Mammalian predator control

Rat body in trap
Rat humanely killed in DOC 200 trap

Around Miramar, the most damaging pest mammals are rats, mustelids (stoats, weasels and ferrets), hedgehogs, mice and possums. Mammalian pests can be controlled with careful trapping or poison. Both are simple methods but must be done safely and as instructed.

Aside from bats, every land mammal in New Zealand is a recent arrival, impacting on native species ill-equipped to defend against them. It’s simple. If our native plants and animals are to survive then mammalian pests have to go.

Rats

Both the introduced ship rat (black rat) and Norway rat are found on the Miramar Peninsula, the ship rat being more common. Both species are good climbers, easily running along tree branches to access bird nests.

Why are rats pests?

  • Rats compete with native birds and insects for food.
  • Rats eat birds, at any stage from egg to adult.
  • Rats eat skinks and geckos.
  • Rats eat invertebrates, including weta and native snails.
  • Rats eat flowers, fruit, seed and seedlings, damaging forest health and preventing restoration.
  • The Norway rat’s burrows can house large colonies of invasive wasps.

Rat numbers also contribute to seasonal fluctuations of mustelid populations, such as stoats.

How can I tell if rats are near my house?

Rats will leave remains of food, such as seeds and snail shells, under logs, between roots and in other hollow areas. Smashed eggs and chewed bird bodies are likely to be the work of rats. Rats’ nests can sometimes be found in hollow areas, often lined by twigs or leaves.

How can I make my property less rat-friendly?

Don’t encourage rats into your garden with bird food, such as bread and seeds. These also encourage aggressive, non-native birds that can spread diseases. See more in our Non-native birds section.

How can I remove a rat from my garden?

The traps ‘DOC150’, ‘DOC200’ and ‘DOC250’ or the new self-setting A24 from Goodnature are effective and easy to handle with instructions. The trap should be placed along a natural runway. Suitable areas includes along fences, hedges or in bush among tree roots and logs. Traps should be baited. Cat food or fresh rabbit or chicken is excellent but does not keep well. A longer-lasting alternative is an egg, which can be left whole or broken. The Goodnature trap comes with auto-lure bait.

www.goodnature.co.nz
www.predatortraps.com/stockists.htm
www.halo.org.nz

Poison is an effective way to control rodents and can be purchased from supermarkets and hardware stores. Always read and follow the instructions.
Rat and mouse traps can also be used and are available from supermarkets and hardware stores too.

Mustelids

Stoats, weasels and ferrets are all mustelids. Introduced in the 1880s to control rabbits, they quickly became public enemy number one for native birds.

Mustelids are widespread and will live in any habitat where they can find prey. They are agile climbers and fast swimmers. Stoats and weasels hunt by both night and day, covering up to 200 hectares. Their good sense of smell and hearing locates prey.

Dead weasel
Weasel

Why are mustelids pests?

  • Stoats and weasels are fearless and will attack even large birds such as kaka, kea, takahe and kereru. Nesting birds are an especially easy target.
  • Stoats and weasels prey on native species including insects (particularly weta), lizards, freshwater crayfish, birds, eggs and fish.

How can I tell if mustelids are near my house?

Little or no native birdlife could mean predation by these animals.

Prey is usually bloody and bitten around rear neck and back of skull. Mustelids will often feed on the warm blood of prey before actually consuming the prey. Stoats will often catch prey by dragging it under cover, so often no prey remains are visible. Broken eggshells on forest floor could also be signs.

How can I remove mustelids from my garden?

Stoats, weasels and ferrets require careful trapping. Traps might have to be empty for some time before trapping begins as human scent can deter mustelids.

The traps ‘DOC150’, ‘DOC200’ and ‘DOC250’ or the new selfsetting A24 from Goodnature is a multi species kill trap with a highly sensitive leaf trigger. All are effective and easy to handle with instructions. The trap should be placed along a natural runway. Suitable areas includes along fences, hedges or in bush among tree roots and logs. Traps should be baited. Cat food or fresh rabbit or chicken is excellent but does not keep well. A longer-lasting alternative is an egg, which can be left whole or broken. The Good nature comes with autolure bait.

Poison is an effective way to control rodents and can be purchased from supermarkets and hardware stores. Always read and follow the instructions.
Rat and mouse traps can also be used and are available from supermarkets and hardware stores too.

www.goodnature.co.nz
www.predatortraps.com/stockists.htm
www.halo.org.nz

Hedgehogs

Hedgehogs may have contributed to the decline and extinction of several bird species. They were introduced to New Zealand by acclimatisation societies to remind settlers of their homeland and control garden pests such as slugs, snails and grass grubs. Today, hedgehogs are a widespread prickly problem.

Why are hedgehogs pests?

Hedgehogs prey on native slugs and snails and various other native invertebrates such as weta. They are known to eat the native snail Wainuia urnula, a species present in Wellington.

Hedgehogs feed on native skinks and geckos, ground nesting birds and their eggs and chicks. They also eat carrion and some plant materials.

How can I tell if hedgehogs are near my house?

You will usually hear movement and snuffling before a hedgehog is sighted. Droppings are black, sometimes with a dark greenish colour if fresh, 30-50mm long and 7-10mm wide. They are usually dry and often contain fragments of insect exoskeleton.

How can I make my property less hedgehog-friendly?

  • Don’t leave milk or food out for hedgehogs.
  • Set a suitable trap.

How can I remove hedgehogs from my garden?

Trapping hedgehogs is simple. The traps ‘DOC150’, ‘DOC200’ and ‘DOC250’ or the new selfsetting A24 from Goodnature is a multi species kill trap with a highly sensitive leaf trigger. All are effective and easy to handle with instructions. The trap should be placed along a natural runway. Suitable areas includes along fences, hedges or in bush among tree roots and logs. Traps should be baited. Cat food or fresh rabbit or chicken is excellent but does not keep well. A longer-lasting alternative is an egg, which can be left whole or broken. The Good nature comes with autolure bait.

Poison is an effective way to control rodents and can be purchased from supermarkets and hardware stores. Always read and follow the instructions.
Rat and mouse traps can also be used and are available from supermarkets and hardware stores too.

www.goodnature.co.nz
www.predatortraps.com/stockists.htm
www.halo.org.nz

Mice

Often overlooked, the common house mouse (Mus musculus) does impact on native ecosystems. Mice eat native seeds and fruit, harming regenerating bush and depriving ground-living animals of space and food. Invertebrates, skinks and geckos also end up on the menu - in winter a cold blooded skink does not have the energy to escape a warm blooded mouse.

Mice are small with a grey to brown coloration of fur and slightly lighter belly. You’ll usually see their tiny droppings rather than the mouse itself. Mice live in small burrows mostly on the ground, but are capable climbers too.

Poison is an effective way to control rodents and can be purchased from supermarkets and hardware stores. Always read and follow the instructions. Rat and mouse traps can be used and are also available from supermarkets and hardware stores.

Possums

Greater Wellington Regional Council floated the ambitious idea of a possum-free Miramar Peninsula in 2000.

The peninsula was heavily infested with possums and bird life was absent. The eradication started in early 2003 and in the following years tui started breeding on the peninsula once again.

The last known possum on the Miramar Peninsula was a juvenile female trapped near the foreshore in Feb 2006. Only a handful of possums have been discovered since eradication, and they were thought to have been deliberately released.

Let us know if you have seen or heard a possum on Miramar or call the Greater Wellington Regional Council on phone (04) 526 5327.