Brian
- I should get in that bark-chewing is still food-related, Galahs and
other cockatoos attacking the sought-after cambium, and ring-barking is not
uncommon. (Joe Forshaw has told me this several times and, if he is
listening, would think little of my memory if I failed to mention it.)
However I still think that in its very obvious seasonal manifestation it
is related to pair behaviour, because it is usually engaged in by paired birds,
takes place most often near the present or proposed nest-hollow, and is often
accompanied by wing-flexing and head-bobbing. I think the goanna theory is
unlikely - you would need a gun-metal finish to deter a goanna and
many smooth-barked trees like E mannifera would be more climbable after a bit of
chewing than before.
Incidentally,
I am told that for the current urban tree-planting program smooth-barked trees
are being preferred for fire-hazard-reduction reasons, even the medium-barked
Yellow Box being rejected for that reason.
From: Brian
Fair [
Sent: Sunday, 12 July 2009 8:12
PM
To: canberrabirds
Subject: [canberrabirds] Galahs Chewing
Bark
I am just writing to
add some thoughts and observations about Galahs chewing bark. Galahs have been
known to ringbark trees with their chewing. They have been known to
chew away the bark of trees that they intend on nesting in and one
theory is that they do this to stop goannas from steeling the eggs from the
nest. They will chew away the bark below where the nest or proposed nest
is located. The removal of the bark would make the trunk smoother thereby making
it harder for goannas to reach the nests.
This is a theory that
my father was told after Galahs had ringbarked a few trees on his property which
is located just outside Tamworth. Any thoughts are welcome and I would be
interested to hear more about the trees that Galahs have been see chewing
in.
