If only they could talk.

The statues walked, Easter Islanders say. Archaeologists are still trying to figure out how – and whether their story is a cautionary tale of environmental disaster or a celebration of human ingenuity.

On a winter night last June, José Antonio Tuki, a 30-year-old artist on Easter Island, did one of the things he loves best: he left his house on the southwest coast and hiked north across the island to Anakena beach. Tuki sat on the sand and gazed at the colossal human statues – the moai. The statues range from four to 33 feet and some weigh more than 80 tons. They were carved long ago with stone tools and then transported up to 11 miles to massive stone platforms. As Tuki stares at their faces, he feels a connection. ‘It’s something strange and energetic,’ he says. ‘This is something produced from my culture, the Rapanui.’ He shakes his head. ‘How did they do it?’

When the first Polynesian settlers arrived at Rapa Nui (Easter Island), there were probably only a few dozen of them. The island lies 2,150 miles west of South America and 1,300 miles east of its nearest inhabited neighbour, Pitcairn. Nowadays 12 flights arrive every week from Chile, Peru and Tahiti, and in 2011 those planes delivered 50,000 tourists, ten times the island’s population. Just about every job on Easter Island depends on tourism. ‘Without it,’ says Mahina Lucero Teao, head of tourism, ‘everyone would be starving on Easter Island.’ And the tourists go there for only one thing: the moai.

Several decades ago, the Norwegian adventurer Thor Heyerdahl, helped ignite the world’s curiosity about Easter Island. He thought the statues had been created by pre-Inca people from Peru, not by Polynesians. Modern science – linguistic, archaeological and genetic evidence – has proved the moai builders were Polynesian but not how they moved their creations. Researchers have tended to assume the ancestors dragged the statues somehow, using ropes and wood.

More recently, Pulitzer Prize winner Jared Diamond has suggested that the moai contributed to the downfall of the islanders. Building and moving the moai needed many people and used up the island’s forest resources. The land which was cleared was fragile and quickly eroded, so fewer crops could be grown – this process of clearing the land was an early example of an ecological disaster, according to Diamond. He sees the collapse of their civilization as ‘a worst-case scenario for what may lie ahead of us in our own future.’

On the other hand, a more optimistic view of the island’s history comes from the archaeologists Terry Hunt of the University of Hawaii and Carl Lipo of California State University Long Beach. They suggest that the inhabitants actually pioneered a type of sustainable farming, building thousands of circular stone walls, called manavai, and gardening inside them. And their theory about how the moai were moved is that they could be ‘walked’ along using a system of only ropes and a few people.

For José Tuki, as he contemplates these enormous statues, the ambiguity is too fine. ‘I want to know the truth,’ he says, ‘but maybe knowing everything would take its power away.’