Overview
The latter half of the 19th century saw large areas of native vegetation converted to farmland throughout New Zealand. Sheep, cattle and horses were imported in large numbers and it was inevitable that many animals strayed into the nearby bush and became feral. The introduction of domestic stock had a huge impact on Māori society which had been based on fishing as the main source of protein. Once the feral populations built up in number they radically altered large areas of vegetation and indirectly impacted populations of endemic birdlife. As settlement progressed the feral animals were pushed further into the back country and today wild horses are restricted to the central volcanic plateau and areas of northland, while wild sheep and cattle are found in many remote areas, but have been eliminated from most offshore islands. The recognition of some island populations of feral animals having unique genetic values (e.g. Enderby Island cattle)resulted in some animals being captured and returned to New Zealand before the remainder were destroyed.
Today some feral populations, such as the Kaimanawa horses, are regarded as an iconic feature of the New Zealand volcanic plateau environment, despite the damage they inflict on native vegetation and ecosystems. The Kaimanawa horse population is listed as a herd of special genetic value by the United Nations' Food and Agricultural Organization, and since 1981 the policy of eradication of the herd has changed to a programme of protection and management through the Department of Conservation.