The stoat is a member of the mustelid family, along with weasels and ferrets. It was introduced to New Zealand in the 1880s to control rabbits and hares but is now a fierce predator of our native species.
Rats have a major impact on New Zealand’s wildlife because they eat native animals and their eggs. They also eat a wide range of native fruit and plants, which puts them in competition with native wildlife for food.
Ship rats (Rattus rattus) do the most damage to our wildlife out of the three rat species found in New Zealand. They are good climbers, so they can access most bird nests high in trees.
Norway rats (Rattus norvegicus) are large enough to kill nesting adult seabirds and prey on animals that live, roost or nest close to the ground.
House mice (Mus musculus) belong to the rat family. Mice, which are smaller than rats, live both in areas of human habitation, and in forest edges and pasture or grasslands. Most active at dusk and dawn, mice feed on invertebrates, vegetation and seeds.
See link at top of right column for a pdf file showing our trapping results.
Trapping at Mangarakau
Pest control has been and continues to be a major task for us. We started in 2004 with what was then considered to be best practise using DOC200 traps, targeting stoats, weasels and rats. Very few mice were caught and were not recorded. Victor Professional rat traps were later introduced as they proved to catch more rats and were considerably cheaper to install. They are also quite effective for mice.
We now have 111 DOC traps, a mixture of 150’s and 200’s, 165 rat traps, predominately Victors and are also trialling Snap Traps. When we started our snail protection area in 2007 we installed Timms possum traps as possums, along with rats are great predators of the snail.
Most of the trap lines are checked every fortnight but some particularly vulnerable lines are often checked weekly. The DOC traps are baited with an egg, rat traps with peanut butter and Timms with apple.
We are now starting to trial the automatic re-setting Good Nature traps and bait stations for rats.
The large spikes of rat numbers caught in 2014 and 2016 we believe to result from the extra heavy fruiting of Kahikatea and Coprosma providing easily available food for the rats.
We are trapping, not only on our land but also 2 areas of adjacent DOC land:
1) the snail patch behind the old Mangarakau school, and
2) the ridge and valleys between us and Lake Mangarakau where we have several pairs of robins breeding.
An extensive range of traps are placed to catch introduced predators preying on wildlife at the swamp.