A number of introduced species, some of which have become invasive species, have been added to New Zealand's native flora and fauna. Both deliberate and accidental introductions have been made from the time of the first human settlement, with several waves of Polynesian[1] people at some time before the year 1300,[2] followed by Europeans after 1769.[3]
Almost without exception,[4][5] the introduced species have been detrimental to the native flora and fauna, but some, such as farmed sheep and cows and the clover upon which they feed, now form a large part of the economy of New Zealand. Possibility of introduced herbivores (deer) to serve as ecological proxies for extinct moa has been questioned.[6][7][8][9][10][11][12]
Biosecurity New Zealand maintains registers and lists of species that are invasive, potentially invasive, or a threat to agriculture or biodiversity.[13] They also manage a small number of species under the National Interest Pest Responses (NIPR) programme. The rainbow lorikeet is the one animal that has been covered by the NIPR, and was eradicated in 2014. All the other species covered by the NIPR, past or present, are weeds.[14]