Giant kangaroos and wombats bigger than cars which once roamed Australia
were killed by climate change and not human hunters, Australian
scientists said on Thursday. The report comes as the country struggles
with what could be its worst drought in 1,000 years, affecting more than
half its farmlands.
Known as megafauna, the huge animals were driven into extinction by a
steady warming of Australia's climate, which in turn saw a once-lush
outback region turn to red desert and grasslands.
"For about the last half-million years it's been consistently getting
drier in Australia," Dr Gregory Webb told Reuters after studying
fossil-rich areas of south-east Queensland state. "The apparent
progressive megafaunal extinction on the Darling Downs does not support
the sudden blitzkrieg model resulting from human hunting," Webb s report
said.
The megafauna -- kangaroos 2.5 metres (8 feet) tall, wombats as big as
cars and cattle, giant Ostrich-like Emus and lizards -- were common in
vast areas of Australia 40,000 years ago before gradually disappearing.
Most theories on their vanishing centre on the arrival in Australia
around the same time of Aboriginal people, who were believed to have
hunted the animals out of existance.
But Webb, from Queensland University of Technology, said a study done
with colleague Dr Gilbert Price had found many animals were probably
drought-stressed when they died.
If humans had been responsible, he said, the fossil evidence would show
the vulnerable and easily-hunted animals dying out around the same
period rather than over thousands of years.
"Whole habitats changed, from forests which required a lot of rainfall
to grasslands, and now it has become much more open and scrubbier," Webb
said.
"Of course the organisms that required more enclosed lush, green habitat
simply had nowhere to live."
Scientists have said that Australia must brace itself for long-term
climate change and water shortages due to the accelerating pace of
global warming.
(Por Rob Taylor,
Planet Ark, 01/12/2006)