Oh dear, I should have known better than to load this just-a-chatline with a
serious comment. As I have suggested before, I think the most coherent
approach is to regard our only true migrants as those that seasonally are
completely absent from SE Aust (or at least from the Canberra area broadly
defined). The trouble is that there is no convenient word for other species
that are not in that category but show some pattern of seasonal movement,
like BFCS, DWS and YFHE. Thus 'migrant' tends to be pressed into service
for any seasonal mover. This leads to inappropriate reports of 'firsts'.
'Partial migrant' does not fit a species whose local population is replaced
by others.
As to the D Firetail, I'll just refer to the HANZAB summary, which reports
considerable seasonal movement, at least in places where it has been studied
systematically. A bird banded at Warranderry, n. of Grenfell, was recovered
at Michelago. As to the Canberra birds, nobody knows where they are when
they are absent from or very scarce in their usual local haunts. If we
could ever get info from the database, we might learn whether the pattern is
annual or - perhaps more likely - cyclical according to conditions, as with
the dry-country woodswallows.
-----Original Message-----
From: Philip Veerman
Sent: Monday, 20 April 2009 11:58 PM
To: 'Julian Robinson'; 'Geoffrey Dabb';
Subject: DW-s Migration & Diamond Firetails
I am confident that the Dusky Woodswallow is a migrant, even if only a
partial migrant (that is not all depart). However rumours about the
Diamond Firetails being migratory surprise me. I would suggest they are
not. I think all the evidence suggests they are not. I don't know that
any of our finches are migrants. However they are dispersers and
clumpers, depending on changing food and water supply and the changing
social calendar through the year. I wrote I think last year of seeing a
large flock of them at Castle Hill. About 30 minutes later, I couldn't
find any. That is enough to show that impressions easily made can easily
be wrong.
And thanks also to Geoff for his comments on mine about the DWS.
Philip Veerman
24 Castley Circuit
Kambah ACT 2902
02 - 62314041
-----Original Message-----
From: Julian Robinson
Sent: Monday, 20 April 2009 1:49 PM
To: Geoffrey Dabb;
Subject: DW-s Migration Narrabundah
Yes I feel a bit bad after reporting those numbers of Diamond
Firetails on two separate days at two adjacent locations in
CallumBrae. Since that day I've never seen one of the buggers there,
it was definitely an erroneous impression! So yes, are they just
nomadic, or also migratory?
About Duskies - and with apologies to those who disagree with this
hotly debated possibility - I think that the single best way of
leading towards a quick initial understanding of what goes on with
them at the Canberra end is for people to post about all the DWSs
they see on this chatline for one season; say another 6 or 7
months. Then if/when they disappear it can be determined
retrospectively by looking for the last post for the season. Or
some reasonable conclusions might be drawn about numbers and even
spatial distribution of those that hang around as well as those that
move out.
Personally I wouldn't mind if 150 messages appeared on this topic, it
would all be interesting in the end and add a lot to our current
formal databases. And these posts can easily be ignored or deleted
by scanning the headings. I honestly don't know why people have
problems with this, unless they are receiving all their chatline
posts unsorted and into their inbox, which would be very irritating
but is easily fixed.
Of the other two possibilities, relying on filed surveys will never
work in practice because most people don't put in records for
everything they see. As has been discussed before, it's not a
successful way of determining last sightings of a season. And
arranging to send all DWS sightings for the next 8 months to one
nominated member will not work as well, simply because most people
will forget about it. It's the visibility and positive reinforcement
of the chatline that makes it ideal for this purpose (chatting about
DSWs and getting consistent reports).
Other than establishing such a mini-reporting-project here on the
chatline, I can't think of any other way of capturing so much useful
info on this kind of topic.
Julian
At 10:40 AM 20/04/2009, Geoffrey Dabb wrote:
>The wanderings of the possibly migratory Diamond Firetail (not to
>mention the DWS) are one of those things we must get to the bottom of
>one day, if ever we can get all the accumulated local data.
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