Travels with my mouse - New Zealand's other immigrants

6 October 2008
A study of the humble mouse in New Zealand shows shipwrecks and trading boats brought mice here far earlier than settlers did.

Waikato University researchers have been involved in a project with researchers at York University in the UK and a former Waikato PhD student, now at Massey University.

The York study found a distinct strain of house mice probably arrived in northern Britain with the Vikings. In New Zealand, the researchers have shown that strains of Asian mice are established in the lower South Island - most likely arriving with the Chinese gold miners.

Waikato University mammal expert Dr Carolyn King says there were no reports of mice in the lower South Island before the 1850s. "Because the Asian strain is so dominant in that area, it means there probably weren't European mice there already and that they could have come with the Chinese gold miners from Canton after 1869."

Trading boats, or fishing or sealing boats were probably also responsible for introducing mice, the researchers found. The Chatham Islands has a particular strain of Asian mice, which could have arrived because of the shipwreck there in 1853 of the Randolph - an English barque trading from China to the Chatham Islands via Melbourne.

Dr King says the strains from the Western European house mice show up strongly throughout most of New Zealand, most likely due to migration to New Zealand from that part of the world after 1840. "People who moved out here from Britain, for example, had boxes and trunks on the ships and straw and hay to feed their domestic animals on the voyage. This gave the mice somewhere to hide - and they needed to hide because they were sharing the ships with rats that would eat them."

Most ships arriving in New Zealand around that time came from Britain, and they usually called at Cape Town, Sydney and other Australian ports on the way. An estimated 500,000 settler had arrived by 1881, according to historian Michael King.

The research into the mouse origins in New Zealand began in 1999 when Waikato University masters student Paul Jamieson decided to find out which of the two European subspecies of mice were here. Later, Mark Stevens, a Waikato University post-doctoral fellow, analysed specimens from the sub-Antarctic islands. Waikato University's Dr King, geneticist Dr Chrissen Gemmill and Dr Stevens collaborated further with the York team and unexpectedly discovered the presence of mice of Asian stock in New Zealand.

A wild mouse of Asian stock

MOUSEY BUSINESS - A wild mouse of Asian stock pictured in southern Fiordland. Photo: Carolyn King.