Horses (Equus caballus) were introduced with European settlement both in Australia and New Zealand. Over time, animals escaped and were released and were first recognised as pests in Australia in the 1860’s. In contrast to Australia, the New Zealand population is protected.
In 1992 Australia was estimated to have 300,000 feral horses, mainly in the cattle raising districts of Queensland, Northern Territory and Western Australia. Smaller populations are located in eastern Australia, mainly in the alpine and sub-alpine areas. The number of horses varies considerably depending on the effectiveness of management programs and the impact of drought and bush fires. For example, it is estimated that the population of feral horses in eastern Australia declined by 70% in 2002/2003 due to the effect of management, drought and bushfires. New Zealand has approximately 1,000 feral horses, mainly at Kaimanawa on the North Island.
Although not well quantified, there is 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 major impact of feral horses is on cattle production. The diet of both is similar and although there is likely to be more pasture than either can consume in normal seasons, competition is great during drought. The presence of feral horses can prevent effective management of pasture and water, especially during drought. While cattle can readily be de-stocked to preserve pasture and breeding stock, feral horses can’t.
Horses are well adapted to the sparsely distributed and unpredictable resources of arid Australia but also do well in the sub-alpine and alpine districts of Australia and New Zealand. They can move up to 50 km a day to food and water and have few predators and diseases. Mortality in arid Australia is mainly associated with drought which causes starvation, lack of water and consumption of usually avoided toxic plants.
Mares breed in spring to summer and on average produce one foal every two years. Under good conditions the population can increase by 20% a year.
The aim of management is to reduce the damage due to horses to an acceptable level. The most common practice is to muster and harvest horses around key points such as feeding areas and water points. Harvested animals can then be sold. Further reduction in density in arid Australia is usually obtained through helicopter-based shooting using highly skilled, trained shooters. On a smaller scale, brumby running (culling the population using horses) and ground shooting may have a role. Fertility control has also been suggested but has limited application for widespread populations because of the difficulty in delivering the fertility agent, which usually has to be administered on a regular basis to ensure ongoing control of the population.
Standard Operating Procedures – feral horse control
- HOR003: Mustering of feral horses - Feral horses (Equus caballus) can cause significant environmental damage and losses to rural industries. Although considered pests, feral horses are also a resource, providing products such as pet meat for […]
- HOR004: Trapping of feral horses - Feral horses (Equus caballus) can cause significant environmental damage and losses to rural industries. Although considered a pest, feral horses are also a resource, providing products such as pet meat […]
- HOR001: Ground shooting of feral horses - Feral horses (Equus caballus) can cause significant environmental damage and losses to rural industries. Although considered a pest, feral horses are also a resource, providing products such as pet meat […]
- HOR002: Aerial Shooting of feral horses - Feral horses (Equus caballus) can cause significant environmental damage and losses to rural industries. Although considered a pest, feral horses are also a resource, providing products such as pet meat […]
- GEN001: Methods of euthanasia - The word euthanasia means an easy death and should be regarded as an act of humane killing with the minimum of pain, fear and distress. Euthanasia of a range of […]
- Model code of practice for the humane control of feral horses - Provides information and recommendations to pest managers responsible for the control of feral horses
- Managing Feral Horses in Namadgi National Park, Australia: A Sensitive Operation - Managing populations of feral horses is a highly contentious issue, not the least because of the high regard in which horses are held by the community. Past attempts to manage […]
- CABI: Invasive Species Compendium - Online encyclopaedic resource that draws together scientific information on all aspects of invasive species (plant and animal) worldwide
- Feral horse – humaneness matrix - Matrix showing the relative humaneness of feral horse control methods. The ‘humaneness’ of a pest animal control method refers to the overall welfare impact that the method has on an […]
- Proceedings of the National Feral Horse Management Workshop - Workshop to discuss current approaches and issues around feral horse management in Australia
- Managing Vertebrate Pests: Feral Horses - A comprehensive review of the history of feral horses in Australia, their biology, the damage they cause, and past and current management
Last updated: July 20, 2016