Rattus exulans

Common Name(s)

Kiore, Pacific rat, Maori rat, Polynesian rat




Kiore occur on a wide range of habitats up to 1300m from very dry to very wet climates, including various grasslands, bracken fernland, shrubland (including coastal shrub areas), secondary and mature forest. They are also can be found in urban habitats. Not a good swimmer, but an agile climber.


Kiore has a slender body and a pointed snout. It has relatively large ears and relatively small, delicate feet. It also has a ruddy brown back and a whitish belly.

Similar Species

Kiore may be mistaken for the other two species of rat in NZ (Rattus rattus, R. norvegicus). However, it maybe distinguished as it is the smallest of the three. In colour it is almost indistinguishable from the ship rat (Rattus rattus).

Threat To Plants

Kiore eat a wide range of foods including seed and fruits of native plants. They also eat insects, lizards and bird eggs and chicks. Research has shown that rats have changed the vegetation on some off-shore Islands. Kiore have substantially reduced recruitment of karo (Pittosporum crassifolium), milk tree (Streblus banksii) and maire (Nestegis apetala) on off-shore islands.


Once widespread; now restricted to Fiordiand, Stewart Island and a number of offshore islands. Kiore also occur on many offshore islands.


Weight: 60-80g; Max. head-body length: 180mm

Year Introduced

Kiore arrived approximately 1280 AD

Reason For Introduction

In some cases it was introduced accidentally as a result of humans arriving by boat on new islands. However, it is thought to have originated from the Malayan region, and to have been deliberately introduced to many islands by Polynesians who considered it a valuable food source (Spennemann, 1997).

Colonisation History

Kiore are poor swimmers and have reached New Zealand mainland and offshore islands through deliberate and accidental introduction by humans. There exists some controversy about the time of arrival of kiore, as 14C bone analysis have given ages between 1205-2155 Bp whereas the Polynesian arrival is generally dated to AD 1250-1300. Till no other sources of evidence can be found the debate will probably persist from some time.