Severe drought in Western Polynesia - Samoa and Tonga - may have led to the settlement of the East Polynesian islands - such as the Cook Islands - earlier than previously thought.
A newly released anthropological study also suggested that settlement of East Polynesia, rather than being a rapid, wave-like event, was a much more incremental process, possibly extending over several generations.
One of those involved in the study, Auckland University archaeology professor, Melinda Allen, said the study appeared to show the people may been probing the margins of east Polynesia.
"Doing some exploration, perhaps leaving some pigs on an island, and coming back later," she said. "So it just suggested a process of building up some knowledge about the islands and maritime environment."
Professor Allen said the currently accepted date for East Polynesian settlement was 1100AD to 1200AD, but this study showed it may have occurred up to 200 to 300 years earlier, from about 800AD to 1000AD.