Modified M-44 cyanide ejector for the baiting of red foxes (Vulpes vulpes)

Abstract

Fox carcasses are seldom recovered after a 1080-baiting program, making analysis of efficacy difficult. Sodium cyanide was selected as an alternative toxin due to its rapid mode of action. A number of bait techniques were trialled in order to develop an appropriate cyanide delivery system that could be used as a buried bait. Techniques investigated included treated wax and gelatine capsules, a wooden capsule holder and a modified M-44 cyanide ejector. Subsequent trials showed that the modified M-44 ejector had greater efficacy in recovering fox carcasses at bait stations when compared with the other techniques trialled. This paper describes the range of baits trialled and the modifications that allow the M-44 to be used as a buried bait. A protocol for deployment of the M-44 in the field, together with a brief assessment of efficacy for each technique is also provided.