Ecological comparison of two Wild pig populations in semi-arid and sub-alpine Australia

Abstract

The ecology of two distinct feral pig populations in south-eastern Australia were compared. Study sites consisted of: 1. a sub-alpine region with open grassy plains and heavily timbered mountains; 2. permanent marshes surrounded by perennial grasslands of the semi-arid western plains. Parameters examined included reproductive data, age structures, mortality rates, food availability, population density, health and age-specific morphometrics.The sub-alpine population appeared to be relatively stable and had a marked seasonality of breeding with a general period of anoestrus through autumn and early winter. This was attributed to a decreasing availability of high protein food during these seasons. Population density was then much lower as that of marsh population which had arelatively constant rate of conceptions throughout the year and potential rates of explosive increase dependant on food availability. Age-specific body weight and body length were greater in the sub-alpine population. Similarly,overall health was much better with no evidence of the heavy parasitic burdens which were found in the semi-arid population.