Their study is the first time that the actual sites involved in the original study have been re-excavated and analyzed.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.
Due to uncertainties in local marine reservoir effects and the proportion of marine carbon incorporated in bone, dates from archaeological skeletal material exhibiting marine dietary signatures have previously been characterized as problematic and removed from further analysis.
Work, funded by the Royal Society of New Zealand Marsden Fund, has resolved the debate using several approaches.
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 pacific rat (kiore) spread with voyaging humans; therefore, its earliest presence in New Zealand indicates initial human contact.
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.
While in certain instances this may be appropriate, in others it is not.This article presents 26 new C ages are not significantly different under varying realistic extreme ranges in estimates of the proportion of marine carbon consumed.They based their results on new radiocarbon dating of Pacific rat bones and rat-gnawed seeds.Their results do not support previous radiocarbon dating of Pacific rat bones.The article argues that this is primarily due to the small local marine reservoir effect measured in Rapa Nui and relatively lower reliance on marine resources in the prehistoric and protohistoric population.Radiocarbon dating of Pacific rat (kiore) bones and rat-gnawed native seeds have provided compelling new evidence into the timing of New Zealand’s colonisation.