This, they say, was the time of the great disaster, not around 1500.
They published their results in a learned paper in New Zealand, which is available on the internet: click here or here This is the map of the Pacific from the Wilmshurst et al paper, showing the two waves of the colonisation of the Pacific. From this Hunt and Lipo build up a completely new story which largely does away with the ecological disaster.The Bahn/Flenley book had distinct “green” overtones and caused a sensation.Easter Island became the prototype of a civilisation that destroyed itself by its ecological carelessness.The dates of Easter Island are currently in flux in that the traditional dates have been challenged, so two different sets of dates must be given.The dates from the island depend on radiocarbon dating.But one of the advantages of pollen analysis is that the bog itself is formed of vegetable matter, which is basically carbon and can therefore be dated, as some of the carbon would originally been radioactive carbon 14, the gradual decay of which provides the basis for radio carbon dating.
Most of the dates therefore are not dates for the erection of the statues but dates for the decline of the tree pollen in the bogs.
The decline of the tree cover was caused not so much human intervention but by the rats inadvertently introduced by the first colonists, who ate the nuts on which the tree cycle depended.
There was no ecological disaster, they argue, but a disastrous decline only in the 18 century after the first contact by the Europeans who brought with them diseases to which the Polynesians had no immunity.
The dates for the decline of tree pollen, and therefore the first settlement, began around AD 900, or possibly a couple of centuries earlier.
The erection of statues was in full swing by AD 1200 and the collapse came around AD 1500.
The process continued when the ecologist Jared Diamond in his book “Collapse” dealing with the collapse of civilisations, made Easter Island into a chapter all of its own and one of the highlights of the book.