Short-term responses of terrestrial skinks to habitat enhancement in a pest-invaded landscape on mainland New Zealand

Habitat loss is a key threat to reptiles; therefore, habitat restoration should be an effective means of reptile conservation. However, there is scant evidence that such interventions provide population-level benefits, particularly where native reptiles are also threatened by invasive predators. We conducted a before-after-control-impact habitat enhancement experiment on skinks (<i>Oligosoma polychroma</i> and <i>O. aeneum</i>) in a predator-invaded area of mainland New Zealand. Pre-enhancement lizard monitoring was conducted in 12 plots for six months. Native plants were added to six ‘enhancement’ plots in months 8-10, minor gap infill planting was conducted in months 10-13, and rock piles were constructed in months 13-15. Post-enhancement monitoring was carried out at 12 and 23 months. Apparent survival of <i>O. polychroma</i> increased significantly in response to enhancement, but this did not result in increased abundance within the 23-month monitoring timeframe. Enhancement did not affect any of the measured population parameters of <i>O. aeneum</i>. Therefore, adding rocks and native vegetation to sites may be a suitable intervention for improving survival or reducing emigration of <i>O. polychroma</i> without affecting co-occurring lizard species.