Thanks Graeme, that is absolutely fascinating!
But maybe I've misread something - how would the Galah looking into its own
reflection actually have its reflection being a Major Mitchell's??
Please explain... thanks,
> Date: Thu, 3 Sep 2015 10:23:30 +1000
> Subject: [Birding-Aus] X Breeding in the wild.
> Cross breeding in closely related parrots in the wild is well known, but the
> reasons why and the associated life history mechanisms are not.
> Many years ago when, with Ian Rowley, I was lucky enough to study Major
> Mitchell's Cockatoos for some years in Western Australia, we were able to
> document, using marked individuals, just what happens.
> This was published in the journal "Behaviour", the paper entitled
> "CROSS-FOSTERING, IMPRINTING AND LEARNING IN TWO SYMPATRIC SPECIES OF
> COCKATOO" in Vol 96, Issue 1, pp 1-16.
> For those unable or less inclined to access this reference, the abstract
> Two species of cockatoo, the galah Cacatua roseicapilla and Major Mitchell"s
> Cockatoo C. leadbeateri are sympatric throughout much of Australia. Both
> species nest in tree-hollows of similar dimensions at the same time of year.
> Their eggs which are very similar are laid every other day and are not
> incubated until at least three have been produced. Parent birds often forage
> a long way from the nest and so the early eggs are largely unattended.
> Sometimes a pair of C. roseicapilla and one of C. leadbeateri both "own" the
> same hollow and contribute eggs to the clutch. When confrontation finally
> arises the C. roseicapilla being smaller, lose out and the C. leadbeateri
> unknowingly incubate a mixed parentage clutch, and may rear a young C.
> roseicapilla with their own offspring. Such cross-fostered C. roseicapilla
> behave as, and associate with C. leadbeateri; they ignore other
> C.roseicapilla. Parts of their behaviour repertoire are inate, parts are the
> result of imprinting and parts, of later learning. They learn to fly and call
> like C. leadbeateri and they also adopt the latter's much more varied diet.
> Cross-fostered C. roseicapilla are probably responsible for those cases of
> hybridisation in the wild between and C. leadbeateri that have been reported.
> So essentially, the initial reason for all this is a shortage of nest
> hollows. Parrots, on the whole have traditional nest sites, that is they use
> the same one year after year, so if an interloper comes along and pops an egg
> in early in the peace, that's where the story really starts.
> My memories of watching one of our main young imprinted galahs, tagged NO,
> are still vivid after 40 years; seeing her leading the flock of 50 or so
> Majors, flying like a Major, calling like a Major - always at the head of the
> flock because the galah had difficulty flying slowly enough.
> It was rather sad to watch her when she eventually became adult and tried
> cuddling up to a handsome young male Major Mitchell, only to be continually
> rejected by him, and effectively in limbo.
> For a long while I've been meaning to write an illustrated version of this
> story for a more popular magazine. I have a stunning picture (made by me) of
> a Galah looking at its reflection in a puddle where the reflection is
> actually a Major Mitchell which I entitle " Mirror, mirror on the wall
> Graeme Chapman
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