Use of automatic feeders to attract feral pigs on Auckland Island

A feasibility study for removing feral pigs (Sus scrofa) from Auckland Island trialled feeders monitored by trail cameras to determine their effectiveness for detecting and attracting feral pigs. Ten automatic feeders were installed during January–February 2019 (summer) and again in August–September 2019 (winter) on Auckland Island. They delivered kibbled maize daily for a period ranging from 25 to 37 days. Sites selected for feeder installation needed to be of appropriate relief and area to allow feeder and trap installation, as would occur during an eradication operation. Feeder success varied across sites during the trial. Site selection where there was evidence of fresh pig presence improved the rate of visitation. Feeders offer significant efficiencies to lethal techniques such as trapping by automatically dispensing feed to allow constant supply over a long period. This automation reduces operator effort, but is also advantageous as consistent feed times train pigs to condition their visits so they can be more effectively targeted. In this trial, most visiting pigs returned to the feeder daily from around 15 days after installation. Automated feeders will be an integral component of the proposed methodology for Auckland Island pig eradication to target nocturnal individuals and family groups, and, importantly, reduce the risk of education through non-lethal engagement.