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   Equus caballus (mammal)
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         Interim profile, incomplete information
    Taxonomic name: Equus caballus Linnaeus, 1758
    Common names: feral horse, horse
    Organism type: mammal
    Equus caballus is a large non-ruminant herbivorous mammal that is not dissimlar in appearance to the domestic horse. E. caballus has an average lifespan of 25 - 30 years, with 20 years of sexual activity. While preferred habitat is open grasslands, E. caballus has been also known to invade desert, semi-desert plains, coastal areas, subalpine regions, tropical savannah grasslands, forests, scrublands and wetlands. In some regions they are protected as they are seen as a valuable asset, but in other places they are considered a pest, as they compete with livestock for resources, degrade plant habitats by grazing and trampling, contaminate water sources, damage fences and decrease native biodiversity.
    The feral horse, Equus caballus, is morphologically similar to the domestic horse, standing an average of 1 - 1.6 m high at the shoulder and weighing 350 - 450 kg. General appearance is variable, including coat colour that ranges from black, brown, tan and white to white with patches of orange or brown. Coat hairs are short and fine, tail is relatively short and there is hair present on the forehead (forelock) and along the neck (mane). The average lifespan of E. caballus is 25 - 30 years. (Csurhes et al. 2009).
    Occurs in:
    agricultural areas, coastland, natural forests, range/grasslands, riparian zones, ruderal/disturbed, scrub/shrublands, wetlands
    Habitat description
    While preferred habitat is open grasslands, Equus caballus has been also known to invade desert, semi-desert plains, coastal areas, subalpine regions, tropical savannah grasslands, forests, scrublands and wetlands.
    General impacts
    Equus caballus is a grazer, feeding on approximately 2–2.5% of its bodyweight in plant matter per day. This grazing, along with trampling, contributes to decreases in native plant biodiversity, and can also fracture saturated turf. This can lead to increased opportunity for weed estabishment, soil erosion and water ponding. Soil compaction can be another issue. Changes in community composition related to feral horse populations have been observed for fish, birds, small mammels, reptiles, crabs and ants. Feral horses compete with livestock for resources, can damage fences and water bodies and can foul water sources through fecal contamination. They can also harbour exotic diseases, such as equine influenza, and may introduce and spread weeds via seed present in fecal matter, manes and tails. (Csurhes et al. 2009; Department of the Environment and Heritage 2004; Nimmo & Miller 2007).
    In the Australian Alps, foxes, hares (Lepus europaeus), house mice (Mus musculus), feral horses (Equus caballus) and weeds have all increased their presence at higher altitudes most likely due to changes in climate (Green and Pickering 2002).
    Geographical range
    Native range: Ancestors of E. caballus had a natural range across Europe, Asia (Equus ferus, Equus ferus przewalskii)
    Known introduced range: E. caballus is present in feral populations in Africa, Australia, Argentina, Canada, Chile, Columbia, Falkland Islands, France, Galapagos, Greece, Hawaii, Hispaniola Island, Iran, Kerguelen Archipelago, Mexico, New Zealand, Portugal, Russia, Patagonia, Spain, Sri Lanka, United Kingdom, United States of America (including Alaska), and the West Indies. (Csurhes et al. 2009).
    Management information
    Control methods include fertility control, capturing excess animals and offering adoption, shooting - both ground shooting and aerial via helicopters, trapping, and mustering. (Csurhes et al. 2009; Department of the Environment and Heritage, Australia 2004; Nimmo & Miller 2007).
    Please follow this link to for details on the management of feral horses in Australia
    Compiled by: IUCN SSC Invasive Species Specialist Group (ISSG) with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment
    Last Modified: Tuesday, 8 June 2010

ISSG Landcare Research NBII IUCN University of Auckland