European Red Fox
The economic impact of foxes in Australia has been estimated at around $227.5 million per annum. This includes $17.5 million in sheep production losses, $190 million in environmental impacts, $16 million in management costs and $4 million in research costs.
Foxes are considered a threat to 14 species of birds, 48 mammals, 12 reptiles and two amphibians, with the orange-bellied parrot, spotted quail-thrush (from Mt Lofty Ranges), herald petrel, Gilbert's potoroo and western swamp tortoise listed as critically endangered.
In 2009 the national impact of rabbits through lost agricultural production was estimated at $206 million per annum. In combined data for Tasmania and Victoria rabbits are estimated to have cost approximately $30 million in lost production for the beef, lamb and wool industries per year.
Rabbit damage to native vegetation can seriously disadvantage native animals. In certain areas, rabbits are in direct competition with native wildlife for food and habitat. Ecological changes associated with high rabbit numbers have been blamed for the disappearance of the greater bilby Macrotis lagotis, and the pig-footed bandicoot, Chaeropus ecaudatus, and for putting many other species under stress.
Parks Victoria estimates that the annual cost to the state caused by feral cats is close to $150 million per annum.
Feral cats are thought to be involved with the extinction of Australian native animals and have been implicated in the failure of endangered species reintroduction programs (eg. numbat, bilby, bandicoot).
It is estimated that approximately 100 endangered and threatened species are at risk from feral cat predation in Australia.
Damage by feral pigs is estimated to cost Australian agriculture over $100 million a year. Feral pigs can kill and eat young lambs, compete with livestock for pasture and drought feed, and damage fences and waterholes.
Feral pigs are known to prey on earthworms, insects, amphibians, reptiles, ground-nesting birds, small mammals, freshwater crayfish, frogs, turtles and their eggs.
Feral pig activity also has a dramatic effect on watercourses and swamps. By wallowing and rooting around the waterline, they destroy the riparian vegetation which provides food and nesting sites for native wildlife and helps to prevent soil erosion.
The cost to Australia as a whole is estimated at up to $25 million per annum Feral goats cause considerable environmental impacts in Victoria. Feral goats cause land degradation through soil damage, over grazing and strip browsing. The soil's crust and its protective cover of vegetation are disturbed through trampling by the goat's hooves
Feral goats are a major environmental and agricultural pest throughout Australia. Competition and land degradation by feral goats is listed as a key threatening process under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).