Overview
Homo sapiens
Of all non-native animals, man has had by far the greatest environmental impact, and is implicated directly or indirectly in all extinctions of native plants and animals since ca.1000AD. The main impact has been through destruction of habitat by fire and axe, and later by machines and chemicals, inadvertent or deliberate introduction of mammalian predators, grazing animals and foreign plants, as well as deliberate hunting of already endangered species. While some species have clearly benefited by the modification of habitats e.g. kingfisher, harrier, ducks, spurwing plover, it is the New Zealand endemic species – those found nowhere else – that have been lost.
Many other animals were liberated - fortunately unsuccessfully, including Zebra, Gnu, Marsupial cat, Bandicoot, Raccoon, Fox, Blue sheep, Alpaca, Llama, Guinea pig, Grey chipmunk, Brown squirrel, Mule deer, Axis deer, Camel, Mongoose, Bear, Cougar, Ringtailed possum, Kangaroo, Roan wallroo and Long nosed rat kangaroo.
Recently, other exotic species have been brought into New Zealand for the pet trade (e.g. chinchilla), but have not become established in the wild. Although otters have occasionally escaped from zoos for short periods, there is no evidence of the existance of a "New Zealand otter" - reported sightings in the late 1800s coincide with areas and dates marsupial cats were liberated.