The province of Alberta, Canada (more than twice the land area of New Zealand) is free of rats.<p>In their case, it was largely by stopping rats entering from the east (Saskatchewan) in the 1950's - there are natural barriers on the other three sides.<p>History: <a href="http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex3441" rel="nofollow">http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agd...</a><p>Still, NZ could be divided into areas that have natural barriers, and peninulas (plenty of them), and start intensive poisoning barriers in those areas, expanding towards the sea.<p>Doesn't need gene editing, which certainly has unknown risks.
>In its raw power, some conservationists see a way of achieving impossible-sounding feats like exterminating an island’s rats by spreading genes through the wild population that make it difficult for the animals to reproduce.<p>How can a gene drive which prevents reproduction spread to the whole population? And wouldn't it be self limiting? I kinda of seems like me to be the opposite of a gene drive.
<i>In 1997, farmers illegally smuggled a hemorrhagic virus into New Zealand to control rabbit pests.</i><p>Interesting. <a href="https://pdfs.semanticscholar.org/798d/8b6f9874ae41d0105b012b8ac61a24f97221.pdf" rel="nofollow">https://pdfs.semanticscholar.org/798d/8b6f9874ae41d0105b012b...</a>