Mon Jul 3, 2006 3:47 PM BST
By Tim Cocks
PORT LOUIS (Reuters) - Scientists who unearthed a mass dodo grave in Mauritius say they have found evidence showing the birds were killed by a natural disaster long before humans arrived on the Indian Ocean island.
Most theories about how the dodo became extinct blame early settlers who found the plump flightless bird on the Indian Ocean island in the 16th century and hunted it relentlessly.
"There are indications that the fossil-rich layer represents the result of natural disaster wiping out a significant part of the Dodo-ecotope," a statement by the researchers said.
While the latest find does not disprove the human theory, the scientists are convinced there was a mass dodo death, possibly caused by a cyclone or flood, pre-dating the arrival of humans, Christian Foo Kune, owner of the site, told Reuters.
"The fact that there are such a wide range of animals there, small and big ones, suggests that there was a sudden natural disaster," Foo Kune said. "The mass grave also shows no domestic animals, so it is prior to the arrival of man."
The bones were thought to be at least 500 years old, he added. "We could be talking about a cyclone or repeated cyclones, flooding or a sudden rise in (sea) water levels that trapped the animals there," he said.
The scientists from the Dodo Research Program last month recovered a wealth of dodo remains and fossils of other animals and plants, including now-extinct Mauritian giant tortoises, parrots and tree seeds, from a sugar estate in the southeast.
Researchers on the project say the fossils should enable them to reconstruct the dodo's world in the 10,000 years before humans found the bird and determine what caused it to die out.
Foo Kune said that since the deaths at his site occurred before the final extinction of the dodo more than two centuries later, the scientists believed it did not rule out the idea that bird became extinct by human causes.
Portuguese sailors discovered Mauritius in the 16th century, and Dutch settlers colonized it the following century, which is when the dodo died out.
Unused to predators, the dodos were not frightened of the human settlers who hunted it and destroyed the forests that provided its habitat. Passing ships also brought rats, which ate the birds' eggs located in nests on the ground.