Feral goats are an invasive animal species in Australia. First arriving in the 18th century with European settlers, feral goat populations originated from escaped domestic individuals. Today, feral goats are found across Australia, where they cause economic and environmental damage through overgrazing and competition with livestock and native marsupials.
History
Feral goats came to Australia with the first fleet in 1788. For instance, cashmere goats were brought into South Australia in 1837. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. In the 1860s, angora goats and cashmere goats were imported from Asia in an order to start a goat fibre industry. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. Some herds were set free when the industry collapsed in the 1920s. Goats were also taken around Australia with settlers, railway construction groups and miners. The recent populations of the feral goat have established from goats used to control weeds in plantation forests and woody weeds in inland New South Wales and Queensland. The current feral goat populations in Australia represent a mixture of these origins.
Distribution
Feral goats are found in all states and in the Australian Capital Territory but are rare in the Northern Territory. They are most prevalent in western New South Wales, which, in 2020, had a feral goat population estimated at 4.9 million. They are also at their highest densities in the arid and semi-arid rangelands, where they are considered a significant agricultural and environmental pest. People, through supplying water and controlling predators to improve sheep production, have modified the natural habitat favourably for feral goats.
Feral goats also occur on many Australian offshore islands. These include islands with important conservation values, such as Lord Howe Island, In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. and islands in the Archipelago of the Recherche. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. Island populations are generally considered to be pests but the feral goats on North Goulburn Island provide a source of trophy animals for a safari operation run by the Aboriginal owners and also provide food for the owners while they visit the island. Feral goats have been eradicated from several islands including Faure Island, Bernier Island, Woody Island In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. and Townshend Island. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. The establishment of new island populations is now less likely than in the past, especially in South Australia where the Animal and Plant Control Act 1986 prohibits the keeping and release of goats on nearly all islands in that state. The chance of natural colonisation of islands is remote as goats will swim (or even wade) only under dire need, In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. but perhaps not impossible because goats have been reported to swim to obtain fresh water.
There were about 2.6 million feral goats in Australia in 1993 but this number has fluctuated widely. The fluctuations in number depends upon the quality of available food, availability of water, natural predation, hunting by people and deaths due to diseases, parasites and poisonous plants.
Economic impact
Feral goats are responsible for an estimated loss of $25 million per year. These are derived from a calculated $17.8 million net loss due to reduced stock production, $6 million In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. contingency loss due to the threat of exotic disease and $1.2 million spent by the government agencies on goat control operations. This estimate does not include the costs associated with the impact of feral goats on the environment, of soil erosion, or pastoral degradation.
Commercial exploitation of feral goats is a valuable industry. Many pastoralists in Australia now consider the capture and sale of feral goats to be an essential part of their business. Meat for export is the main product from feral goats. Some live feral goats are also exported. Goat skin is a by-product. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. Recently, feral goats have been crossed with the South African Boer goat to produce a heavier animal for export.
According to Meat & Livestock Australia, 2,364,307 goats were slaughtered in Australia in 2023. The bulk of them were feral rangeland goats, captured and gathered through goat depots, and then sent to an abattoir.
As of the early 2020s, Australia was responsible for only 0.4% of worldwide goat meat production, and its domestic market was small; only 9% of locally produced goat meat was consumed there. However, the country was also the world's largest exporter of the product: 35% of all of its exports, accounting for 44% of its global export value, or . Most of Australia's goat meat exports were in the form of frozen whole carcasses. The country's biggest market for the product was the United States, with an average 60% volume share in the first half of the decade.
Feral goats are also used as a biological method of controlling weeds such as blackberry (Rubus fruticosus), briar (Rosa rubiginosa), In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. serrated tussock (Nassella trichotoma), St John's wort (Hypericum perforatum) and thistles (family Asteraceae). They are particularly useful for controlling heavy weed infestations in difficult terrain. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. Goats have a preference for such weeds over other pasture species. Control of these weeds is usually expensive and herbicides are not appropriate in some environments.
Environmental impact There are no documented examples of feral goats severely damaging large areas in absence of other herbivores, but they contribute their share of damage to the vegetation, soil and native fauna in areas of overgrazed pastoral land. Feral goats can deplete the soil's protective cover of vegetation and break up the soil crust with their hooves. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. This leads to wind erosion during droughts, water erosion during rain storms and can cause slips in steep areas. Increased erosion rates can have a significant long-term impact on biodiversity through the removal of soil and nutrients, and the alteration of soil structure leading to reduction in potential productivity. Feral goats may also affect perennial vegetation by feeding on established plants and by preventing the regeneration of seedlings. These goats, by browsing, can kill established plants by defoliation. They affect the regeneration processes indirectly when they reduce the ability of plants to produce seeds and directly when they eat young plants. Feral goats are particularly devastating to island ecosystems, causing direct and indirect impacts through overgrazing, which often results in ecosystem degradation and biodiversity loss.
It has also been found that the removal of feral goats leads to a decline in introduced annual grasses and an increase in native woody perennials and introduced fire-promoting perennial grasses. So, even though the initial impact of goats is often difficult to assess, elimination of goats may lead to increases in fire frequency and further invasion by introduced grasses.
Impact on native fauna Feral goats affect the native terrestrial fauna of Australia by direct competition for resources such as food, water and shelter, and by contributing to changes in ecosystems. These impacts are usually undesirable because they reduce the biodiversity of the ecosystem.Reeves, A. (1992) Goats as a threat to conservation. Pp.21-22 in: D. Freudenberger ed., Proceedings of the National Workshop on Feral Goat Management. Bureau of Resources Sciences, Canberra. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. Feral goats compete with domestic livestock for food and water, although dietary overlap in some habitats may be high only when food is limiting. When it comes to water, feral goats can even exclude some animals aggressively.Norbury, G. (1993) The use of 1080 to control feral goats in Western Australia. Appendix 3 in: The proposed use of 1080 to control feral goats in Western Australia. Public Environmental Review EPA Assessment No. 752. Agriculture Protection Board of Western Australia. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. The goats can cause water levels in rock holes to be so lowered as to exclude other animals or cause animals to fall in, drown and consequently, pollute the supply. Goat dung can be deposited around waterholes and springs to a depth of several centimetres. Dung, along with the bodies of goats that fall in water and decompose, is likely to eutrophicate the water and have a major impact on the freshwater biota. Feral goats also compete with the native animals for shelter especially in rock caves. They have also found to eat some invertebrates such as gall-forming and scale insects. But whether this deliberate or incidental is unknown.
Goats are also considered a serious threat to yellow-footed rock-wallaby (Petrogale xanthopus) populations as there is considerable overlap in both species’ diet and habitat.Dawson, T.J. and Ellis, B.A. (1979) Comparison of the diets of yellow-footed rock-wallabies and sympatric herbivores in western New South Wales. Australian Wildlife Research 6: 245-254. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. Rock-wallaby numbers recovered after the 1983 drought in Gap Range, New South Wales where goats had been culled but concurrently failed to recover at the nearby Coturaundee Range, where goats were present in very high densities because they were not culled.Lim, L.; Sheppard, N.; Smith, P.; Smith, J. (1992) The biology and management of yellow-footed rock-wallabies Petrogale xanthopus in New South Wales. New South Wales National Parks and Wildlife Service Species Management Report 10. Sydney. In Parkes, John; Henzell, Robert; Pickles, Greg (1996). Managing Vertebrate Pests: Feral Goats. Canberra: Australia Government Publishing Service. Feral goats have been implicated in the decline of the brush-tailed rock-wallabies (Petrogale penicillata) in South Australia.