Hi Julian,
I've just had a look Ian Rowley's excellent book on Galahs [Rowley, I.
(1990). Behavioural Ecology of the Galah Eolophus roseicapillus in the
Wheatbelt of Western Australia (Surrey Beatty & Sons Pty Ltd, Chipping
Norton)] to see if the behaviours you observed could be explained.
He describes three social behaviours which may match what you observed:
1. Scarring (bark-stripping) - the stripping away of bark to expose the
tree's cambrium, or removing both the bark and cambrium to expose the xylem.
Scarring occurs on the main trunk of the tree below or around the nest
entrance, usually extending up to 10 cm from the tree hollow. Scarring
occurs at the start of the breeding cycle and usually continues until
incubation begins.
2. Bill-stropping - rubbing alternate sides of the bill on bare area of the
scar or nearby areas of the tree, sometimes done vigorously.
3. Eye-wiping (particularly by males) - wiping sides of face on bare scar
only.
Ian Rowley suggests that these three behaviours are forms of territorial
advertisement because the incidence of scarring is much higher at greater
nesting densities. He also suggests that Bill-stropping may be a form of
bill maintenance, and perhaps as a form of communication with its partner.
Of course, Philip could also be right that the Galah that was rubbing its
face against the branch could just be scratching itself (in attempt to get
rid of feather mites?). But with the other bird actively working at or
around the hollow makes me think it could be one or more of the behaviours
described by Ian Rowley.
Stephen Ambrose
Ryde NSW
-----Original Message-----
From: Birding-Aus On Behalf Of
Philip Veerman
Sent: Wednesday, 31 December 2014 1:35 PM
To: 'Julian B'
Cc:
Subject: Unusual Galah behaviour
Doesn't seem to me that either behaviour is unusual. One was preparing a
possible nest site, the other wiping its beak or scratching its face.
Philip
-----Original Message-----
From: Birding-Aus On Behalf Of
Julian B
Sent: Wednesday, 31 December 2014 9:08 AM
To:
Subject: Unusual Galah behaviour
Greetings All
Yesterday Fay and I were surveying the edge of open woodland adjoining
Tarong Power Station property [South Burnett region, Queensland]. Noted a
pair of Galahs in the fork of a nearby gum. One bird appeared to be
excavating, or at least clearing out, a small hollow about a metre up along
the left-hand branch of the fork while the other Galah, at the fork junction
itself, appeared to be rubbing its cheeks against the right-hand branch. It
repeated this several times.
Never having previously observed this behaviour in Galahs was wondering if
anyone could offer an explanation.
Cheers
Julian
www.birdingsouthburnett.com
@osprey00
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