Human behavioural ecology, anthropogenic impact and subsistence change at the teouma lapita site, central Vanuatu, 3000-2500 BP
Creators: name: Hawkins, Stuart Charles
Publisher: name: The Australian National University
Year: 2015

description: This thesis investigates early human palaeoecological interaction at the Teouma Lapita site on Efate Island, central Vanuatu, and how it changed during a period of cultural transition between 3000-2500 BP. Here I take a quantified approach through an evolutionary ecological theoretical framework using optimal foraging models (Prey Choice, Patch Choice and Central Place Foraging) to generate predictions of optimal economic behaviour in response to temporal variation in prey abundances. These optimal foraging models (OFM) which typically focus on foraging cultures had to be adjusted to the broad spectrum Lapita mixed economy which combined foraging within marine and terrestrial resource patches and horticulture, incorporating pig husbandry and plant cultivation. To this end mammal, bird and reptile vertebrate taxa were divided into three broad resource patches, coastal, terrestrial and the domestic patch. Alternative social theoretical perspectives were also built into the models such as costly signalling theory. OFM predictions were then tested using multiple zooarchaeological datasets to demonstrate changes in foraging efficiency and mobility between resource patches as a result of human induced resource depression. Datasets used include measures of prey diversity, relative abundance, demography, skeletal element representation, and butchery intensity. The results indicate that Lapita foragers focused initially on high ranked fruit bat and large bodied sea turtle resources in concentrated and predictable proximal locations which yielded high post encounter return rates. Giant tortoise exploitation in distant resource patches gained in importance over time as these proximal resource patches became depleted. Domestic patch resources were established and pig abundances increased very quickly but had initially high infant mortality rates due to nutritional deficiency and/or selective culling to reduce associated labour costs. Pigs were closely managed and regulated for a range of purposes which included daily household meat consumption as well as ritualistic feasting events. Faunal abundances peaked during the later post-cemetery period as Lapita settlement and foraging intensified which had a huge impact on the terrestrial and coastal resources due in part to direct foraging, forest clearance. An ecological tipping point followed which saw the disappearance of crocodile and a number of fruit bat and bird species from the record. As encounter rates of high ranked taxa declined so did foraging efficiency and the transition from Lapita to post-Lapita culture saw a dramatic change in subsistence patterns. Tortoise and sea turtle nesting populations were devastated as giant tortoises became extinct around the transition between Lapita to early Erueti, rat demography and the large New Guinea Spiny rat declined likely as a result of human predation as settlement intensity appears to have peaked by the end of the Lapita period. Pig production also declined likely in response to ecological and social developments, and a switch to hunting feral pigs may have occurred. These subsistence changes and declines in foraging efficiency appear to have been associated with changes in settlement patterns which conform to the ideal free distribution model as well as declines in social stratification.