Mustela erminea

Threats Status

Unwanted Organism

Common Name(s)





Stoats inhabit various habitats from coastal to alpine, wherever they can find suitable prey. They are generally more abundant in forest habitat in comparison to ferrets which prefer open grassland habitat. They may also occur in urban habitats. Stoats are carnivorous with a large proportion of their diet being birds, feral house mice, rabbits and hares, rats, possums and insects. Lizards, fish, crayfish and carrion are less frequently eaten. They are agile climbers and excellent swimmers (1,1km),


Males stoats have long, thin bodies with smooth pointed heads, and their ears are short and rounded. Their fur is dark brown with creamy white under-parts. Stoats have relatively long tails with a bushy black tip.

Similar Species

Stoats may be mistaken for the other two species of Mustelidae in NZ:Ferret (Mustela furo) and Weasel (Mustela nivalis vulgar)

Threat To Plants

Prey on birds, rats, mice, rabbits and insects may also have secondary effects on the vegetation due to changes in ecosystem processes.


Throughout both North and South Island and on islands within 1.0-1.5 km distance the mainland, but absent from many offshore islands such as the Chatham, Great Barrier and Little Barrier, Kapiti and Stewart Island.


Weight: 200g (female), 320g (male); head to body length: 20-31cm

Year Introduced

1884 by Mr Rich of Palmerston

Reason For Introduction

Biological control of rodents

Colonisation History

First introduced to New Zealand by Mr Rich of Palmerston in 1884 (numbers and location unknown). Further animals were released at Lake Wakatipu (55, 1885); Wilkin River, Makarora, Lake Ohau and Waitaki (82, 1886); Marlborough and west Wairarapa (32, 1886); and Orongorongo Valley (55,1886). By the end of the 19th century stoats were widely distributed throughout the North and South Island. In 1936 imports of stoats were restricted and their legal protection was removed.

Control Options

Traps (most common method in New Zealand); Pesticides (through secondary poisoning by feeding on poisoned pray, but rapid re-invasion by stoats from surrounding areas); barriers (fences)