How Easter Island’s statues got their hats
THEORY EXPLAINS A CENTURIES-OLD MYSTERY
Agroup of U.S. researchers believe they’ve answered the long-pondered question of how Easter Island’s stone statues got their hats. Dozens of the statues punctuating the isolated, inhospitable island are accessorized with these red hats — a baffling feat of engineering, especially considering that merely surviving there is an impressive accomplishment.
“That’s why it’s sort of mindblowing,” said Carl Lipo, an anthropology professor at Binghamton University in New York. “Finding one of these things would be remarkable almost anywhere, but on this island you find nearly 1,000 statues that can be up to three storeys tall.
“How does any of this happen, much less with a giant hat on top of it?”
It becomes a complicated question when you consider the details: The hats — called pukao — are made of red scoria, a volcanic rock from one side of the island, while the statues are made from stone quarried at the opposite end. And Easter Island, some 3,000 kilometres from Chile in the south Pacific Ocean, is bereft of useful resources like timber to assist in trekking great slabs of sculpted stone. The hats alone can weigh more than 11 tonnes and the statues are as high as 10 metres.
So it’s not just a question of how a small population sometime in the 15th or 16th century managed to lift the big hats onto the even bigger statues, it’s why?
“Really, why would they do this here?” Lipo asks. “You look at them and it’s not obvious. Standing next to (the hats), they’re as tall as a six-foot person. They’re massive. And you’re like, ‘How the heck did they get (the hats) on top of these things?’ ”
Lipo, along with researchers from around the United States, published an explanation in the Journal of Archaeological Science last week, refuting decades of speculation from other scholars.
Until now, the prevailing theory was the Rapa Nui people on Easter Island lay the statue on the ground, attached the hats, then stood the whole thing up together.
But after examining the statues, Lipo and his group found that would be impossible. The necks of the statues are required to bear the weight of the hats without snapping. Discarded statues strewn around the island — the ones that never made it — also hinted that they were never laid on the ground; they were transported and installed upright. The bottoms of those statues were slanted, so that they would have leaned forward. That way they could be pushed back and forth, essentially walking from the quarry to the designated spot, where the heel would be shaved off before it was installed so it stood upright on the platform.
On a research trip to the island, they found another crucial clue. In the middle of the cylindrical hats, there were grooves that appeared to have been left by ropes. There was also rubble scattered around the base of the statues.
That was enough to lead the team to parbuckling, an old technique used around the world, usually to move large barrels or even ships. It involves wrapping a rope around the centre of a large, cylindrical object, then pulling the rope from the top, so it rolls upward.
“It’s like a yo-yo — pulling a yo-yo up a ramp,” Lipo said. The ramps used to pull the hats to the top of the statue would have been made from stones, which were taken down and littered around the base afterward.
“In the end, it’s sort of like, ‘Of course!’” Lipo said. “It looks mysterious but if you sort of think about it — they had centuries and they were just good at it.”
While the science of figuring out the age of stone is imprecise, the Easter Island statues likely date to the 12th century. The hats appear to be on later versions from the 15th and 16th century — a product of what Lipo calls “escalating elaboration.”
“In other words,” he said, “they’re making bigger and bigger statues and eventually someone was like, ‘Oh, I’m going show you! I’ ll put a hat on top to make it even greater.’ ”
The statues aren’t exactly unique to Easter Island, but instead appear to be part of a broader Polynesian tradition of erecting stone monuments to honour ancestors, Lipo said. The statues on Easter Island, however, are among the largest and most elaborate, including carved faces when others on more prosperous islands only erected plain stone slabs.
It seems strange that people on a tiny island with little resources and a landscape poorly suited for agriculture would busy themselves with constructing grand statues. But, for Lipo, it makes a lot of sense.
“How did they persist on this tiny, tiny island for so long?” he said. “The answer really comes down to, well, they did it by making the giant statues.”
Think about it, he said. Survival in such a place would hinge on collaboration. And how better to strengthen the bonds between people on the island than to undertake a near impossible task together, over and over.
Lipo’s team included Terry Hunt from the University of Arizona, Ben Mcmorran from the University of Oregon and then under graduate student Sean Dixon, now a graduate student a Penn State.