People, climate, and water supply all played a role in the extinction of Australia's megafauna

NOVEMBER 25, 2019 

by Flinders University

The mystery of the role of people and climate in the fate of Australian megafauna might have been solved in a breakthrough study published today. 

"Megafauna,' giant beasts that once roamed the continent—including wombat-like creatures as big as cars, birds more than two meters tall, and lizards more than seven meters long—became extinct about 42,000 years ago. But the role of people in their demise has been hotly debated for decades. 

The new study, led by a team of researchers from the ARC Centre of Excellence for Australian Biodiversity and Heritage (CABAH), analyzed fossil data, climate reconstructions, and archaeological information describing patterns in human migration across south-eastern Australia. 

The team developed and applied sophisticated mathematical models to test scenarios to explain regional variation in the periods during which people and megafauna coexisted. 

For the first time, the research suggests a combination of climate change and the impact of people sealed the fate of megafauna, at least in south-eastern Australia. And that distribution of freshwater—a precious commodity for animals and people alike as the climate warmed—can explain regional differences in the timing at which megafauna died out. 

"There has been much debate among scientists about what conditions led to this extinction event," said lead author Dr. Frédérik Saltré, Research Fellow and Coordinator of the Global Ecology Lab at Flinders University. 

"Resolving this question is important because it is one of the oldest such extinction events anywhere after modern human beings evolved and left Africa," he added. 

The findings, published in Nature Communications, are the result of analysis and complex modeling based on data including more than 10,000 fossils and archaeological records. Using high-quality fossil data and archaeological evidence of human activity, the researchers were able to map regional patterns of megafauna extinction. 

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