Hedgehogs may look cute, but they are super-killers, eating chicks, eggs, lizards, skinks, wētā and other rare insects. They are also hosts to many parasites and diseases, various worms, fleas and mites.

They were first brought to New Zealand by Acclimitisation Societies. There are even reports of train drivers releasing crate-loads of the spiky pests on journeys through the South Island.

They thrived here, loving the New Zealand natives – a 2009 report in the New Zealand Journal of Ecology found a single hedgehog gut containing 283 wētā legs. Our monitoring of braided river birds like turiwhatu/banded dotterel has caught hedgehogs on trail cameras eating eggs from nests.

The project has attached GPS trackers and found them as high as 1937m in the mountains.

Given the high numbers of hedgehogs in the environment, they can have a huge impact on endangered species.

On a positive note, we have learnt hedgehogs have small home ranges, and tend to hunker down through winter at higher altitudes rather than move to warmer areas. This lack of seasonal movement means the populations are more stable and easier to manage, and once we get rid of them they are also slow to reinvade an area.

Photos : Nick Foster and Wikimedia Commons Karori Wildlife Sanctuary