Pest Control

Total pests trapped since May 2001 - 2024

Pest control in the Whakatāne Kiwi Project area is carried out mostly by volunteers of the Whakatāne Kiwi Trust. There are currently more than 90kms of trapping lines that cover over 2000 hectares of kiwi habitat! Pest control is focused on mustelids (ferrets, stoats and weasels), rats, possums and feral cats. More recently, the Whakatāne Kiwi Trust has also been carrying out vespula wasp control to reduce the number of wasps in the project area that compete with native birds for food and eat native invertebrates.

The biggest threat to kiwi chicks are stoats and in an area with no stoat control kiwi chicks have less than 5% chance of surviving. The ongoing pest control in the Whakatāne Kiwi Project area has enabled the kiwi population to grow from just 4 adult pairs to over 350 kiwi! Consistently low numbers of rat and possums have allowed the other native bird life to flourish as well creating a positive impact on the whole ecosystem.

Main threats to Kiwi:

#1 Mustelids

#2 Cats

#3 Dogs

#4 Other

Which mustelid have you trapped?

Here are some photos to help show the differences between weasels, stoats and ferrets.

Generally stoats are bigger than weasels and they have a black bushy tip on their tail, while weasels have a straight brown tail. Stoats have a straight line between the creamy white underbelly and brown back whereas weasels have a more uneven line and spots of brown under their chin, this can be remembered by thinking of straight stoats and wavy weasels. A ferret is the largest of the three and looks quite different to the smaller stoats and weasels. If you are still unsure which mustelid you have trapped send us some photos through to admin@whakatanekiwi.org.nz.

Stoat or Weasel? How to tell them apart

A ferret family walking on dry leaves on the forest floor, with one large ferret leading and two smaller ferrets following closely behind.
A small, brown animal with a white underside and face, dark eyes, and sharp teeth, standing on a forest floor covered with dry leaves and green plants.

Stoats are much larger than weasels, approx 34-40cm in length nose to tail. They can also be distinguished from weasels by the presence of a large bushy black tip on their tail.

A small brown ferret standing on a forest floor covered in dry leaves and green plants, with its mouth open showing small teeth.

Weasels are smaller, 18-21cm long. They also have no black tip on their tail.

A ferret on the forest floor surrounded by fallen leaves, showing its sharp teeth and dark fur on its face and tail, with a lighter brown and yellowish fur on its body.

Ferrets are much larger than either a weasel or a stoat, approx body length of 32-46cm. If you include its tail, these creatures can reach over 50cm in length.

A small mammal, likely a Weasel, lying on its back on a forest floor covered with dry leaves, with paws raised and belly exposed.

Stoat’s white underbelly edges are straight, hence the phrase 'straighty stoaty'.

Dead mouse lying on forest floor surrounded by dry leaves.

Weasels white underbelly is jagged and uneven, hence the phrase 'wavy weasel'. Also note the brown spots under the chin of the weasel, another distinctive feature of this animal.

Baby animal, possibly a bear cub, lying on its back on a bed of fallen leaves and twigs.

Ferrets you can easily tell by its patchy body fur and black feet.

Cats and Dogs

  • A tabby cat with green eyes lying on a tree branch surrounded by green leaves.

    Cats

    Cats have a major impact on native birds, bats, lizards, wētā and other insects. Feral cats are one of the most ferocious predators in our ecosystem.

    They feed on rabbits, birds and bird eggs, rats, hares, bats, lizards, mice, wētā and other insects. It is estimated that cats kill up to 100 million birds in New Zealand each year.

  • A black and white dog on a forest trail, intently observing a small brown bird perched on a branch next to a tree

    Dogs

    Dogs are a huge threat to kiwi due to kiwi’s strong smell, habit of living in shallow burrows and lack of ability to fly, it only take one shake by a dog and its rib cage is crushed.

    Once a dog has killed a kiwi, they develop a taste for kiwi and will most likely kill again; one dog can decimate a kiwi population.

Other

  • A Tasmanian devil on a fallen log in a dense green forest.

    Possums

    Possums destroy native trees and shrubs, and eat the berries needed by native birds. They also eat New Zealand’s native land snail, lizards and insects, and chase birds off their nests to eat the chicks and eggs.

  • A hedgehog with spines and a young face, surrounded by fallen autumn leaves.

    Hedgehogs

    Hedgehogs are not kiwi killers, but they do compete with kiwi for native insects and snails. Hedgehogs also eat lizards and the eggs of ground nesting birds.

  • A small rodent with gray fur and a long tail stands among green foliage and branches near a body of water.

    Rats and Mice

    Rats and mice are usually in the bush in large numbers. They pose two problems for kiwi. Firstly, they degrade native forests by eating the fruit that native birds depend on for food and the forest needs for natural regeneration. Secondly, they are food for the kiwi’s predators including mustelids and cats which means they inadvertently help keep the populations of these lethal predators high.

  • A pig in a forest setting with green foliage and sunlight filtering through the trees.

    Pigs

    Pigs cause significant rooting damage to the forest floor and pasture areas. Pigs compete with kiwi for earthworms, a crucial component of the kiwi’s preferred diet. Furthermore, the destructive behaviour of pigs extends to ground nesting birds, as they are known to consume both the birds and their eggs.

  • Two wasps on a paper wasp nest with a wasp carrying an insect.

    Wasps

    Wasps - New Zealand has five social species of wasps that have been accidentally introduced since the 1940s and are classed as pests (German and common wasps, and three species of paper wasp).  Introduced wasps are a significant pest which harm our native birds and insects (especially for competition of food sources), and are a threat to human health and recreation.

  • A deer lying down in a lush green forest surrounded by ferns and dense foliage.

    Browsers

    Browsers including deer, wallaby, and goats, exert significant impact on forest habitats through their destructive feeding behaviors. These animals contribute to the degradation of the forest environment by engaging in activities such as ring barking trees and stripping vegetation from the forest floor. These browsers pose a threat to the forest ecosystem by targeting various elements, including seedlings, saplings, and fallen leaves .  Their degradation of the habitat of the forest floor impacts on the food available for kiwi and other native species.