Ferals

Feral animals are a threat to native animals and plants. These animals compete with native species for food, habitat and shelter and can spread disease and parasites. Some predate on native and endangered species, reducing their numbers dramatically. Others cause major impact by eroding soil and waterways.

Rangelands NRM often work with appropriate groups on control projects, including the Regional Biosecurity Grouops (RBGs).

Key feral species in Australia

  • Feral cats (Felis catus) – Feral cats are the same species as domestic cats, however they live and reproduce in the wild and survive by hunting or scavenging. Feral cats threaten the survival of over 100 native species in Australia. They have caused the extinction of some ground-dwelling birds and small to medium-sized mammals and are a major cause of decline for many land-based endangered animals such as the bilby, bandicoot, bettong and numbat. They can also can carry infectious diseases which can be transmitted to native animals, domestic livestock and humans. Control of feral cats is challenging as they are found in very low densities over large home ranges and are shy, making them difficult to locate. The current control methods of shooting and trapping feral cats are quite difficult, expensive and time consuming and require skilled staff. The most effective form of feral cat control over large areas is poison baiting, and there are currently a number of baits being trialled for feral cats including Curiosity® and Eradicat®.
  • Wild dogs– The term wild dog is used to describe pure-bred dingoes (Canis lupus dingo), feral/escaped domestic dogs (Canis lupus familiaris) and their hybrids. Wild dogs are a major pest species impacting on grazing industries across mainland Australia and their predation on livestock is taking a heavy economic and emotional toll on livestock producers in affected pastoral and agricultural areas. Controlling wild dogs is a complex issue. Some strategies include baiting and barrier or cell fencing.
  • Cane Toads – Cane toads (Rhinella marina, formerly Bufo marinus) were introduced into Queensland and New South Wales in the 1930s to control beetles that were decimating sugar cane crops. Since then, they have been breeding out of control and poisoning native species. Because cane toads aren’t native to Australia, there are no natural predators or diseases that could control them, or keep them in check. In 2009 they spread into the Kimberley region of Western Australia, reaching Kununurra in 2010 and Halls Creek in 2014.
  • Feral camels – Australia may now have the largest wild population of Arabian camels (Camelus dromedarius) in the world. First introduced into Australia in the 1840’s to assist in the exploration of inland Australia, they live in most of Australia’s desert country. Camels add to the total grazing impact, destroy fences, foul water holes, damage cultural sites and are a potential carrier of exotic diseases that may be a threat to livestock.
  • European red fox – Foxes (Vulpes vulpes) are opportunistic predators and scavengers and pose a threat to livestock, preying on poultry, lambs and goat kids. They have few natural predators in Australia.
  • Feral horse – Horses (Equus caballus) were introduced with European settlement and gradually escaped or were released, particularly in cattle country.   Because their diet is similar to cattle, horses cause particular stress during drought. There is also good evidence that horses cause significant environmental damage including fouling waterholes, damage to native vegetation and through soil compaction. Areas used by horses during drought are believed to be important refuge areas for many native plants and animals. The feral donkey (Equus asinus) has a similar impact.
  • Feral pigs – Feral pigs cause agricultural damage through preying on newborn lambs, reducing crop yields, damaging fences and water sources, and competing with stock for feed by consuming or damaging pasture.
  • Feral goats – Australia has an estimated 2.6 million feral goats (Capra hircus) that degrade pasture and impact negatively affect conservation values and biological diversity by damaging the vegetation and competing with native animals. They are, however, also considered by many pastoralists, a resource.  Commercial exploitation of feral goats is now an industry worth about $29 million a year.
  • Feral wild rabbit – Rabbits (Oryctolagus cuniculus) graze on native and introduced vegetation, crops and pastures, which can prevent seedlings from regenerating and reduce crop yields. They compete for feed with livestock and their digging and browsing leads to a loss of vegetation cover, which in turn can result in slope instability and soil erosion. Rabbits also damage native plants and directly compete with native wildlife for food and shelter.

Control methods

Conventional methods of control include fencing, trapping, baiting and shooting. Fencing is used to exclude feral species (such as dogs, cats and foxes) from a particular area. A variety of traps can be used to catch animals, particularly when to come to watering holes to drink. Baiting of feral animals is usually done using the poison 1080 and many native herbivores have evolved a much higher tolerance to 1080 than feral animals. Shooting by trained shooters (particularly from helicopters) is common where ferals are in vast remote areas or in rugged terrain. This is quick and humane. More recently, biological control is being used where pests are controlled by nature predators, parasites or bacteria and viruses.

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