Australian and New Zealand mammal species considered to be pests or problems.

In New Zealand and Australia, 25 and 16 introduced mammals are viewed as pests, respectively, as well as a further 17 native mammals in Australia. Most introductions were deliberate and the deleterious effects became apparent later. These pests affect primary production, act as a sylvatic reservoir of disease, cause degradation of natural ecosystems, or threaten rare or endangered native animals and plants. Many species have multiple impacts. In Australia, some native mammals, particularly kangaroos and wallabies, are also controlled because of their adverse impacts on primary production. In both countries, current control depends largely on the use of poisons, shooting, the spread of disease (in the case of rabbits), trapping, habitat alteration, and commercial or recreational hunting. Methods of control by interfering with fertility (immunocontraception) are currently being investigated for rabbits, house mice, foxes, and kangaroos in Australia, and for the brushtail possum in New Zealand. If these methods prove effective, they may be applied to other mammal pests, but the need to tailor the particular approach to the ecology and behaviour of the species means that there will be a necessarily long lead time.