Introduced Birds and Mammals in New Zealand and Their Effect on the Environment.
Tuatara 27 (2): 77-104 (December 1984).
Thirty three species of introduced birds and thirty two species of introduced mammals are now widely accepted as a part of New Zealand fauna. The history of the introduction of these vertebrates into New Zealand is documented, and consideration is given to their effect on the native vegetation and fauna. The status of introduced mammals in the late 1940's (Wodzicki 1950) is compared with the present, and the success of control is discussed. Improved technology and the high export value of quality animal products led to a population decline of certain mammals as farming became commercially viable. While the distribution of many introduced mammals has expanded, population numbers have generally decreased since the first survey. A notable exception is the possum.