A number of introduced species, some of which have become invasive species, have been added to New Zealand's native flora and fauna. Both deliberate and accidental introductions have been made from the time of the first human settlement, with several waves of Polynesian people at some time before the year 1300, followed by Europeans after 1769. Almost without exception, the introduced species have been detrimental to the native flora and fauna but some, such as sheep and cows and the clover upon which they feed, now form a large part of the economy of New Zealand. Registers, lists and indexes of species that are invasive, potentially invasive, or a threat to agriculture or biodiversity are maintained by Biosecurity New Zealand.
A small number of invasive species of New Zealand origin are creating problems in other countries.
The domestic cat (Felis catus or Felis silvestris catus) is a small, usually furry, domesticated, and carnivorous mammal. It is often called the housecat when kept as an indoor pet, or simply the cat when there is no need to distinguish it from other felids and felines. Cats are valued by humans for companionship and their ability to hunt vermin and household pests.
Cats are similar in anatomy to the other felids, with strong, flexible bodies, quick reflexes, sharp retractable claws, and teeth adapted to killing small prey. Cat senses fit a crepuscular and predatory ecological niche. Cats can hear sounds too faint or too high in frequency for human ears, such as those made by mice and other small game. They can see in near darkness. Like most other mammals, cats have poorer color vision and a better sense of smell than humans.
Despite being solitary hunters, cats are a social species, and cat communication includes the use of a variety of vocalizations (meowing, purring, trilling, hissing, growling and grunting) as well as cat pheromones and types of cat-specific body language.