Feral pigs can have major effects on our native flora and fauna, threatening biodiversity. They eat the tops of native plants and dig up their roots, resulting in the decline of some species. Pig rooting (digging in the soil for roots to eat) can decrease the diversity of seedlings and saplings and dramatically reduce leaf cover on the forest floor.

Vegetation is around 70% of a pig’s diet; however, they are opportunistic omnivores (eat both plants and animals) and also feed on many native invertebrates, native land snails and large quantities of native earthworms. They are also a threat to rural properties, as they root up pastoral land and have been known to kill and eat lambs.

• Size: Feral pigs grow anywhere from 90 to 200 centimetres long and weigh 50–90 kilograms. 
• Appearance: Their colour varies from dark grey to brown or black. Adult males develop large tusks that stick out from their mouth. 
• Signs: Hoof markings, scat (droppings), intensive grazing of smaller trees and shrubs, and rooting. 
• Similar species: Pigs are classed as an ungulate (a hoofed mammal). Similar pest species include feral goats and feral deer. 
• Habitat: Feral pigs inhabit a diverse range of environments, including wetlands, native forests, forestry blocks, high country and pastoral land.  

Feral pigs are managed as pests under the Wild Animal Control Act 1977. They can be hunted as a resource, but their control is necessary to prevent damage to native ecosystems, and it is illegal to release them into the wild without a permit.  

To improve and prevent further damage to indigenous ecosystems, feral pigs are in the site-led programme of the Otago Regional Pest Management Plan (2019–2029). The site-led areas are Dunedin's West Harbour (including Mt Cargill, Quarantine island and Goat island) and Otago Peninsula. 

No person shall keep, hold, enclose or otherwise harbour feral pigs in any place, either in transit to or present in site-led areas.  

To achieve this, ORC takes a lead role in supporting the goals of community groups and agencies in site-led areas in relation to feral pigs. This may be through advice, education, funding, or requiring landowners to undertake control when needed. 

For information on controlling feral pigs, visit the Department of Conservation website. 

orc.govt.nz/pig