The study, one of the largest studies of its kind, has shown that the country was not visited by humans over 2000 years ago, as some previous research suggests.
The work is published in the journal Proceedings of the National Academy of Sciences in the United States.
The bite marks from rat incisors are well preserved in these seeds which were radiocarbon dated. Image - J Wilmshurst Searching for gnawed seeds is a time consuming and laborious task, a little like looking for a needle in a haystack.
Janet Wilmshurst and Tom Higham looked for sites with peat deposits drained by farmers, exposing sections which could be searched by coring and by digging test pits.
Furthermore, the reliability of the bone dating has been questioned, with explanations for their anomalously old ages ranging from variations in laboratory pre treatments to bone contamination through either post-mortem processes or dietary- related offsets.
Work, funded by the Royal Society of New Zealand Marsden Fund, has resolved the debate using several approaches.
Their results do not support previous radiocarbon dating of Pacific rat bones.
Their study is the first time that the actual sites involved in the original study have been re-excavated and analyzed.
Radiocarbon dating of kiore bones suggests they were introduced to New Zealand c. However, these radiocarbon ages are controversial because there is no supporting ecological and archaeological evidence for the presence of kiore or humans until c. An international team of researchers, led by Dr Janet Wilmshurst from Landcare Research, spent 4 years on a study which shows conclusively that the earliest evidence for human colonisation is about 1280-1300 AD, and no earlier.
They based their results on new radiocarbon dating of Pacific rat bones and rat-gnawed seeds.
The presence of rat-gnawed seeds in this ash means that 1314 AD provides an upper age limit for initial rat arrival in New Zealand.Tags: Adult Dating, affair dating, sex dating