|
Hi David,
Thanks for the enquiry and having
made the suggestion and that is a really good and sadly vexed
question. I would really like to be able to give a positive answer to this. I
hope you don't mind that I post the message also to m("canberrabirds.org.au","canberrabirds");"> to show
the interest out there (and my thoughts on this are hardly unknown). As with
having included most things of relevance, in my 21 Year GBS report (in the
section called "the future", at the middle of page 17), I described the fire
event and mention the value of the study and this report as a baseline on which
to look at possible impacts of the fire (as you suggest). So yes this should be
done.
As bad as the fires were, the impact (on birds) was
no doubt far greater in the ranges to the west of Canberra than the Canberra
suburbs as a whole. However the data we have for those parts is not assembled in
the same way that allows assessment of bird abundance relative to variable
observer effort. So the impacts are really hard to establish. Work is being done
on Superb Lyrebirds at Tidbinbilla (Fullagar / Davey), that no doubt you have
seen. Not that suburbs on the western side of Canberra weren't devastated but
many other suburbs were not. The GBS collects and pools data from the whole city
(plus Queanbeyan), so when the data are pooled, it is hard to see the specific
impacts. No doubt there are local impacts. But when birds move from one area to
another, statistics if they balance out, can obscure the changes. It will take a
more sophisticated system than we have established to look at this. COG
publishes Annual Bird Reports each year and anyone is welcome to peruse these. I
would wish anyone luck in doing so. Apart from just fire, there is the far
bigger effects of drought over the last few years. This comes on top of the
increase in abundance of many of our small resident native birds over the
duration of the GBS, largely due to maturation of the suburban vegetation. The
contrast of Canberra suburbs to surrounding rural areas is a real challenge
also.
The most obvious and really immediate impact on
birds was the huge numbers of Yellow-tailed Black-Cockatoos that
infiltrated the city and over time, in big flocks of up to hundreds. Many other
changes have occurred but it is so hard to tease out what cause and effect
connections there may be.
You are right to suggest that the Canberra
garden bird surveys may provide some answers. One of the sites that
had contributed very well to each of the first 21 years of the GBS year was
burnt out. The owner has written up what would ordinarily be considered a good
and reasonably interesting report about this. Although it is absolutely
fundamental that all scientific papers should refer to prior relevant studies, I
believe that this paper suffers greatly diminished credibility by not
comparing data or even mentioning the existence of a compiled publication on the
GBS data, to which this site had contributed for all 21 years. Also it only
addresses this one person's observations at his own site and does not attempt to
use or even acknowledge the broader depth of information available from the
GBS Reports. But even with this flaw, if someone is exploring the event, I
suggest this paper as borderline worthy of citation. See Holland, J (2005),
'Post-fire activity in the north-west part of Chapman during 2004-05, with
particular reference to breeding', CBN:30(3): 97-116.
Now as to why it is vexed. Sadly, interactions of
committees and people who show personal initiative and value their work and who
actually do things, can lead to problems. After my many voluntary years of work
in conceiving and building the GBS database (with help from others of course)
and compiling and analysing and publishing the results of the survey, for COG's
direct and immense benefit and after I gave COG the completed GBS
database and after my years of desperate pleading for COG to publish my report
on COG's survey (which they had earlier agreed to do), and seeing how successful
this publication had become after they didn't publish it and I did (at my own
initiative, risk and expense), things deteriorated and COG Committee decided to
prevent any further availability of the GBS to me. So sadly, I don't have any
knowledge of GBS results since then, beyond the very limited data in the ABR. It
cries out for a proper analysis that considers the full background of the survey
but I think this is unlikely ever to happen. Certainly even after all this time,
there is no visible or audible sign that it is about to happen. I estimate it
would only have taken several weeks for me to do it.
The GBS is now onto its third coordinator since
then and although it is continuing, its potentially useful output at this
time, when so much of interest could come from it, my assessment of it is that
it has reverted to the ultra limited, confused and simplistic
interpretations of single species by single years of the COG ABR, diminished in
quality even by comparisons with the ABR of many years ago, long before the
database existed and all the data were compiled (that showed abundance
histograms by month and information on seasonal patterns).
Sorry about that.
Philip
|
