Birds and the drought in SE Australia - and climate change

[Andrew Taylor <>]

On Sat, Oct 18, 2008 at 12:32:17PM +1100, michael norris wrote:
> In their alarming book "Climate Code Red" David Spratt and Philip Sutton say
> that "Australia's birds are moving south at 100-150km a decade",

This seems to have come from the "State of Australia's Birds 2007"
where its a statement about the change between atlases in the range of
just 3 birds: White-headed Pigeon, Pheasant Coucal and Pied Butcherbird.

White-headed Pigeon range has certainly expanded through coastal southern
NSW into Victoria in the past century.  It seems hard to attribute this to
climate (temperature)  as their expansion seems to precede any signficant
temperature rises - as a frugivore you'd expect its climate repsosne
to lag temparture rises as its food trees wouldn't respond quickly.
Another frugivore, Figbird, has made a similar expansion but earlier
so it was expanding south during the 40s and 50s when temperatures were
stable or declining in SE Australia.  

Looking at the 2 Atlases the picture for Pied Butcherbird isn't clear
to me it looks as if its range has increased south in some areas but
its abundance has declined in other areas of its southern range.

Pheasant Coucal did seem to have increased in abundance between atlases
but not clearly at the southern edge of its range - and its a species
you'd worry about being affected by the change in methods between atlases.

So there is little reason to believe that these 3 species' ranges has
changed due to anthropogenic climate change.

The discussion in the Bird Australia report is quite interesting:
http://www.birdsaustralia.com.au/images/stories/downloads/soab/soab2007s.pdf
and SE Australia temps can be seen here
http://www.bom.gov.au/cgi-bin/silo/reg/cli_chg/timeseries.cgi?variable=tmean&region=seaus&season=0112

Andrew