Mainly during the period 1860–80 numerous attempts were made to introduce overseas birds from Europe, North America, and Australia. Of these, 25 species became permanently established. In the main they are birds of the parks, gardens, orchards, and of pastoral land with its hedgerows and plantations: they are tree-inhabiting birds. In the present-day landscape these introduced birds are a familiar and well established element, in association with certain of the originally forest-inhabiting native birds. The following are almost universally distributed, their origin being in the British Isles or Europe: song thrush (Turdus musicus), blackbird (Turdus merula), hedge sparrow (Prunella modularis), greenfinch (Chloris chloris), goldfinch (Carduelis carduelis), redpoll (Carduelis flammea), chaffinch (Fringilla coelebs), yellow hammer (Emberiza citrinella), house sparrow (Passer domesticus), starling (Sturnus vulgaris), rook (Corvus frugilegus) (some districts), and (only in the South Island) little owl (Athene noctua). The Australian white-backed and black-backed magpies (Gymnorhina hypoleuca and G. tibicen) are also familiar; as is the Indian myna (Acridotheres tristis) in much of the North Island. The skylark (Alauda arvenis) is everywhere a common farm-land and open-country bird (it extends to the highest mountains). The game birds, of varying origin, include the pheasant (Phasianus colchicus), Californian quail (Lophortyx californica), Himalayan chukor (Alectoris graeca) (South Island districts), and Australian brown quail (Synoicus ypsilophorus) (northern North Island).

It is perhaps remarkable that, apart from the game birds, the importations were largely based on sentiment, and only in a few instances were birds brought with a view to their utility to agriculture. While there may be limited competition between native and introduced species (e.g., for nest holes between kingfisher and starling), the blend of the few widely distributed natives with these introduced birds has probably developed into a stable bird fauna. There is not likely to be further penetration by introduced birds into the remaining extensive tracts of native forest: three of the introduced species (blackbird, song thrush and chaffinch) have spread into this habitat; and the hedge sparrow is an inhabitant of the forest edge.