Courtesy of UMass Amherst News Office
Analysis of the bones of what was once the world’s largest bird has revealed that humans arrived on the tropical island of Madagascar more than 6,000 years earlier than previously thought, according to a new study published in the journal Science Advances.
A team of researchers including UMass Amherst professor emerita of anthropology, Laurie Godfrey, discovered that ancient bones from the extinct Madagascan elephant birds Aepyornis and Mullerornis show cut marks and depression fractures consistent with hunting and butchery by prehistoric humans. The cut-mark and tool-mark analysis was performed by Ventura Pérez, UMass Amherst associate professor of biological archaeology, at the UMass Amherst Violence and Conflict Lab using a state-of-the-art Keyence VHX5000 microscope with built-in visualization software.
Using radiocarbon dating techniques, the team, which was led by the Zoological Society of London, were then able to determine when these giant birds had been killed, reassessing when humans first reached Madagascar.
Previous research on lemur bones and archaeological artifacts suggested that humans first arrived in Madagascar 2,400-4,000 years ago. However, the new study provides evidence of human presence on Madagascar as far back as 10,500 years ago – making these modified elephant bird bones the earliest known evidence of humans on the island.
“Scientists have long thought that the populations of Madagascar’s giant elephant birds and other ‘megafauna’ (the big animals) declined shortly after people first settled on Madagascar. We now know this isn’t true,” Godfrey says. “People arrived over 10,000 years ago, and they hunted some of Madagascar’s big wild animals, but populations of these big animals did not decline until many thousands of years later. There were subsequent human arrivals – waves of them, and an important trade network across the Indian Ocean was established between 1,500-1,000 years ago. We don’t yet know whether the first people to arrive in Madagascar went extinct. If that happened, we don’t know when. We do have butchered bones of elephant birds that are 6,000 years old, and other evidence of human presence several thousand years ago, so prolonged human presence is plausible.
“The bottom line is this,” she concludes, “it is increasingly clear that humans and megafauna coexisted for thousands of years with limited biodiversity loss.”
The extinct elephant birds were flightless megafaunal birds, which were once widespread on Madagascar. They weighed at least 500kg and stood at around 3m tall. It is thought that one of their giant eggs could have fed an entire family.
The bones of the elephant birds studied by this project were originally found in 2009 in Christmas River in south-central Madagascar – a fossil “bone bed” containing a rich concentration of ancient animal remains. This marsh site could have been a major kill site, the scientists say, but further research will be required to confirm the possibility.