Was it a year ago I reported on the seminar we were all
invited to at NLA, at which one presentation was on spread of Galahs, including
their relatively recent arrival in Canberra. This should now be a chapter
in the much-touted ‘Boom and Bust’ book, although I do not yet have a copy
myself.
It would follow that galah-damage has increased overall, and my
impression is that it has again increased recently. My theory is that it
is done by mated birds territorially as part of pair-bonding and not by the
huge flocks of visiting ground-feeders, which I believe are young birds (see
discussion of eye colours from last winter).
Incidentally my local pair offer a good example of the sex
differences in the eye in adult birds, F on left:
From: Peter Ormay [
Sent: Friday, 10 July 2009 9:24 PM
To: Denis Wilson;
Subject: Re: [canberrabirds] Galahs
Hi
Denis, Julian, Geoffrey et al,
I
remember seeing a Galah in the fork of a Red Spotted gum and chewing the
bark in the park one door away from my place when I was building my house
around 1970. The exposed wood was fresh and there was no hole there. I wondered
if a hole might develop there and looked at it from time to time over
the next few years. The Galah(s) kept on chewing the
regenerating edge of the bark within reach of the fork. Today there is a
hole in that fork and I have seen a Galah go in. I have no idea if
it was the same Galah and doubt whether it/they did it with the aim
of creating a hollow. More likely they do it out of boredom while
resting or to sharpen/wear their beak and in some cases a hole will develop
there after a few decades if the bark is prevented from growing over the
scar.
I
suspect that Galah numbers have increased in the ACT area since settlement if
there were any here to start with and they do a lot more damage to trees than
they used to. Have they? Does anyone know? I remember seeing the first
Galahs in Tidbinbilla Nature Reserve after I worked there for about 5
years ca 1981 and think they had just arrived there. i e there were none
in the Tidbinbilla area before.
-----
Original Message -----
Sent: Friday, July 10,
2009 3:29 PM
Subject: Re: [canberrabirds]
Galahs
Hi
Geoffrey, Julian and others.
I
have heard or read that Galah chewing of bark actually helps fungi and insects
to invade the wood of Eucalypts, thus leading, in the long term, to the
creation of new hollows.
I
cannot provide scientific evidence of this, but it does appear to make sense to
me.
I
cannot credit the Galahs (and other Cockatoos) with the foresight to plan for
that outcome, but on an instinctive level, such behaviour could well advantage
those species (and fellow hollow-dwelling creatures).
