Abstract
Our study used two consecutive years of aerial culling then molecular ecology techniques (microsatellite analysis) to obtain parentage data from a widely dispersed and low density feral pig population during drought conditions in the semi-arid rangelands of Australia. This data was analysed geo-spatially to provide estimates on the actual minimum movements of feral pigs. The aim of this exercise was to obtain data that could be used to improve models that investigate rates of disease spread. The derived data revealed that some individuals will move much greater distances than previously recorded. The maximum recorded movement was 143km between a boar and pregnant sow in less than 1 year, with the mean boar to successfully mated sow distance being 43km. Thus, home ranges in this situation could be assumed to be much larger than previously calculated. Movement models were developed from this data and were based upon three assumptions of home range affinity; fixed home range, moving home range and no home range. Mean daily movements generated were 3km linear distance away from a previous mating for boars. Models revealed that currently planned disease eradication zones for Australia may be inadequate if an exotic disease outbreak remains undetected for only a short period of time (1 week). Using previously generated deterministic models for foot–and-mouth disease spread, and this data to alter home range size, the threshold population density below which disease will not transmit declines markedly.