There are three species of rat present in New Zealand. Kiore arrived here with the Polynesians much earlier than the Norway Rat and the Ship Rat which came ashore from sailing ships in the late 18th century. Rats are omnivorous and opportunistic and will eat anything palatable. They will eat indigenous birds, their eggs, lizards and invertebrates.
Populations of all three species of rats exist in New Zealand's North, South and Stewart Islands. Population levels vary from habitat to habitat. In Marlborough, populations of all three species of rats exist in most habitats.