Journal article

Causes and consequences of ground disturbance by feral pigs (Sus scrofa) in a lowland New Zealand conifer-angiosperm forest

John P Parkes, Tomas A Easdale, Wendy M Williamson, David M Forsyth



The ecological impacts of feral pigs (Sus scrofa) are of concern in many places around the world. One noticeable impact is soil disturbance, although the causes and consequences are often unclear. We measured the effect of ground disturbance by feral pigs on seedling recruitment and soil ecology over 25 months on a forested riparian terrace at Waitutu, south Fiordland, New Zealand, and assessed the diet of pigs from the area from stomach contents of animals shot by hunters. Foraging by feral pigs for below-ground food disturbed between 7.4% and 12.4% of the soil. Pigs were seven times more likely to redisturb a site than to disturb a new site. Below-ground food items constituted a third of p..

View full abstract

University of Melbourne Researchers


Awarded by New Zealand Ministry of Science and Innovation Ecosystem Resilience Outcome-Based Investment

Funding Acknowledgements

This research was funded by the former New Zealand Ministry of Science and Innovation Ecosystem Resilience Outcome-Based Investment (Contract C09X0502), investment of Landcare Research's retained earnings, and the New Zealand Department of Conservation. We are grateful for the assistance of Department of Conservation (Murihiku Area) staff in this project, and to Graham Metzger and other members of the Waitutu Incorporation for permission to work on iwi land. Johan Groters (Wairaurahiri Jet) and the pilots at South West Helicopters assisted with transport and Peanut Osborne provided hospitality at Waitutu Lodge. We thank David Wardle for his advice on the soil analyses, Richard Heyward and Nigel Young for conducting most of the fieldwork, Morgan Coleman for analysing pig diets, and Bruce Warburton and Andrew Woolnough for comments on the manuscript. We also appreciate the thorough comments on the manuscript by Chris Lusk and two referees.