Exotic Animals - Moderate Pests
Goats
Family: Bovidae
Scientific names: Capra hircus
Bacground
Feral goats occur in all states and territories except on the mainland of the Northern Territory. The main concentrations are in western New South Wales, southern Queensland, central eastern South Australia and Western Australia. Feral goats occur in a wide range of habitats but are not very successful where dingoes are present.
Current feral goat populations in Australia reflect rather mixed origins. Goats originally came to Australia with the First Fleet in 1788. Feral populations established when domestic goats escaped, were abandoned, or were deliberately released. Today, feral goats occur in all states and territories of Australia, albeit primarily in semi-arid areas. In these areas, food is usually plentiful, water available, and natural predators such as dingoes and feral dogs are controlled.
In the Northern Territory, feral goats are absent from the mainland. In the late 1980s and early 1990s several pockets of feral goats north and north east of Alice Springs were eradicated. No known populations currently occur in the southern region of the NT. Feral goats do occur on a few offshore islands, North East, North Goulburn, Truant, and Vanderlin.
Feral goats, especially under pressure of harvesting, are capable of maturing sexually at an early age, extending their breeding season, conceiving while lactating, and producing more than one kid in a year. They have a very high invasive potential and can increase at over 50% each year.
Impacts
Feral goats are a major environmental and agricultural pest. In the Endangered Species Protection Act 1992 the Commonwealth Government has listed 'competition and land degradation by feral goats' as a Key Threatening Process to the survival of native species. They compete with domestic stock for food and cause land degradation through soil damage, overgrazing and strip-browsing. The soil's crust and its protective cover of vegetation are broken up through trampling of feral goats.
Feral goats are capable of inflicting a substantial loss of biodiversity, especially where population growth is not managed. Woody and non-woody native plants stand little chance of regeneration in the presence of goats. Island habitats that evolved without large browsers are particularly susceptible.
Management Practices
Mustering and trapping are used where goats are intended for the meat trade. It is estimated that mustering beyond 30-40% of the population becomes uneconomic. Management of low density herds and those in broken or densely vegetated country require aerial or ground shooting. The use of 'Judas' goats can improve the efficiency of these techniques. Dingoes are useful as a bio-control option.
