The single biggest threat to native biodiversity in suburban Auckland is the rat. A single pregnant female at the start of summer can lead to hundreds of rats. Significantly reducing their numbers has been proven to give native wildlife a chance. To do that we need a rat trap in every fifth back garden, or every 50 metres in reserves.
Aotearoa was rat-free until Polynesians brought the kiore (Rattus exulans) here around 700 years ago. Some Māori consider it a taonga and the kiore is not an Urban Ark target species. In suburban Auckland, the kiore has long been out-competed by bigger and more voracious rodent invaders brought here from Europe.
Ship rat (Rattus rattus; aka black rat, roof rat or house rat). This long-tailed rodent is the predominant rat in most areas in NZ. It is a great climber and generally looks darker than the Norway rat. In suburban Auckland, ship rats may reproduce year-round and have as many as 5 litters per year with 4–8 young per litter.
Norway rat (Rattus norvegicus; aka brown rat, common rat or sewer rat ). Generally larger than a ship rat but with a shorter tail, the Norway rat doesn’t generally climb but is an excellent swimmer. You’ll find them all over Auckland but particularly close to waterways, wetlands and beaches.
While we accept that poison bait is an important element in the predator-free toolkit, we encourage people to trap rats. As long as it is done humanely, we don’t mind which traps people use, but many of our groups favour the Victor Pro trap (like a giant traditional mouse trap). These are typically deployed in a wooden tunnel which protects curious fingers, household pets and non-target species. See our Setting rat traps page.
Be part of a team
We encourage trappers to become part of a team by joining your local group. Some groups have a membership and formal meetings, but most are just a collection of people out there trapping in their back gardens and doing the occasional planting session. Your group will:
- supply you with a trap and tunnel (either free or for a small donation)
- encourage you to check your trap 2–3 times a week, or even daily
- encourage you to record your catches
- keep you informed about trapping successes in your area