Parrots of New Zealand
New Zealand is geographically isolated, and originally lacked any mammalian predators, hence parrots evolved to fill habitats from the ground dwelling kākāpō to the alpine dwelling kea as well as a variety of forest species. The arrival of Māori, then European settlers with their attendant animals, habitat destruction and even deliberate targeting, has resulted in their numbers plummeting. Today one species is on the brink of extinction and three other species range from vulnerable to critically endangered. Further parrot species were not introduced by acclimatisation societies, but occasion releases, both deliberate and accidental, have resulted in self-sustaining populations of some Australian species.
Apart from the occasional bird blown in from Australia, all the parrot species naturally occurring in New Zealand are found nowhere else (endemic). There are eight surviving parrot species endemic to New Zealand.
The mainland species are the kea (Nestor notabilis), the New Zealand kaka (Nestor meridionalis), the kākāpō (Strigops habroptila), and three species of kākāriki: the yellow-crowned parakeet (Cyanoramphus auriceps), the red-crowned parakeet (Cyanoramphus novaezelandiae) and the orange-fronted parakeet (Cyanoramphus malherbi).
The other New Zealand parrot species are the Chatham kaka (N. sp.) and Chatham parakeet (Cyanoramphus forbesi), from the Chatham Islands, and the Antipodes parakeet (Cyanoramphus unicolor) and Reischek's parakeet (Cyanoramphus hochstetteri), endemic to Antipodes Island.
The total kākāpō population of 126 individuals (2012) is being carefully managed to save it from extinction. Malherbe's parakeet is critically endangered, the kākā is listed as endangered, and the kea is vulnerable.
An unidentified parakeet lived on Campbell Island, but was extinct by 1840, so had disappeared before it could be scientifically described. The Chatham Island kaka (Nestor sp.) was extinct by 1550–1700, so is only described from sub-fossil remains., and the Norfolk Island kaka (Nestor productus) was extinct by 1851.
Various Australian species have either been deliberately introduced or accidentally released. But only two appear to have significant self-sustaining populations - the eastern rosella (Platycercus eximius) and the sulphur-crested cockatoo (Cacatua galerita). Crimson rosellas (Platycercus elegans) and Galahs (Cacatua roseicapilla) may be present in small numbers.
The eastern rosella can be found in the northern half of the North Island (i.e. north of Taupo), the Wellington Region, and in the hills around Dunedin. It is reported that an attempt to import eastern rosellas about 1910 was refused by customs, so the birds were released at sea off the Otago heads resulting in the present Dunedin population. The Auckland population dates from about 1920 and the Wellington one from about 1960. As early as 1928 the rosella was reported as being a pest around Auckland.
The sulphur-crested cockatoo population appears to be result of escapes of captive birds which have built to a total population of fewer than 1000 birds. Feral birds were first seen in the Waitākere Ranges in the early 1900s. There are now populations in the Auckland Region, western Waikato, the Turakina–Rangitīkei region, Wellington Region and Banks Peninsula.
Around 1992 an attempt was made by a breeder to establish a wild population of rainbow lorikeets around Auckland. The species was considered a competitor to native species and a threat to horticulture. So in 1999 it was declared an 'unwanted organism' under the Biosecurity Act, and a plan to remove the estimated 200 feral birds was made. Live trapping of the birds was carried out  The population appears under control, and there is an ongoing program to ensure they do not establish a self-sustaining wild population.
- One of world's rarest birds flourishing after DOC work, press release by Chris Carter, Minister of Conservation, 20 January 2006. Retrieved 22 January 2010.
- Millener, P. R. (1999). "The history of the Chatham Islands' bird fauna of the last 7000 years – a chronicle of change and extinction. Proceedings of the 4th International meeting of the Society of Avian Paleontology and Evolution (Washington, D.C., June 1996)." Smithsonian Contributions to Paleobiology. 89: 85–109.
- BirdLife International (2008). "Nestor productus". IUCN Red List of Threatened Species. Version 2008. International Union for Conservation of Nature. Retrieved 24 December 2008..
- Falla RA, Sibson RB & Turbot EG (1966) A Field guide to the birds of New Zealand. Collins, London (ISBN 0-00-212022-4)
- Te Ara: The encyclopedia of New Zealand online
- Notornis (Ornithological Society of New Zealand journal), 2002
- "ROSELLA PARAKEETS" Evening Post, Volume CVI, Issue 27, 4 August 1928, Page 11
- Department of Conservation and Land Management (February 2005). "Impact of the Rainbow Lorikeet" (PDF).
- Department of Conservation (1999-07-15). "aussie lorikeets join unwanted list". Archived from the original on April 28, 2001.
- Department of Conservation (2001-01-16). "lorikeets head north for summer?". Archived from the original on April 29, 2001.
- Department of Conservation. "Rainbow lorikeet: Animal pests".