‘What killed the forests of Easter Island?’ is a question that has bamboozled experts for years. Outcomes have ranged from natural disasters, to disastrous ecology – but an invasion of rats? It’s the latest posit doing the scholarly rounds, thanks to University of Hawaii professors Terry Hunt and Carl Lipo. But before you’re conjuring hoards of rodent Jack Sparrows patrolling the Pacific, the pair do have hard evidence backing their claim.
It’s widely agreed that Europeans are largely to blame for the demise of the Easter Islanders, famous for their eerie megalithic statues, following its European discovery in the mid-18th century. Dutch, British and Spanish explorers brought deportation, slavery and, crucially, smallpox to the tiny outcrop, killing a catastrophic number of people. The outbreak, which reached its zenith in the 1860s, was so devastating some were not even buried.
The island’s palm forests once covered over 70% of its surface around 1100. Yet they were all but obliterated come the arrival of the Europeans. Many feel the islanders reaped their own disaster by cutting down trees for statue sledges and roofs. Yet Hunt and Lipo’s theory sets the island’s apocalyptic gears in motion at the very second of their arrival.
First the duo point to a radiocarbon dating project they completed three years ago, which pushes Easter Island‘s colonisation forward about a hundred years past previous data, to 1200 AD. Then they use DNA material and chewed palm fragments to argue these first immigrants brought Polynesian rats with them which ate palm nuts, devastating the island’s forests.
“An ecological catastrophe did occur on Rapa Nui, but it was the result of a number of factors, not just human short-sightedness,” Hunt tells American Scientist magazine.
But ‘Ratageddon’ has its opposers – not least in the German duo of Andreas Mieth and Hans-Rudolf Bork, from the Christian Albrechts University of Kiel. In wonderful scholar-speak, the pair “disagree with the hypothesis of a major rat impact” on Easter Island – instead pointing towards a subterranean layer of charcoal as evidence of widespread forest fires. Deforestation, they conclude, was a human act.
But the archaeological hot potato isn’t dropped there. Hunt has been defending his hypotheses, telling USA Today: “It’s very tempting to see one explanation for everything, all people or all rats, but what we were saying was that rats surely played a role on Easter Island. How can you explain the idea of rats not having an effect?”
He argues the German pair’s answer is too clean; that a combination of people and rats contributed to the destruction of the forests. “Blaming humans for everything is too simple,” he says. “The question is how much of a role did each player have and how did they interact?” It seems the ball is in Mieth and Bork’s court. We can see this one lasting a while…
