atlas are worth a look:
The winter map shows some records for Canberra, the most
pronounced movement being north from Tasmania and the area (se NSW, e Gippsland)
to the south of Canberra. This I think lends support to the view that many
birds seen in Canberra in the ‘moving’ months (April being typical)
are passing through. Note that the species does not in general favour
coastal areas.
On the value of the Garden BS data, non-Canberrans might need to
be told that these 3ha sites are not limited to gardens but in some cases take
in parts of woodland reserves. I would not regard the DWS as a ‘garden
bird’ and I would not expect it below tree-top height unless the site
included some woodland-type habitat.
However, a characteristic of this species is that it is quite
frequently observed flying in numbers at extreme heights. At that height,
they can turn up anywhere, but an observer who does not constantly scan the
skies for such flocks is likely to miss quite a few of them. Your
reference to numbers in Curtin makes me think that the eagle-eyed Richard Allen
is bringing to account over-flyers that he, but perhaps not the average
bird-bath-watcher, has been able to pick up. Even under the (I think now abandoned)
protocol that non-site-using overflyers were not to be recorded does not rule
out high flocks because it is almost impossible to say that they are not
feeding on high-flying insects.
From: martin butterfield
[
Sent: Thursday, 23 April 2009 5:43 PM
To: COG List
Subject: [canberrabirds] Are Dusky Woodswallows migrants
Following the recent discussion on this topic I have
ferretted in the GBS database to see whether value can be added to the
debate. As the result:
- is too long for Gang-gang;
- but doesn't cover all the bases that need a lid
for CBN; and
- some folk may not like an attachment
I have put the outcome at
http://franmart.blogspot.com/2009/04/are-dusky-woodswallows-migrants.html.
Martin
