From Brand: It wasn’t ecocide. In fact the Rapa Nui appear to have worked out an astutely delicate relationship to each other and to the austere ecology of their small island and its poor soil. They were never violent. The remarkable statues appear to have been an inherent part of how they managed population and ecological balance on their desert island. (Their method of moving the huge statues was clever and surprisingly easy—-they “walked” them upright.)
The famous collapse came from a familiar external source—European diseases, the same as everywhere else in the Americas and the Pacific. All this is in a thoroughly persuasive book by an archaeologist and an anthropologist who did extensive field work and historical study on Easter Island—- THE STATUES THAT WALKED: Unraveling the Mystery of Easter Island, by Terry Hunt and Carl Lipo.