A field experiment on selective baiting and bait preferences of pest mustelids (Mustela spp.)

Abstract

We tested whether a new automated bait dispenser, the Scentinel®, could be programmed to deliver non-toxic bait selectively only to animals of specified dimensions (>400 g body weight and <110 mm body diameter, the size of a ferret or a mink). We tested whether wild ferrets would discriminate between two types of bait (egg/oil and homogenised brain tissue). We set 24 Scentinels in 12 randomised pairs for 11 weeks on a 2400-ha area of pastoral farmland in New Zealand. Of 1559 visits by small animals, 198 were by ferrets (c. 28 individuals). The Scentinels correctly delivered 895 baits to visitors weighing >400 g, and no baits to 543 visitors of <400 g. The mean body weight of live ferrets recorded by Scentinels was not significantly different from that of 34 carcasses collected from the same area by professional trappers. Of the 145 baits dispensed to ferrets, egg/oil bait was significantly more often eaten. We conclude that the Scentinel can reliably deliver bait to specified sizes of animals and deny it to others. It can also facilitate extensive bait preference tests on unrestrained wild pests.

Keywords:

• Predator control
• Mustela
• ferret
• mink
• bait preference

Acknowledgements

For core funding and support we thank the Foundation for Research Science and Technology (Contract CO6X0303), supplemented by the Lotteries Commission, the Animal Health Board, Environment Waikato, Environment Bay of Plenty, the Alma Baker Trust and the University of Waikato. For assistance in the field and for technical support we thank M. Stirnemann, I. Stirnemann, A. Winterink, our collaborators (University of Waikato, Epro Ltd (J. Day, C. Speedy), Philproof Pest Control, Animal Control Products, RAD Technologies); and the farmers who gave us permission to work on their land. For statistical advice we thank Neil Cox, AgResearch, Ruakura. For drawing Figure 1 we thank Paul Martinson, HortResearch. For helpful comments on previous drafts of this and related manuscripts we thank C. Gillies, A Byrom, J. Innes, M. Johnston, C. Miller, P. Morris, R. Powell, P. Schaare, B. Ward and A. Gunson.

Notes

¹ This article includes two words, Scentinel® and Pestoff®, which are a proprietary trademarks. Their inclusion does not imply they have acquired for legal purposes a non-proprietary or general significance, nor is any other judgement implied concerning their legal status.