An Anthropologists' conference in the US has been told that the demise of Rapa Nui, or Easter Island, may have been caused by rats which ate palm seeds to deforest the island of its 16 million palm trees.
The theory has been developed by anthropologist of the University of Hawaii, Terry Hunt, after surveys done since 2001.
His team found that the rat population peaked at about 20 million in 1300 and then fell off dramatically.
Terry Hunt also says the Polynesian people were decimated by disease brought by Dutch traders in the 1700s.
Earlier theories suggest the island was deforested because the Polynesian settlers used the trees to move the giant statues they had built.
A New Zealand expert told USA Today that the latest theory is unlikely because rats didn't deforest other islands.