With great interest I have read recent
various comments and suggestions seeking to explain the low number of birds of
certain species ( or absence of others) during my Mt. Ainslie blitz
tour.
The suggestions included: changes in bird
behaviour in the course of a breeding cycle, i.e. affecting detectability
(Esme); to movement from less favourable to more favourable patches within an
area (Geoffrey); and local differences (Jack). All comments are valid.
However, the changes (reduction in number of birds
and species) I noted did not occur over night, or just on the day of the blitz.
Some areas which were part of my tour I also visited earlier on several
occasions, and the picture was very much the same as on the blitz day. But it
was a surprise to see that the changes were more wide-spread than I had
anticipated. The decline has been going on for several years (I could also have
added that I saw neither cuckoos nor Dollarbird on the blitz day).
I also know several other areas (not at Mt
Ainslie) that I visited in recent times show Rufous Whistler, Grey Fantail and
Leaden Flycatcher are not as numerous in 2008 as they were previously. Perhaps
we can agree that some areas no longer support certain species (or no longer in
the numbers of previous years) most likely due to drought-related habitat
degradation?
That is, my comments were mainly aimed at raising
awareness of drought impact. We have all too often seen the drought as bringing
us the excitement of inland species which are usually absent from our area, but
I think we do not give enough focus of what the drought does to our local
breeding birds.
To top it all off, yesterday I visited
the Lake
Bathurst area
only to find what little water that has been there is close to disappearing
again. Since April 2000 the lake has either been dry or had just very small
areas under water for limited periods. This is despite that the area has
received similar rainfall to what we have experienced in
Canberra in recent
times, but the only difference this has made is to have slightly delayed the
drying up.
So, this is my suggestion: we should enjoy the
good patches of bird life while they last even more so than in the past, but we
should also not forget to keep a watchful eye, and good records, on areas which
show signs of negative climate impact on bird populations.
Michael
Lenz
