New study: overhunting by humans killed off Australia's megafauna

Jeremy Hance
mongabay.com
January 21, 2010



For over a century and a half researchers have debated whether humans or climate change killed off Australia's megafuana. A new paper in Science argues with new evidence that Australia's giant marsupials, monstrous reptiles, and large flightless birds were brought to extinction not by an unruly climate, but by the arrival of humans.

Employing improved dating methods for fossils and tools, the researchers have discovered that Australia's unique megafauna only co-existed with humans for a short time, pointing to unsustainable hunting and habitat change as the likeliest cause of the megafauna's demise.

In addition, "Australia was colonized during a time when the climate was relatively benign, supporting the view that people, not climate change, caused the extinctions here," Dr. Barry Brook, co-author of the study and professor at the University of Adelaide, says.

However researchers supporting the theory that climate change caused the megafauna's mass extinction point to a site in New South Wales, Australia, known as Cuddie Springs. Here, fossils of Australian megafauna have been found in the same sedimentary layers as human tools, leading them to proclaim unequivocal evidence that humans and Australia's megafauna overlapped for a significant period of time.

However, Professor Richard Roberts from the University of Wollongong and lead author of the study says: "these results provide no evidence for the late survival of megafauna at this site." He points out that using direct dating of the fossils and tools shows that they were mixed together over many thousands of years.

"Given that people arrived in Australia between 60,000 and 45,000 years ago, human impact was the likely extinction driver, either through hunting or habitat disturbance," he concludes.







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CITATION:
Jeremy Hance
mongabay.com (January 21, 2010).

New study: overhunting by humans killed off Australia's megafauna.

http://news.mongabay.com/2010/0121-hance_ausmega.html