Elephants driven to extinction by man, not climate change

Elephants have been hunted to extinction on several continents and their global demise over the millennia is the direct result of human migration rather than climate change, scientists have found.

Elephants have been hunted to extinction on several continents and their global demise over the millennia is the direct result of human migration rather than climate change, scientists have found.

Mastodons, mammoths and other elephant-like proboscideans - large mammals with trunks - were once common throughout the world, from South and North America to Europe and central and east Asia. But they survive today only in sub-Saharan African and the Indian subcontinent.

Some scientists have suggested that the demise in non-tropical regions was the direct result of climate change, such as the many ice ages that have occurred over the past million years.

But a study by Todd Surovell of the University of Wyoming in Laramie along with Nicole Waguespack and Jeffrey Brantingham of the University of California at Los Angeles has found evidence to suggest that it was man that killed the elephant.

The scientists studied 41 archaeological sites where Stone Age humans were known to have engaged in major slaughters of elephants. to see if they could detect evidence suggesting that hunting led directly to extinction. If climate was responsible then there should be little or nor correlation between the time at which a local elephant population went extinct and the date when the first human migrants arrived in that region, the researchers said.

"If mammalian Pleistocene [Stone Age] extinctions resulted from human overkill as humans expanded their range across the globe, now extinct large mammals should have experienced complementary range contractions," they write in the Proceedings of the National Academy of Sciences.

To test this theory they had to date precisely the first appearance of humans and the last appearance of extinct mammals. When they analysed the distribution of the killing sites, they found a strong correlation between the elephant extinctions and the arrival of the first human hunters: "A repeated pattern is evident in the global archaeological and palaeontolgical records. Humans disperse into new regions. They exploit proboscideans. Proboscideans suffer local extinction."