The stable isotope measurements on all our dated bones (reexcavated and museum collection) (Table S1) show a strong terrestrial vegetal signal, indicating a low probability of large reservoir offsets from their contemporary atmospheric C levels.
Thus, suggestions of dietary-related offsets (39, 40) are untenable as an explanation for the old rat bone dates processed in 1995–1996.
The first long-accepted colonization model for New Zealand was the “orthodox” archaeological model, which set the date for initial colonization to ≈800 A.
D., several centuries before the earliest-dated archaeological sites.
Our method exploits the fact that the omnivorous rat was transported throughout the Pacific by prehistoric people and multiplied rapidly after its initial introduction.
Consequently, introduction of rats to previously rat-free islands is unlikely to remain invisible in the palaeoecological record for any length of time.
Symbols show location of redated laughing owl bone sites (20, 21) (blue), seed deposits (red) mentioned in text, and test pits (black) examined during the search for seed sites, but which did not contain preserved seeds.Subsequent dating of Pacific rat bones sampled from both laughing owl (32) and archaeological sites (33–38).The most telling criticism of the original dates is that they fall into two distinct groups according to when the bones were processed in the same dating laboratory (22, 36, 37) (see Fig. The early series of rat bone dates processed in 19 are all older than the oldest-dated archaeological evidence (≈1280 A.2) showed that none was older than 780 ± 70 yr before the present (BP) (Wk-8548), whereas 18 intact seeds from the same deposits (Fig. Here, we present an additional 51 dates on seeds from the South Island (Fig. Of these, 29 seeds were from a deposit at Nguroa Bay (, Fig.2), ≈50 km from Predator Cave, which produced the oldest rat bone dates (20, 21). The upper age limit for initial rat arrival can be further constrained by the age of the Kaharoa Tephra, a volcanic ash found in northeastern North Island, which has been wigglematch-dated to 1314 ± 12 A. (45), because rat-gnawed seeds have been found buried within this ash (22).