Development of re-setting toxin delivery devices for stoats and rats

Abstract

Rats and stoats continue to have a major impact on biodiversity in New Zealand, and improved control techniques are required to avoid further extinctions. A resetting toxin delivery device (Spitfire) is being developed as part of a programme entitled 'Pest Control for the 21st Century', funded by the Ministry of Business, Innovation and Employment. The Spitfire works by firing a paste containing a toxin on to the belly of stoats and rats as they pass through a tunnel. The device then resets. When the stoats and rats groom the paste from their fur, they ingest the toxin. Each Spitfire is capable of approximately 100 doses and is fitted with a counter and a delay mechanism. The first successful field trial of the stoat Spitfire was undertaken in the Blue Mountains, West Otago in late 2013. Stoat abundance was significantly reduced but technical problems meant the trigger mechanism had to be re-designed. Para-aminopropiophenone (PAPP), the toxin used for the stoat trial, is not lethal enough for rats, so 1080, Zinc phosphide, cholecalciferol, C+C (cholecalciferol + coumatetralyl) and sodium nitrite are being investigated as alternative toxins for the rat Spitfire. Field trials are planned for both stoats and rats using Spitfires in 2014/15.