This new addition to a popular series delves into a fascinating field of New Zealand's natural history. In prehistory, only a few bats, marine mammals and odd quadrupeds constituted our local land-breeding mammals; but today these have been joined by a throng of colonisers. These include several carnivores, rodents, and various hoofed mammals from Europe and North America, as well as several marsupials from Australia. Many are unwelcome: some have decimated native birds and reptiles, while others attack the bush; but all are now here to stay and are worthy of study for their interesting habits and ecological impact. In addition to these land mammals are more than two dozen native species of marine mammal, including dolphins and whales. This account from one of New Zealand's premier mammalogists fills a gap in the market.