Rats feed on lizards, young plants, seeds, bird eggs and chicks, they also threaten other native species as they eat invertebrates, frogs and a variety of fruit. Controlling rats is the responsibility of land owners, however Waikato Regional Council is happy to provide advice to anyone who wishes to undertake rat control on their property.
There are two introduced European rat species in New Zealand.
Rattus novegicus, commonly known as the norway rat, water rat or brown rat, is the largest rat in New Zealand.
Norway rats are competent swimmers and are commonly called ‘water rats’. This ability enables them to colonise offshore islands. In favourable conditions a crossing of 600 metres is possible.
Rattus rattus, commonly known as ship rat, root rat or black rat, is the most widespread rat in New Zealand.
Although rarely seen, ship rats are the biggest threat to breeding birds as they are exceptional tree climbers.
Watch our video of ship rats predating on native birds:
Making your backyard unfavourable to rats is probably one of the simplest means of control. Clearing your backyard of rubbish or any scrubby weed areas, as well as enclosing your compost heap, will mean that rats will have less habitat to live in on your property.
The most effective time for control is in the winter and spring. Rat ‘snap traps’ are available from hardware stores and some supermarkets. Locate traps in places where rats are likely to live, or where signs of rats are seen. Bait traps with peanut butter or chocolate, ensuring the bait is firmly attached to the bait pedal. If traps are placed outside they need to be covered or placed in a tunnel to avoid accidents by pets or children.
Some rat specific baits, such as ‘Natural No Rats’, have no secondary poisoning effects, making them a much safer option for use around cats and dogs. Other bait such as ‘Pestoff’ is effective on both rats and possums. Extreme caution should be taken when using any poison around pets – not just your own but your neighbours’ too. Bait stations should always be used when using any bait. Rat bait and bait stations can be purchased from farm supply stores, hardware stores and some supermarkets.
Possums affect native birds by preying on their eggs and young, and competing with native birds by eating young leaves, flowers and fruit. They also ruin fruit trees and roses, carry bovine Tb, and generally cause a nuisance. Controlling possums is the responsibility of land owners, however Waikato Regional Council is happy to provide advice.
Browsing possums often leave behind distinctive signs, such as discarded and partially eaten leaves, flowers and fruit. They often leave behind the leaf stalk, base and mid-rib and tattered leaf remains. Heavy and persistent possum browsing will kill a tree.
Other possum signs to watch for include:
Waikato Tree Trust have Timms traps available for gully restorers to borrow. Timms traps are lightweight and easy to set. They can effectively control possums in small to moderate sized areas, such as urban gardens and gullies.
When using Timms traps make sure that you:
To borrow a Timms trap email Kirsten Gerry or phone 07-8566563 (please leave voice message if not available).
Check out our information on possums.