Now that I am back in Australia I am
catching up with some of the discussions on the chat line.
RW: Steve Holliday?s recent comment on the scarcity of RWs made me check
out some suburban areas where there were normally good numbers of this species.
Indeed, on a walk last Sunday, Haig
Park in Braddon,
Corroborree
Park and many streets of Ainslie
hardly yielded any RWs.
In 2007 RWs also left our area in autumn, but, according to many reports,
there were large-scale mass movements of RWs to and up the coast over many
weeks. In 2009 the situation appears to be different. I have not seen any
reports of mass migration of RWs from the coast (at least not on the chat line).
Taking Mark Clayton?s comments that the exodus from Canberra may have started
during the hot February, it may well be that the movement was more of a steady
trickle and geographically more restricted, hence no noted mass movement on the
coast, RWs just vanishing almost unnoticed (if my assumption are correct) from
our area.
The only recent sign of RW migration, apart from Matthew Frawley?s obs.,
was a flock of about 100 birds that I saw on 27 April flying over Gundaroo to
the NE.
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DWS: Just a few small additional comments. Reporting all the obs. on the
chat line to get an idea what is happening this season is certainly good.
However, it will generate a picture only for this season, and the conclusions
cannot necessarily be generalized. In order to fully appreciate the current
situation we also have to go back and compare with the past. Martin
Buttterfield?s excellent analysis and summary of GBS obs. for this species
clearly demonstrates notable differences over time.
Taking the long-term view, it is most important (in my view even more
important) that all these observations are also entered in the COG data base
(just stressing the point Martin made yesterday). Unless the obs. are added to
the COG data base they are basically lost to the system!
The current frequent encounters with DWS may reflect a healthier status
of DWS numbers, as Jack Holland has been suggesting, or not. Assuming these are
not local birds (and the local population last summer was certainly down on
other years) then it all depends on the size of the ?catchment? area from which
these birds originate, whether we can conclude that the species is doing
reasonably well.
It is always amazing how little we still understand what even our common
species do. At the same time this gives everyone, even with the observations in
their own backyard, the opportunity to contribute to a better understanding of
our birds. With the extreme weather patterns of recent years we probably see
bird responses we have not experienced before, or only rarely so. All very
fascinating!
Michael Lenz
