What Are Mustelids and Why Are They a Problem?

Mustelids – including stoats, ferrets, and weasels – were introduced to New Zealand in the late 1800s to control rabbits. Unfortunately, they also prey on our native wildlife. With no natural predators and a fast breeding cycle, they have become one of the most damaging pest groups in Aotearoa. Mustelids are agile hunters that feed on birds, eggs, lizards, and invertebrates, placing huge pressure on threatened species such as kiwi, whio, and skinks.

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The Impact on Native Wildlife

Unlike many introduced pests, mustelids are skilled climbers and swimmers, giving them access to nests in trees, burrows, and waterways. They can travel long distances in search of food and will kill more than they need for a single meal. This “surplus killing” behaviour means even a small number of mustelids can devastate local wildlife populations in a short time.

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How Mustelid Control Works

Effective mustelid control involves a combination of trapping, habitat management, and long-term monitoring. Kill traps designed to meet humane standards are commonly used in conservation projects, alongside regular checks to ensure traps are set correctly and bait is fresh. In some areas, community trapping networks work together to cover larger landscapes, reducing reinvasion and giving native species a chance to recover.

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How You Can Help

If you live near bush, farmland, or waterways, you can contribute by setting approved traps on your property and reporting sightings. By working together, we can protect Aotearoa’s unique wildlife for future generations.