November 26, 2008

Ancient Humans Did Not Cause Cave Bear Extinction

A recent study published on Wednesday shows that giant cave bears froze to death during the last Ice Age in Europe about 28,000 years ago and were not hunted into extinction by man thousands of years later "” as scientists previously thought.

The largely vegetarian bears apparently died off as sharp cooling of the climate led to a freeze that killed off the fruits, nuts and plants they ate.

Despite surviving on a mostly plant-based diet, the large bears weighed up to a ton and were bigger than modern polar bears or Kodiak bears.

The scientists in Austria and Britain studied bear remains at hibernation sites in the Alps using radiocarbon dating. They now believe the bears vanished 27,800 years ago, or about 13,000 years earlier than previously believed.

The researchers wrote in the journal Boreas: "There is little convincing evidence so far of human involvement in extinction of the cave bear."

Past reports have suggested that the cave bears' demise was linked to over-hunting.

The cave bears lived everywhere from what is now Spain to the Ural Mountains, and were one of several large creatures -- such as the woolly mammoth, woolly rhinoceros, giant deer and cave lion -- to vanish during the Ice Age that ended 10,000 years ago.

Martina Pacher, one of the co-authors at the University of Vienna, said the new evidence shows that the cave bear was one of the earliest to disappear.

"Other, later extinctions happened at different times within the last 15,000 years," she said.

Studies in the past showed errors in dating samples and sometimes confused remains of cave bears with those of brown bears, which still survive.

"A fundamental question to be answered by future research is: why did the brown bear survive to the present day, while the cave bear did not?" said Anthony Stuart, the other author at the Natural History Museum in London.

He believes possible answers might include differing diets, hibernation habits, geographical ranges, habitat and perhaps hunting by people.

Image Courtesy Wikipedia


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