Well, of course there are highland specialists further north (the Atherton
Tablelands suite of birds).
My understanding is that during the last two million years or so the upland
areas in Australia's south-east have been very dry during each glacial
period. This would probably have decreased productivity and probably wiped
out (possibly in successive stages), any alpine specialists there may have
been. The Atherton Tableland by contrast, though it was affected by drying
phases, did retain small refugia of rainforest for the specialists to
persist in.
Also it may have been that the upland areas in se Australia were never big
enough for any alpine spp to evolve (ie upland populations could always be
reabsorbed into lowland parent spp in time of climatic fluctuation before
they had had a chance to establish new genetic boundaries).
John Leonard
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John Leonard (Dr)
http://users.bigpond.com/john.leonard
PO Box 243, Woden, ACT 2606, Australia
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