Document ID: chunk:federal_register_of_legislation:F2017L00257:body:0:p3
Version: federal_register_of_legislation:F2017L00257
Segment Type: other
Provision Reference: 
Character Range: 5819–8833

scrofa) (2017)
1.1. Description of the process and its impacts
Feral pigs are found in all states and territories of Australia, particularly in association with wetlands and river systems. An estimate of the size of the nation's feral pig population is difficult as numbers fluctuate widely in response to wet and dry periods, and availability of food and water. In warmer areas of Australia, feral pigs' poor heat tolerance restricts their distribution to the vicinity of watercourses and floodplains. This factor is less critical in the forested parts of eastern and south-western Australia where they are more widespread.

Ecological parameters affected by feral pigs include plant species composition and succession, nutrient and water cycles, and water quality. Impacts can be direct, such as through predation and digging, or indirect, through long-term changes in species composition. Impacts may be seasonally influenced, and vary across Australia with different habitats.

Feral pigs are opportunistic omnivores and will consume animal material including small mammals, birds, reptiles, frogs, crayfish, eggs, and carrion; earthworms and other invertebrates; underground fungi; and all parts of plants including the fruit, seeds, roots, tubers, bulbs and foliage. Feral pigs vary their food consumption to match seasonal changes in food availability and quality. They have a poor capacity to digest cellulose and relatively high protein requirements, therefore regularly supplement their diet with carrion and animal prey.

Habitat changes due to feral pigs include: destruction of plants, sometimes threatening the  survival of specific plant species through reduced or failed recruitment of new plants; changing the composition of plant communities; alteration of soil structure through digging and rooting; increased invasion and spread of weeds through spreading seeds via faeces or in fur, or creating suitable habitat through soil enrichment with urine and faeces or ground disturbance; reduced water quality through disturbance of riparian zones and bodily wastes; and creation of habitat suitable for plant disease vectors.

Feral pigs provide reservoirs for endemic animal diseases such as leptospirosis and brucellosis, which can cause birth defects, abortions and infertility in mammals. They may be vectors of exotic diseases such as foot-and-mouth disease, should they ever reach Australia. They can spread exotic plant pathogens such as Phytophthora cinnamomi, which causes plant dieback, through soil movement on their feet and fur, and by passing viable spores in their faeces.

For further detail, consult the Background document.

1.2. Managing the threat
It is not possible to eradicate feral pigs from Australia with current resources and techniques, and it is unlikely to be possible in the near future, as they are so widely established. As such, the focus of feral pig management must be on abatement of the impacts unless they are in small isolated areas (e.g. islands) where