The influence of pasture distribution, temperature and sex on home-range size of feral pigs in a semi-arid environment

Abstract

In this study the home-range sizes of feral pigs (Sus scrofa) at Nocoleche Nature Reserve, semi-arid New South Wales were measured by radio-telemetry over the course of a drought. The abundance of food was indexed simultaneously by the amount of pasture in the four most common habitats at Nocoleche (shrubland, woodland, riverine woodland, and ephemeral swamps). The influence of the pig's sex, and mean maximum temperature and pasture biomass on the home-range size of pigs were examined using ANOVA and multiple regression, respectively. Mean home-range size of males was 7.9–11.6 km² and that for females was 4.2–8.0 km² . Males had significantly larger home ranges than females, and their home-range size did not change significantly over the course of the drought. In contrast, the size of the home ranges of females changed significantly and was correlated negatively with the abundance of pasture biomass in shrublands and mean maximum temperature, and positively with the abundance of pasture biomass in ephemeral swamps. The conclusion from this study is that males maintained a large, unvarying, home range to maximise access to females while females changed their home-range size according the abundance of food and the constraints of high temperature.