We brought hedgehogs here to save our gardens, but now they’re a 'deadly threat' wiping out our native birds.

In 1885, New Zealand released European hedgehogs to kill garden pests. Now, 140 years later, the Department of Conservation says they are a major threat to native wildlife. These animals eat eggs and chicks, and one hedgehog can cause an entire colony of endangered black-fronted terns to abandon their nests.