The only native land mammals in New Zealand are two species of bats. However, we also have several species of marine mammals that can often be found around the coast, and many whales and dolphins at sea. Unfortunately we also have several species of introduced mammals, and these foreign pests have decimated many of our indigenous ecosystems — driving many species to extinction.
Four species of rodents have been introduced by people to New Zealand. The impact of each species varies, but as a group they have been catastrophic for our endemic wildlife which are completely naive to mammalian predation.