Using Palaeoproteomics to Measure the Impact of Early Lapita Subsistence Strategies on Fruit Bat Populations in Vanuatu

Loren Howell

Fruit bat bones dominate Lapita midden assemblages in Vanuatu. This is despite evidence for intensive hunting of local fauna during the early settlement periods being a direct cause of extinction for several other taxa. Currently, there are two large extant species of fruit bat in Vanuatu, however previous faunal analyses have estimated that between 3-13 distinct morphological variations of fruit bats exist in Lapita middens, suggesting population impact of Lapita foraging may have been substantial. To overcome the challenges of fragmentation and non-diagnostic bone facing conventional methods of taxonomic identification, this study applied a shotgun palaeoproteomic technique (LC MS/MS) to measure the difference between present and prehistoric fruit bat diversity. A database of enzyme sequences was developed from bone collagen sampled from museum and wild caught specimens and compared to protein signals produced by a selection of archaeological samples from various Lapita middens. The results demonstrated that fruit bat diversity and distribution was quantifiably greater at the time of human arrival in Vanuatu, with the detection of nonextant taxa, as well as extant taxa far beyond their modern range of distribution. Further, due to the selectivity of sampling, it is predicted that full taxonomic diversity was likely to be much higher than suggested by the data presented. Not only do these findings broaden the current understanding about the scale of impact from intense, foraging during the initial Lapita settlement phase, but also highlight the potential role of palaeoproteomics in palaeodietary and palaeoecological reconstructions for archaeology in the tropics.